# Slaying the Greenhouse Dragon. Part IV

While I seriously doubt whether climate skeptics will thank me for pointing it out, I don’t believe their arguments impress the swing voters in the climate debate as convincingly as they might.  With this in mind I’d like to propose a strengthening of the skeptic argument that downward longwave radiation or DLR, popularly called back radiation, cannot be held responsible for warming the surface of the Earth.

On a clear summer day, when the surface temperature is 20 °C (as it is outside my house this morning), the atmosphere is below freezing at all altitudes above 2 km, based on a lapse rate of 10 °C/km.  That is, 70% of the air above is colder than a block of ice.  When I measure the DLR by pointing my Microtemp MT250 infrared thermometer at the sky it registers 20 degrees below zero, icy indeed and corresponding to 2.534 * 5.67 = 232 W/m2 of DLR.  Pointing it at the ground, it registers 20 °C or 2.934 * 5.67 = 418 W/m2 of upwards longwave radiation.

Meteorologists tell us that this block of ice overhead warms the ground.  Well known meteorologist Alistair Fraser, who taught meteorology at Penn State from 1978 to 2001 (CV at http://www.ems.psu.edu/~fraser/cv/ ), puts it this way at http://www.ems.psu.edu/~fraser/Bad/BadGreenhouse.html :

“The surface of the Earth is warmer than it would be in the absence of an atmosphere because it receives energy from two sources: the Sun and the atmosphere.  The atmosphere emits radiation for the same reason the Sun does: each has a finite temperature. So, just as one would be warmer by sitting beside two fireplaces than one would have been if one fireplace were extinguished, so, one is warmer by receiving radiation from both the Sun and the atmosphere than one would be if there were no atmosphere.  Curiously, the surface of the Earth receives nearly twice as much energy from the atmosphere as it does from the Sun.”

Now if you sit beside a block of ice, does it make any sense whatsoever to say that the block of ice is warming you?  Obviously it cools you, and you’re warming the ice, not the other way round.

The counterargument would be that the ice block, as a black body at 0 °C, is radiating 2.734 * 5.67 = 315 W/m2 towards you.  But that’s just a number, what does it actually mean as a physical phenomenon?  Well, moving the ice further away reduces its cooling effect on you and your warming effect on it,  so presumably that number must be reconciled with the evident fact that you’re warming the ice, not vice versa.

Thinking perhaps that Professor Fraser’s remarkable statement would have elicited at least one objection, I searched the web for references to his website.  I found a great many praising him for the clarity with which he explained global warming, but not a single objection to his claim that the atmosphere warms the surface.

On that basis it seems safe to assume that the proposition “the atmosphere warms the surface” has been assimilated and accepted by the non-skeptical public as an axiom about global warming.

So what’s going on here?  In particular what is the basis for Professor Fraser’s seemingly extraordinary claim that an aerial object significantly colder than a block of ice supplies twice as much energy to the surface as the 5700 K Sun?   Could it really be so, or is this just misleading numerological prestidigitation?

While Fraser does not supply a reference at that page, one need not look far to confirm this factor of two.  Figure 7 of the famous 1997 paper of Kiehl and Trenberth shows the Earth’s surface receiving 168 W/m2 from the Sun and 324 W/m2 from the atmosphere.

At this point let me digress with a popular skeptic argument about net CO2 fluxes into the atmosphere.  Consulting any figure depicting the carbon cycle, http://earthobservatory.nasa.gov/Features/CarbonCycle/ for example, we see that, of the 220 GtC (gigatonnes of carbon) or so being emitted annually into the atmosphere, only about 9 GtC or 4% is of anthropogenic origin.  Evidently our contribution is negligible compared to nature’s.  What’s the big deal?

The problem with this argument is that the CO2 flux is bi-directional, and it is the net flux that matters.  Preindustrially this flux was in balance and CO2 was not under any great pressure to change rapidly in a single century (though over millions of centuries it has certainly drifted greatly).

The problem with that “small” 4% we’re adding is that, unlike nature, we’re not taking it back out!  Hence that 4% is accumulating, as we can see from the Keeling curve, which shows atmospheric CO2 rising at about 2.3 ppmv these days.  That 2.3 ppmv per year represents roughly half of our 4% contribution; nature has stepped up her own removal program and is busy removing the other half of the 4% as we speak.

Back to Professor Fraser’s claim.  Well, what do you know, the exact same fallacy.  At the same time as 324 W/m2 is entering the surface from the atmosphere, 390 W/m2 is leaving the surface.  The net flux is 66 W/m2 upwards.  The atmosphere is not warming the surface, it’s cooling it!

But this should have been obvious when I pointed my IR thermometer at the sky and the ground and observed 232 W/m2 down and 418 W/m2 up, a net flux of 186 W/m2 cooling the surface.  On a cloudy day the sky might be 13 °C or 2.864 * 5.67 =  379 W/m2, a mere 39 W/m2 less than the radiation from the 20 °C ground.  And at night a cloudy atmosphere may even occasionally warm a slightly cooler Earth.  So an annual global average of 66 W/m2 upwards may well be the case, but that’s still cooling.

Experienced meteorology professor Alistair Fraser says the atmosphere warms the surface.  I, an amateur hack in this area with no meteorological credentials at all, say the surface warms the atmosphere, and moreover at an average power density of 66 W/m2 and sometimes hitting upwards of 200 W/m2.  Who’s to be believed?

Judging from the many favorable references on the web to his website, it is clear that Fraser has persuaded the public of the correctness of his argument.  His reasoning is just as plausible as the 4% argument about CO2 made by the other side, and he taught the subject for nearly quarter of a century, so one would have to be firmly wedded to the skeptic position to object to his website.

Those who’ve thought long and hard about whether back radiation makes sense may well have arrived at the conclusion that it doesn’t.  Furthermore even if they can’t articulate their conclusion with the force they would like, it may nevertheless seem intuitively clear and irrefutable to them.

What we have here is a failure to communicate.  If climate science has any expectation of being able to communicate with the skeptic community, I don’t think shooting down skeptic arguments on the ground that they’re obviously weak is the way to go about it.  You’ll get nowhere attacking what skeptics say, you have to address what they’re thinking, which may be based on sounder intuition than is expressed in their arguments.

Which is tough to do if they have a harder time articulating exactly what they see wrong about back radiation than seeing intuitively that the atmosphere cools the surface.  To them it is totally unreasonable to view the atmosphere as warming the surface, and they find it very frustrating not being able to explain to the satisfaction of the non-skeptics what they find unreasonable about it.

Hopefully I’ve made skeptical thinking a little clearer here, at least as it bears on the back radiation concept.  If this were to help the two sides to focus on their real differences instead of getting off on irrelevant tangents to do with their communication difficulties and incompatible thought processes I’d be thrilled.

Just to clarify my own position, it is clear to me, based solely on the temperature and CO2 records to date, that if CO2 continues on its present course it will reach between 850 and 1000 ppmv by 2100, by which time temperatures worldwide will have increased some 2 °C.  The concept of back radiation does not enter into my projections, and I have no idea how I would use it for forecasting climate change.  I’ve been unable to persuade myself that back radiation is anything more than a computationally unusable extrapolation from John Tyndall’s insightful experiments in the 1850s.

### 2,041 responses to “Slaying the Greenhouse Dragon. Part IV”

1. Charlie A

Sitting near a block of ice at ) degrees C may cool you, but sitting near a block of a substance at -270 C would cool you even more.

The cold atmosphere warms the earth, when compared with the alternative of approximate 4K space.

• Luis Dias

Ok, this may be a shock to you, but this is the first time I’ve heard “vacuum” be referred metaphorically as a “block of a substance at -270C”.

The basic problem seems to be that the author is confusing radiation with conduction and convection, etc.

• Yes, that is exactly the error that Vaughan Pratt is making. The whole article is ridiculously unphysical. The *temperature* of the atmosphere at 2000m, as measured by radiation *from* the atmosphere above him, does not suck up more upward infrared, aka outgoing longwave radiation! Different comparisons can make it *seem* to be “small” but there is no denying back radiation. Or at least, there is no scientifically literate denial of back radiation.

For there to be *no* back radiation, which is his claim, his “Microtemp MT250 infrared thermometer” would need to have measured absolute zero, aka 0K, aka -273.15°C, when pointed upward. It did not. Downward longwave radiation is thus *confirmed* by his own results, which he ignorantly interprets to mean the opposite.

Hilarious.

PS Dr. Curry, how much undergraduate physics would I have to *forget* in order to be invited to ‘blog for you?

• Sometimes I wonder, whether my browser shows the same article that another commenter has read.

Perhaps I cannot read Vaughan’s article similarly with others, who have not read his comments earlier this year, but I’m sure that you have read something that he doesn’t mean.

• After a second reading, it does seem that he was presenting a denialist argument that is not his own view. I had never read Pratt before and assumed that all the opinions he was expressing were his own. But that doesn’t change my reaction much, because denial of back radiation is such an awkward example to use to illustrate Skepticism. It’s actually an example of denial.

There is no rational basis to dispute it, and people who would “think” like Pratt’s example don’t know conduction from radiation. They need to stop lecturing the pros based on junk they “learned” passively from watching teevee or worse, listening to conservative talk radio, and start to *ask* “what am I missing?”

That’s the real problem with the public understanding of climate science, and having the best climate scientists dumb everything down until high school dropouts can “get it” won’t solve that problem. So okay, Pratt knows that’s junk science. I still see no value in imagining that hacks doing junk science will come round, if only the competent professionals would communicate better.

Other industrial nations, where learning and achievement other than amassing wealth are generally respected, do not have this problem with disbelief in the basic, settled underlying theory of anthropogenic climate change. It is not a scientific problem, it is a cultural problem and only undercutting the cultural validity of being an obstinate idiot will solve this problem.

• Settled, your diatribe is no substitute for reasoned argument. You are wasting our time. Feel free to join the debate at some point.

• The presence of passion does not necessarily mean the absence of reason. It’s admittedly less sophisticated, and much less detailed, than Pratt’s essay, but I did present a reasoned argument.

When I measure the DLR by pointing my Microtemp MT250 infrared thermometer at the sky it registers 20 degrees below zero, icy indeed and corresponding to 2.534 * 5.67 = 232 W/m2 of DLR. Pointing it at the ground, it registers 20 °C or 2.934 * 5.67 = 418 W/m2 of upwards longwave radiation.

I present a well-reasoned argument that anybody who concludes from that measurement of 232 W/m2 of DLR that there is no such thing as DLR, colloquially known as “back radiation,” is ignorant enough that they need to be asking questions, not making ANY assertions; and if such a person uses such crude methods to presume that all the leading experts are wrong, then that’s a presumptuous unteachable scientific illiterate who is not entitled to be the purpose of scientists’ efforts.

I realize that’s your target audience and this truth is likely to hurt you, but that is your own fault for taking the side opposite the truth, David.

• cwon1

Another arrogant, “smartest person in the room” wannabe warmist expert. What is it about leftist culture in particular that thinks this would be accepted as a personna?

“the side opposite of the truth”???

It’s a joke post right?

“The presence of passion does not necessarily mean the absence of reason.”

In your case it probably does.

Andrew

• @cwon1
I did not say I was smarter than you. You inferred that yourself.

I will leave your inferential skill for others here to judge. Good day, sir.

PS It’s no joke. DLR is Settled Science, and nobody who says otherwise has any right to expect to be taken seriously. I find Vaughan Pratt’s approach terribly flawed, in that it systematically wastes the time of the best scientists, in servitude to folk too ignorant to inform themselves and too arrogant to admit their egregious ignorance.

• Settled, you present no argument, just a measurement, known already to all. If this simple measurement settled the issue we would not have 3000 comments and counting on this topic. What is your reasoned argument?

• Duster

If you re-read the original article, the subject is not the science but rather the communication skills of skeptics and faithful – not a good term but they are generally no better trained or informed than their debate opponents; maybe we should call the skeptics ‘heretics.’ As long as each side persists in misdirected argumentation, no discussion takes place. The author noted that a “skeptical” view may be the result of an intuitive judgement that is not presented in a well-framed argument (presumably not couched in the accepted jargon of the discipline). He demonstrates this several times himself. This semantic confusion _started_ historically with the misuse of the term “greenhouse” to describe how the atmosphere and oceans mediate the diurnal swing of temperature on the planet. Since it was experimentally shown before 1910 that the atmosphere and a greenhouse achieve their effects in physically, and mechanically distinct fashions, the word “greenhouse” should have vanished from the climatological lexicon long ago. The fact that it didn’t can appear _intuitively_ to a critical thinker as if the users of the word are actually ignorant of physics and thermodynamics. That in turn can lead to a blanket distrust of anyone who does use the term seriously.

In reality, the vast majority of scientifically trained heretics and faithful are not arguing over anything but details of how the system may actually work, given their _common_ assumptions are correct. They (heretics and faithful) effectively agree on the basic tenets, but the devil is in the details, magnitudes and signs of the interactions. Even Postma’s critique is little more than an appeal to apply Occam’s Razor to the issue and insure that the science applied on earth is equally applicable on Mars and Venus (it is not otherwise science) and to avoid applying overly-simple simplifying assumptions to models – e.g. 1/4 uniform radiation as opposed to a proper day-night cycle.

Equally, it is clear to anyone trained in geology that the natural catastrophes prophesied by the faithful are empirical nonsense. The planet has already been (as far as CO2 goes) there and far beyond. This is as much a fact as DLR is a fact. It is also a fact that no natural catastrophes have ensued. At the same time, while the heretics may comfort themselves with this, there is reason to argue that regional anthropogenic effects may very well lead to social catastrophes. Small changes weather patterns driven by regional anthropic effects that the planet and the biosphere will shrug off easily could very well effectively destroy the subsistence bases for many people.

• @Duster

If you re-read the original article, the subject is not the science but rather the communication skills …

Thanks, I got that last week, from Pekka Pirilä.
I disagree with absolutely everything you say after that observation of something that had already been pointed out to me, and which I already acknowledged.

… of skeptics and faithful – not a good term but they are generally no better trained or informed than their debate opponents

That’s demonstrably wrong.
http://www.pnas.org/content/early/2010/06/04/1003187107.abstract
Forget about your amateur opinions about climate science, and forget about my amateur opinions. Within the field of legitimate experts — which by definition is the professionals publishing research in the field of climate, those surveyed in this study — the consensus is overwhelming, 97% or 98% to 2% or 3%, and the deniers are less accomplished in their field by the standard objective measurement of scientific accomplishment, publication history.

… maybe we should call the skeptics ‘heretics.’

Or maybe, instead of lumping people into camps, it would be useful to discuss only points of supposed scientific uncertainty without reference to group affiliation of any kind, especially political, and just let each participant state our own understanding of each issue.

Note that the peer reviewed study I just cited does not lump people into arbitrarily defined, subjective or ill-defined camps, it divides them along scientifically defined terms according to their stated understanding of a well-defined physical phenomenon. That is a legitimate distinction that Anderegg, et al made.

As long as each side persists in misdirected argumentation, no discussion takes place.

As long as even one side persists in misdirected argumentation, no productive discussion can take place.

The author noted that a “skeptical” view may be the result of an intuitive judgement that is not presented in a well-framed argument (presumably not couched in the accepted jargon of the discipline).

And I note that egregious ignorance of climate science, motivated cognition and outright dishonesty are more plausible explanations for disputing the best 98% of experts in this or any scientific field. (Those three factors of course apply in different proportions to different climate science deniers, but at least one of them applies to every climate science denier.)

My hypothesis regarding the roots of climate science denial also wins on the principle of parsimony, by the way.

• Since it was experimentally shown before 1910 that the atmosphere and a greenhouse achieve their effects in physically, and mechanically distinct fashions, the word “greenhouse” should have vanished from the climatological lexicon long ago.

Presumably you’re talking about Wood’s February 1909 paper in Phil. Mag., which claimed to prove no greenhouse effect in either greenhouses or the atmosphere. This was just a short page and a half, and contained no numerical information whatsoever besides what he reported as the common temperature of the two boxes, along with a previous reading he decided couldn’t be right which he dealt with by placing a glass window over the salt window (hopefully with some ventilation). Wood used this result as evidence against the possibility of warming of the Earth by IR-trapping gases in the atmosphere.

The conclusions of Wood’s little note were challenged in the July issue by none other than the Director of the Smithsonian Astronomical Observatory, Charles Greely Abbot, later Secretary of the Smithsonian from 1930 to 1945, who pointed out that three glass covers on a box had been demonstrated at the Observatory ten years earlier to raise the internal temperature of the box to 118 °C. Unlike Wood, Abbot did a number of calculations of the expected effect, taking into account the typical atmospheric conditions above the location of Wood’s experiment (Baltimore MD), and expressed puzzlement as to Wood’s results.

People then forgot about Wood’s experiment until it was noticed in the latter part of the century and given a new lease on life by those arguing that greenhouses warm only by trapping air and not radiation. What they neglected to notice was Abbot’s challenge a few months later. Instead Wood’s experiment went viral, reborn in the public’s mind as a thoroughly researched icon of experimental physics in the service of climate science, when in fact it was nothing of the kind.

No one familiar with experimental methods in physics could possibly take this experiment seriously. It is riddled with methodological errors. One glaring one is that Wood neglected to take into account that his extra glass covering the salt window will itself trap radiation and heat up even when ventilated. He also made no attempt to investigate possible sources of errors, or to document the experiment in any reasonable detail. No dimensions or any other numerical parameters of the experiment were given and we have no idea whether the boxes were 2 inches or 2 feet on a side (presumably closer to the former since large IR-transparent windows are a rarity in optical labs), or whether they were cubes or flat trays, or how thick the windows were other than that they were the same thickness, etc. etc.

This makes it impossible to repeat Wood’s experiment using the same dimensions. It cannot be considered a serious physics experiment, and Wood explicitly disclaimed it as such in the paper.

I’ve tried tried duplicating the experiment myself with the same combination of glass and optical quality salt windows as Wood, using 6 mm thick windows for both and the largest optical quality salt window I could find at optical supply houses, 2″ x 2″. The temperatures within each box vary by more than 20 °C, increasing towards the bottom, and it is easy to get any result one wants by suitable positioning of the thermometers. Wood was presumably unaware of this variation since he speaks only of “the temperature inside the box”, which is like talking about the temperature of a fridge without specifying whether you mean the freezer portion or somewhere else.

I found that the corresponding points in the two boxes differed by 2-4 degrees, with the glass box being hotter (in accordance with the theoretical calculations). I’m still in the process of calibrating the apparatus more carefully (it currently has three TMP05B digital thermometers per box, which I may increase — I just bought another 25 from Digikey last month, they’re only \$2.50 each at that quantity), and collecting more measurements (I sample all 6 thermometers every 5 seconds, giving a lot of data to work with during warm up, cool down, etc.). I’ll be writing all this up in due course, this year has been rather hectic with a number of other projects taking precedence.

Incidentally this question “how do greenhouses work” is discussed in a chapter of a book by Craig Bohren. You can read the relevant section here, or just google for “delicate shade of purple while sputtering” (in quotes). Bohren describes a controversy that erupted in 1974 over this question, discussed in the Journal of Applied Meteorology and Optical Spectra and running for a couple of years. At the end Bohren concludes with the point that greenhouses that don’t show the effects of IR trapping tend to be “set in windy environments and have thin walls.”

I am disappointed that a scientist like Judy would repeat what smacks of junk science without even raising an eyebrow, and worse yet, proposing that a perfectly sound name be changed to “Tyndall effect” without bothering to check whether there is any substantive justification for this urban legend that originated with Wood’s parody of a physics experiment.

• Vaughan,

Nasif Nahle repeated Woods experiment and plans some more variations. You may be interested in reading his results and contacting him if you haven’t heard of it already:

http://www.biocab.org/Wood_Experiment_Repeated.html

• Kuhnkat^2, I pointed out some weeks ago to Nahle (via an intermediary since this was on Facebook) that the 3 micron polyethylene he said he was using as a proxy for a salt window would have problems with reinforcing reflections because it was so incredibly thin as to be a quarter-wavelength at those wavelengths. (Actually I was amazed he could get polyethylene bags that thin.) Nahle responded by restating the thickness as 0.3 mm — apparently he’d misread the datasheet.

I am mystified that any serious experimental scientist could be off by a factor of 100 in estimating thickness of anything. That’s like looking at a 100 meter sprint track and estimating it at 1 meter.

I then pointed out that 0.3 mm would not work as a salt window proxy because it was so thick its absorption would be close to that of glass. This would explain why Nahle was unable to see any difference between polyethylene and glass. If there’s a difference, one isn’t going to see it with 0.3 mm thick polyethylene.

• Vaughan,

Thank you for the information.

• To make a repetition of the Wood’s experiment have any significance, it must be done in a way, where physics predicts an observable effect. It’s of no significance to do it so that everybody predicts the same outcome.

That means in practice that the temperature of the glazing must differ significantly from the temperature of the surface being covered, because with the same temperature the radiation absorbed and emitted by the window will not change the energy loss from the greenhouse. If the internal convection is by far the strongest energy transfer mechanism, then the temperatures will be essentially equal, and no effect is expected based on any theory I have heard about. That’s typical for standard greenhouse. Therefore the results of Wood may well agree with basic physics knowledge and repeating the experiment may give non-conclusive results.

• hunter

ss,
You are confusing your mania with passion and very few people would think that what you present here represents an example of reason.
You are losing what little reason or passion you had because you are frustrated that a group of skeptics dares to openly point out the problems in your faith. Problems which, from your extreme anger and defensivness when they are discussed, you probably know at some level are not without merit.
The need of the AGW faithful approach skeptics as dishonest schills part of a cynical conspiracy is not simply childish on your part, it is not supported by facts.
You admit you are an amateur in this, so your opinion on this is no stronger than the opinion of any other lay person involved in this.
And the history of science teaches us that what you do rely on- consensus and authoritative claims, is not actually an effective way to determine the truth.
So I would suggest that you would far more successful if you would wipe off the spittle you have sprayed out in your anger and consider that the skeptics also care about the Earth, the future, our children and grandchildren, and truth.
Dehumanizing your opponents really only exposes weaknesses in yourself.

• @Vaughan Pratt… I used the proper polyethylene, as it is specified in the article on the results, and followed the correct scientific methodology.

You used a similar polyethylene film and you didn’t report any problems with the reflectivity of your polyethylene film used in your “experiment”, which lacked of proper control.

I didn’t limit my experiment to a solitary class of polyethylene, but I used two kinds of LDPE film.

My results are not biased and the peer reviewers of the article have photographs of each phase of the experiment, including photographs of thermometers taken each five minutes.

Sorry, but my experiment is absolutely correct and yours is biased.

settledscience,

I just wanted to commend you on your cleverly conceived moniker. It gives your comments that intangible splash of sincerity they might otherwise lack.

Andrew

• Vaughan Pratt

Sorry, but my experiment is absolutely correct

Very compelling. You should trademark the “experiment is absolutely correct” phrase, like Safeway’s trademarked “Eating right” label on their sugarless icecream.

and yours is biased.

Very insightful of you. I freely admit a bias towards anything that improves our understanding of atmospheric physics. Good catch there, obviously we need to be more respectful of those that don’t tolerate that kind of understanding.

Your complete lack of bias presumably has to do with making sure that no one believes this cockamamie AGW theory. In that sense you could not possible be any less biased. Good on yer, mate, for your total lack of bias in this difficult area.

My interest is solely in the science, not in the biases of those discussing it. If you’re only interested in those biases then we can agree to agree.

• For there to be *no* back radiation, which is his claim,

Just for the record, what I’m claiming is not that there is no back radiation but that the only sense in which back radiation warms the Earth is the same sense in which a block of ice next to you warms you. That point of view may work for some people, but there may be people for whom it doesn’t work because they regard the ice as cooling you.

Committed climate skeptics may not care either way, but those trying to make sense of the subject without just taking it all on faith may have a hard time with the idea of ice as a warming agent. Why push that point of view on them when it isn’t necessary?

• Because those are the facts, and by the way you never took them on faith, did you?

• Nick

@settledscience you have a point here and I’m just as surprised as you appear to be that my fellow skeptics fail to see what is to me absolutely obvious.

Mr. Pratt knowingly or not gives misleading and counter-intuitive example with the block of ice which people intuitively regard as “cold” . To make a fair comparison you’d need to place yourself in the vacuum in the open space (same as the Earth) and then the block of ice next to you would indeed warm you. Just ask yourself whether you last longer in -1°C or -269°C (4 K) … it’s quite obvious you would prefer the block of ice over near absolute zero.

Why is this so hard to understand? I’m seriously shocked that this issue gets so much attention … Mr. Pratt measured infrared back-radiation himself, surely he must realize that this radiation has to warm the Earth in comparison with no radiation (no atmosphere, no back-radiation) and it would be cooler if it were absent – of how much may be in dispute but the fact that it would be cooler is undeniable, at least I thought so – it’s just so incredibly obvious!

You also made perfectly valid argument similar to mine above pointing out that he would measure -273°C if there was no back-radiation, so the mere fact that he measured more actually proves back-radiation. And that gets called “leftist culture” for displaying dismay at the fact that people do not get this basic and simple point? It really doesn’t reflect well on a broader skeptic community if some skeptics are acting like this and what’s worse, it doesn’t seem to get challenged from the more reasonable folks … that raises the question, where are they?

Is calling people leftists for challenging your position while not addressing the actual argument presented acceptable?

• Nick, let me repeat your argument back to you just to make sure I understood it.

You seem to be saying that if there are two objects nearby, both cooler than you and one warmer than the other, then you are being cooled by one of them and warmed by the other.

Did I understand you correctly?

• hunter

Dr. Pratt,
Everything is warming everything, just not very much.
IOW, the practical warming from a block of ice next to, say a warm body in an open place with convective protection is going to be a minor bit of trivia.
And everything is at the same time cooling.

• Sam NC

Nick,

” To make a fair comparison you’d need to place yourself in the vacuum in the open space (same as the Earth) and then the block of ice next to you would indeed warm you.”

The warmists basic problem is unable to realise that ice warmer than 0K has reduced the body radiation towards the space which is absolute zero. Ice does not heat up the body, it reduced the heat loss by radiation to space having it in between the body and the space. It acts as a buffer similar to the atmosphere between the space and the Earth surface. Here Stefan-Boltzmann radiation law applys.

Just ask yourself whether you last longer in -1°C or -269°C (4 K) … it’s quite obvious you would prefer the block of ice over near absolute zero.”

• All warm objects (above absolute zero) radiate. Assume the block of substance surrounding the earth is at absolute zero then the earth receives no radiation from this source (it actually has a temperature of course so does radiate). Pointing your (by now useless ) IR thermometer away from the earth (and at NO other body) you will read absolute zero.

QED you have proved downward radiation! and you have shown tha

• Frank

Vaughan: I think that you have expressed the dilemma very well, but you may be reluctant to follow the consequences of your ideas to their logical end. Can a block ice “warm” a person or can a cold atmosphere “warm” the much-warmer surface of the earth? The “establishment” view recognizes that both a person and the surface of the earth are constantly losing energy to and gaining energy from the surroundings by radiation. In the establishment view, “warming” means increasing the rate at which a person or the surface of the earth gains energy from the surroundings. You probably don’t feel comfortable calling this process “warming” when the radiation comes from a colder location, but the term is perfectly sensible. Anything that contributes radiant energy to a person or the surface of the earth warms it.

A block of ice can warm a person by increasing the amount of radiation a person receives from their environment. Go to Antarctica where the air temperature is -50 degC on an absolutely calm day. Build an igloo and wait until your body heat warms the inside air and inside surface of the igloo to 0 degC. Those blocks of ice with a surface temperature of 0 degC will emit more infrared radiation in your direction than the air at -50 degC did before you built the igloo.

For our planet, the “outside” air is space, which is filled with blackbody radiation at 2.7 degK. Our atmosphere, which is 200-300 degK, obviously radiates much more energy towards the surface of the earth than it would receive from space alone and therefore warms the surface.

In the case of radiation, the NET flow of energy is always from hot to cold, but there will always be some photons flowing from cold to hot. Those photons make the hotter object warmer than it would have been if the cold object had not been present. (If the cold object is removed, what is present? Empty space at 2.7 degK!)

• Hum

Gee Frank ya think conduction and convection have anything to do with your igloo example???

• Vaughan Pratt, 8/14/11, 1:38 am, Vaughan Pratt

Your analogy sitting next to a block of ice is brilliant.

Of course back radiation exists, but it is not heat, and consequently cannot warm Earth. But the block of ice just below 0ºC will nicely warm a block of dry ice, our beloved CO2, just below -60ºC.

Of course CO2 has a positive greenhouse effect to prevent the surface from cooling. It’s just not measurable, that’s all.

By committed climate skeptics are you distinguishing between AGW believers, like those who post here, who ought to be committed?

• @Vaughan Pratt… As I said in that facebook discussion, it was not me who “calculated” the thickness of the LDPE, but a wrong information from the retailer. It was not my mistake. I called to the manufacturers, MAPASA, and they made me know the real thickness of the LDPE I used in my experiment.

I used two kinds of LDPE, 0.3 mm and 0.051 mm thick. I reported the results from 0.3 mm LDPE, but it seems you don’t know there is not any problem with thickness because the records of temperature were the same using 0.3 mm thick and 0.051 mm thick.

Sorry, try again… :D

• By the way, I didn’t place my boxes directly on the floor; I constructed wood structures to hold them away from the floor.

Additionaly I wrote a guide to the experiment for any scientist or high school student can reproduce my experiment.

http://www.biocab.org/Booklet_Experiment_on_Greenhouse_Effect.pdf

:D

• BlueIce2HotSea

settledscience

“The whole article is ridiculously unphysical. The *temperature* of the atmosphere at 2000m, as measured by radiation *from* the atmosphere above him, does not suck up more upward infrared, aka outgoing longwave radiation!”

On the other hand, Temperature difference is the cause of convective Heat flow from the surface to the colder atmosphere. It seems that Net Energy flows from a higher energy potential to a lower one. (See electrical circuits, fluid mechanics, thermodynamics, etc.) Perhaps, one day, that too may also be known as settled science. :)

P.S. Observations of atmospheric circulation confirm the Heat flow pattern of rising at low latitudes and descending at higher latitudes (where atmosphere is warmer than surface).

You had best apologize Vaughan Pratt on this one.

• Like hell I should apologize, you disingenuous ignoramus. Conduction and convection in fact do not suck up more infrared radiation, and his argument is in fact unphysical where it takes low temperature to mean zero back radiation. In fact, for all temperatures above 0K, there is some thermal radiation. That is what I actually said.

Different comparisons can make it *seem* to be “small” but there is no denying back radiation. Or at least, there is no scientifically literate denial of back radiation.

The point of his article was to try to make the least scientifically illiterate argument against back radiation. Misrepresent what I said all you want. The truth is that nothing I said contradicts any facts of heat transfer.

You had best apologize to me on this one.

• Dear Luis,
Nicely explained!
Work is required to transfer heat from a cold reservoir to a hot reservoir. Where is this work in the mathematics of the greenhouse gas theory?

• gbaikie

In terms of radiative energy space could describe a “block of a substance at -270C”. And in regards to space and bodies in them energy can’t be transfer via conduction or convection.
And in space a block of ice could be warmer than space, but isn’t warmer than a living body [which would need to be in a spacesuit to be living- a dead human not in spacesuit would remain warmer longer if near a block of ice in space. Or if spacesuit is designed so that in space an person is cold, being near the block ice would make that person warmer- very slightly.]

I gather from the comments that the above article is suppose to be wrong- but is suppose to serve the purpose of something to slay.
With the goal of causing dragons to become extinct apparently- how uneco friendly.
I would say the cold sky doesn’t cause pavement to increase in temperature, but certainly causes the air to be warmer. Humans are more interested in air temperature in a white box 5 feet off the ground than the ground [surface] temperature.
If you measure the watt per square meter from the Sun, at noon on a clear day with sun directly over head at sea level on earth it will be about 1000 watts per square meter. Without there being an atmosphere, in same time and location instead of 1000 watt, one would have about 1300 watt per square meter. Therefore one would have more energy heating the pavement [dirt/sand/whatever]. And a cold sky isn’t going cause any significant heating of the pavement [certainly not 300 watts worth].
The 300 watts is lost somewhere, and seems on clear day much of it must be “lost” warming the atmosphere.

• Joel Shore

Luis,

Charlie is correct. From the point of view of radiation, that is exactly what a vacuum is. What confuses everyone is that you have to have the correct comparison case. An earth without IR-absorbing substances (greenhouse gases and clouds) is an earth where all the radiation it emits escapes to space. An earth with IR-absorbing substances is one where some of that radiation heats the atmosphere, which emits radiation some of which returns to earth. The heat flow (i.e., net flow of energy) is still from the warmer earth to the colder atmosphere but that flow is less for a given surface temperature than it would be if the atmosphere were transparent to IR radiation.

And, by the way, even if you don’t believe back-radiation exists (despite the wealth of experimental information that it does), as long as you believe the Planck Equation (i.e., that the heat [i.e., net energy] flow from a warmer object to its cooler surroundings depends on the temperature of its surroundings as well as the temperature of the object), you have to believe in the greenhouse effect.

• ferd berple

The radiation model is much too simplistic. Why is the surface temperature of Venus the same on the dark and light side, even though night on Venus is 120+ earth days?

What the atmosphere does is moderate the surface temperature. It makes days cooler and nights warmer. The more atmosphere (Venus) the atmosphere, the greater the effect, until the dark and light sides are the same temperature. This effect can easily be observed on earth whenever it is cloudy as compared to clear.

The problem with simplistic radiation models is that radiation is a 4th power function and the average of the 4th power is not equal to the 4th power of the average. Physics tells us that radiation is the average of the 4th power, while climate science would have us believe that radiation is the 4th power of the average. So long as climate science works with average global temperature to calculate a radiation budget it is unphysical nonsense.

• Climate science does not work with global average temperature to calculate a radiation budget. Climate models calculate radiative transfer and fluxes in grid cells all over the globe in response to the temperature and humidity profile, cloud characteristics, and gaseous and aerosol composition at the grid cell at that particular point in time (multiple calculations are made in each grid cell for each day in the model integration.) Setting up a straw man (like climate scientists do back of the envelope calculations and base their entire argument on such simple things) and then knocking it down is pointless, not to mention confusing and misleading.

If you want to understand why we have confidence in calculations of radiative transfer by sophisticated radiative transfer codes use in most climate models, see this previous thread

• “cloud characteristics, and gaseous and aerosol composition at the grid cell at that particular point in time”

Is this a grid cell on the surface or 3D cells above the surface? Do these models take into account the Energy Pressures (aka Temperature) and Enthalpy of the layers of atmosphere and surface?

Both temp and Enthalpy decline with altitude showing that it takes less time to heat and cool those regions. If you model a cooler region with lower enthalpy “warming” a region that is higher in Energy Pressure (Temp) and Enthalpy (Oceans as Air are an extreme example), you will find the cooler less dense region does even a poor job at slowing the cooling rate of the Warmer region.

Now one might postulate that there is enough cooler atmosphere to slow the cooling below, but we also need to take into account the elasticity of the atmosphere. Since the atmosphere expands as it gets warmer, temperature is converted into work to increase the volume against gravity. The Energy is not lost, it is simply represented by the increase in volume. As altitude increases the amount of work needed to expand decreases. The Variable Height of the Tropopause is a good reference for this phenomena.

So what we find is that an atmosphere that significantly slows the surface cooling will simply increase the rate at which the atmosphere expands, and in doing so creates a bigger volume to store the “trapped” energy. Smash the Tropopause at the equator down to polar altitudes and you will experience a TRUE GreenHouse Effect.

What I don’t believe the GH Dragons take into account is how elastic our atmosphere is. Nor do I think they are considering the declining Enthalpy as altitude increases.

• The radiation model is much too simplistic. Why is the surface temperature of Venus the same on the dark and light side, even though night on Venus is 120+ earth days?

First a not-so-small correction: that’s a sidereal night, the solar night is only about 58 Earth days. (And weirder still, the Sun rises in the west and sets in the east.)

That said, this is a nice question, and one that Marov and Grinspoon make a point of addressing early on in Chapter 7 (IIRC) of their comprehensive treatment “The Planet Venus”. The simple answer depends primarily on two factors.

(i) At night the top of the SO2 cloud rises from its daytime altitude of 65 km to some 90 km (they don’t say why IIRC) where it is extremely cold, around 170-200 K, whence relatively little radiation to space happens, considerably less than takes place from the night surface of Earth which has enough wide open atmospheric windows for significant radiative cooling of its ~280 K surface. Assuming 200 K is correct (I’m down in Pacific Grove today, where my MT250 shows the clear but humid 7 pm sky at -6 C incidentally, and won’t have access to my copy of M&G until tomorrow afternoon), this would cool Venus at 90 W/m2, whereas 280 K on Earth radiates at 350 W/m2. At 170 K it’s down to 47 W/m2 though I suspect the night radiation doesn’t get this low.

(ii) Whereas it is the Earth’s surface that is cooled by radiation to space, it is only the SO2 clouds in a range below 90 km that are cooled by this 90 W/m2. The clouds down to 45 km or so damp out any remaining diurnal variation so that the subcloud atmosphere is oblivious to it except for perhaps 25 W/m2 of visible sunlight throughout the subcloud and surface switching off abruptly at night, not a big difference.

A third factor is that the 734 K surface of Venus is exchanging heat with the atmosphere immediately above at a flux density of 15 KW/m2 (the surface emissivity is 0.9 or it would be 16.5 KW/m2). This so dwarfs these small diurnal fluctuations that it is impossible to have any significant temperature variation at the surface in the course of a Venusian night, even if those fluctuations could penetrate the clouds. But they don’t, except for the miniscule visible 25 W/m2 switching off, so this third factor doesn’t even come into play. When all hell breaks loose, turning off the lights doesn’t turn off the heat.

• kuhnkat

Vaughan,

this is the REAL Greenhouse you are describing, per Real Climate and the IPCC, that the average radiative altitude rises to where the components are too cold to radiate the same amount of energy. My counter argument is that the rising atmosphere is an expansion that decreases the density of the particles allowing the radiation through to space from a warmer level that wasn’t making it before. I have, so far, not seen this particular concept addressed, although it may have been. Any idea?? Would the models correctly deal with this?

The diagram I saw of the Venusian atmosphere is more of a compression of the day side. That is, it would appear that it has been pushed down possibly by the solar wind. Being much closer to the sun there would be a much stronger effect by the solar wind. Having a much longer day allows for more of a distortion also. This is just a guess but seems to fit the shape.

One other cool thing I ran across, the Russian pictures were taken with AMBIENT LIGHT!!! They are apparently near IR pictures!!!!!!

• kuhnkat

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• My counter argument is that the rising atmosphere is an expansion that decreases the density of the particles allowing the radiation through to space from a warmer level that wasn’t making it before.

Not quite sure what you’re referring to here, but if you mean the lapse rate on Venus, it is very close to that of Earth, with the formula g/c_p for lapse rate requiring only small adjustments to gravity g and constant-pressure specific heat c_p. Theory and observation are in excellent agreement for Venusian lapse rate, just as for Earth.

One other cool thing I ran across, the Russian pictures were taken with AMBIENT LIGHT!!! They are apparently near IR pictures!!!!!!

Did they say they were using IR? During the day the surface is illuminated with some 15 W/m2 of sunlight, which is plenty of ordinary visible light for even a commercial off-the-shelf video camera. According to Marov and Grinspoon the sunlight has a distinctly orange hue.

• I am referring to the issue of more CO2 alledgedly raising the average emission altitude so that it becomes colder and cannot emit as much energy bottle necking emissions until the atmosphere heats to the ground as explained by RC and IPCC. This is the real Greenhouse effect that was supposed to give the large C increases.

http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/

What I am saying is that as the GHG’s increase, the atmosphere from ground level on up will warm marginally due to the extra GHG’s transferring more energy to the atmosphere causing a small expansion of the atmosphere. The density of the GHG’s or particulate that could bslow or block the radiation directly to space is lowered as the atmosphere is warmed and expands. 200ppm of CO2 will not significantly increase the density of the atmosphere as it is “well mixed.” The extra space between IR blockers or absorbers should allow emissions from absorbers that are almost as warm as before the addition. I THINK, I don’t KNOW, that this should offset the amount of GHG’s that are added to colder altitudes reducing their temperature and effectiveness.

The IPCC claimed the Hotspot would result from this bottleneck, yet, we never seem to see it reach measureable size for any period of time. I don’t think they made it up so the alternative is that they missed something and this would seem to be a possibility. The actual numbers are pretty small so it would also seem possible that there is an unintentional error in these computations that create the bottleneck and it could be in any of the parameters or more than one or be in the algorithym created to make it possible to make the computations in the model

Either that or the humidity is dropping!!.

Venus or any atmosphere with GHG’s should be similar. On a diurnal basis this would be a small change in the radiation rate as the atmosphere heats and expands. On Venus, the compression of the atmosphere on the dayside would be the opposite pushing the GHG’s closer together and slowing a little more IR.

Of course this is probably built into the models correctly and I’ve got nuttin.

Yes, the consensus IS that there is actual insolation at ground level on Venus. The light was quite red though so, along with other issues, it has made some think that this may be a mistake and it is the glowing lava providing near infrared for the viewing.

You may have heard of John Ackerman, a retired Physicist who has written some books considered pseudo-scientific by many. Of course, they label anything pseudo that doesn’t fit their belief, so I don’t really know. I found his descriptions of a possible Sulfur cycle on Venus quite compelling. Unfortunately I don’t have the knowledge to evaluate it. I think he is also disliked because he thinks Velikovsky got some things right!! Orange?? Definite difference from the red Ackerman stated. Orange would probably fit the temperature better. Did they suggest what caused the orange?

http://www.firmament-chaos.com/papers/fvenuspaper.pdf

• I am referring to the issue of more CO2 alledgedly raising the average emission altitude so that it becomes colder and cannot emit as much energy bottle necking emissions until the atmosphere heats to the ground as explained by RC and IPCC. This is the real Greenhouse effect that was supposed to give the large C increases.

Let me start by responding to this much, which may have the side effect of also addressing some of the other parts of your comment.

The way I think of Venus’s atmosphere is as a gaseous ocean of CO2 molecules and photons. Photons are bosons and hence pass through each other like ghosts. They also have ill-defined identities, unlike fermions, and one should think of them as short-lived, surviving no longer than between their emission and subsequent absorption. Absorption can be viewed as colliding with a CO2 molecule whose cross-section depends strongly on the energy (aka wavelength) of the photon: the molecule looks “larger” when the photon is nearer some resonance of the bonds of the molecule.

My justification for this viewpoint is that photons leave Venus’s atmosphere quite analogously to the way water molecules leave Earth’s ocean, namely by slow evaporation from the surface. (Hawking has pointed out that even black holes can evaporate slowly, albeit via quantum tunneling rather than the straightforward radiative evaporation from Venus’s atmosphere.) Most of the photons remain trapped in the atmosphere

Insolation can be understood as much higher-energy solar photons that can only collide with clouds and the surface. Clouds both absorb and scatter solar photons, and a few of the scattered ones, particularly the orange ones which are least likely to be absorbed by sulfur atoms, avoid capture by the clouds and make their way into the subcloud where they can viewed as ordinary wave-nature radiation beaming down to the surface with negligible interaction with the relatively clean CO2 of the subcloud. They constitute sunlight at the surface of Venus, which down-converts them to slow-frequency (longer-wavelenght) photons that replenish the photon component of the atmosphere. This replenishing together with the corresponding conversion taking place in the clouds is sufficient to offset the very slow evaporation at the top in order to maintain a stable (and huge) photon population in Venus’s atmosphere ocean over millions of years.

Photons dart about of course, but so do CO2 molecules. What photons and molecules have in common is that the bulk of them remain trapped in the ocean.

One can think of both photons and molecules as being compressed by the huge amount of ocean above them, more at the bottom than the top. Pressure is expressed as kinetic energy. KE in molecules is speed squared, in photons it is frequency. KE in molecules is linear in pressure, in photons it is linear in depth with coefficient g/c_p, called lapse rate. (Hence KE of molecules is not linear in that of photons because pressure is not linear in depth.)

Does this way of thinking about Venus’s atmosphere, along with the two principles in the preceding paragraph that quantify the qualitative picture, address any of your questions?

• depends strongly on the energy (aka wavelength)

Sorry, replace “wavelength” by “frequency”.

• @Vaughan Pratt…

VP: “Photons are bosons and hence pass through each other like ghosts.”

You’re forgetting photons have inertial mass. Your second assertion is not a scientific argument even if you believe in ghosts.

VP: “Absorption can be viewed as colliding with a CO2 molecule whose cross-section depends strongly on the energy (aka wavelength) of the photon: the molecule looks “larger” when the photon is nearer some resonance of the bonds of the molecule.”

The cross-section of a carbon dioxide molecule doesn’t depend “strongly” of the energy of the photon, but of the internal energy of the molecule.

The cross section of a molecule of carbon dioxide is well defined and it is 5 x 10^-22 cm^2.

VP: “My justification for this viewpoint is that photons leave Venus’s atmosphere quite analogously to the way water molecules leave Earth’s ocean, namely by slow evaporation from the surface. (Hawking has pointed out that even black holes can evaporate slowly, albeit via quantum tunneling rather than the straightforward radiative evaporation from Venus’s atmosphere.) Most of the photons remain trapped in the atmosphere.”

So carbon dioxide on the Venus works as a coolant of the surface, not as a warmer. All scientific literature on evaporation clearly states that evaporation is a coolant process. If you say that carbon dioxide on Venus surface, like water molecules on Earth, then you’re on my side, i.e. carbon dioxide is a coolant, not a warmer.
On your final assertion, a molecule that “retains” the absorbed thermal energy by only 120 picoseconds cannot “trap” photons. Your argument is unphysical.

VP: “Insolation can be understood as much higher-energy solar photons that can only collide with clouds and the surface.”

I don’t know where you take this argument from, but it is twisted physics. Insolation is the load of incident solar power on Earth’s surface. It can be applied to any other celestial body (not ghosts, okay?).

Insolation is mitigated by the atmosphere before solar radiation hits on the surface. Sorry, but this series of confusions and twisted concepts are the roots of AGW pseudoscience.

VP: “Photons dart about of course, but so do CO2 molecules. What photons and molecules have in common is that the bulk of them remain trapped in the ocean.”

Neither carbon dioxide neither we can “trap” photons. Remember uncertainty principle. It is the energy carried on by photons what is momentarily retained as long as an electron leaves a high energy microstate down to its fundamental stationary microstate. 

VP: “One can think of both photons and molecules as being compressed by the huge amount of ocean above them, more at the bottom than the top.”

Sorry, Vaughan but your argument above is nonsense. Could photons be compressed? Yes or not?

No, we cannot think of both photons and molecules as being compressed by mechanical compression as you suggest. We could compress virtual pulses by means of virtual data, not quantum/waves.

Photons are not compressed by the density of the medium. Gravity has an influence on both wavelength and frequency of a photon, but you cannot say the photon is compressed as if it were a gas. Imagine a piston filled with compressed photons. 

It seems you believe that photons can be compressed by hydraulic pressure.
VP: “Photons are bosons and hence pass through each other like ghosts.”

You’re forgetting photons have inertial mass. Your second assertion is not a scientific argument even if you believe in ghosts.

VP: “Absorption can be viewed as colliding with a CO2 molecule whose cross-section depends strongly on the energy (aka wavelength) of the photon: the molecule looks “larger” when the photon is nearer some resonance of the bonds of the molecule.”

The cross-section of a carbon dioxide molecule doesn’t depend “strongly” of the energy of the photon, but of the internal energy of the molecule.

The cross section of a molecule of carbon dioxide is well defined and it is 5 x 10^-22 cm^2.

VP: “My justification for this viewpoint is that photons leave Venus’s atmosphere quite analogously to the way water molecules leave Earth’s ocean, namely by slow evaporation from the surface. (Hawking has pointed out that even black holes can evaporate slowly, albeit via quantum tunneling rather than the straightforward radiative evaporation from Venus’s atmosphere.) Most of the photons remain trapped in the atmosphere.”

So carbon dioxide on the Venus works as a coolant of the surface, not as a warmer. All scientific literature on evaporation clearly states that evaporation is a coolant process. If you say that carbon dioxide on Venus surface, like water molecules on Earth, then you’re on my side, i.e. carbon dioxide is a coolant, not a warmer.
On your final assertion, a molecule that “retains” the absorbed thermal energy by only 120 picoseconds cannot “trap” photons. Your argument is unphysical.

VP: “Insolation can be understood as much higher-energy solar photons that can only collide with clouds and the surface.”

I don’t know where you take this argument from, but it is twisted physics. Insolation is the load of incident solar power on Earth’s surface. It can be applied to any other celestial body (not ghosts, okay?).

Insolation is mitigated by the atmosphere before solar radiation hits on the surface. Sorry, but this series of confusions and twisted concepts are the roots of AGW pseudoscience.

VP: “Photons dart about of course, but so do CO2 molecules. What photons and molecules have in common is that the bulk of them remain trapped in the ocean.”

Neither carbon dioxide neither we can “trap” photons. Remember uncertainty principle. It is the energy carried on by photons what is momentarily retained as long as an electron leaves a high energy microstate down to its fundamental stationary microstate. 

VP: “One can think of both photons and molecules as being compressed by the huge amount of ocean above them, more at the bottom than the top.”

Sorry, Vaughan but your argument above is nonsense. Could photons be compressed? Yes or not?

No, we cannot think of both photons and molecules as being compressed by mechanical compression as you suggest. We could compress virtual pulses by means of virtual data, not quantum/waves.

Photons are not compressed by the density of the medium. Gravity has an influence on both wavelength and frequency of a photon, but you cannot say the photon is compressed as if it were a gas. Imagine a piston filled with compressed photons. 

It seems you believe that photons can be compressed by hydraulic pressure.

VP: “Photons are bosons and hence pass through each other like ghosts.”

You’re forgetting photons have inertial mass. Your second assertion is not a scientific argument even if you believe in ghosts.

VP: “Absorption can be viewed as colliding with a CO2 molecule whose cross-section depends strongly on the energy (aka wavelength) of the photon: the molecule looks “larger” when the photon is nearer some resonance of the bonds of the molecule.”

The cross-section of a carbon dioxide molecule doesn’t depend “strongly” of the energy of the photon, but of the internal energy of the molecule.

The cross section of a molecule of carbon dioxide is well defined and it is 5 x 10^-22 cm^2.

VP: “My justification for this viewpoint is that photons leave Venus’s atmosphere quite analogously to the way water molecules leave Earth’s ocean, namely by slow evaporation from the surface. (Hawking has pointed out that even black holes can evaporate slowly, albeit via quantum tunneling rather than the straightforward radiative evaporation from Venus’s atmosphere.) Most of the photons remain trapped in the atmosphere.”

So carbon dioxide on the Venus works as a coolant of the surface, not as a warmer. All scientific literature on evaporation clearly states that evaporation is a coolant process. If you say that carbon dioxide on Venus surface, like water molecules on Earth, then you’re on my side, i.e. carbon dioxide is a coolant, not a warmer.
On your final assertion, a molecule that “retains” the absorbed thermal energy by only 120 picoseconds cannot “trap” photons. Your argument is unphysical.

VP: “Insolation can be understood as much higher-energy solar photons that can only collide with clouds and the surface.”

I don’t know where you take this argument from, but it is twisted physics. Insolation is the load of incident solar power on Earth’s surface. It can be applied to any other celestial body (not ghosts, okay?).

Insolation is mitigated by the atmosphere before solar radiation hits on the surface. Sorry, but this series of confusions and twisted concepts are the roots of AGW pseudoscience.

VP: “Photons dart about of course, but so do CO2 molecules. What photons and molecules have in common is that the bulk of them remain trapped in the ocean.”

Neither carbon dioxide neither we can “trap” photons. Remember uncertainty principle. It is the energy carried on by photons what is momentarily retained as long as an electron leaves a high energy microstate down to its fundamental stationary microstate. 

VP: “One can think of both photons and molecules as being compressed by the huge amount of ocean above them, more at the bottom than the top.”

Sorry, Vaughan but your argument above is nonsense. Could photons be compressed? Yes or not?

No, we cannot think of both photons and molecules as being compressed by mechanical compression as you suggest. We could compress virtual pulses by means of virtual data, not quantum/waves.

Photons are not compressed by the density of the medium. Gravity has an influence on both wavelength and frequency of a photon, but you cannot say the photon is compressed as if it were a gas. Imagine a piston filled with compressed photons. 

It seems you believe that photons can be compressed by hydraulic pressure.

• Thank you for sharing your interesting understanding of physics with us, Nasif. Would you have any objection to its use as an illustration of the depth of that understanding by climate skeptics?

• gbaikie

“An earth without IR-absorbing substances (greenhouse gases and clouds) is an earth where all the radiation it emits escapes to space. An earth with IR-absorbing substances is one where some of that radiation heats the atmosphere, which emits radiation some of which returns to earth. The heat flow (i.e., net flow of energy) is still from the warmer earth to the colder atmosphere but that flow is less for a given surface temperature than it would be if the atmosphere were transparent to IR radiation.”

Ok, so we will ignore the much higher heat transfer of a warm surface conducting heat to any gas [whether greenhouse or not] and the convection of this gas [warm air rises] heating the cooler air [and lifting such things as gliders in thermals]. And just talk of heat transfer via radiant energy:
First, of course, something has to get hot to radiate much energy- water 70% of the surface planet doesn’t get a hot as sand or rocks. So tropical oceans may be say 80 F and sand might be +160 F. Since oceans dominate this world we might take a average surface temperature of say 70 F daytime [since ocean retain their heat, say 60 F average nite time].

So basically we talking about a surface temperature of 60-70 F warming an atmosphere.
Now, the blog post we replying to said: “the atmosphere is below freezing at all altitudes above 2 km, based on a lapse rate of 10 °C/km.”
I don’t know how accurate 10 °C/km is, I usually use 3 F per 1000′ [which is less than 10 °C/km]. But temperature does lower at a standard rate as one goes higher- if go up 1000′ of elevation anywhere on earth, the temperature will drop by about 3 F.

So, you are in the middle of the ocean the average temperature is 70 F and it’s nite time. You get into a balloon and go up to 1000′ above sea level.
Below you is body of air and the ocean itself which is about 70 F, the sky above you is colder, and the air temperature is 67F. If you go another 1000 feet higher it will be about 64 F. In terms of radiant heat, nothing much has changed- the sky above is cold and the air and ocean is warm.
If you seeing in infrared, it all looks the same. If measuring the radiant, nothing has changed, except the air temperature is colder. You have the same area radiating heat to warm the air which is surrounding you- and very little changes in this regard even if you you up 100 miles- other than there is very little air to warm.

2. Tom Choularton

Judith,

I agree with Charles, why on earth have you allowed an article like this to be pulished on your blog, when clearly the author doesn’t understand basic physics ?

• Maybe to give you the opportunity to teach the author (and others)?

• Kermit

Nah, Its to give Tom a chance to express his indignation.

• Tom: Vaughn has posted a detailed scientific argument for discussion. Saying it should not be posted and that he does not understand basic physics just makes you look stupid, as neither is a counter argument. We are here to work, not to trade insults.

• Thanks David. Vaughan has written an essay that is useful in focusing the greenhouse dragon discussion.

• Judith,
You should thank David here.

I wrote a comment in the previous “dragon thread”.

That presents in very rough terms a different way of looking at the same physics – and without direct reference to back radiation in any way. As I said, the physics is still the same, only the way of looking at it differs.

• Tom Choularton

Judith,

I am sure I don’t need to lecture you on how the’ greenhouse effect’ works. I can support your idea of wide ranging discussion of climate change involving a wide audience but that has to be predicated by sound basic physics or we are all going to waste a lot of time.

It is true that much of the atmosphere is colder than the surface but the point about greenhouse gases is that they reduce surface cooling by reducing the outgoing long wave radiation to space which is close to absolute zero. They do this by absorbing the outgoing radiation and then emitting isotropically.

• Tom, you know this and I know this. Stating that others should believe this because people like you and I know this hasn’t worked for some hard core group of skeptics (which by now are becoming increasingly marginalized, but do remain hard core, Claes Johnson being a case in point). Since this seems to be such a popular discussion topic, and I have been trying to slay this particular dragon, I am trying to focus the dialogue in order to chip away at the skydragons and the people that are persuaded by their perspective. In the process, many are learning something and people are honing their arguments and improving their methods of explanation.

• Tom

Dr. Curry, Well said, I say…

“Tom, you know this and I know this. Stating that others should believe this because people like you and I know this hasn’t worked for some hard core group of skeptics (which by now are becoming increasingly marginalized, but do remain hard core, …”

almost biblical.

• Brian H

You have your metaphors crossed. The “skydragons” are the atmospheric warming effects of CO2 et al. You appear to be feeding and coddling them, not slaying them.

• I don’t know anyone who disputes that CO2 randomizes or diffuses directional IR radiation. The question is…how much “work” can this diffused energy do? Can it increase the temperature of the emitter or is the effect already “built-in” to the emitter’s temperature?

• The atmosphere expands.

• The cold, rarefied atmosphere which intrinsically has small thermal mass and correspondingly small thermal storage capacity expands (and contracts).

• How does this happen without the absorption of energy, a significant part of which comes from IR emitted from the surface. BTW, this happens where the atmosphere is neither cold nor rarified.

• I don’t know anyone who disputes that CO2 randomizes or diffuses directional IR radiation.

While it is true that CO2 scatters IR, it also absorbs it, and it is the latter that is the relevant effect. The absorbed EM energy initially becomes vibrational energy in all vibrational modes of the absorbing molecule, and is subsequently redistributed as kinetic energy in all permitted degrees of freedom of nearby molecules as a result of collisions.

• Yep, it absorbs energy and emits the absorbed energy just 120 picoseconds after it has absorbed that energy. Besides, the photon emitted by carbon dioxide has a longer wavelength and a lower frequency, so this energy cannot be absorbed by other molecules of carbon dioxide.

• kuhnkat

Tom,

the Greenhouse Effect is about the “bottleneck” of energy in the upper tropopause to stratosphere according to RealClimate and the IPCC. The NetEnergy flows have nothing to do with it. This is why the term backradiation is silly. It is used to describe one particular direction, down, of a radiative function in all possible directions. The energy is standard SB net energy flux. Trying to talk about it without its causative factor, the OLR, is silly. Without one you do not have the other.

The alledged reduction in radiative capacity due to a colder average radiation temperature from extra CO2 is what causes AGW as it backs up the energy in the troposphere. There is no exceptional increase in how much the net radiation from the surface is slowed from the extra CO2.

http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/

Concentrating on the ground level effects completely misses what the IPCC and RealClimate have been saying for years. Or have I missed a NEW AGW Theory??

Why are we still discussing ground level radiative transfer??

• GHE is not about either what happens at TOA or about energy fluxes at surface, it’s about both both. And it’s influenced by the lapse rate in between. All these must be considered to get the right picture. CO2 has a significant influence both at the top and at the bottom. In particular it has a large influence on the bypass of energy from the surface to the space by IR that’s not absorbed even once on the way, but that’s not the only important mechanism.

• Joel Shore

kuhnkat: You are basically correct. It is not a new theory…It is just different levels of refinement. The simple radiative picture allows you to understand the basic qualitative effect, but ultimately it is not that useful because its focus is on what is happening in terms of radiation at the surface, whereas we know that convection plays a large role in the transport of energy from the surface.

That is why, ultimately, you have to include convection and when you do this, it turns out that the easiest way to figure out what happens to the temperature at the surface is to start at the top of the atmosphere where again you need only worry about radiation and then work your way down using the fact that the role of convection is to maintain the lapser rate in the troposphere at the adiabatic lapse rate.

• Further, I regard it as a major coup for climate blogospheric dialogue for someone like Vaughan Pratt to enter the fray
http://en.wikipedia.org/wiki/Vaughan_Pratt

a person of demonstrated “meta-cognitive expertise”

• Very impressive biography. And originally from Australia no less. Who would have thunk it?

in series of posts on my blog:

and show that it to belong to fiction and not physics. I thus agree with Vaughan.

Since you open to debate Judy, don’t you have to say something yourself,
or do not have any opinion at all?

• Back radiation is a phrase, one that I don’t use myself, and it is not a word that is used in technical radiative transfer studies. The argument is made technically from the spectral infrared absorption and emission of CO2 and other gases.

• Congratulations Judy: You are making progress, after 2500 Dragon comments: So now you agree with me that back radiation is not physics, just a phrase.

But it is a phrase that matters, because CO2 alarmism comes from inflating one-way net transfer by a factor of 10 by replacing it with the difference of massive two-way transfer = the difference between upward and downward longwave radiation.

It is like writing 1 = 11 – 10, and claiming that a 1% change will be 0.1 instead of 0.01.

This is how climate sensitivity is inflated from a realistic physically motivated non-alarming 0.3 C to an unphysical freely invented alarming 3 C of IPCC. This is the result using the phrase “back radiation”.

Do you accept this consequence of viewing “back radiation” and “greenhouse effect” only as a phrase and not physics?

• Claes, there is much physics that makes your argument incorrect. Lets lose the back radiation terminology, we all agree on that.

• Why? As has been pointed out we observe radiation from the atmosphere.

You are doing an Obama here

• BlueIce2HotSea

The goal ought is to slay the Dragon, not to play with it.

The phrase ‘back-radiation’ – while physically correct – has encouraged sloppy thinking and an unending distraction.

On the other hand an explanation in terms of heat flow and the role of clouds as thermal insulation is also correct and more intuitively sensible. Why not this?

• BlueIce2HotSea

I ought to have written “the role of the atmosphere as thermal insulation”.

• Please keep in mind that any atmospheric insulation is in series with the nearly-perfect insulation of the vacuum of space. In addition, please keep in mind that temperature comes from matter…and there isn’t much in space, so it’s better to say space has no temperature than to say it has a low temperature.

• The space is not an insulation for radiative energy transfer.

We have a succession of insulations, and we have also in part parallel energy transfer mechanisms so that one of them bypasses others.

In the succession we have

– energy transfer from surface to the atmosphere, which occurs mainly by IR and evaporation

– energy transfer in the atmosphere, which happens by IR, convection and transport of latent heat

– energy transfer from the atmosphere to the space, which happens solely by IR emission.

IR bypasses in part other pathways as the radiation can pass through the whole atmosphere or large parts of it without being absorbed in between.

I like the approach based on insulation, but unfortunately it becomes difficult to use for quantitative analysis. That’s partly due to the fact that part of the IR radiation can penetrate long in the atmosphere, but that’s also due to all issues related to convection and latent heat.

Finally the quantitative physical calculations are done in the same way independently of the language that we use in describing the processes in words. Finally only the formulas and the calculations can tell, what our theories imply.

• BlueIce2HotSea

Pekka Pirilä

I agree that we ought to use the most convenient and sensible quantitative models and methods for calculations. However, increased confidence comes from divergent methods which also produce identical results.

Nevertheless, the problem with the Sky Dragon seems more one of sloppy qualitative analysis and terminology. Ironically, this sloppiness is not always transparently obvious to those with technical backgrounds. It is, I believe, partly because the missing details are unconsciously supplied and also due, for example, to niche engineering jargon that is useful but may still carry misleading connotations. However, for non-technical people who are nevertheless critical thinkers, the sloppiness can cause abrupt, stubborn resistance to further learning.

• Brian H

BI2HS;
I’d be interested in your opinion of an alternate “thought experiment” analysis I’ve come up with.
1. Posit the Earth with current atmosphere, sans CO2, with temperatures cycling about a set “balance” point;
2. Instantaneously add 0.04% CO2, and mix well;
3. The effect will be to slow/lag some of the OLR on its path to deep space, and the atmosphere and surface will be heated by an effect amounting to IRP x Lag duration (a few dozen milliseconds?);
4. A new set point will be reached, and stabilize when the net OLR again matches DWIR (i.e., after the lag has passed.)
5. Now, instantaneously remove the CO2.
6. Over the duration of the lag, the equivalent of the heat energy accumulated in step 3 will dissipate into the deeps of space;
7. The system returns to step 1.

There are two, theoretically measurable, quantities to know, here. 1) CO2-intercepted OLR energy, and 2) lag duration.

Problems?

• Brian H

Correction to 4., above: when OLR again matches DWSW.

• gbaikie

“There are two, theoretically measurable, quantities to know, here. 1) CO2-intercepted OLR energy, and 2) lag duration.

Problems?”

I doubt the affect would be measurable.
I doubt anyone would say there would be a measurable affect within days.
A volcanic eruption could have much larger affect, and doubt even that is measurable in days.
Doubt if you removed all greenhouse gas including water vapor, it would be measurable within days.
And natural variability could overwhelm the effect in terms of weeks and months. Though with all greenhouse gases removed, one probably see it within years. But without any clouds, global temperatures also could be significantly warmer. But if somehow kept the effects of clouds, it would cool the planet by a bit.

Doing something far more drastic, such as reducing the sun’s output by 10%, would also be difficult to measure within days [obviously in terms of “global temperature measurement”- rather than directly measuring the sun itself].

• BlueIce2HotSea

Hi Brian H-

Been away from the internet for a couple of days. Don’t know if you’ll get my reply.

Great poser – a trick question.

The biggest problem is that 0% CO2 implies not even single cell life. Not only would the albedo be drastically changed, but the overall lag duration would be measured in the billions of years while is evolving. This stretches the definition of long-term research project!

Of course there would be a rather dramatic impact on temp. if actual CO2 sensitivity was close that used by Dr. Pratt (i.e. well less than 2C).

BlueIce

• Judy – I tend to agree with Eli on this point,. Back radiation is a very familiar term in legitimate climate discussions (Raypierre made this poiint on RC a while back), and conveys a fairly accurate picture of what is actually happening – infrared (IR) radiation is being emitted downward rather than upward, and in quantities sufficient to substantially alter surface temperatures. The problem with the term, as I see it, is that it fails to distinguish all downwelling IR from that portion that is redistributed downward (“backward”) from GHG molecules that have been excited as a direct or indirect result (thermalization) of IR originally travelling upward from the surface. There is an additional portion that was always headed downward in the form of solar IR, and which was intercepted by GHGs and again emitted downward at wavelengths characteristic of these molecules.

Even so, “back radiation” creates an accurate mental image overall, is widely used, and does not have a clearly superior alternative. “Downwelling IR” fails to indicate the role of GHG molecules in redirecting energy downward that would otherwise have escaped to space. I don’t see any compulsion to use the term “back radiation”, but neither do I see a reason to discard it.

• Jim D

Fred, downwelling longwave, apart from the negligibly small amount from the space background or sun, should all be considered emitted, the sources being GHG molecules, clouds if present, and dust. The history of these photons before their emission does not need to be taken into account, so reflection/redirection is not an important process in IR (though some small reflection may occur from cloud droplets since their emissivity may not be exactly 1.)

• Jim – I think either term is fine. “Back radiation” appeals to me because it reminds readers that atmospheric GHG molecules can send a large quantity of IR back to earth when in their absence, all IR emitted from the surface would escape to space.

• Jim D

But, ‘back’ implies some kind of reflection when really it is emission. It would exist even if the ground was somehow at absolute zero and not emitting anything upwards.

• simon abingdon

Fred, you say “infrared (IR) radiation is being emitted downward rather than upward”. How’s that square with “isotropically”?

• Isotropic emissions convert radiation that was emitted upward into radiation in all directions, about half of which is downward (at various angles).

• simon abingdon

Quite so. I was querying the words you used “infrared (IR) radiation is being emitted downward rather than upward” which could easily confuse if the context was not already understood.

• simon abingdon

Fred, I would like to understand in simple terms, what is the evidence that the angle of scattering of the outgoing IR photon is isotropic and therefore independent of the angle of incidence of the incoming IR photon?

• Scattering is rare. What really happens usually is that IR gets absorbed and the energy transferred to thermal motion of the molecules by collisional deexcitation. At the same time many molecules are in excited state due to collisional excitation and a small fraction of those emits an IR photon isotropically to any direction. When the mean free path of the wavelength is short the rate of absorptions and the rate of emissions is equal far from the surface. Near the surface the rates may differ significantly as a part of the energy transfer from the surface to air.

• The total power output is sigma/pi T^4; sigma T^4 means isotropic radiation.

• simon abingdon

“The total power output is sigma/pi T^4; sigma T^4 means isotropic radiation”.

Chris, no doubt it’s a commonplace that sigma T^4 means isotropic radiation but some definition of terms and their relevance here might help the interested reader to understand you.

• Pekka Pirila… You say:

“Scattering is rare.”

Your assertion is nonsense. Statistically, scattering has the same chances of happening than absorption because they occur at the same time, to the same photon impinging on the same particle.

Show me a blackbody in nature, Pekka.

• kuhnkat

Even your attempt to start explaining this silly concept is confusing. So called backradiation is only one vector of all possible directions that GHG’s can emit energy and is slightly smaller quantitatively than the other directions. It is simply IR radiation. Giving it a special name distorts what it is supposed to do.

Backradiation isn’t emitted instead of, but along with. Trying to force the use of this abused term will continue the problems and is not necessary to explain the atmosphere effect that alledgedly BOTTLENECKS the OLR and causes AGW!!!

• Let’s face it Judy: If you give up back radiation, then the greenhouse effect evaporates up into the atmosphere. How can you give up so easily? Now you have to tell precisely what physics makes my argument incorrect, my argument showing that back radiation is fiction, an argument which you now apparently embrace. So what physics make my argument incorrect? You understand that you will have to answer.

• Claes, you don’t get it. I give up back radiation as a misleading phrase. I do not give up the infrared emission and absorption from gases like CO2. Or maybe you do get it, and your whole argument is sophistry rather than physics.

• Joel Shore

Or maybe you do get it, and your whole argument is sophistry rather than physics.

Bingo…I think we have a winner!

• Dear Dr. Curry:
CO2 absorption and emission of radiations is a correct science. It is the claimed heat trapping effect of CO2 that is fiction. The mathematics used in the models accounts only for the heat trapping effects of trace gases such as CO2 and ignore atmospheric air. This is a wrong mathematics. Because carbon dioxide is an integral part of the air mixture and exchanges with the atmospheric air heat of absorption and radiation. The atmosphere as a whole, considered as air mixture, exchanges heat including radiation, with the surface for there is an interface between them. There can be no exchange of radiations between the layers of the atmosphere, as the radiative forcing theory wrongly suggests, because air mixture is homogeneous and there are no interfaces between air layers.

I vote for the latter. Judith, no matter how many times you try to explain this to him, Claes won’t get it. The whole greenhouse effect debate is a big word game for him, in which he likes to argue — he says — in parables. Claes’ arguments are nothing but sophistry.

• Dr. Curry… You owe me two cents… Remember? You can send me my two cents via Pay Pal… :)

• Dr. Curry, you don’t owe a humbug like Nahle anything. Like his fearless leader John O’Sullivan, Nahle pads his resume with many dubious academic and professional credentials and he will not provide any information by which they can be verified. A “scientist” who claims to have earned a “certificate” from the “University of Harvard,” is a laughable humbug.

• I have no clue why people continue to entertain Claes. At least in Lindzen or Spencer’s case, they have a PhD in a relevant field to make people pay attention to them time after time.

• Edim

Science is the belief in the ignorance of experts.

• Anti-science is belief in the ignorance of ignoramuses.

• Claes has some serious credentials
http://www.csc.kth.se/~cgjoh/

he is widely published and cited in applied mathematics.

Apart from his misunderstanding on this particularly topic, I can’t understand is why he would be hanging out with the skydragon group, and why he would pull a stunt like quoting me out of context after explicitly calling him on it here.

This kind of behavior is really destroying his credibility. Ignoring or insulting such people doesn’t make them go away. Identifying the flaws in their argument and then seeing them demonstrate untrustworthy behavior is the way to diminish any credibility they have.

• It is good Judy that you understand that I am not a crank. I do not want to
misinterpret what you say or quote out of context. I just want you to show your cards. Will you do that?

• Judith– PhD’s can still say the sun revolves around the Earth

• Philip

From the point of view of normal physics, Claus’s position is incomprehensible. But I think he either rejects or is critical of a large mass of modern physics — including QM, SR, not to mention thermodynamics — and it may be easier to appreciate – if not agree with – his criticisms from that light. Perhaps part of the reason for his skepticism is the belief that a purely reductionist approach is not the best way to approach physics. If so, he is in good company (even if many do take vigorous exception). In this belief at least, there must surely be some resonance with the ideas of chaos and abrupt change in the climate system, which I’ve often seen discussed here.

• Jim D

The scientific term is surface downwelling longwave flux, sometimes qualified as broadband to indicate an integration over all IR wavelengths. There are measurements of this and papers about it. The science community has no dispute with the magnitudes of hundreds of W/m2.

• I know, i discussed this extensively on the thread “why we have confidence in radiative transfer models” but this nonsense continues. Still trying to get to the bottom of why people don’t understand this. Or maybe this is all about sophistry and knocking down margin terminology like back radiation and greenhouse effect, that have been introduced to explain all this to nontechnical people.

• Jim D

I realized it is the terminology you are after. I wanted to just add that scientists have a different term, so you won’t find back radiation in papers, but if you look for downwelling longwave flux you find a lot of references to it as a known, understood and measured quantity.

• gbaikie

“I know, i discussed this extensively on the thread “why we have confidence in radiative transfer models” but this nonsense continues. Still trying to get to the bottom of why people don’t understand this. Or maybe this is all about sophistry and knocking down margin terminology like back radiation and greenhouse effect, that have been introduced to explain all this to nontechnical people.”

No one thinks CO2 is responsible for “magnitudes of hundreds of W/m2”,
they aren’t that stupid, right?
And we know clouds are responsible for “magnitudes of hundreds of W/m2”.
And everyone realizes that the greenhouse affect has little to do with daytime temperature, and what it’s main affect is suppose to be on night time temperature and winter temperatures. Correct?

It’s also generally accepted that CO2 has little affect upon causing ice ages- if you half or double CO2 it doesn’t cause an ice age, and the idea that CO2 levels was originally considered as possible explanation for ice ages- was an incorrect hypotheses. Wrong because earth has been in cooling period for millions of years- that this long term cooling is major factor causing ice ages in the geologic record and this long term cooling is unrelated to CO2.

• To help you answer my questions Judy: Do you think that “downwelling longwave radiation (DLR)” is also just a phrase? And not real physics?

• Leo G

Dr. Curry, try this one. We are all driving in our own cars, leaving town for a long weekend. As more people enter the highway, the traffic slows, as the traffic slows to a crawl, some of the motorists pull a u-turn and return to the city, and will try to leave again the next morning.

Very simple I know.

• Downwelling longwave radiation is better terminology to describe what is going on. Back radiation implies reflection of IR radiation which is incorrect. Infrared emission of infrared radiation is nearly isotropic, so some portion of the emission from atmospheric gases goes in the direction of the Earth’s surface, which is “down” if you are sitting on the Earth’s surface.

• Jim D

IR radiation is best visualized as an intrinsic emission of a gas at a given temperature with a given composition, plus anything transmitted through it from a background. These concepts come up in astronomical spectroscopy too.

• kuhnkat

Leo, your idea is correct but applied at the wrong level of the atmosphere according to the IPCC and RealClimate. It is upper trop through strat where this alledgedly occurs and is due to the average radiation altitude increasing, lowering the average radiation height. This is what the models say, NOT a bottleneck at the ground!!! At the ground the temperature has no constraint and the GHG’s can keep emitting more to keep up with the increased emission of the surface!!!

• John Q. Lurker

Prof. Curry: They don’t understand it because they don’t understand that the warming in question is warming relative to a situation with a lower CO2 level, not warming relative to a situation with the same CO2 level. (I know, warming might continue for a while even if the CO2 increase was halted, until equilibrium was reached, but you can’t deal with that until you’ve dealt with the basic misconception.)

This doesn’t address the technically advanced arguments, such as Claes Johnson’s, even though, for all I know, they might depend on the same error, but I am convinced that some great majority of the people who believe that the greenhouse effect violates the 2nd Law of Thermodynamics are laboring under the misconception that I’ve indicated. Despite the difficulty of describing the difference between the two “kinds” of warming, I fail to see why it is not obvious that these people are missing it.

Why they are missing it is another question. I think part of the answer is that their critics are missing it, too. A scientifically informed critic will object to my idea by saying that warming is warming; there are no two kinds. OK, fine, but this misses the difference between warming relative to a situation with less CO2, etc., which is the same thing the “2nd Law” people are missing, so it can’t help them.

If you think I’m wrong, please comment.

• gbaikie

“This doesn’t address the technically advanced arguments, such as Claes Johnson’s, even though, for all I know, they might depend on the same error, but I am convinced that some great majority of the people who believe that the greenhouse effect violates the 2nd Law of Thermodynamics are laboring under the misconception that I’ve indicated. Despite the difficulty of describing the difference between the two “kinds” of warming, I fail to see why it is not obvious that these people are missing it. ”

If you surrounded the sun with mirrors reflecting back the sunlight, can you heat up the sun?
Or are stars which surrounded by dust [star formation] hotter because of the dust?
Or why is the Sun interior so much hotter than it’s surface?
I suppose you look at that question in two ways, how about, why isn’t there runaway greenhouse affect with the sun?

• John Q. Lurker

gbaikie said: If you surrounded the sun with mirrors reflecting back the sunlight, can you heat up the sun? Or are stars which surrounded by dust [star formation] hotter because of the dust? Or why is the Sun interior so much hotter than it’s surface? I suppose you look at that question in two ways, how about, why isn’t there runaway greenhouse affect with the sun?

Your message is indented too far to have a “reply” thingie, so I’ll reply as if to myself. I’m not sure what surrounding the sun with mirrors would do. There’s probably a gotcha in the question (not that I think you know this), having to do with the fact that the mirrors would mainly be reflecting visible light and UV, and with what the sun is made of. I’ll guess that it would make the surface of the sun hotter, but that is a guess. With the dust, I’ll guess the same, with slightly more confidence, not much. Your last two question are just too too difficult for me.

Do you mean to be defending the idea that the greenhouse effect violates the 2nd Law? You don’t say. If it does violate it, it certainly doesn’t violate it in any easy-to-understand way. If you introduce “insulation” to the earth’s atmosphere, it changes the vertical distribution of temperatures. What’s hard to accept about that? Suppose you have a sphere surrounded by some material that’s transparent to UV. You shine UV on the whole affair, and the sphere radiates IR. Now you introduce a layer of material near the sphere that’s largely opaque to IR, or more opaque than the original material. The surface of the sphere will now be warmer, and the region of material outside that layer will be cooler.

• gbaikie

“I’m not sure what surrounding the sun with mirrors would do. There’s probably a gotcha in the question (not that I think you know this), having to do with the fact that the mirrors would mainly be reflecting visible light and UV, and with what the sun is made of.”
[The sun mostly [about 90% of it’s total energy] emits infrared and visible light and these wavelengths would reflected by a mirror {99.9% of it}.
Sun is mostly hydrogen and helium.]
I’ll guess that it would make the surface of the sun hotter, but that is a guess. With the dust, I’ll guess the same, with slightly more confidence, not much. Your last two question are just too too difficult for me.

Do you mean to be defending the idea that the greenhouse effect violates the 2nd Law?”
No I just saying these similar issues. And in case with dust around a star- something which may be observable- and therefore have means of falsifying. But I believe the 2nd law would say that mirrors or dust would not increase the sun/star’s heat. Or at least the convention is to ignore this aspect.
In my opinion I would say when something is say 90 degrees there is less uniformity than what some might think there is, and to simplify one thinks of it as uniform. And therefore some heating is possible.
But I think the more important issue is the amount energy emitted from a “cold sky” is insignificant- on the order of the amount energy from Moonlight.

“Suppose you have a sphere surrounded by some material that’s transparent to UV. You shine UV on the whole affair, and the sphere radiates IR. Now you introduce a layer of material near the sphere that’s largely opaque to IR, or more opaque than the original material. The surface of the sphere will now be warmer, and the region of material outside that layer will be cooler.”

As said above UV isn’t a significant portion of energy from the Sun- and about 1/2 of Sun energy is infrared, but anyhow, a material opaque to infrared [or long wavelength infrared- and/or infrared spectrum of all objects on earth heated by the sun] will heat up and re-radiate energy. Perhaps you seen TV shows where people behind walls can seen- they are seen using a scope that can see infrared- the shows aren’t accurate but there some grain of truth regarding this aspect. Firefighter also use these scopes to see thru smoke.
And therefore “region of material outside that layer will be cooler” is incorrect. instead it would the opposite, it would be warmer [generally].

But I believe the main point is of article is that the colder sky doesn’t heat the warmer ground. And I agree with the obvious, the sky doesn’t radiate a significant amount heat [nfrared] to the ground.

• John Q. Lurker

gbaike:

[The sun mostly [about 90% of it’s total energy] emits infrared and visible light and these wavelengths would reflected by a mirror {99.9% of it}. …]

You’re right that I overestimated the ultraviolet. Eyeballing this graph, I get 10 percent UV andt 45 percent UV+visible). A lot would depend on the type of mirror, I think, but possibly that doesn’t matter to the question of whether mirrors surrounding the sun would heat it up. As I said, I think the answer is yes.

In my opinion I would say when something is say 90 degrees there is less uniformity than what some might think there is, and to simplify one thinks of it as uniform. And therefore some heating is possible.

I don’t understand. 90 degrees of what? Temperature? Elevation (above the horizon)? I don’t understand regardless of which of those I pick.

And therefore “region of material outside that layer will be cooler” is incorrect. instead it would the opposite, it would be warmer [generally].

Sorry, no.

But I believe the main point is of article is that the colder sky doesn’t heat the warmer ground. And I agree with the obvious, the sky doesn’t radiate a significant amount heat [infrared] to the ground.

How do you explain the fact that even strongly AGW-skeptical scientists, such as Richard Lindzen, Roy Spencer, and Lubos Motl, affirm that, ceteris paribus, an increase of the CO2 level does increase the surface temperature of the earth? If your argument is correct, this is astonishing, not “obvious.”

Do you think that Lindzen et al. are dupes or traitors? If they were, this would just about cancel your chances of figuring anything out. I’ve seen attitudes like yours in other areas, esp. economics. I’m referring to people who casually reject even what their own side’s experts claim. Often this is because they don’t know what their own side’s experts claim, but it’s not easy to see how this would be a factor in the question of global warming.

• Alexander Harvey

Back radiation is perhaps a good term at least for those that understand it. But it is a rotten metaphor, and for as long as people base argument on metaphor it will be problematic.

I am not sure that it is even a reasonable analogy for it may imply that it originates as a return flux whereas its origins are isotropic. It may also imply that it is directly the result of the outward ground flux, when it is only indirectly related being mediated by temperatures. Fluxes that originate in the atmosphere due to its temperature are sometimes referred to as the path thermal emissions. Part of the results of the integration of these emissions is called the back radiation. It may be that because people rarely refer to the path emission into space as the forward path radiation it seems that the back radiation is in some way unphysical e.g. one might query how it knows to go backwards. Also it may give the mental impression of a vertical beam whereas commonly much of it is oblique and weakest from the zenith.

We might do well to consider at what level terminology will be grappled with by those that are not well versed in the argot. By all means keep back radiation as a technical term but be prepared to forever fight off its metaphoric resonance.

Alex

• This is part of vaughan pratt’s argument, that the terminology, and how it is (mis)interpreted, is a big part of the communication problem.

• Jim2

Why not call it atmospheric radiation? That’s what it is, after all.

• Alexander Harvey

Judith,

Yes indeed, it is also an unintended battle field. People are not so dumb as not to know how to exploit a wobbly scientific metaphor of which the GHE probably tops the all time listings but back radiation is climbing the charts.

It concerns me that I find little in the form of video recorded graduate/under graduate level lectures dealing with radiative transfer as I for one should like to watch them. Such lectures must occur annually and some universities are better at archiving such material than others, MIT and UC probably stand out as exceptions.

There comes a level where people must have some common basis of understanding and when a subject like the radiative properties of the atmosphere are underpinned by well understood physics perhaps the physics must be made available and freely so. If this is the important issue I believe it to be, those that put no trust in the illusory realm of the scientific metaphor should be exposed to the real science behind it and if the can’t hack that then be informed that there are intellectual hurdles to understanding however unintended and with the best will in the world those that can’t or won’t learn are at a major disadvantage.

Alex

• Alex,

I have been thinking on writing up (just for fun or), how radiative heat transfer proceeds in gas. The theory is closely similar to that of thermal conductivity in gas, when the mean free path is not too long. Of course doing this effort would be wasted, if someone could provide a link to such a presentation, which is written sufficiently well, but I haven’t been able to find one.

Different wavelengths can be handled separately and the total effect is just the integral over wavelengths (or sum over bands).

• Alexander Harvey

Pekka,

while I remember I found this PPT:

file:///C:/Documents%20and%20Settings/Administrator/Local%20Settings/Temporary%20Internet%20Files/Content.IE5/9LSB5RCX/Barnet2%5B1%5D.ppt#679,15,“Curve of Growth” of a Molecule Band Model

That indicates an explanation of the linear, square root, and logarithmic regimes which I was so openly ignorant about and for wich you tried to correct me.

I think anything anyone with a muture understanding of the issues and perhaps teaching the subject can do would be useful. As to where and how to attract viewers you would just have to pug away at it. However if you have said all that needs to be in most cases a simple “here is my presentation go and read it might say a lot of effort in the long run, or it might not.

Alex

• Pierrehumbert’s book contains related considerations, but not exactly, what I had in mind, which should explain some important things in simpler terms, but which has also restrictions in applicability that don’t affect Pierrehumbert’s formulation as much. Thus Pierrehumbert’s formulation is likely to be more useful for complete calculations of the the heat transfer through atmosphere taking into account the changing density and other important issues.

• John Carpenter

“I have been thinking on writing up (just for fun or), how radiative heat transfer proceeds in gas.”

Pekka,

I would find such a write up very informative. Please inform us if you do so.

• dlb

Pekka, I would be keen to learn more. I can understand that CO2 and H2O do the absorbing but what does the emitting? Is it the GH gases or does the bulk of emission come from thermally excited N2 and O2? Does the emission happen instantaneously or is there some sort of heat capacity of the atmospheric gases?

• If and when I get that ready, I’ll make a pdf file out of it, because it will contain formulas and some figures. I’ll put that in the file area of my site and give the link both here and on my own site. I may also ask, whether Judith is willing to have a shorter version with less formulas as a posting here, but that’ll depend on the form the text will have, when it’s (hopefully) done.

It’ll certainly not be a text book. Thus it can’t answer all related questions. The central idea is the close similarity between radiative heat transfer and conduction, when certain conditions are met, but I’ll certainly discuss to some extent also the problems of meeting those conditions. This issue is actually a subproblem, where I’m not sure, what I’ll finally conclude, i.e. I haven’t thought in full detail how far the approach similar to conduction remains practical. I’ll learn myself more about that, when I write it up, because that involves also some work with the mathematical formulation of the conditions.

The easy part is, what happens safely inside the troposphere for radiation of high absorptivity/emissivity. That’s already interesting enough in my opinion, but, what happens to the mathematics when the mean free path is so long that atmospheric density or the temperature gradient changes significantly over that distance, that I haven’t checked in detail.

The overall role of the radiative energy transfer in understanding the atmosphere is an issue that I must discuss to some extent, but that’s an area that I certainly cannot handle in full detail, but will be limited to some semiquantitative statements at best.

Another open question is, how much I’ll include such issues as those dlb asked. The main part of the text will certainly take answers to those questions given, and I don’t know now, how much effort I’m willing to put in justifying the starting points rather than just stating them.

If the text will be discussed here or elsewhere, that’ll offer opportunities for further questions and answers.

• curryja, 8/13/11, 11:50 am, Vaughan Pratt

How far should we go when we lose the back radiation terminology ? We will have to throw out Kiehl & Trenberth, Earth’s Annual Global Mean Energy Budget, 2/1/1997. AR4, FAQ 1.1, Figure 1, p. 96. And since The term “radiative forcing” has been employed in the IPCC Assessments to denote an externally imposed perturbation in the radiative energy budget of the Earth’s climate system. (TAR, ¶6.1 Radiative Forcing, ¶6.1.1, p. 353), we will have to throw out radiative forcing, too.

You imply we should rely on radiative transfer instead. 8/13/11, 10:10 am. Yet, the uncertainty in RF is almost entirely due to radiative transfer assumptions. AR4, ¶2.3.1, p. 140.
Your recommendation looks like throwing out the baby and keeping the bathwater.

Yet you wrote, Climate models calculate radiative transfer and fluxes in grid cells all over the globe in response to the temperature and humidity profile, cloud characteristics, and gaseous and aerosol composition at the grid cell at that particular point in time (multiple calculations are made in each grid cell for each day in the model integration.) And then recommend the thread, Confidence in radiative transfer models. 8/13/11, 11:14 am.

We did indeed have a nice dialog on radiative transfer there. The result, however, instilled no confidence in this highly precise but impossibly inaccurate theory. Indeed, what distilling that thread might show is the reason why RT is the biggest source of error in RF. The accuracy of RT is limited by the accuracy with which one can characterize the atmosphere, including its lapse rates and CO2 distribution. It is further limited by the fact that it is non-linear, so that the average flux in a cell cannot be determined from the flux for an average atmosphere. Perfecting the atmospheric model is a waste of time.

As you point out on both scores, GCMs may not start with a global average temperature but they do require a temperature and humidity profile. If you mean a daily average temperature and humidity, the diurnal effects alone should make the problem of determining an average radiative flux prohibitive. Then throw in the confusion over the CO2 distribution in the atmosphere! The on-line MODTRAN routine makes CO2 proportional to atmospheric pressure, based presumably on the well-mixed assumption. The AIRS results show that it is far from well-mixed, but regardless, RT needs the CO2 lapse rate to be known accurately just to get the radiation instantaneously right.

The ugliest part of all this is that the RF model can’t get the shortwave radiation right, back radiation or not. And that as IPCC admits, that error is as great as the whole climate sensitivity estimate based on the simplest theoretical grounds. 4AR, ¶1.5.2 Model Clouds and Climate Sensitivity, p. 114.

The core problem with the back radiation concept is that one-way radiation doesn’t supply heat. Thermodynamics defines radiant heat as the net radiation between objects. Heat is what changes thermal energy, not as some claim, back radiation. E.g., Fred Moolten, 8/13/11, 12:03 pm. K&T, on the other hand, got that part right in their hybrid budget: for thermodynamic modeling, radiation must always appear in pairs, up and back. The net in their budget is 66 W/m^2, about a fifth of what it receives from the Sun, and the net was sufficient for the budget.

That the atmosphere might heat the surface on some global scale is silliness, no matter who said it or whether it was published. Neither the atmosphere nor CO2 is a source or a sink. One could model either as a source or sink, but the model would have to take into account the appropriate heat capacity to have any predictive power. As it turns out, those heat capacities are negligible. The atmosphere is a blanket. AR4, FAQ 1.1, p. 95. It’s a wet blanket to AGW, including CO2. As a blanket, it is a resistance to heat, not radiation. The atmosphere acts as a resistance to the cooling of the surface through radiation to deep space.

When Vaughan Pratt pointed his IR thermometer at space and the surface, he was sensing a net radiation for each. He was sensing the energy in the form of heat as it impinged on the detectors in his thermometer, whose microprocessor then calculated the impinging radiation from an algorithm using an estimate of the detector temperature. His device converted that impinging radiation to temperature using Stefan-Boltzmann’s perfectly nice and useful equation as if the detector were at 0K and using some sort of standard or selectable emissivity. We don’t measure the theoretical concepts of up and back radiation. We don’t sense them. We estimate them always from intercepted energy. And that is how they work with Earth.

I endorse your notion to throw out back radiation, but don’t stop there. We should return to the lost art of estimating climate with a thermodynamic model. In that domain, heat is a flow variable, the greenhouse gases are a variable, passive resistance, and feedback can be modeled rationally and productively.

• Jeff, that is extraordinary common sense. Thank you.

• Jeff – I’ve read through your long discourse, and except for a variety of undocumented assertions, I find nothing in it to contradict the observationally confirmed magnitude of downwelling longwave radiation (colloquially “back radiation”). In addition, you are incorrect in asserting that this IR can’t change the thermal energy of the Earth’s surface. Of course it does. The fact that “radiation appears in pairs”,and the net effect is paramount, doesn’t contradict this principle – the back radiation changes the net as long as there is an energy imbalance, and this results in a rising temperature (more thermal energy in the oceans, for example), until balance is restored at a higher temperature.

• Fred Moolten, 8/13/11, 3:27 pm, Vaughan Pratt

Since you couldn’t be specific about my undocumented assertions, you leave me to guess where you need help. Note that previously I did provide documentation, just not enough for you, meanwhile you chronically provide none. These references, though, might fill the bill.

The gain or loss of internal energy, equal to the difference between the energy of the thermal radiation which is absorbed and that which is radiated, is called heat. Bold added, Zemansky, M. W., Heat and Thermodynamics: An Intermediate Textbook for Students of Physics, Chemistry, and Engineering McGraw-Hill, Fourth Ed., 1957, p. 105.

We have for the heat transferred by radiation between a body at the temperature θ and walls at θ_W, is Q_dot = A*α•σ*(θ^4 – θ_W^4), where α refers to the temperature θ. Id., p. 106. Note: the radiation from the walls of the assumed enclosure is the back radiation.

You wrote, the observationally confirmed magnitude of downwelling longwave radiation (colloquially “back radiation”). In addition, you are incorrect in asserting that this IR can’t change the thermal energy of the Earth’s surface. This is wrong on a couple of counts. As I explained at 3:10 pm, what we observe is not back radiation, but instead a heat flux. Secondly, your assertion that back radiation changes thermal energy violates the thermodynamic definitions cited above.

Your wrote, the back radiation changes the net as long as there is an energy imbalance, and this results in a rising temperature (more thermal energy in the oceans, for example), until balance is restored at a higher temperature. Balance is not restored. Earth has no preferred thermal state as long as long as TSI and gravitational forces exist. This is a big error repeated in the AGW model. It was an error expressly avoided by G.S. Callendar when in 1938 he published what became known as the Callendar Effect. Earth’s climate is stabilized and regulated by albedo, cloud albedo in the warm state (Callendar), and surface albedo in the cold state (Glassman).

Equilibrium does not exist because it is convenient for the analysis. It must be explicitly invoked by the existence of a principle of physics. Minimum kinetic energy leads to equilibrium for lossy mechanical systems. Minimum torque leads to equilibrium for a balance scale. And for climate, the Second Law of thermodynamics leads equilibrium, but you have to include the Sun and deep space along with Earth’s climate and wait forever.

When last I tried to explain this error of yours with equilibrium (6/7/11, 12:35 pm, Toward sane policies thread), and more, all you could muster up was this crack: Jeff–I can see the medication isn’t working. My own sane policy informs me not to expect a more intelligent response this time. Nonetheless, my Rx for you is a dose of Zemansky. When you just repeat IPCC dogma, you inherit all its many errors.

• Jeff – You repeat the erroneous assertion that back radiation can’t change the thermal energy in the surface (including the ocean). Since it can and does, and since understanding that is critical to understanding the greenhouse effect, I believe your other conclusions become largely irrelevant. There is no violation of thermodynamics. When more back radiated energy enters the ocean from an increase in CO2, the ocean’s thermal energy increases. Its temperature also increases and so the ocean radiates more energy outward, but if the back radiation has increased, restoring a radiative balance requires the upward radiation to increase, which can only happen with a temperature rise. Indeed, it would violate thermodynamics for an increase in incoming absorbed energy to be matched by an increase in outgoing energy without an increase in temperature. That would permit two bodies with the same composition, temperature and emissivity to radiate different amounts of energy.

I think this is well enough understood to require us not to waste too much more time on it.

• ‘It is true that much of the atmosphere is colder than the surface but the point about greenhouse gases is that they reduce surface cooling by reducing the outgoing long wave radiation to space which is close to absolute zero. They do this by absorbing the outgoing radiation and then emitting isotropically.’ From Tom above

An atmosphere warmed as a result of less emission to space – emits in all directions including down and reduces the net IR up from the surface. Surface cooling is reduced – including in the oceans.

• Fred Moolten, 8/13/11, 5:09 pm, Vaughan Pratt

FM: You repeat the erroneous assertion that back radiation can’t change the thermal energy in the surface (including the ocean).

Assertion: 1. a positive statement, usually made without an attempt at furnishing evidence

2. the act of asserting World English Dictionary

I made no such assertion. I gave you book, chapter, and verse from first year thermo on what heat and radiant heat are, and where thermal energy and back radiation do and do not fit. 4:47 pm.

FM: The Earth receives thermal energy from the sun and from IR back radiated from the atmosphere at altitudes varying from less than a millimeter up to many kilometers. 12:03 pm.

See? No evidence; not even an attempt to supply evidence. THAT is an assertion.

You are back-radiating; i.e., providing no energy to the dialog.

• kuhnkat

Fred,

“Since it can and does, and since understanding that is critical to understanding the greenhouse effect, I believe your other conclusions become largely irrelevant.”

You assert that understanding the misnomer Backradiation is critical to understanding the Greenhouse effect. I declare it is NOT critical to understanding the Greenhouse effect as put forward by the IPCC and RealClimate.

This is what THEY claim:

http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/

Notice all the action has happened before there is a significant rise in surface temperature??

This is why SOME of us DENIERS claim there IS NO GREENHOUSE EFFECT!!! The physics described here is all about average radiation altitude and average radiation temperature, NOT the surface conditions that aren’t affected until Greenhouse is well advanced!!!!!

Why are we still arguing over the downwelling part of GHG’s IR radiation mislabeled Backradiation?!?!?!?! Is this the new communication methods, keeping the argument about something not integral to the THEORY?!?!?!?!

OR did someone decide to change the theory and the models without telling anyone??

• Joel Shore

Why are we still arguing over the downwelling part of GHG’s IR radiation mislabeled Backradiation?!?!?!?! Is this the new communication methods, keeping the argument about something not integral to the THEORY?!?!?!?!

First of all because downwelling IR radiation really does exist. And, second of all, because it is useful to understand the energy balance in simple models of the greenhouse effect before graduating to more complicated models.

However, I for one have continually pointed out that what the greenhouse effect really relies on is the notion that the net heat exchange by radiation of two object depends on both of their temperatures and not the interpretation (well-supported by experiment) that this represents two “streams” of radiative energy. [And, despite Claes’s false claims, changing your interpretation does not change the quantitative effect that you calculate because the effect is not calculated as some percentage perturbation but rather as an actual magnitude.]

• Tom

Mr. Fred Moolten, It sounds to me that the current science is only able to tell us the difference between a ‘balance spring’ & the ‘escapement’, but still can’t tell us what time it is, for sure.

• Joel Shore

Jeff Glassman says:

You imply we should rely on radiative transfer instead. 8/13/11, 10:10 am. Yet, “the uncertainty in RF is almost entirely due to radiative transfer assumptions”. AR4, ¶2.3.1, p. 140.
Your recommendation looks like throwing out the baby and keeping the bathwater.

(I put in quotes because I don’t know how to do italics like he did.) I think this illustrates how Jeff Glassman uses selective quotation to support his point of view. Clearly, he wants us to believe that there is some huge uncertainty regarding the RF due to these radiative transfer assumptions. However the fuller text around that selective quote actually reads:

Table 2.1 summarises the present-day mixing ratios and RF for the LLGHGs, and indicates changes since 1998. The RF from CO2 and that from the other LLGHGs have a high level of scientific understanding (Section 2.9, Table 2.11). Note that the uncertainty in RF is almost entirely due to radiative transfer assumptions and not mixing ratio estimates, therefore trends in RF can be more accurately determined than the absolute RF.

and from the table caption footnote:

90% confidence ranges for RF are not shown but are approximately 10%. This confidence range is almost entirely due to radiative transfer assumptions, therefore trends remain valid when quoted to higher accuracies. Higher precision data are used for totals and affect rounding of the values. Percent changes are calculated relative to 1998.

So, it turns out that the radiative transfer assumptions contribute to errorbars of +/-10% at the 90% confidence level. (And, the point of the note that the uncertainty in the radiative transfer is the biggest contributor to the uncertainty in radiative forcing is just made to make the point that changes in radiative forcing due to changes in concentrations are known more accurately than one might infer if one thought the concentrations values were the main source of the uncertainty.)

So, I think this little exercise illustrates how a true skeptic would be extremely unskeptical to believe anything that our friend Jeff Glassman writes on face value.

• Joel Shore, 8/13/11, 10:10 pm, Vaughan Pratt

I do indeed use selective quotes to support [my] point of view. Only a fool would do less. If only all the champions of the lost cause who post here would do the same. I quoted accurately, and unlike your post, I put no spin on the quotation.

You accurately quoted IPCC’s restricted context for that quote, but what you quoted was hyperbole and brochuremanship. IPCC did claim that the 90% confidence limit on a list of radiative forcing calculations was about 10%. By using this language from the art of statistics, IPCC appears to convey the impression that the radiative forcing calculations are accurate to within 10% at the 90% confidence level. However, IPCC provided no data for assessing RF accuracy.

The most that the data can mean is that the models are mutually consistent within 10% for the LLGHGs after a concerted undertaking of model and radiative transfer intercomparison projects (AR4, ¶1.5.3 Coupled Models: Evolution, Use, Assessment, p. 118; ¶10.2.1.4, p. 758): e.g., AeroCom, AMIP, C^4MIP, CMIP, EMDI, MIP, OCMIP, PCMDI, PILPS, PMIP, RTMIP, SIMIP, TransCom 3. While IPCC noted efforts to maintain independence of model outputs during intercomparison (AR4 ¶1.5.3, p. 118), that the models have not subsequent to the intercomparisons converged to better than 10% just on LLGHGs is surprising.

The passage you cited casts radiative transfer in the best light possible by citing results for radiative forcing calculations on LLGHGs. That is a small part of the application of RT. The dominant GH gas is water vapor (AR4 FAQ 2.1, p. 135), which is neither long lived (it’s not on the long-lived lists) nor a radiative forcing in IPCC models (AR4 ¶TS.2, p. 23.). IPCC treats water vapor as a feedback so the GCMs can release water vapor to amplify the CO2 effect. AR4 FAQ 1.3, p. 116. Even configuring CO2 as an LLGHG, not enough accumulates in the atmosphere to cause the desired warming.

In addition to its amplifying effect, water vapor by itself is more than twice as important as a GHG than is CO2, contributing 60% versus 26%. Kiehl & Trenberth, 1997, Table 3, p. 203, cited at AR4 ¶3.4.2, p. 271. Note also that K&T call water vapor absorption of longwave radiation a forcing (id.), and that their estimates are based on radiative transfer (id., p. 200).

The discrepancy in models caused by radiative transfer is not just the 10% effect ascribed to LLGHGs. And as far as that goes, CO2 is the only anthropogenic, radiative forcing LLGHG that counts, contributing 1.66 Wm^-2 out of a net of 1.6 Wm^-2. AR4, Figure TS.5, p. 32. In one intercomparison of total predicted longwave forcing, IPCC identified only RT as the culprit in model discrepancies about five times as large as what it gives for present day CO2 alone.

The radiative forcings by long-lived greenhouse gases computed with the radiative transfer codes in twenty of the AOGCMs used in the Fourth Assessment Report have been compared against results from benchmark line-by-line (LBL) models. The mean AOGCM forcing over the period 1860 to 2000 agrees with the mean LBL value to within 0.1 W m–2 at the tropopause. However, there is a range of 25% in longwave forcing due to doubling atmospheric CO2 from its concentration in 1860 across the ensemble of AOGCM codes. There is a 47% relative range in longwave forcing in 2100 contributed by all greenhouse gases in the A1B scenario across the ensemble of AOGCM simulations. These results imply that the ranges in climate sensitivity and climate response from models discussed in this chapter may be due in part to differences in the formulation and treatment of radiative processes among the AOGCMs. Bold added, AR4, Ch. 10 Executive Summary, p. 751.

IPCC doesn’t provide the model data for these various discrepancy reports. In a rare instance that is instructive and relevant, IPCC did report model variability. It reported the radiative forcing for a doubled CO2 concentration, F_2x, from 19 models. AR4, ¶8.SM, Table S8.1, p. 8-73. It reported the climate sensitivity, T_2x, from the same set. AR4, ¶8.6.2.3 What Explains the Current Spread in Models’ Climate Sensitivity Estimates, Table 8.2, p. 631. The radiative forcing, F_2x, varies between 3.09 and 4.06 Wm^-2, a range of ±13.6%, and is approximately uniformly distributed (P = F – 3.12). Likewise the climate sensitivity, T_2x, varies between 2.1 and 4.4ºC, a range of ± 35.4%, and is approximately uniformly distributed (P = 0.40 * (T – 1.88)).

Uniform distribution is the condition of maximum entropy. Because the outputs of these models are approximately uniformly distributed, the underlying AGW algorithm is little more than a random number generator. That is what explains the current spread.

The story with water vapor doesn’t end there. IPCC reports that cloud feedback is the largest uncertainty in the GCMs, and that it can produce another 100% variation under the simplest theoretical grounds. AR4, ¶1.5.4 Model Clouds and Climate Sensitivity, p. 114. IPCC wants you to believe that its models agree within 10% at 90% confidence.

Satellites are now providing the first check on model accuracy, as opposed to variability. As reported and discussed here on the Lindzen and Choi threads, empirical climate sensitivity is running about 0.7 ºC, not 3 ºC, and well below IPCC’s likely range of 2 to 4.5 ºC. AR4, SPM, p. 12. The GCMs which operate under the radiative forcing paradigm, augmented by radiative transfer, are being invalidated by remote sensing. Radiative transfer remains the largest source of error, but after IPCC’s failure to account for cloud feedback.

These conclusions are not as you say [my] point of view. This is not a theological matter of believers vs. skeptics (nonbelievers) as you imply. The conclusions are a deduction from evidence, analysis and model building. It’s a matter of one scientist against the self-proclaimed consensus. It is a skeptic against a conspiracy.

• Brian H

Mercy buckets; well said.

I am reminded of the citation of Schack by G&T:

Never forget that climatology is not even a field, much less a science:
“Rather, the atmospheric greenhouse mechanism is a conjecture [= preliminary guess without evidence, which may lead to a hypothesis with pass-fail proposals, which may eventually qualify as a theory], which may be proved or disproved already [= previously] in concrete engineering thermodynamics [95{97]. Exactly this was done well many years ago by an expert in this field, namely Alfred Schack, who wrote a classical text-book on this subject [95]. [In] 1972 he showed that the radiative component of heat transfer of CO2, though relevant at the temperatures in combustion chambers, can be neglected at atmospheric temperatures. The influence of carbonic acid on the Earth’s climates is definitively unmeasurable [98].”

“Falsification of The Atmospheric CO2 Greenhouse Effects Within The Frame of Physics,” International Journal of Modern Physics B, v23, n03, January 6, 2009, pp. 275-364. Free download at http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.1161v4.pdf.

Definitively unmeasurable means irrelevant, IMO.

• I agree the phrase matters and it is not a very useful phrase. What mystifies me is that most people understand the role of water vapor but totally lose it with CO2. Part of the confusion I believe is the frame of reference used. On the surface CO2 is lost in all the other action. From space you only see the net. At the tropopause CO2 is significant upward not so much downward. You need to travel through the layers of the atmosphere to “see” the changing significance of various gases and the changing transmission window clarity that limits outwards LWR.

• Claes:

Not sure how you calculate things. “CO2 alarmism” does not inflate “one way net energy transfer”. Energy transfer is a well studied field. Many things that work are designed based on the science. The values that the climate alarmists developed are very VERY close to those used in other fields, particularly combustion engineering. If you are going to question things like this and posit such massive errors, you must then explain why they are NOT so out of whack in a blast furnace. Because if the climate alarmists are so wrong, then so are the combustion engineers. And something else decreases the amount of coal you need to create a ton of steel. Something that varies with a one to one direct and continuous relation to atmospheric CO2 concentration. You must also be able to explain why temperatures in a hot pipe in air change the way they do, because right now, we can successfully predict this using values for CO2 absorbance almost identical to the values that climate alarmists use.

Radiant energy absorption from an energy source by intervening gases causes the intervening gases to warm up. These warmer things (which were already radiating energy) radiate energy at a higher rate. If you want to call that ‘back radiation’, so be it, but please don’t embarrass yourself and claim that climate alarmists exaggerate this by a factor of 10. They don’t exaggerate it at all.

If you go to my blog, you will see a paper that uses combustion engineering methods to estimate climate radiant transfer impacts. You will see that they are nearly identical to what the climate alarmists use.

I am strongly on the skeptic side. Your assertions make Al Gore look reasonable and that isn’t good for the cause.

• Brian H

See my citation above of the G&T citation of a themodynamic engineer’s observation: “the radiative component of heat transfer of CO2, though relevant at the temperatures in combustion chambers, can be neglected at atmospheric temperatures.” So your admission that you use values identical to those climate alarmists use is to say the latter are violating boundary conditions.

• Professor Claes Johnson: “It is like writing 1 = 11 – 10, and claiming that a 1% change will be 0.1 instead of 0.01.”
Indeed, the GHE is a concocted superfluity that is sustained merely by statistical shenanigans by charlatans who have no real world evidence evidence to back their claims. As Alan Siddons has repeatedly stated:

” Predicted earth emission without a greenhouse effect: 239 W/m²
Actual earth emission WITH a (supposed) greenhouse effect: 239 W/m² “

• Joel Shore

As Alan Siddons has repeatedly stated:

” Predicted earth emission without a greenhouse effect: 239 W/m²
Actual earth emission WITH a (supposed) greenhouse effect: 239 W/m² “

Look, if you guys are competing for who can make the stupidest statement, could we please just call it a tie? Do you guys understand absolutely NOTHING about the science you are critiquing? I can’t believe you (or at least those of you who have a science background) are really that ignorant and must therefore conclude you are purposely deceptive. Shame on you!

Joel, John O’Sullivan and his fellow Slayers are not trying to understand science. They are trying to create public misunderstanding and mistrust in science through the deliberate spread of falsehoods.

Just look at the outrageous falsehoods in John O’Sullivan’s “science report” last month — which was a shameless fabrication:

John O’Sullivan: Shock News: Disgraced Climategate Scientist Made Top UN Weatherman”
Friday, July 1st 2011, 10:22 AM EDT
http://climaterealists.com/index.php?id=7970

“Jim Salinger, one of the scientists suspected of criminal misconduct in the Climategate scandal has been elected to the prestigious role of President of the Commission for Agricultural Meteorology of the World Meteorological Organization (WMO). Climate skeptics are aghast at the news.”

As Gareth Renowden pointed, South Korean Byong Lee — not Jim Salinger — was elected president of the WMO’s Commission for Agricultural Meteorology for a four-year term in 2010.
http://hot-topic.co.nz/so-many-lies-and-the-liar-who-tells-them/

Jim Salinger had been elected president of the Commission for Agricultural Meteorology in 2006 — years before the so-called “Climategate scandal.”

And O’Sullivan piled on the lies: “In an ironic twist it’s the Kiwi government department now trumpeting his new WMO appointment on the NIWA website.”

And he got fellow Sky Dragon Slayer Joe Olson to chime in: “Joe Olson of the Slayers group of skeptics was quick to comment, ‘This is how the greens recycle their ‘waste’.”

And then topped it off with an even more outrageous whopper:

“Salinger remains a suspected accomplice in the tight knit international clique of climatologists involved in the data corruption scandal at the University of East Anglia (UEA), England. Commenting on that ongoing criminal probe, Senior Investigating Officer (SIO), Detective Superintendent Julian Gregory said: ‘This has been a complex investigation, undertaken in a global context and requiring detailed and time consuming lines of enquiry. Due to the sensitivity of the investigation it has not been possible to share details of enquiries with the media and the public and it would be inappropriate for us to comment any further at this time.’”

NO. Salinger is NOT a “suspect” in any criminal probe. Detective Superintendent Gregory’s comment, which O’Sullivan misquotes, was referring to his office’s investigation of the the illegal theft of emails from the University that were used to perpetrate the so-called Climategate Scandal.
http://www.telegraph.co.uk/earth/environment/climatechange/7594656/Police-question-climategate-information-seekers.html

Clearly, O’Sullivan and his partners are not misunderstanding climate science — they are misrepresenting it in to deceive the public to spread doubt and mistrust.

• DocMartyn

I always thought that if fire/firebricks had been used as an analogy, it would have been much better than the glass/greenhouse one.

• For the thermometer I am looking at right now, the only thing it essentially shows is the temperature of the (nearly) 1,000,000PPM of N, O and Ar. I ask myself…how did this gas get to this temperature? Heat was conducted into it and it was convected to my surroundings. Sure, there is a thermal path to from CO2 to the rest of the atmosphere, but this path is bidirectional and it is more accurate to say that nearly 1,000,000PPM controls the the temperature of the 390PPM…rather than the reverse.
I know radiation is a mysterious thing…how does this spooky, instantaneous, action-at-a-distance really work? Still, the idea that you could “do” something significant (measurable) with weak, diffuse radiation–like increase the surface temperature of the earth by nearly 10%–is just plain silly.

“Greenhouse” gases can delay outgoing radiation a little. How long? Microseconds? Milliseconds? How do you conflate the effects of this small time delay into higher and higher record temperatures?

• First go look up the zeroth law of thermodynamics. Let Eli Google that for you. Also allow Eli to point you to devices that measure temperature by radiation

Second, arguments from personal incredulity are not very impressive from the credulous.

Third, for all practical purposes, the delay in emissions within the wavelengths at which greenhouse gases absorb is forever. There is zero probability that a photon emitted from the surface at a wavelength that CO2 or H2O absorbs will make it into space. The photons in that region that are emitted to space come from vibrationally excited molecules high up in the atmosphere.

• I urge you to look again at Vaughan Pratt’s statements. He cites ONE meteorologist as his authority. Yet the term ‘atmospheric greenhouse effect’ does not occur in any fundamental work involving thermodynamics, physical kinetics, or radiation theory.

Moreover, it’s hard to take anything that Arthur Smith (Eli Rabbett) writes as serious after the debacle of his efforts in Halpern et al. (2010). No journal would publish these GHE devotees because their work contains a fatal flaw after the authors introduced effective quantities by averaging over the entire globe (see their Eqs. (7) to (9)) with violations of basic rules of calculus. Their equations (3), (6) to (8), and (11) are flawed by dimensional inaccuracies. All rebutted via peer-review here:

– Reply to “Comment on ‘Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics’ by Joshua B. Halpern, Christopher M. Colose, Chris H0-Stuart, Joel D. Shore, Arthur P. Smith, Jorg Zimmermann”
(International Journal of Modern Physics B, Volume 24, Issue 10, pp. 1333-1359, April 2010)- Gerhard Gerlich, Ralf D. Tscheuschner

Bottom line: back radiation does not supply ANY additional heating to our planet and GHE adherents are refuted for their bogus arguments that our atmosphere operates as a ‘closed’ system when in fact it is an ‘open’ system.

Thus energy in = energy out or boom! As Alan Siddons has repeatedly stated:

” Predicted earth emission without a greenhouse effect: 239 W/m²
Actual earth emission WITH a (supposed) greenhouse effect: 239 W/m²

– Reply to “Comment on ‘Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics’ by Joshua B. Halpern, Christopher M. Colose, Chris H0-Stuart, Joel D. Shore, Arthur P. Smith, Jorg Zimmermann”
(International Journal of Modern Physics B, Volume 24, Issue 10, pp. 1333-1359, April 2010)- Gerhard Gerlich, Ralf D. Tscheuschner

Back radiation does not supply ANY additional heating to our planet and GHE adherents are refuted for their bogus arguments that our atmosphere operates as a ‘closed’ system when in fact it is an ‘open’ system.

The term ‘atmospheric greenhouse effect’ does not occur in any fundamental work involving thermodynamics, physical kinetics, or radiation theory. Rabbett et al’s paper relies on guesstimates about the scientific properties involved to ‘calculate’ the chaotic interplay of such a myriad and unquantifiable array of factors that is beyond even the abilities of the most powerful of modern supercomputers.

• Joel Shore

Great, John, so you have read their reply. Could you kindly explain for the benefit of all of us how they explain their claim that the atmospheric greenhouse effect violates the 2nd Law. Please in particular focus on the part where we show via simple models of radiative transfer that the reasons that they seemed to claim that the Second Law is violated are nonsense…Good luck finding it though!

No, John O’Sullivan, No science journal anywhere will publish ANYTHING you and your fellow denier’s write about global warming. Now why is that? Oh, right, it’s that evil conspiracy like this guy says:

While we’re on the subject of scientific credibility, let me point out that we’re still waiting for YOU to provide evidence for ANY of the professional and academic credentials you claim in your resumes.

You say your representing fellow Slayer Tim Ball in the Supreme Court of British Columbia against libel charges brought by climatologists Andrew Weaver and Michael Mann. How is that possible since you’re not licensed to practice law in British Columbia?

• kuhnkat

Ahh, Brer Rabbett also showed up. Why are you also not arguing the RC and IPCC theory that is about the upper atmosphere?? The so called backradiation is a side show. Is that the real scam??

• Ken:
In radiant heat transfer calculations (better described as energy transfer), we use a value called “Path Length”. This is the product of partial pressure of the gas and distance. Thus a very concentrated gas over a short distance will have the same path length as a very dilute gas over a very long distance. For CO2 in the atmosphere, you come up with a path length somewhere between 200 to 300 bar cm (my estimate is 270 bar cm at 400 ppm). This is actually very high. 500 bar cm is about the concentration at which saturation occurs and there is no further impact from increased CO2. As such, from a radiant heat transfer point of view, there is a lot of CO2 in the atmosphere. What is really interesting is the fact that if there were a lot less CO2, small changes would then have a much larger effect. It is only because there is so much CO2 that the effect of CO2 change we are talking about is relatively small.

I tutor university undergrads in physics. The first lesson I teach is: Common sense is your enemy.

Cheers

JE

• Hi John. I don’t dispute radiant energy is diffused by CO2 and that every CO2 molecule will radiate based on its temperature. However, how did the molecule get its temperature? Sure, some of its temperature comes from being tickled by IR, but here on the earth’s surface where I care about things, the overwhelming control is via collision with nearly 1,000,000PPM of N, O, Ar, H2O, etc. Frankly, I don’t care about the atmosphere where it is very cold and highly rarefied. The earth’s surface is hotter because the thin air temp at cruising altitude is -45 instead of -55C? Right-o.

The idea of a TOA human-controlled outgoing radiation modulator is very silly. Radiation is fun to study and fun to think about, but using diffuse, low-power IR radiation for something useful like increasing the earth’s surface temperature by almost 10%? My gosh, cut back on the herb you’re stuffing in your magic pipe, okay?

For every climate science explanation, step-by-step, of how human-caused warming works, there is always and inevitably a hand-waving stage. I’m tired of hand-waving by bright, fully-indoctrinated people who want to explain to me, a tired and grumpy old electrical engineer, how heat transfer works. I get paid very well because I know how heat transfer works, thank you very much.

• Ken:

The “forcing” quoted in the IPCC reports can be calculated by engineering methods used to design things like blast furnaces. The values are pretty close.

I have NO hand waving stages in my math. Please visit my blog and read the paper at the top. It describes a method of calculating “forcing” that is independent of that used by the climate scientists. You will see that the methods used to design things that work, such as a blast furnace, provide results that are very similar to those used in the Global Circulation Models. It also explains what 300 ppm CO2 is a LOT of CO2, from a heat absorption point of view.

I too get paid very well. I get paid to perform heat transfer calculations. I’m a grumpy old metallurgical engineer. That’s an argument from authority though and is not relevant to the topic.

We are not talking about the method that causes the surface temperature to be 10% warmer than a black body radiator would be. We are talking about whether there is a greenhouse effect due to CO2.

If you want my opinion on why we are 10% warmer than a black body radiator, I believe it is primarily the oceans that absorb and retain sufficient energy to account for the increase and the atmosphere has little impact on it. But that isn’t the topic at hand.

Cheers

JE

• Claes: I thus agree with Vaughan.

Great. This ought to qualify me as a mediator for whatever might be the biggest point of disagreement between you and Judy. Not right now though, maybe in a few days.

4. Eyal Porat

“You’ll get nowhere attacking what skeptics say, you have to address what they’re thinking…”
Oh yes, why argue with facts when you can attack the person presenting them…
The pretension of “knowing” what or how one thinks is quite arrogant.
And just to prove my point – I think your assumption that CO2 natural release is constant is wrong (“Preindustrially this flux was in balance and CO2 was not under any great pressure to change rapidly in a single century” – where did you get this idea from?), and also wrong is your notion that nature cannot cope with extra few PPM a year properly (extra plant growth does it quite well actually).
It is obvious that Earth has seen much higher rates of CO2 with no catastrophic effects. What brings a reasonable person to think THIS time is different? I wonder.

• Joel Shore

Eyal Porat:

It is obvious that Earth has seen much higher rates of CO2 with no catastrophic effects. What brings a reasonable person to think THIS time is different? I wonder.

So, you think that sea levels tens of meters higher and completely different climates around the world are no big deal?!? On that scale, I suppose that terrorists flying planes into buildings wouldn’t even register. So clearly, all the money we are wasting on fighting terrorism is silly…After all, the Earth has seen terrorists fly planes into buildings with no catastrophic effects.

• Kermit

Tens of centimeters not meters. Ten of meters was debunked on another thread a few weeks ago.

• Kermit – Differences of 125 meters (not centimeters) have been associated with different climates in the past.

• Kermit:

Many tens of meters. The present barrier coral reefs are direct evidence of this. They are located far from shore in deep water even though coral needs shallow, warm water to thrive. They started growing where they are when the glaciers were at a maximum. Were all the glaciers to complete their melting that started many thousands of years ago, the net remaining increase in sea level would indeed be more than 100 meters. Only time will tell if this global warming trend, started many thousands of years ago, will continue and cause the remaining glaciers to fully melt, or if a new ice age will start. Both alarming prospects if you ask me.

Let’s be accurate (if not precise).

Cheers

JE

• Kermit

The average rate is about 3.1 mm per year based on 1993 to 2003 and its not increasing since that time. Even if that did increase to 4 mm per year, which would quite an unrealistic increase, that would take 250 years to increase 1 meter. Daily high tide to low tide variation is way more than that. These sorts century and decade changes are nothing new to civilization.

Go to the older threads like http://judithcurry.com/2011/07/12/historic-variations-in-sea-levels-part-1-from-the-holocene-to-romans/

• Kermit:

I think you will find that the current rate of rise is dropping to 0. This is not the point. The point is that there is sufficient water in the glaciers that the current phase of global warming have not melted, to raise the sea level more than 100 meters. Given that these glaciers did not melt the previous 5 periods of global warming, I am skeptical that they will melt this time either.

Cheers

JE

• hunter

Joel,
Thank you for demonstrating the alarmist clap trap AGW faith depends on.
SLR is not going to be in meters, much less tens of meters range.
Think of your shoe. Stand it heel down, toe up. Maybe put one shoe heel on top of the toe of the one pointing up. Somewhere between the floor and the toe of the second shoe is our risk.
Unless you are Sideshow Bob, of course.

• Joel Shore

I was responding to the statement “It is obvious that Earth has seen much higher rates of CO2 with no catastrophic effects,” i.e., what has happened in the Earth’s history. It is really ridiculous to see people who apparent think it would be just fine and dandy to relive some of the events that have happened over the earth’s geological history!

How high the sea level changes are likely to get under the current scenarios is another topic…although it is one where you have to recognize that the rise by 2100 is likely to be just the tip-of-the-iceberg.

• hunter

Joel,
If you ‘recognize’ that the slr in 2100 is the tip of the iceberg, get your eyes checked.
But now you are recanting the statement you made that we would see tens of meters by 2100?

• Joel Shore

hunter: Most of the sea level rise is indeed expected to occur over a fairly large period of time, although there are currently arguments going on in the cryosphere community over how fast the land ice might break up.

Since I didn’t make that statement that you claimed that I made, there is no need to recant it. I already clarified what statement I was making, although I also think it was fairly obvious from the context of the comment that I was responding to.

• simon abingdon

Joel “I suppose that terrorists flying planes into buildings wouldn’t even register. So clearly, all the money we are wasting on fighting terrorism is silly…After all, the Earth has seen terrorists fly planes into buildings with no catastrophic effects”. You’re quite right Joel, “all the money we are wasting on fighting terrorism is silly”, it’s just that the “oxygen of publicity” frightens a credulous public.

• Eyal Porat

Joel, I believe you are mixing actual threat (terrorism) with a non problem issue (global warming).
It is the Precautionary Principle gone mad.
In fighting terrorism we try to keep our way of life and belief , with all these Carbon Taxes we actually destroy it.

• Tom

Mr. Joel Shore,

Terrorists ‘hate our freedom’… George W. Bush
(what freedom?) TSA, HSA, NSA, ICE, ATF, PATRIOTACT, Predator drones, tasers…

We need to ‘save the world from the ‘unwashed’, with more death & taxes placed upon families around the world… futerra.uk
(In ss-O many words)

How are these two lies any different?

The Bible or An Inconvenient Truth. You must Choose between them.
You will have from now, until 2035, when glacier water will cover the face of the Earth and mankind will all be dead. This may be true, science says…

What is to be, our take-away? We will all need to know these things, just to make informed decisions about our planets safety.

Oh yeah Joel, how much time did it take for Bldg. 7, to hit the ground on 9/11? You can watch the event and time it yourself. Any problems or questions about this terrorist act? I still can’t explain it. No one even flew a plane into this building and it still collapsed into its own footprint. What other examples can you direct me to so that I can see another steel structured building do the same thing after a small fire. We need to work together, be Gung-Ho! Time is essential in coming to a firm understanding of all these events. Another dragon to slay, it seems.

• Tom

Joel,…

Have you, ever wondered why the elephants paint their toenails red?

It is so they can hide in the cherry trees.

Have you ever seen an elephant, in a cherry tree?

See how good; it has worked?

Okatsune

• kuhnkat

Tom,

why do you guys have so many myths??? Building 7 had major structural damage from steel and chunks of one of the towers ripping off part of the face. Fires were burning even before the twin towers collapsed from jet fuel and debris raining on it. The Truthers use the testimony of one of the workers who showed up late to try and make their conspiracy case. His statement, parphrased includes, I looked out the window to the right and saw smoke and flames, I looked to the left (where the bulk of the building should have been) and there was no building there. So much for another Truther conspiracy!!!

• Porat (quoting me)” “You’ll get nowhere attacking what skeptics say, you have to address what they’re thinking…”
Oh yes, why argue with facts when you can attack the person presenting them…

It’s fascinating how people will take what you say and claim you said the exact opposite. I said you’ll get nowhere by attacking the person presenting the facts, and Eyal responds, if I understand him, with the implication that I said the opposite.

If he was referring to the second half of what I said, I would say that anyone who thinks “address” means “attack” is not cut out to be a diplomat.

Eyal, you’ll get nowhere attacking people with inflammatory rants accusing them of arrogance. By all means claim that CO2 is harmless, this after all is what this blog is about, but lacing it with vitriol does not strengthen your claim.

5. “Curiously, the surface of the Earth receives nearly twice as much energy from the atmosphere as it does from the Sun.”

Its the chicken and the egg all over again. If the Earth wasn’t warmer the sky would not be warmer. That is my issue with down welling radiation as a tool to explain the greenhouse effect. A warmer atmosphere retains more heat at the surface. The surface temperature is somewhat in balance because of the composition of the atmosphere and CO2 contributes about 5% to the overall effect. So “receives nearly twice…” is not as convincing as loses nearly half.

6. al in kansas

1.Using an IR thermometer this way can give very misleading results. They are not normally calibrated for low temperatures. The altitude that they are reading will depend on what wavelengths they read at and the atmospheric transparency at that wavelength.
2.”back radiation” is as poor and ill defined as “greenhouse effect” when applied to the atmosphere. Miskolczi wrote a paper using HARTCODE and radiosonde data defining the temperature profile and radiative transfer in the atmosphere. The important concept is optical depth at various wavelengths. At CO2 wavelengths the atmosphere is opaque until you get to high altitudes. The change in CO2 ends up making no significant difference in the heat loss to space.

• Al, I am pretty sure I know what you mean by “CO2 wavelengths”… CO2 absorbs some wavelengths very strongly, and others not very much at all; so I presume you mean those wavelengths which CO2 absorbs. (Correct me if I misunderstand you.)

However, note that there is a continuous variation. One of the major reasons CO2 makes a significant difference as you keep increasing it anywhere along the range from 10 ppm to 100,000 ppm is that the atmosphere as a whole becomes opaque to more and more wavelengths. For example, let us say the atmosphere is “mostly transparent” at those wavelengths where 50% or more of that wavelength gets through, and “mostly opaque” at wavelengths where 50% or more is absorbed. As concentrations of CO2 increase, more and more wavelengths move from being mostly transparent to mostly opaque; this is called absorption in the “wings” or “shoulder” of the main absorption band.

Hence the concept of optical depth is indeed crucial, as you say. However, your concluding inference is back to front. It is the continuous relationship between optical depth and wavelengths which means that you do get a significant and continuous change in the loss of heat from the surface into space (very close to a logarithmic relationship) as CO2 concentrations range over values anything from 10 to 100000 ppm. What we could plausibly see on Earth is all well inside that range.

BTW. The atmosphere heats the surface in the same sense exactly that a blanket heats a sleeper. (Though the physical mechanism is a bit different.) As Vaughan points out, the net heat flows are from the surface to the atmosphere; the surface heats the atmosphere, and the atmosphere cools the Earth. So too, look at the heat flows and you see that a blanket doesn’t heat you; YOU heat the blanket.

You are warmer with the blanket than without, and so in normal speech we do say that a blanket is warmer than a sheet, or than nothing at all. Objections to this usage may be pedantically correct; but I’m still going to speak of “sunrise” for the Earth turning towards the Sun, of being warmed by a wool blanket, and of being warmed by the atmosphere.

• simon abingdon

“in the same sense exactly that a blanket heats a sleeper”. Did you mean to say exactly? It’s the metabolism of the human body heats a sleeper. Blankets don’t heat corpses.

• simon abingdon

Sorry. Reading on you admit this. However, pedantically correct objections are essential for clear thinking.

• simon abingdon

“I’m still going to speak of … being warmed by the atmosphere”. But that’s just the sort of loose expression that confuses. The atmosphere doesn’t warm us; it prevents us from cooling more than we otherwise would have done. The term “back radiation” is just an accounting device; something that doesn’t exist at the macroscopic level at all.

• Joel Shore

Simon,

You are not incorrect when you say “it prevents us from cooling more than we otherwise would have done” but I have found that such statements tend to be misinterpreted by some. I.e., they say, “So greenhouse gases can just slow cooling a little bit; they can’t cause warming.” The reason that this is incorrect is that the temperature of the earth’s surface is determined by the balance between what it receives from the sun and what it emits back into space. So, indeed, slowing cooling can warm the Earth in the sense of increasing the average temperature. I think that you understand this but some of your compatriots do not.

• Jim D

The blanket analogy works, and it is important to realize that it keeps you warm without the blanket having to be as warm as the human body.

• simon abingdon

Nonsense. The human body keeps the human body warm, not the blanket.

• Jim D

You don’t think a blanket is warmer than no blanket?
Likewise the sun keeps the surface warm, not the atmosphere, but the atmosphere (like the blanket) helps.

• simon abingdon

“You don’t think a blanket is warmer than no blanket?” No, not for a corpse (or anything else without an internal heat source). Just as cold come sunrise.

• simon abingdon

Your second sentence is OK. Just don’t confuse the issue by introducing analogies involving us warm-blooded creatures.

• Jim D

The analogy was with the solar-warmed earth. I think it holds.

• Simon, I agree with you on the points you made in response to my comment on warming with blankets, and am glad to confirm that.

When I am speaking for myself, I prefer to be as accurate as possible without being confusing or technical. Hence, I would much rather say that the atmosphere keeps the Earth warm; not that the atmosphere warms the Earth. It’s a subtle difference which would be lost on very non-technical folks, and I don’t think it is important to explain the difference UNLESS and UNTIL it has become germane.

In the meantime, I am not going to fuss with other people who speak of the blanket warming them, or the atmosphere warming them, even though this is technically inaccurate as a comment on where heat is flowing. I made this point as a response to this paragraph by Vaughan:

>>> Experienced meteorology professor Alistair Fraser says the atmosphere warms the surface. I, an amateur hack in this area with no meteorological credentials at all, say the surface warms the atmosphere, and moreover at an average power density of 66 W/m2 and sometimes hitting upwards of 200 W/m2. Who’s to be believed? <<<

The answer, I suspect, is that it is not about who to "believe", but about comprehending what someone means. Fraser might be more accurate to say that the "atmosphere keeps the surface warm", but it's not a big deal in most cases. Certainly adding an atmosphere to a planet will make it much warmer, a bit like adding a blanket makes you warmer in bed. I suspect he's just using simple language to convey a simple point.

I'm not insisting this is good usage; but rather suggesting this is probably a case for understanding what someone means rather than deciding not to believe them.

• simon abingdon

• Back radiation refers to the radiation coming to the surface from the atmosphere. It’s a real measurable flux, and the first direct measurements (confirming theoretical expectations) were in 1954. See Stern, S.C., and F. Schwartzmann, 1954: An Infrared Detector For Measurement Of The Back Radiation From The Sky. J. Atmos. Sci., 11, 121–129..

Since the atmosphere has thickness, you don’t actually have equal upwards and downwards radiation for the whole atmosphere. The top of the atmosphere is cooler than the bottom, and so the radiation at the top is much less than at the bottom.

At any given fixed level, you can speak of a fixed emission, which is equally up and equally down. But that emission level is less as you go up into cooler levels.

It’s easy enough to give the full calculation, but the simple intuition is this. At a fixed altitude you have isotropic radiation. But at different altitudes the radiation is different. So the radiation up out the top is less than the radiation down out the bottom. Of course, the whole thing is driven mostly by radiation coming up from the surface, plus the 100 W/m^2 or so from non-radiant heat flows. The net flow of heat continues to be up from the surface through the atmosphere and out into space, as required by thermodynamics.

• simon abingdon

Thanks Chris; I’ll think about that. But when you say “Back radiation refers to the radiation coming to the surface from the atmosphere. It’s a real measurable flux” I feel there should be an equal and opposite (and potentially measurable) flux from atmosphere to space which traced back is really a loss of radiation from the surface where it originated. (I need to think about this some more to see it correctly).

• Try this thought experiment. (Much simpler than the real atmosphere, but at least it can help show why you don’t have the flux at the top equal and opposite to the flux at the bottom.)

Take a surface receiving 240 W/m^2 of radiant energy (in visible wavelengths, from the Sun). Place above that surface a stack of “n” layers, each of which is transparent to visible light but absorbs a fraction “p” of infrared passing through. Each layer also radiates all the energy it receives, equally up and down. For simplicity, there’s no other way heat flows in this example, other than radiation.

By conservation of energy you have 240 W/m^2 escaping out the top layer. There’s radiation A coming up from the layer below. A.p of that is absorbed into the top layer, and re-radiated, half up and half down. A,(1-p) is simply transmitted through the top layer.

Hence 240 = A.(1-p) + A.p/2 = A(1 – p/2).

If p is 0.1, then 240 = A.0.95 and A = 240/0.95 = 252.63

That is, there is 12.63 W/m^2 going back down from the top layer to the second top layer, and 252.63 W/m^2 going up from the second top layer to the top layer, and 240 W/m^2 going up from the top layer out into space.

You can extend down through the lower and lower layers, and if you presume EACH INDIVIDUAL LAYER radiates the energy it absorbs equally up and down, you end up with the top layer radiating much less than the bottom layer.

If you double n and half p you are in effect breaking each layer into two. Proceed to the limit, and you have a continuous atmosphere, cooler at the top and warmer at the bottom, with the backradiation out the very bottom layer being more than the atmospheric radiation out the top.

A real atmospheric model has to deal with a lot of additional issues, such as non radiant heat flows. (Easier to manage than you might think, as long as you know the atmospheric lapse rate.) But the bottom line is, you do get differing amount of emission at different altitudes, and the backradiation out the bottom therefore does not have to balance with the outward radiation from the top. The balance, or isotropic emission is assumed at each level, or for each molecule. This does not lead to isotropic emission when comparing different altitudes.

For people who really want to follow this, nothing beats trying to work through a standard textbook. It may take months to learn the details this way (based on my own experience of using this method) but the end result is very helpful.

• Thanks al for ref to Miskolczi
See Miskolczi’s publications
Especially the most recent presentations:
Poster presentation at the European Geosciences Union General Assembly, Vienna, 7 April 2011 by Miklos Zagoni.
e.g. See Slides 8 and 10 of 20. The downward long wave emission from the atmosphere is shown as Ed compared to the short wave transmitted radiance St.
See definitions in his Summary
See Slides 8 and 10 of 20.
The downward long wave emission from the atmosphere is shown as Ed compared to the short wave transmitted radiance St and the Surface Upwelling radiation Su. Ed can be measured as a function of wavelength.

• See Science of Doom for why this is (in SOD’s words) just equation soufflé.

• Eli Rabett
Other than an ad hominem attack, are there any specific errors in Miskolczi’s models or calculations that your can identify?
i.e. I referred to Ed and Su. Miskolczi also calculated the total IR optical depth.

1) Line By Line Code:
Miskolczi has posted his original HARTCODE code. See:
F.M. Miskolczi et al.: High-resolution atmospheric radiance-transmittance code (HARTCODE). In: Meteorology and Environmental Sciences Proc. of the Course on Physical Climatology and Meteorology for Environmental Application. World Scientific Publishing Co. Inc., Singapore, 1990.
(He has improved the accuracy since then)
Have you found any errors in his code?

2) Optical Thickness definition:
Can you show any theoretical error in Miskolczi’s definition of “TRUE INFRARED FLUX OPTICAL THICKNESS” See slide 6 of 20 which he calls “Tau”?

3) Quantitative evaluation
Then Miskolczi quantitatively models the atmosphere with 250 layers, each location with 9 “streams” (3D directions), using 11 molecular species, each of which is calculated over 3490 spectral intervals.

Have you shown any substantial quantitative error over his choice of quantitative intervals?

4) Historic Data
Miskolczi used NOAA’s TIGR2 which has the longest 61 year data.
See (A. Chedin and N. Scott 1983).

I understand the primary challenges are over the variation in water content over time between the different data sets.
In Slide 17/20, Miskloczi calculates the total IR optical thickness for six sub intervals as well as the total 61 year period. That makes little difference.

When someone calculates Miskolczi’s True IR Flux Optical Thickness for each of the data sets then we can see what the quantitative impact of those variations are.

The other objections appear to be over Miskolczi’s subsequent simplifications and theoretical models.

So can you rise to any quantitative substantive comment to Ed, Su or Tau?

• David, I am hoping for a clearer explanation from Miskolczi et al. regarding their argument, Christopher Game tells me such an explanation is in the works. Until then, I suspect that we aren’t going to get very far in discussing their argument.

• Judy – When I last looked, Miskolczi’s conclusions required atmospheric water vapor to decline as a compensatory mechanism opposing CO2 increases. At one time, there was some slight evidence for this in the NCEP/NCAR reanalysis data, but this has now been shown to be wrong. Humidity is rising at all tropospheric altitudes, and the principal remaining question is whether it rises fast enough with temperature to maintain high tropospheric relative humidity at a near constant level or whether RH declines even as specific humidity is rising.

Unless there is some new twist to this, I don’t see Miskolczi as worth discussing.

• Fred Moolten
I linked to Miskolczi’s presentation because he quantitatively calculates as a function of frequency the Downward Longwave Radiation (DLR) (his “Ed”) that was being discussed. He further calculates the global optical depth. Even if you don’t agree with his resulting stationary model, his evidence of empirical relations between the various upward and downward paramaters is insightful. See his “Empirical Facts” in slide 10 of 20. That data for calculated parameters is based on the observed NOAA data for the respective period. That should be understandable, regardless the long term trends.

On humidity vs time, do you have any good quatitative reviews of the evidence and the uncertainties involved?

WIth temperature trends leveling off since 2000, has humidity continued to rise or not this last decade?

• David – Here are a few links on rising atmospheric water vapor as a function of temperature. Some of the old reanalysis data utilized only radiosondes, while more recent studies have included satellite observations. Of the reanalysis studies, only one of five (NCEP/NCAR) showed declining trends, while the others showed rising humidity – see Dessler and Davis 2010. Although not discussed in that reference, the NCEP/NCAR data are characterized not by a smoothly declining curve but rather by downward jumps following instrumentation changes. The latter entailed substituting instruments with slow on/off times with faster-responding instruments. This reduced contamination of water measurements at one altitude by water at different altitudes, and this is thought to explain the jumps.

The recent data entail satellite observations. The two most salient studies were those of Minschwaner and Dessler 2004 and Soden et al 2005. Both reported rising specific humidity (water vapor concentration as a fraction of total molecular concentration), but the former found the humidity response to be shallower than the temperature change, implying that relative humidity (RH) did not keep pace with specific humidity. The Soden et al paper estimated a constant RH as a function of temperature. Both studies are subject to quantitative uncertainties, but it appears that the direction of water vapor change is to increase with rising temperatures, inconsistent with the requirements for the Miskolczi conclusions to be validated. It is also in line with all expectations of what happens to water vapor when the climate warms, but the fact that these expectations are confirmed by observations is important.

• Here is the correct Minschwaner and Dessler link.

• Thanks Fred for the humidity references.

May I recommend:
Prediction of the Standard Atmosphere Profiles of Temperature, Pressure, and Density with Height for the Lower Atmosphere by Solution of the (S-S) Integral Equations of Transfer and Evaluation of the Potential for Profile Perturbation by Combustion Emissions Robert H. Essenhigh* Energy & Fuels 2006, 20, 1057-1067
http://pubs.acs.org/doi/abs/10.1021/ef050276y
That is the most thorough thermodynamic model of the lapse rate I have seen, including water and CO2 absorption.

principal predictions and conclusions thus supported are
then
(1) the (approximately) linear variation of T4 with pressure, P (eq 21, Figure 4);
(2) the (approximately) linear decline of T with altitude, h, up to the tropopause (eq 23, Figure 1);
(3) the more complete, nonlinear solutions for the variation of pressure, P, and density, F, with altitude, h, up to 20-30 km (eqs 6, 20, and 23, Figure 2);
(4) the operational validity of the dependence of the group pair (kp) on density (eq 7) with the value of n determined as unity and constant; and
(5) that the equations show no evident potential for “forcing” or bifurcation behavior that would result in any significant change in the temperature profile because of “small” increments in the atmospheric concentration of carbon dioxide.

• Fred
There appear to be other major errors in the ERA reanalysis. See:
Indictment Of The ERA-40 Reanalysis In A New Paper “Erroneous Arctic Temperature Trends in the ERA-40 Reanalysis: A Closer Look” By Screen and Simmonds 2011 which extracts key sections of:
Screen, James A., Ian Simmonds, 2011: Erroneous Arctic Temperature Trends in the ERA-40 Reanalysis: A Closer Look. J. Climate, 24, 2620–2627. doi: 10.1175/2010JCLI4054.1.

This study explicitly documents a discontinuity in the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) that leads to significantly exaggerated warming in the Arctic mid- to lower troposphere, and demonstrates that the continuing use of ERA-40 to study Arctic temperature trends is problematic. . . .Decadal or multidecadal Arctic temperature trends calculated over periods that include 1997 are highly inaccurate, particularly below 600 hPa.

As temperature rise is overestimated, I expect that the humidity rise is also overestimated.
So a lot of climate models will likely have to be “retuned”.
It will be interesting to see how corrected models and miskolczi fare on the same data.

• David – I’m familiar with reanalysis issues. I think Miskolczi is a lost cause, because we now have compelling evidence from multiple sources, including satellites, that atmospheric water increases at all tropospheric altitudes as the climate warms. Other errors in his analysis have been identified by other participants here, but given the humidity data, his conclusions become largely unsupportable from that information alone.

• Jim D

My interpretation of Miskolczi is as follows. It all comes down to his definition of optical depth which is actually very special. It comes from the amount of IR leaving the top of the atmosphere that originated directly from the surface. That is, it is dominated by the window photons, perhaps with a small contribution from side-bands. So he takes this top radiation and divides by the total leaving the surface, and from these two numbers derives his optical depth. Not surprisingly, since he only looks at window photons, CO2 and H2O emission have little effect on his defined optical depth. So his statement that his optical depth may not have changed may be correct, but says nothing about emitted radiation from the atmosphere, which is where the signal should be.

• Jim D
Re “is dominated by the window photons, perhaps with a small contribution from side-bands . . .his optical depth may not have changed may be correct, but says nothing about emitted radiation.”

Please go back, reread and try to understand both Miskolczi’s definition and method of calculation, and his results.
He calculates the emission across ALL 3490 spectral frequencies with the latest evidence for ALL GHG, not just CO2 and H2O (not just for the “window” photons). This is across 250 levels using an average atmospheric lapse rate calculated from the TIGR2 data weighted across the globe for each of the 61 years. (I think this average TIGR2 lapse includes the effect of clouds on atmospheric temperature.)

This global optical depth is directly linked to the “emitted radiation” including “the signal”.

• Jim D

You have to look at how he defines S_T. It is very specifically the part of the IR out of the top that can be traced to the surface. This is all he used in his optical depth.

• David,

I think that Miskolczi’s and Claes Johnson’s work are similar in the respect that the math looks correct to me. Tomas may disagree with that statement based on his own perusing of Dr. Johnson’s work, but it looks right to me.

What is also similar is that when faced with criticism about the theoretical underpinnings of their work (the real physics the math implies) they point to the math or computer code from which their numerical analysis comes from. They say ‘show me where the math is wrong’. To which I would ‘it’s not wrong’.

But the physics they are implying with correct math is wrong.

Specifically, for Miskolczi’s work the atmosphere has to ‘know’ where water molecules are and how many water molecules there are in order to condense the right number of them to maintain a specific value of the optical depth in the IR. But because he has come to this problem from observations, he has no physical mechanism in analytical mathematical form from which we could decipher such a mechanism.

More than that, to a molecular spectroscopist like myself, it’s hard to believe because why wouldn’t the samples in my lab do the same thing? Why would it only happen in the IR region? Would the same phenomena happen if earthlight were spectrally centered in the UV such that we were discussing electronic transitions versus vibrational transitions?

The conclusions he’s made based on his analysis of observational data are much too strong in my opinion. Without a serious accounting for the physical process that ‘entangles’ disconnected GHG molecules and the light passing through the atmosphere, it doesn’t matter if his math or code are correct. The physics itself simply doesn’t add up to form a coherent picture with what we already know to be true.

I think Roy Spencer did a good job of discussing Miskolczi’s work and, I think, even admitted that he wanted it to be right. But it doesn’t add up.

• Maxwell, the role of math in science is something I study. If the math is correct but the physical results are incorrect then at least one of the initial (that is, not derived) physically interpreted mathematical expressions must be physically false. You need to find that one.

• David,

You’re looking at the situation in reverse. Miskolczi isn’t deriving mathematical equations to determine how atmosphere works physically. He is fitting a theoretical framework to a specific set of observational data that, he thinks, show that water content of specific columns of air are constant over time. From there he argues this means the atmosphere ‘wants’ to maintain a specific magnitude for the greenhouse effect (IR depth) and so adding CO2 to the atmosphere just condenses water.

So there are no ‘initial physically interpreted mathematical expressions’. It’s really just data fitting.

But even if there were equations, as in the case of Dr. Johnson’s work, I know that if I take a container of water vapor and CO2, water is not going to condense upon my adding more CO2. Dalton’s law of partial pressures tells us that the vapor pressure of water will only change by adding more water. Not more CO2.

There is no evidence in the spectroscopy literature that anything even closely resembling what Miskolczi concludes to true plays a role in the absorption of light in any frequency region. So I’m not going to waste my time, and I would advise others not to waste their time, looking for ‘initial physically interpreted mathematical expressions’. They’re somewhere and it doesn’t really matter where.

• Maxwell
Re “to a specific set of observational data that, he thinks, show that water content of specific columns of air are constant over time.”

I think you misunderstand Miskolczi’s method. He takes the actual observed varying TIGR2 humidity and CO2 etc over time and calculates the consequent optical depth from that. The objections are whether the observed decline in humidity in the TIGR2 with rising CO2 is real or not. Miskolczi’s method just calculates the global optical depth from whatever the available GHG’s including humidity and CO2. From the data he used, that appears to be stable.

Regarding the rest of his model, he applies an entropy production optimization which results in the stable global optical depth.

Even with other data sets, I would not be surprised if the Planck weighted global optical depth does not vary strongly. E.g., during the last decade when the global temperature has not warmed as projected by IPCC.

There are numerous methods besides condensation for the atmosphere remaining stable. See Willis Eschenbach It’s Not About Feedback

I say, and have discussed elsewhere, that the temperature of the Earth is kept within a fairly narrow range through the action of a variety of natural homeostatic mechanisms.

Whatever the GHG concentrations, we still need an accurate Planck weighted calculation of the optical depth. Miskolczi if the first to provide a quantitative Line By Line calculation with available long term data that I am aware of.

• David H,

I think you’re right. He’s looking at constant IR optical depth, not humidity.

Thanks for making that point clearer.

In either case, however, Miskolczi is not deriving first principles physical law and then looking to substantiate it. It finds ‘curious’ data and then tries to fit that data to a particular physical model. So there are still no ‘initial physically interpreted mathematical expressions’.

Cheers.

• maxwell
Re: “You’re looking at the situation in reverse.”
Please go back and see the progression.
Miskolczi has identified 7 major empirical relations between IR parameters in the atmosphere based on that TIGR evidence. He also calculates the optical depth from that original evidence.

From thse empirical observations and correlations, he develops his consequent relationships from which he infers a stable atmosphere and stable optical depth. He then measured the optical depth from the reanalysis data over 61 years. That shows a stable total optical depth.

The optical depth method can equally be applied to any atmospheric data.

• Pat Cassen

David – Even the math is wrong. Work your way through Appendix B of Miskolczi (2007) and find the error(s). They count; they nullify his claim to have found a revision of the classical Milne gray atmosphere result.

• Pat – Please provide a link or publication to where those errors have been identified and preferably corrected. Do those corrections better address the surface step jump in ground vs air temperature?

See my post above Do any of those changes affect his calculation of the global optical depth? Or of his method of averaging the TIGR2 data?

If not, any differences over that other portion of his model should NOT make any impact on these calculations of either the global optical depth or the Downwelling Longwave Radiation (DLR) (or Ed) that we were addressing here.

• kuhnkat

It may have been suggested before, but, a possible mechanism would be that increased CO2 actually displaces water moisture in the parcel. That is the air can only hold so much and the CO2 interferes with the ability to hold the water vapor. No I do not have any idea if this is physical. Should be possible to disprove experimentally if it hasn’t been already.

• suricat

kuhnkat.

“It may have been suggested before, but, a possible mechanism would be that increased CO2 actually displaces water moisture in the parcel.”

With all due respect, water ‘condensate’ absorbs CO2 at an alarming rate (CO2 is the first Earthly gas to diffuse into pure water) and if there isn’t a disparity of low CO2 in the strat compared to higher levels in the lower tropo I’ll be surprised (theoretical assumption based on standard physics and ‘diffusion pumps’). :)

I’d need a ‘precedent’ scenario to swallow this because I can’t envisage how CO2 can ‘precipitate’ water from Earth’s atmosphere. However, I’m open to the suggestion that CO2 ‘ionises’ “water moisture” in Earth’s atmosphere and alters its PH. Perhaps this could be a ‘clue’?

If not, Archimedes may come to the rescue when all players are in a ‘gaseous state’ within the ‘parcel’. CO2 is heavy and WV is light. It’s possible that CO2 weights the overall parcel to lower altitudes where WV can be absorbed into existing “water moisture” (water droplets).

It’s a ‘minefield’! :)

Best regards, Ray Dart.

• Thanks Ray,

you probably heard my arms flapping!!

I found it an interesting idea. It would displace water vapor if anything and based on the actual amount of CO2 added couldn’t be a large effect. It was interesting based on it being counterintuitive that water vapor is NOT increasing noticeably in a warming world. Of course, there is the issue that we may NOT be warming or not much, and only poor measurements and adjustments say we are.

My vague idea was also electrostatic. The weight based I was considering more on the idea that under a certain set of temperature/pressure conditions there would be an upper limit on the mass that could exist in a parcel. Basically our CO2 emissions filling up really small holes!! See what fun it is to be ignorant? 8>)

• Follow the link. SoD looks at the equations that Miskolczi presents as well as the data for optical depth and the calculations. This had previously been done in detail by Nick Stokes who came to the same conclusions. As Fred points out, the data that Miskolczi used were cherry picked.

• Eli
“the data that Miskolczi used were cherry picked.”
Miskolczi used NOAA’s TIGR2 which has the longest available record of the major atmospheric GHGs – H2O and CO2. THat is not “cherry picking” but using the longest available record.

There are now questions on the accuracy of that humidity data, as well as of recent ERA temperatures.

We both need an accurate way to calculate Ed and the optical depth. Miskolczi is the first to provide that Planck weighted global IR optical depth that I am aware of. That can then be applied to other data sets.

I expect the impact will be that the optical depth does not vary much and that the major variations will be in albedo from cloud variations and transport mechanisms – wind and latent heat.
e.g. see Willis Eschenbach

Keep on “kicking the tires” to see what is true.

• Pat Cassen

Reply to David L. Hagen at | August 14, 2011 at 9:15 am |

David – Haven’t we discussed this before?

Sorry, I don’t have a link handy, but you can easily work the math out for yourself. Briefly, Miskolczi’s ‘solution’ (eqn B-11) violates the assumptions under which it was derived, fails to satisfy the upper boundary condition (zero downward LWR at tau = 0), and implies that the function Bo has no maximum in tau. This last point nullifies his claim that there is a particular optical depth that maximizes the energy transport (yes, that optical depth which he claims matches the observational results to three(!) significant figures). So there is no valid revision of the Milne solution under Miskolczi’s hypothesis, and no theoretical basis for the idea that the atmosphere is self-regulated by optical depth adjustments.

Regarding the calculation of Ed and a gray atmosphere optical depth, it is clear that these quantities depend on atmospheric structure, which varies with GHG content, etc., and so have no ‘universal’ values, despite Miskolczi’s attempt to justify such.

All this and more was hashed out a couple of years ago at David Stockwell’s website and elsewhere. It’s not worth revisiting; there is virtually nothing valid in Miskolczi (2007) beyond eqns (1) and (2).

• TIGR 2 has a well known dry bias in the troposphere. TIGR 3 is much more representative and larger and TIGR 2000 is even better. He picked the cherries

• David Hagen: Eli Rabett: Other than an ad hominem attack, are there any specific errors in Miskolczi’s models or calculations that your can identify?

The one that really caught my attention is that after laborious calculations that entailed splitting the atmosphere into 2000 layers, Miskolczi computed the total kinetic energy of Earth’s atmosphere at 1/5 of its correct value. From this he obtained that the potential energy of the atmosphere (which he did compute correctly) was twice its kinetic energy when it’s easy to see from the constant-pressure specific heat of air that it is 2/5 of it. And it wasn’t an isolated mistake, he’d thought this for several years, including half a year after Viktor Toth had pointed it out to him. Details at

• Vaughan Pratt
Re:

Miskolczi computed the total kinetic energy of Earth’s atmosphere at 1/5 of its correct value.

Sadly it appears that you misread/misunderstood Miskolczi, and presumed that he calculated the “TOTAL kinetic energy” – rather than read what he actually calculated:

Virial concept − hydrostatic atmosphere
Internal energy computed with one degree of freedom
Gravitational potential energy referenced to the surface

(Only ONE degree of freedom, NOT the total kinetic energy of a diatomic gas with 5 degrees of freedom) See Slide 21/24 of Presentation at the Hungarian Academy of Sciences, Budapest, 17 January 2011 http://miskolczi.webs.com/academy.pdf
He then shows that the “Gravitational potential energy” Omega is two times the SINGLE degree of “kinetic energy” (or internal energy).

I encourage you to review and compare Toth (2010) Pacheco (2003) and Miskolczi (2011) slides 21, 22. I understand that they agree with each other with a bit of algebra between the two methods of presentation.

On the 1/5th factor, by the equipartition theorem for a diatomic gas, there are three translational degrees of freedom for a gas molecule (XYZ), and two rotational modes for a diatomic gas (~ air as mostly N2+O2) for a total of 5 degrees of freedom (DOF). However, only the vertical translational Degree of Freedom Kz of the internal thermal energy is involved in the virial theorem. Thus Miskolczi calculates ONLY the ONE Vertical degree of freedom when calculating the vertical component Kz of the thermal energy – thus Miskolczi’s calculation of the vertical degree of freedom as 1/5th of Toth’s total “kinetic energy” (or Pacheco’s internal energy U). Then Miskolczi shows that the total gravitational potential energy Omega is twice the single vertical component of the kinetic or internal (thermal) energy T (equal to one fifth the total kinetic energy ). This gives Toth’s equation (25) of 2/5 = U (or Pacheco’s U/P = ev/R = 5/2).

Re: “he’d thought this for several years, including half a year after Viktor Toth had pointed it out to him”, I think you slander him without evidence. Toth and Miskolczi were discussing this issue with colleagues in April 2010 after Toth paper mid March 2010. They agreed that they arrived at algebraically equivalent statements on the virial calculation, and the degrees of freedom.

• Vaughan Pratt

Sadly it appears that you misread/misunderstood Miskolczi, and presumed that he calculated the “TOTAL kinetic energy” – rather than read what he actually calculated:

This raises a number of interesting questions, David.

1. How come you’re just pointing this out now when neither you nor Miskolczi had this response to my December post? You had several responses none of which mentioned this possibility.

2. Energy is not a vector but a scalar. What does “vertical component of energy” mean?

3. Miskolczi’s journal paper assumes energy is conserved. How can this be true if he’s only working with 1/5 of the kinetic energy of the atmosphere? Conservation only holds for the TOTAL kinetic energy plus potential energy.

4. Why is there no discussion in his journal paper of this idea that energy is a vector with components that you can take one of? Introducing nonstandard concepts like that is a sure-fire way of sneaking fallacies into a paper.

5. What’s with this “sadly” stuff? You’re always the one sanctimoniously holding us to a professional standard of discourse. Your “sadly” drags you down to my street-fighter level, for which I make no apologies. (I apologize for any apologies I may have made inadvertently—I know for sure I haven’t apologized exactly once.)

• al in kansas

And thanks to you for your comments below. They track well with my thinking. I am on a dial-up connect (slow) and have way too many other things to do to even get this blog read.
This may be of interest.
http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/Ferenc.pdf
It gives a more detailed explanation of Miskolczi. I was also hoping Dr. Curry would find the time to read. As per comments on a previous thread, Miskolczi is a bit short on detail. This is one of the better explanations I have found.

• al in kansas

Note: comment above in reply to David L. Hagen

7. “While I seriously doubt whether climate skeptics will thank me for pointing it out, I don’t believe their arguments impress the swing voters in the climate debate as convincingly as they might”.

The swing voter pays little or no attention to either side. We just like to think we’re very influential …

http://thepointman.wordpress.com/2011/08/04/i%e2%80%99m-not-a-scientist-but-%e2%80%a6/

Pointman

8. hunter

Dr. Curry,
Most skeptics I am aware of do not agree with the Greenhouse Dragon.
Using the Dragon as a proxy for ‘what skeptics believe’ is a bit of a straw man.
Spencer, Lindzen, Pielke, Sr. and Salby all have critiques of AGW catastrophism that has nothing to do with the Dragon.
While it is as much fun to attack a fringe like the Dragon, as it is to jump on Gore or Romm or Hansen for their ‘fever’ talk, or spittle flecked spews or tipping points, I do not believe that many in the AGW community actually support such extremist non-science from that side either.
Perhaps it would be more constructive to not kick a dead dragon?

• Hunter, the skydragon group is quite difficult to slay, see the previous threads where the dialogue continues unabated. This is one that I would really like to slay, so I keep trying some different things. so this particular dragon isn’t dead yet, but this group is becoming increasingly marginalized IMO.

• Bryan

on the previous thread the recent Postma paper was discussed.
He is loosely associated with the skydragon group.
His Paper ran for 44 pages with detailed calculations.
He even suggested an experiment to test the Greenhouse Theory.
We all believe in experiments, don’t we?

The arguments to counter the paper were very weak or non existent.

The fact that world temperatures have not risen for 15 years while CO2 levels have surely must have some greenhouse advocates scratching their head.

• Joel Shore

Actually, the only legitimate debating topic regarding Postma’s paper was whether he was actively deceiving others or severely deluding himself. Personally, I am on the side of actively deceiving, but I admit that this is a legitimate subject of discussion.

That Bryan thinks “the arguments to counter the paper were very weak or non existent” is frankly laughable.

• Luis Dias

I’ve seen plenty of empirical confirmation of the CO2 theory but I am replying due to your last paragraph. Surely that the fact that the world’s temperatures haven’t risen as fast as the previous years are interesting, but in no way they are sufficient evidence for the basic CO2 mechanism to be doubted.

There just wasn’t enough time for that. However, there were and there are people scratching their heads because their own predictions were quite more catastrophic than the reality.

• Joel Shore

Oh what the hell, let’s have a look at some of the nonsense that Postma has written. Here is one section, regarding the lapse rate:

Now, it is expected that an increase in GHG’s will increase the temperature of the bottom of the atmosphere, while decreasing that at the top, and because the atmosphere is essentially fixed in depth, this would require the ‘lapse rate’ distribution of temperature to be larger, as there would be a larger temperature differential over the same atmospheric height. However, this is obviously the effect the postulated back-radiation GHE must have in the first place with the existing, presumed already quite significant, effect from already-existing GHG’s in the atmosphere, no matter what the thickness the atmosphere is. That is, the lapse rate should already be faster than -10K/km because there is (ostensibly) already a GHE in operation in the atmosphere. Yet this is clearly not the case, and the fastest lapse rate derived in meteorology is still that value as can be derived from equation {32}, independent of any pre-existing GHE. Additionally, if we examine the effect of the strongest GHG on the lapse rate, which is water vapour, we find that it acts to reduce the rate of temperature change, not increase it, which is again in direct opposition to the requirements of the GH postulate. The observed average lapse-rate of the atmosphere, called its environmental lapse rate, is actually far smaller in magnitude at -6.5K/km. Once again, there does not seem to be any room for the postulate of a back-radiation heating GHE because observations from the real world seem to disallow it.

Here are just a few problems:

(1) He hasn’t justified why the atmosphere is “essentially fixed in depth” or, more importantly, why the part of the atmosphere that we call the troposphere, where the lapse rate is equal to the adiabatic lapse rate, must be fixed in depth. I see no reason why the latter must be true…and in fact it is not expected (or measured) to be true under increasing greenhouse gases.

(2) He pretends that the lapse rate is some condition that is at the adiabatic value in the absence of greenhouse gases but that greenhouse gases would be expected to modify modify from what he has computed. However, that is not how it works. The adiabatic lapse rate is a stability limit. So, whatever heating from below, be it the solar input or the heating from greenhouse gases or what-have-you tries to raise the lapse rate,instability is produced, convection sets in, and the lapse rate is pushed back down to its adiabatic value.

(3) He argues that water vapor lowers, rather than raises the lapse rate (as he has wrongly argued greenhouse gases should do). Apparently, one is supposed to entertain the idea that water vapor has no other properties besides being a greenhouse gas. Water in fact is a condensable gas and so when it condenses it releases a lot of energy…its heat of vaporization…which for water happens to be particularly large. This is why the moist adiabatic lapse rate is lower than the dry one. The evaporation-condensation mechanism is, of course, an important way by which heat is transferred in the atmosphere. Surely, Postma is aware of this fact and yet he omits it.

So, in less than one paragraph of his 44 pages of nonsense, we have identified 3 major errors that render pretty much his entitle argument about the adiabatic lapse rate and its relation to greenhouse gases as nonsense. Exactly how many paragraphs do we have to do this for before people accept that the only use for Postma’s work is for studying how people go about peddling pseudoscientific nonsense?

• Bryan

Joel thinks I have been over dismissive of his claims to have found flaws in Postmas paper.
Are these points significant or “fatal” if correct
Lets see.

“(1) He hasn’t justified why the atmosphere is “essentially fixed in depth” or, more importantly, why the part of the atmosphere that we call the troposphere, where the lapse rate is equal to the adiabatic lapse rate, must be fixed in depth.”
If you read Postmas papers he clearly says the environmental lapse rate (ELR) differs from the DALR mainly because of latent Heat of water effects.
So the average emission level moves up and down accordingly.
All other things being equal what would a 1degree C rise in average surface temperature entail.
(after all there has only been a rise of 0.7C over the last 150years)
Well lets use the ELR
It looks at first that this might increase the mission height by 100/5000 or 2%
However though the linear increase because of temperture suggests 2% the emitting space is related to the volume or a cubic effect.
Its resonable to think that this would reduce the increase to an even smaller figure by back feedback to increase ELR.
I will leave it as an exercise for you to do the same analysis for the DALR
Postma is correct but even if he was not this point is not central to the paper.
“(2) He (pretends!!!!!!!) that the lapse rate is some condition that is at the adiabatic value in the absence of greenhouse gases but that greenhouse gases would be expected to modify modify from what he has computed. However, that is not how it works.”
Note the pretends here!!!
All part of the usual Joel smear tactic.
There seems to be general agreement among a wide range of opinion that radiative transfer has nothing to do with the DALR.
So I don’t know what kind of point Joel is making here.
Incidently Joels personal model predicts an 80K troposphere effect.
What happens to radiative transfer in the troposphere during a day when DALR is followed?
This is one of the inconvenient facts that Joel chooses to ignore.
Further if you look at other threads in this series you will find Joel deeply confused about the DALR.
He reluctantly had to agree that I was correct in an earlier exchange.
Postma is correct but even if he was not this point is not central to the paper.

(3) Joel’s silly point about Postma not knowing about the Latent Heat of Vapourisation of Water I have already dealt with.

So there you have it Joel’s points that he was so excited about proved to be hot air as usual

• Joel Shore

I think I’ll just leave this as a challenge to other readers here: If you can make any sort of coherent arguments out of the blather from Bryan above, could you kindly do so and let us in on what those arguments are?

• Joel Shore

Oh what the heck, let’s have a look at some of the nonsense that Postma has written. Here is one section, regarding the lapse rate:

Now, it is expected that an increase in GHG’s will increase the temperature of the bottom of the atmosphere, while decreasing that at the top, and because the atmosphere is essentially fixed in depth, this would require the ‘lapse rate’ distribution of temperature to be larger, as there would be a larger temperature differential over the same atmospheric height. However, this is obviously the effect the postulated back-radiation GHE must have in the first place with the existing, presumed already quite significant, effect from already-existing GHG’s in the atmosphere, no matter what the thickness the atmosphere is. That is, the lapse rate should already be faster than -10K/km because there is (ostensibly) already a GHE in operation in the atmosphere. Yet this is clearly not the case, and the fastest lapse rate derived in meteorology is still that value as can be derived from equation {32}, independent of any pre-existing GHE. Additionally, if we examine the effect of the strongest GHG on the lapse rate, which is water vapour, we find that it acts to reduce the rate of temperature change, not increase it, which is again in direct opposition to the requirements of the GH postulate. The observed average lapse-rate of the atmosphere, called its environmental lapse rate, is actually far smaller in magnitude at -6.5K/km. Once again, there does not seem to be any room for the postulate of a back-radiation heating GHE because observations from the real world seem to disallow it.

Here are just a few problems:

(1) He hasn’t justified why the atmosphere is “essentially fixed in depth” or, more importantly, why the part of the atmosphere that we call the troposphere, where the lapse rate is equal to the adiabatic lapse rate, must be fixed in depth. I see no reason why the latter must be true…and in fact it is not expected (or measured) to be true under increasing greenhouse gases.

(2) He pretends that the lapse rate is some condition that is at the adiabatic value in the absence of greenhouse gases but that greenhouse gases would be expected to modify modify from what he has computed. However, that is not how it works. The adiabatic lapse rate is a stability limit. So, whatever heating from below, be it the solar input or the heating from greenhouse gases or what-have-you tries to raise the lapse rate,instability is produced, convection sets in, and the lapse rate is pushed back down to its adiabatic value.

(3) He argues that water vapor lowers, rather than raises the lapse rate (as he has wrongly argued greenhouse gases should do). Apparently, one is supposed to entertain the idea that water vapor has no other properties besides being a greenhouse gas. Water in fact is a condensable gas and so when it condenses it releases a lot of energy…its heat of vaporization…which for water happens to be particularly large. This is why the moist adiabatic lapse rate is lower than the dry one. The evaporation-condensation mechanism is, of course, an important way by which heat is transferred in the atmosphere. Surely, Postma is aware of this fact and yet he omits it.

So, in less than one paragraph of his 44 pages of nonsense, we have identified 3 major errors that render pretty much his entitle argument about the adiabatic lapse rate and its relation to greenhouse gases as nonsense. Exactly how many paragraphs do we have to do this for before people accept that the only use for Postma’s work is for studying how people go about peddling pseudoscientific nonsense?

• Jim D

My favorite part is where he finds that 5 km is the altitude for -18 C, which is the radiative equilibrium temperature (255 K), then seems to think it must always be 5 km even without greenhouse gases. Priceless,

• Bryan

Jim D

He does not think that the the ensemble radiation level “must always be 5 km”
Where did you get that silly idea?
I’m surprised at you.

• Jim D

Does he concede that -18 C can occur at the surface when you don’t have GHGs? I don’t see it. He insists on his gravity argument.

• Joel Shore

I agree Jim. That is probably the single most fundamental error that pervades both of his papers.

• Bryan

Joel says

Surely, Postma is aware of this fact says Joel at the bottem
The answer is yes what makes you think otherwise?
Hence this paragraph could be written by a headless chicken.

(3) He argues that water vapor lowers, rather than raises the lapse rate (as he has wrongly argued greenhouse gases should do). Apparently, one is supposed to entertain the idea that water vapor has no other properties besides being a greenhouse gas. Water in fact is a condensable gas and so when it condenses it releases a lot of energy…its heat of vaporization…which for water happens to be particularly large. This is why the moist adiabatic lapse rate is lower than the dry one. The evaporation-condensation mechanism is, of course, an important way by which heat is transferred in the atmosphere. Surely, Postma is aware of this fact .

• Joel Shore

Bryan: If he is aware of this and yet he uses the fact that the lapse rate is what it is to support an argument that it doesn’t support, then he is intentionally deceiving people.

• Bryan

Joel
You realy are scraping the bottom of the barrel here.

After deep thought and weighty deliberation youhave identified a fatal error in Postmas paper.
Perhaps he does not know about the Latent Heat of Vapourisation and its effect on the lapse rate.

Certain things are taken for granted at this level.
Every high school physics pupil knows about Latent Heat.

He has not mentioned Newtons second law perhaps this is the next fatal flaw you will find.

Of much more interest to readers would be an explanation of how radiation alters the lapse rate.
That was a point made by Jim D and yourself but neither of you gave an example where it was fully accounted for

• Joel Shore

Bryan,

(1) The point is not that he hasn’t mentioned the explanation of a certain phenomenon but that he has used the phenomenon to imply that it tells us something about the greenhouse effect when it does not.

(2) Your sentence “Of much more interest to readers would be an explanation of how radiation alters the lapse rate” shows that you have either failed to read what I have written or you are engaged in active deception. Which is it? [Hint: We are not saying it alters the lapse rate over the troposphere, where it is limited by convection, but it can and will alter where the tropopause is and it will alter where the effective radiating level is.]

I think that everyone should look at your response here to understand how peddlers of pseudoscience like yourself operate and why you can write nonsense about how we haven’t found any major errors in G&T and Postma. We identify them and you ignore them. For any thoughtful person, your responses here are doing your cause more harm than good by illustrating in black-and-white how you operate.

• Bryan

Joel
I thought we should revisit your recent model of the atmosphere

In it you show a 3 layer model of the atmosphere producing a 80K effect all on its own by radiative transfer.(pg 1318,1319)
Now such a model must be considered to be at the pinnacle of research from the Golden Age of the Greenhouse Theory.
Yet the action of the gravitation field on the air as represented by the adiabatic lapse rate(See Postma pg 16) will in itself produce a similar range of temperature given that the Sun directly heats the ground.

This doubling of the expected temperature range to 160K for the troposphere shows that your model has some fatal flaws.

You might argue that even more slabs or layers are required.
You said that more layers would produce an even better result.
If we have a very large number of slabs then the ” f ” factor will tend to 2 .
See Postma 12 and 13.
This results in the ground temperature being independent of the Sun.
I find it hard to comprehend that such a fantasy model was ever seriously considered.
The model you are describing today is nothing like your model from 2010.
Perhaps you should tell us why you discarded the previous one

• Joel Shore

Bryan,

So, after a lame attempt at a counterargument to one of the 3 major errors I found in **less than 1 paragraph** of Postma’s paper, it seems you have decided to change the subject from Postma’s nonsense paper. I assume that means you will no longer make the false claim that nobody has shown major errors in Postma’s work?

Your critique of our paper continues the same sort of nonsense your other posts contain.

In it you show a 3 layer model of the atmosphere producing a 80K effect all on its own by radiative transfer.(pg 1318,1319)
Now such a model must be considered to be at the pinnacle of research from the Golden Age of the Greenhouse Theory.
Yet the action of the gravitation field on the air as represented by the adiabatic lapse rate(See Postma pg 16) will in itself produce a similar range of temperature given that the Sun directly heats the ground.

This doubling of the expected temperature range to 160K for the troposphere shows that your model has some fatal flaws.

(1) We say right in the paper that the model is not good for quantitative calculations. The reason that we use it is that we want the simplest possible model that allows us to demonstrate G&T’s misconceptions. Hence the 80 K value should be taken with a grain of salt.

(2) Your claim of this doubling of the temperature difference due to the adiabatic lapse rate is simply nonsense. As we have pointed out to you many times now, the adiabatic lapse rate is only a stability limit on the actual lapse rate. That means that in regions of the atmosphere where the radiative physics wants to impose a larger lapse rate than this (i.e., the part of the atmosphere heated strongly from below), convection occurs and limits the lapse rate to the adiabatic value. But the cause of the large lapse rate is the heating of the atmosphere from below (by both solar radiation and greenhouse gases), not the adiabatic lapse rate (which is why the lapse rate is nowhere near the adiabatic lapse rate in the stratosphere). Your argument is analogous to the following: I drive my car down the Thruway at 65mph, so I cover 65 miles in one hour. However, there are also these signs (called “speed limit signs”) along the side of the road that say 65mph, so that contributes another 65 miles in an hour. Therefore, I must travel a total of 130 miles in an hour.

You might argue that even more slabs or layers are required.
You said that more layers would produce an even better result.
If we have a very large number of slabs then the ” f ” factor will tend to 2 . See Postma 12 and 13.
This results in the ground temperature being independent of the Sun.
I find it hard to comprehend that such a fantasy model was ever seriously considered.

(1) Postma’s f tending toward 2 is not related to our statement about a large number of slabs. In Postma’s model, it makes no physical sense to set f greater than 1 since it represents an absorptivity, which must be a value between 0 and 1.

(2) We say that “a more realistic model would split the atmosphere into a much larger number of layers for integration and take into account the detailed spectral dependence of absorption and emission, as is done with line-by-line radiation codes.” Note the parts you left out. Also, when you split the atmosphere into more and more layers in this manner, each layer will have a small absorptivity. It is like successive approximations of an integral by dividing the area up into more and morerectangles that have each have a smaller and smaller base.

(3) Even though I have explained how you misread what we said, it is perhaps instructive to look at what would happen if we instead just added more and more BLACKBODY layers to our model (which means we are changing the physics of the situation with each additional layer, rather than converging to a better approximation of the same physics). The answer is indeed that the surface temperature gets larger and larger without bound. Is this realistic? Of course not, and the reason is that the assumption that we have made is that the layers are transparent to solar radiation but perfect absorbers of terrestrial radiation. This approximation is not too unreasonable when the surface temperature is such that the emission spectrum barely overlaps that of the solar spectrum, but it will become a very bad approximation as the surface temperature approaches that of the sun! Kirchhoff’s Law intervenes and prevents us from ever being able to make the surface temperature of the earth hotter than the sun no matter how much greenhouse gases are in the atmosphere.

The model you are describing today is nothing like your model from 2010.
Perhaps you should tell us why you discarded the previous one</blockquote.

I'm not even sure what you mean by "the model you are describing today" as I have not been describing one particular model.

But, as I have explained above and previously to you, models serve different purposes. If, in our comment on G&T, we had plopped down tens of thousands of lines of computer code to do line-by-line radiative-convective transfer calculations, this would not have been a very useful way to illustrate the elementary errors that G&T made when they claimed that the greenhouse effect violated the Second Law. Therefore, we tried to use the simplest models that illustrated why their claims are nonsense.

Bryan: Frankly, you are adding nothing but pseudoscience to this thread. Why you continue to do this is unclear. Perhaps you are trying to make AGW skeptics look as bad as possible. If that is your goal, you are doing a most excellent job and I suggest you keep it up.

• Joel Shore

…whoops … Sorry about the formatting: I screwed up the final tag in that previous post!

• Bryan

Joel Shore says
He has found fatal flaws in the Postma paper.
He thinks Postma has not heard of the Latent Heat of Vapourisation.
……and…. apparently nothing else?
Very impressive.
I said about the paper co-written by Joel
In it you show a 3 layer model of the atmosphere producing a 80K effect all on its own by radiative transfer.(pg 1318,1319)
Yet the action of the gravitation field on the air as represented by the adiabatic lapse rate(See Postma pg 16) will in itself produce a similar range of temperature given that the Sun directly heats the ground.
This doubling of the expected temperature range to 160K for the troposphere shows that your model has some fatal flaws.
Joel says
“(1) We say right in the paper that the model is not good for quantitative calculations. The reason that we use it is that we want the simplest possible model that allows us to demonstrate G&T’s misconceptions. Hence the 80 K value should be taken with a grain of salt.”
I dont take any of it seriously but you have still to say how it fits into the already structured troposphere
Joel says
“(2) Your claim of this doubling of the temperature difference due to the adiabatic lapse rate is simply nonsense. As we have pointed out to you many times now, the adiabatic lapse rate is only a stability limit on the actual lapse rate.”
I say
You have this exactly back to front
The dry adiabatic lapse rate is set by the gravitational field acting on the atmosphere.
Its fundamental and gives the structure around which the environmental lapse rate is formed.
What you have said here is like saying if you jump out of an aeroplane and parachute down you have changed the Gravitational Field Strength.
Very silly.
You said
(1) Postma’s f tending toward 2 is not related to our statement about a large number of slabs. In Postma’s model, it makes no physical sense to set f greater than 1 since it represents an absorptivity, which must be a value between 0 and 1.
Postmas calculation was for Venus (see graph)
You said
(3) Even though I have explained how you misread what we said, it is perhaps instructive to look at what would happen if we instead just added more and more BLACKBODY layers to our model .
I say
Filtered line spectra are not black bodies or even gray bodies

I said
The model you are describing today is nothing like your model from 2010.
You said
I’m not even sure what you mean by “the model you are describing today” as I have not been describing one particular model.
I say
Well when making some incorrect statement about the average emission level I asked what difference would including greenhouse gases make.
You said none it is all at the top of the atmosphere.
But apparently you have backed of this model.
Perhaps you realised it was too close to the model that Postma proposes
Joel you have slip slided any awkward questions but for me the big disappointment was your confusion over the dry adiabatic lapse rate.
Generally physicists have a feel for the underlying structure and forces.
This seems to be absent as far as your concerned.
Its a pity.

• Joel Shore

Bryan says:

He has found fatal flaws in the Postma paper.
He thinks Postma has not heard of the Latent Heat of Vapourisation.
……and…. apparently nothing else?
Very impressive.

Your mischaracterization of my criticisms of Postma is an outright lie and everyone who looks at my criticisms can see what a liar you actually are.

The rest of your post are more mischaracterizations and evidence that your understanding of the adiabatic lapse rate is essentially non-existent. There is no need for me to continue to respond to such nonsense. You have done a better job showing how dishonest and ignorant you are than I can do by prolonging this nonsense any longer.

• Joel Shore

Just so people don’t have to wade through all of Bryan’s sophistry to see what I said about the three major errors in just part of one single paragraph of Postma’s “paper”, here is the main part: http://judithcurry.com/2011/08/13/slaying-the-greenhouse-dragon-part-iv/#comment-98524 You can look below that for additional discussion (especially JimD’s post directly below).

• Bryan

Joel Shore reverts to form once he has lost the argument.
For instance he thought he had found fatal flaws in the Postma paper.

He thinks Postma has not heard of the Latent Heat of Vapourisation.
……and…. apparently nothing else of substance?
Very impressive. Judge for yourself !!!!
He also thinks Postma is a liar and of low moral character.
Gross unsubstantiated abuse is pretty much par for the course with Joel.
I have had several exchanges with Joel and they usually end up with him admitting I was right.
Joel thinks Michael Mann is an honest and careful scientist.
He thinks climategate shows only harmless e-mail communication
He is part of an extreme fundamentalist global warming fanatic faction which includes Joshua B. Halpern, Chistopher M. Colose, Chris Ho-Stuart, Arthur P. Smith
They wrote a comment paper together which even Joel now admits contains basic errors in thermodynamics
To say that they are big fans of Judith Currie would indeed not be true.
Joel often gets things wrong but if you correct him, expect gross abuse.
Plenty of abusive attacks mounted by Joel on different posters can be found in these threads.

• Bryan,

You are either incapable of understanding Postma’s paper and learning from those who know better, or are actually trying to deceive people who know better. Which is it? It is a continued source of entertainment though.

• Joel Shore

Thanks, Bryan, for the continuing your tirade of nonsense. I particularly love this part:

I have had several exchanges with Joel and they usually end up with him admitting I was right.

Joel often gets things wrong but if you correct him, expect gross abuse.

So, which is it: Do I admit you are right? Or do I grossly abuse you when I get things wrong and you so graciously correct me?

These are the actual facts: I don’t get things wrong very often. This is not because I am more brilliant than anybody else but simply because I don’t tend to mouth off about things that I don’t understand…and I try to check things before I say them if I am not fairly confident that they are correct. But sometimes, I still make mistakes and when I do, I admit them. For example, here I admitted to kuhnkat that he was right and I was wrong about clouds on Venus reflecting (as opposed to absorbing and emitting) a lot of IR radiation: http://judithcurry.com/2011/01/31/slaying-a-greenhouse-dragon/#comment-97325

I have also admitted that we ended up being somewhat careless in terminology in our use of the word “heat” in our comment on Gerlich and Tscheschner (G&T)…However, I doubt that it would cause any serious confusion with most readers, although it may annoy a few. It makes absolutely positively no difference to our conclusions, since our conceptualization was absolutely correct even if our use of terminology was imperfect. At any rate, I have learned from this mistake and am always careful now to use the term “correctly”. This seems not to be good enough for Bryan, however, who can’t stop harping about it and deceptively tries to make people believe that it in any way impacts our conclusions on the fatal conceptual errors that we pointed out in G&T’s work.

As for abuse: One thing that I am quite intolerant of is people who engage in pseudoscientific tactics like distorting the facts, misrepresenting what others say, and so forth … That is really why Bryan and I don’t get along as he is both a master of these tactics and a defender of others (Postma, G&T, the Slayers) who employ these tactics. If there was a prize for peddling pseudoscience on the internet, I would certainly nominate Bryan with gusto.

[I am also a little intolerant of people who consistently say things with the utmost confidence that are simply incorrect. It is fine to be ignorant about certain things, as all of us are, but to combine that ignorance with a large degree of arrogance…and an unwillingness to learn…is a really toxic combination.]

• Joel Shore | August 14, 2011 at 9:09 pm | says

“These are the actual facts: I don’t get things wrong very often.”

just the thermodynamic definition of heat flow, that’s all

So Joel, how come you guys haven’t published a rebuttal to G&T’s published reply to your “comment” or even a letter to the editor of the journal? When a rebuttal is published, but no rebuttal to the rebuttal, one would have to assume you have no valid reply. Comments on blogs don’t count.

http://arxiv.org/PS_cache/arxiv/pdf/1012/1012.0421v1.pdf

• hunter

One good method of extermination is starvation…….

• Only rarely will any of the vested interests on any side change their minds, but that is not the battlefield. Who influences the minds of the general public which gradually absorbs information to influence behavior and voting preferences? I feel very safe and comfortable saying the Dragon Slayers are on the winning side of history.
At what point will I accept an apology from honest academics in the climate community and deal with them reasonably? Sometime after Hansen and Mann and Jones and Trenberth and Schmidt and Gore and all the others are removed from public funding and take their proper (shameful) place in our mad and chaotic human history.
No pressure.

• Joel Shore

I think the best analogy is that the “Dragon Slayers” and their fellow travellers represent the “Young Earth creationists” of the movement…i.e., they are the people who believe things that don’t just require a selective reading of the evidence but things that are scientifically nonsense and demonstrably wrong.

• Joel: The arguments do not seem like nonsense. Where is your demonstration?

• David,

the fact that the 4 K cosmic background radiation from the Big Bang itself is absorbed by 300 K radar dish is all the demonstration one needs to know the Dragon Slayers are wrong.

• kuhnkat

Maxwell,

that would be nice except it needs to be isotropic. It appears that the most recent surveys are showing anisotropies to an excessive degree which could mean it is from more local sources compared to the theory.

• Joel Shore

See this post for a summary of why Claes work is nonsense: http://judithcurry.com/2011/01/31/slaying-a-greenhouse-dragon/#comment-95247 You can find more discussion by reading in that thread.

• Ken, you mistake the influence of the skydragons on the broader issue of AGW skepticism. It is very small. The skeptical arguments that have influence are associated with climate sensitivity and feedbacks, and understanding natural climate variability.

Individual academic scientists have nothing at all to apologize for, they publish their scientific research, almost always with caveats, and scientific understanding increases as hypothesis are confirmed or rejected, models improve, the observational data base improves, and our theoretical understanding increases. Some individual scientists are overconfident in their results, this is not surprising

The issue of concern is at the science-policy interface, which is badly broken in the case of climate science. This issue has been the subject of many posts here. If AGW policies have broken down, it is associated with problems at the policy – science interface (incuding the IPCC), and has nothing to do with faux scientific arguments that there is no greenhouse effect.

• As someone who studies the diffusion and demographics of climate beliefs I am not sure that the influence of the dragons is small, or even what that means exactly. Most people who follow the debate know that this position exists, so I suspect that most skeptics give it some credence.

But of course this is a scientific question and a hard one at that. We basically do not understand how we come to understand what we understand. The flow of information and belief is too diffuse to be visible. The diffusion of scientific knowledge and belief is only now beginning to be studied. Note too that the policy-science interface does not have different people on different sides of it. Everyone is on both sides.

9. live free or die

It is hard to tell whether this article is making a point worth contemplating or not. It seems to me the gist is that the net longwave flux is upward. That is, the upweard is bigger than the downward. This nasa presentation:

http://science.larc.nasa.gov/ceres/STM/2003-05/pdf/smith.pdf

does a nice job of showing the values. But whether that makes any difference at all in the arguments comes down to whether the climate models include BOTH the downward and upward flux, which is net upwards, or if they only take the downward into account in which case they would be totally wrong.

Since I don;t know whether the models include both, with the net being upward, then I don;t know whether the point of this article favors skeptical arguments or the AGW modelers.

• Climate models include infrared radiative transfer that has fluxes in both the up and down direction. As I interpret it, the point of this article is completely consistent with the understanding of the radiative transfer models used in climate models, but deals with some semantic issues and tries to explain things from the perspective of skeptical arguments.

10. Vaughan Pratt
What evidence do you have for your statement:

“Preindustrially this flux was in balance and CO2 was not under any great pressure to change rapidly in a single century”

The ice core CO2 evidence suggests massive CO2 swings as well as massive temperature changes – with the temperature often LEADING the CO2.

The 4% anthropogenic contribution must be compared with varying natural CO2 fluxes caused by variations in temperature and moisture etc. See Murry Salby’s presentation
JoNova provides some figs. Blockbuster: Planetary temperature controls CO2 levels — not humans

• PhillipS

David,

Interesting article you link to – but can you tell me why the graphs cut off before the present time? Currently, CO2 levels are around 390 ppm. Where is the temperature rise that Salby claims raised the CO2 level from 280 ppm to today’s 390 ppm? Just eyeballing the graphs you linked to indicates it would have taken around a 10 C temperature rise to produce a 110 ppm CO2 rise. Yet the recorded temperature rise is nowhere near that large.

An alternative hypothesis, of course, is that the 110 ppm CO2 rise since the start of the Industrial Revolution is the result of human activity. Nah, we’d have to be burning giagtons of fossil fuels to cause a CO2 increase that large..

• Jim D

This is perhaps the next meme (or dragon) for JC to attack: that temperature led CO2 in the past (as no one denies), so CO2 can’t lead temperature in the future. We see this over and over.

• Jim, I don’t know anyone who says that the Vostock ice core data (where CO2 is shown to lag temp changes) proves the opposite is impossible. What is said is: you can’t use the ice core record to support the case for CO2-caused warming.

• PhillipS

Ken, can you help me understand why you say that the data proves we can’t use the ice core record to support the case for CO2 caused warming? Clearly something caused the roughly 8 C warming at the end of the last glacial period. The insolation change due to orbital forcing was only about 1 watt/m2, way too low to trigger an 8 C temperature rise unless you assume a very, very high climate sensitivity. It wasn’t a massive increase in water vapor because water vapor precipicates out at those low temperatures, and any large increase in precipitation would have shown up in the ice core and geologic record. It wasn’t the sun, and it wasn’t water vapor, so what was it?
If you are going to assert that all of the evidence pointing towards CO2 induced warming is wrong then you need to offer at least a hypothesis for a physical process that better explaiins ALL of the data.

• I have some ideas, but it’s not an area I’ve studied in detail. I can say this: you can’t use data that shows temperature leading CO2 changes by 800 years to justify a case for CO2-caused warming, that’s all. I think the link between solar radiation and our climate is very complex…we don’t know all the variables yet. It’s far too early to claim certainty in anything. I’m much more inclined to believe small changes in solar output have effects much greater than small changes in the composition of rarefied gases in our atmosphere.

Anyone who looks at the ice core data should come away very humble. Mother nature is not always our friend–she has a very ugly and nasty temperament.

• gbaikie

“Ken, can you help me understand why you say that the data proves we can’t use the ice core record to support the case for CO2 caused warming? Clearly something caused the roughly 8 C warming at the end of the last glacial period.”
We should know that CO2 can’t get below 150 ppm. And it’s claimed 270 ppm is “normal” or pre-industial. So you have a range of 120 ppm.
No one thinks adding 120 ppm of CO2 will increase temperature by 8 C.

“The insolation change due to orbital forcing was only about 1 watt/m2, way too low to trigger an 8 C temperature rise unless you assume a very, very high climate sensitivity. It wasn’t a massive increase in water vapor because water vapor precipicates out at those low temperatures, and any large increase in precipitation would have shown up in the ice core and geologic record. It wasn’t the sun, and it wasn’t water vapor, so what was it?”

Well the real question is what caused the cooling. And the cooling started about 50 million years ago, and the Antarctic due to continental drift move to where it is, starting about 50 million years ago.
So before 50 million years ago, all the ice in the Antarctic wasn’t there.
And btw, there is no ice on earth more than 2 million year old.

Antarctic has been gaining ice and losing ice over the last 50 million years- having periods of no permanent ice in the Antarctic during the warmer periods. And as ice mass or no ice mass the Antarctic has profound affect upon global climate.
We also have records that show a relationship between no sunspots and cold climate. So perhaps one reason for cooling, was first, the presence of the antarctic continent at the south pole and plus perhaps long periods of low or no sunspot activity. And addition you have the Milankovitch cycles.
Milankovitch cycles is mostly significant because of the earth’s unequal distribution of land masses and the relation to ocean areas. And I would guess due to Milankovitch cycles one could get dramatically different climatic patterns. One such change in climatic patterns might cause massive snow fall during the winter in Europe and/or North America. Having temperate region having prolonged period of snow cover could further alter climate.

So contrary to the common claim, it isn’t warm climate that causes variability but rather cooler conditions of the last few tens of millions of years has brought wide swings in global temperature in terms of tens of thousands of years. And there is no doubt that within a few thousand years, we will once again begin to return to ice age conditions.

• Jim D

Ken, no one, who knows what they are talking about, has used the ice core record to suggest CO2 leads temperature. They may have used the correlation between CO2 and temperature (like Gore has), but that is entirely different because there is no mistaking that they are tightly coupled in the climate system.

• Edim

“…there is no mistaking that they are tightly coupled in the climate system.”

I agree Jim, CO2 and temperature are tightly coupled in the climate system.

• Jim D

That’s interesting coming from a skeptic. So you didn’t object to how Gore used his lift in his movie?

• Edim

I didn’t see the movie.

If you think they are coupled, how can you think that anthropogenic emissions can affect atmospheric CO2. Do you think that natural sinks are limited (in Gt/year) and that they can’t handle the anthropogenic input? That they need more time (100s of years) to remove it from the atmosphere?

• Jim D

For those who didn’t see it, Al Gore showed, on a long large graph resembling a cinema screen, the CO2 record since the ice ages with minima near 180-190 ppm, increasing to pre-industrial values of 280, and current values over 380, and then used a lift as he gradually revealed large projected values in a relatively short time span with the line almost vertical, stating that the difference between the ice ages and pre-industrial (190 to 280) is several miles of Ice over New York (I think), then using the lift for dramatic effect to show the future values being a much bigger difference.
On your question, yes, natural sinks are limited, particularly in a warming climate. They can’t cope with more input being already saturated with respect to CO2.

• Edim

“On your question, yes, natural sinks are limited, particularly in a warming climate. They can’t cope with more input being already saturated with respect to CO2.”

Why the ocean acidification scare then?

• Jim D

The ocean acidifies to stay in equilibrium with the increasing CO2 in the atmosphere. It is a tricky concept, but it is the ratio of CO2 in the ocean to atmosphere that depends on temperature, not the actual CO2 amount in the ocean. More in the atmosphere means more in the ocean. Warmer temperatures reduce the ocean fraction, but not enough to counter the increasing atmospheric CO2 effect.

• Edim

Jim D,

You say:
“…it is the ratio of CO2 in the ocean to atmosphere that depends on temperature, not the actual CO2 amount in the ocean.”

Of course. So any anthropogenic (or natural) CO2 emissions into the atmosphere will go into oceans in order to restore the ratio that depends on temperature (NOT on anthropogenic input). It seems that you agree with me (and Salby).

Warming will decrease the ratio of CO2 in the oceans to atmosphere and consequently increase the concentration in atmosphere. If there’s anthropogenic input on top of the input caused by warming, the ratio ocean-to-atmosphere will still depend on temperature. Anthropogenic CO2 will not affect the ratio.

So, I’m back to my question:

Do you think that natural sink rate is limited and can’t restore the ratio, which depends on temperature, as you agree? That it takes 100s of years to remove anthropogenic CO2 from atmosphere?

• Jim D

Edim, so once the ocean restores the ratio, by using maybe half of what man added, what happens to the rest of it? It stays in the atmosphere. In the same way, the ocean can never completely remove what man adds because that would change the ratio.
This is the surface part of the ocean which overturns slowly due to the ocean circulation, and gradually is replaced by water that hasn’t been exposed to so much CO2 that can absorb more, but that just adds another time-scale over which CO2 can be removed. Once the ocean is acidified deeply enough it becomes much harder to get CO2 out of the system.

• Edim

Jim D, thanks for the time to answer.

“…so once the ocean restores the ratio, by using maybe half of what man added, what happens to the rest of it? It stays in the atmosphere.”

Once the oceans (and other non-atmospheric reservoirs) restore the ratio, determined by climatic factors (mostly temperature of the reservoirs), any anthropogenic inputs (and other temperature-independent disturbances in CO2 fluxes) will be distributed between the atmosphere and the reservoirs exactly according to the restored CO2 atmosphere-to-ocean ratio. By constant climatic factors the ratio will be constant and the net flux will be zero. Adding anthropogenic influx will force the natural net flux to become efflux of exactly the same magnitude as the anthropogenic influx.

At variable climatic factors the ratio will be variable too and the overall (anthropogenic and natural) net flux will match exactly the amount needed to restore the ratio. The question is only how long it will take to remove the disturbance and restore the ratio.

If I understand the consensus position correctly, either the capacity of the reservoirs (oceans) is limited and it takes time (100s of years?) to restore the capacity or the maximum efflux rate into reservoirs is limited and it takes time to remove the anthropogenic input. I think neither is true and the ratio can be restored in less than ~3 years. Most of the anthropogenic input will be removed “locally” and almost immediately.

“In the same way, the ocean can never completely remove what man adds because that would change the ratio.”

Yes, but since the capacity of the ocean (and other reservoirs) is much larger than the atmospheric CO2 capacity, the ratio will not be affected significantly/measurably. In other words, sensitivity of the atmospheric CO2 concentration is much higher than the sensitivity of the oceanic CO2 concentration. So, the ocean will practically remove what man adds completely, once the ratio is restored.

Basically, it’s like anthropogenic H2O emission – it does not affect atmospheric H2O, because it’s determined by temperature.

I predict again that if the cooling continues, the percentage of the anthropogenic emissions removed by the ocean will increase and at some point all will be removed. Atmospheric CO2 will plateau. After that, even more than anthropogenic input will be removed (to restore the ratio) and atmospheric CO2 will start decreasing.

• Yes this is probably worth discussing. One problem re dealing with this in the short term is that as of Mon, my schedule is insane until mid Oct. I will be needing guest posters for anything substantive starting next week.

• hunter

Good luck with the start of school.

• hunter

JimD,
You are really making a strawman and then congratulating yourself on knocking it over.

• Jim D

OK, perhaps that is just those people at WUWT, not here, who suggest that because the ice core shows temperature leads CO2, it can’t be the other way around. If we can unanimously knock this meme down on Climate, Etc., that would be fine by me. Next.

• Luis Dias

Well sure it can be the other way around. The major problem was that this graph was used extensively as evidence for Co2 driven climate, even after the 800 year lag was shown. I do remember realclimate people still banging on this point, as if there was a sudden blackout of logic.
Of course, their “logic” dictated that because their models couldn’t represent reality without that CO2 added on effect, therefore it was evidence for the CO2 ´drives temperature thesis.

• Jim D

As I mention elsewhere on this thread, the graph was used to show a correlation (at least by Gore), which is an OK use if you don’t go too far with cause and effect that can only be determined by lags. I doubt anyone who knows anything about Milankovitch cycles would say CO2 drove the ice ages, and if RC had people saying that, they would not be the experts.

• hunter

JimD,
And perhaps it is only the AGW true believers who cling to the idea the ice core proves that CO2 is causing a climate crisis.

• The ice core CO2 evidence suggests massive CO2 swings as well as massive temperature changes – with the temperature often LEADING the CO2.

David, you may have overlooked the word “century” in my “CO2 was not under any great pressure to change rapidly in a single century”. You’ll have to point out to me the century in the ice core data showing anything remotely near the 80 ppmv rise we witnessed between 1900 and 2000.

And bear in mind that the temporal resolution of the ice core data is only 70 years, making it hard to even tell what sort of change could happen in a century. You need a window of several hundred years to even begin to see patterns in the ice core data.

As far as T leading CO2 in the ice cores, of course, that’s what Milankovitch theory predicts. AGW theory predicts that anthropogenic CO2 leads T, without however ruling out the possibility that natural variations in T, e.g. due to ohmic heating by geomagnetic secular variation, could lead corresponding natural CO2 variations. But in any event not by 800 years; the IPCC suggests using 20 years for the anthropogenic impact though to me the data suggests more like 25-30 years while the GSV variations we’re aware of today involve at most 80 year periods and less.

• Ian Blanchard

With regard to the lag between heating adn CO2 rise, I’ve never had a problem with the theoretical argument that the temperature change could begin for one reason (Milankovic / albedo change or ocean circulation variations) and then be extended because of CO2 -related heating. However, there is also the other lag, that temperatures begin to decrease while the CO2 levels continue to rise (at least on the assumption that ice core derivations of temperature and CO2 are reasonably reliable). Surely this is an indicator that the climate sensitivity to CO2 increase has to be relatively low, and certainly points against the ‘tipping points’ and positive feedbacks that are often publicised.

Has anyone actually attempted to derive a sensitivity based on this turn round (i.e. what happens around the temperature peaks) – if we have a reasonable idea of the rate of change of temperature, rate of change of CO2 and maximum amount that can be attributed to natural variability, surely it should be possible to put an upper bound (at least) on the CO2 insulating effect*?

* In my opinion, a better phrase than the ‘greenhouse effect’, which is probably the poorest bit of terminology in the whole AGW discussion. Even worse than ‘back radiation’.

• Vaughan Pratt, 8/14/11, 1:05 am, Vaughan Pratt

Vaughan, you are fostering one of IPCC’s fatal errors. RSJ, IPCC’s Fatal Errors, http://rocketscientistsjournal.com/2009/03/_internal_modeling_mistakes_by.html . Heavily smoothed data are not directly comparable to lightly smoothed data. The slow closing of the firn is a mechanical low pass filter on the ice core records with a time constant of 30 to 1500 years, depending on the accumulated snow fall. Modern instrument records, at least since Keeling’s time, have a time constant of one minute in the manual mode, and much less in the automatic mode. Furthermore, the ice core record is sampled with a long interval — 1450 years at Vostok. The modern record is relatively speaking continuous, and averaged for most purposes over one month. As a result the modern record is a single transient sample with a probability of 7% of an equivalent even being sampled at Vostok. That the modern record didn’t exist in the paleo record is valid, but with a confidence level of 7%.

The mechanical low pass filter in the ice core records can’t be reversed. If you want a comparison of any validity between the ice cores and, say, the MLO record, you would want to first pass the MLO data through a low pass filter with a time constant of 30 to 1500 years. This is but a thought experiment, but sufficient at that.

• Joel Shore

However, different places where ice cores have been drilled have different rates of snowfall accumulation and hence different time constants for the low pass filters. Does it seem very plausible to anyone that the actual CO2 levels have conspired in such a way that these different data are in good agreement with each other and there is never a period long enough when the CO2 levels remain above 300 ppm so that it shows up in the various low-pass-filtered data?

And, does it seem plausible that ever since we started emitting CO2 into the atmosphere, nature has conspired to absorb all of it but then also conspired to independently decide to emit into the air consistently about half of what we emit each year into the atmospher?. (Yes, there is some annual variability but it is remarkably consistent once you average over several years.)

That’s one heck of a natural conspiracy theory!

• Vaughan
Regarding speed of change, I found the following:

A more detailed ice core analysis shows an occasional abrupt change of climate during the last interglacial (the Eemian, at 120 kBP), changing by as much as 10K during only 10 -30 years.

from Ice cores, CO2 concentration, and climate B. Geerts and E. Linacre
That appears to be more than thirty times faster than in the 20th century.

In his 2011 ACS presentation, The geological context of climate change as a basis for policy Bob Carter shows geological records of CO2 being about 16 times higher than present about 430 to 550 million years ago.

• Joel Shore

That’s a rapid change in CLIMATE, not CO2 levels, and furthermore it is a rapid change in LOCAL climate. I think the evidence is that those rapid climate changes were likely a shifting of heat around in the climate system (e.g., due to changes in ocean currents), with the global temperature change being a fair bit less.

“I don’t believe their arguments impress the swing voters in the climate debate as convincingly as they might.”

More speculation in climate science that is really just politics. Just what we need. Yawn.

Andrew

• Luis Dias

Everyone’s entitled to an opinion.

12. Last time I tried this posting, it did not get much attention. Maybe that is what it deserves. But let me try again anyway.

The earth resides in space, and the only way it can receive and get rid of heat is by radiation. Let us suppose that the earth receives an amount of heat, E, where E is a rate of heating. If the earth is in equilibrium, then it must emit exactly E, or it’s temperature will change. Some of this heat is radiated directly from the earth’s surface, through a series of windows in the atmosphere where greenhouse gases do not absorb radiation. This part of the energy would not be affected by adding CO2 to the atmosphere. But the majority of the energy is emitted from the somewhere else in the atmosphere, and this must be transmitted through the atmosphere from the surface to wherever it is radiated from, and this process will be affected when more CO2 is added. Let us denote the energy that is emitted from the TOA as Et.

The earth will be in equilibrium when the earth has a temperature such that exactly Et leaves the earth’s surface, is transported to wherever it is radiated from, where the temperature of there is such that exactly Et is radiated into space. Now suppose that the amount of CO2 in the atmosphere is suddenly doubled. According to this theory of greenhouse gases, the transport of heat from the earth’s surface to wherever it is radiated from will be inhibited, and less heat will reach there. Let us call this reduction delta Et. Two things will happen. Almost immediately, the temperature of the place doing the radiating will decrease so that exactly (Et – delta Et) is radiated into space. At the same time the earth will accumulate heat at the rate of delta Et. Over time, the earth’s surface will heat up, until exactly Et is once again transmitted to the whevever the radiation escapes from, the temperature there is restored to it’s original value, and exactly Et is radiated out into space. A classic example of how the greenhouse gas effect works.

What is wrong with this idea that greenhouse gases work, not by heating the earth’s surface by back radiation, but by inhibiting the heat from getting to where it is radiated out into space?

• ferd berple

The problem for the CO2 model is that the atmosphere is already almost totally opaque at the frequencies at which CO2 absorbs. There is very little energy available for any increased CO2 to absorb.

• Joel Shore

You are now where the science was about 60 years ago, which I guess is progress. That was before it was understood that the wings of the absorption lines matter too and there is always a part of the wings where it is not yet saturated. However, more importantly, the issue is not whether the radiation gets absorbed once or not at all. Multiple absorptions and emissions must be considered. What matters is in fact the level in the atmosphere where the radiation is able to successfully escape to space without being absorbed again. That level rises as one adds more CO2, which means that the emission is occurring from colder regions and hence is less (by the T^4 dependence of radiative power on temperature).

• Luis Dias

Ok, that is interesting, where is your evidence for this?

• Jim D

Jim Cripwell, your interpretation is fine and more general in including the importance of what goes out to space. The backradiation idea is a surface-centric view that is really only part of the more full picture that you lay out. It is often said that the atmosphere insulates the surface more effectively when CO2 is added, which is along the lines that you have suggested.

• Jim – The Earth receives thermal energy from the sun and from IR back radiated from the atmosphere at altitudes varying from less than a millimeter up to many kilometers. For it to “accumulate heat at the rate of delta Et”, one or both of those must increase. If it’s not the sun, then it must be the atmosphere – otherwise the Earth would have no way of knowing that it is supposed to warm up. This extra heating arises because there are more CO2 molecules emitting energy isotropically (some of it directed downwards), and to a greater extent because the average emission from the CO2 molecules is greater as a result of their increased temperature – the latter due to the fact that CO2 molecules above them are intercepting IR that would otherwise escape to space, and sending some of it back down to lower levels of the atmosphere.

The above is a qualitative description of what can be computed quantitatively on the basis of the radiative transfer equations, atmospheric CO2 concentrations, the absorption coefficients at different wavelengths (including pressure and temperature broadening effects), and atmospheric temperature profiles, as well as a few other modifying factors.

• Curious

“This extra heating arises because there are more CO2 molecules emitting energy isotropically (some of it directed downwards)”

That GHGs emit energy isotropically is repeatedly stated during this sort of discussion. There are two kinds of radiative emission: spontaneous emission (which would be expected to be isotropic), and stimulated emission (which would not be expected to be isotropic). Has anyone actually investigated the behavior of CO2 in the atmosphere under the influence of the upward-directed IR flux to see if that flux gives rise to stimulated emission of radiation from CO2? Because if the overall radiative emission from CO2 is not isotropic, but is biased upward, the result would be a lower amount of “back radiation” and a reduced heating of the surface in consequence. Stimulated emission of radiation can occur without actual lasing, and CO2 lasers exist.

• Curious – The vast majority of IR photon emissions from GHGs arise as a result of excitation from collisions with energetic neighboring molecules such as N2 or O2 – i.e., they are a function of the temperature of the atmospheric layer where they reside. Only at very high altitudes is the fraction of emissions that result directly from photon absorption rather than temperature greater than minimal. I’m unaware of any reason why GHG emissions should be appreciably biased upward (or in any other direction). Do you have any reason to think otherwise?

• Curious

Fred – When a CO2 molecule in the atmosphere is in an excited state such that it can emit an IR photon of a given frequency, and it is close to the surface, it is also immersed in an upwelling bath of IR photons of similar frequency from the surface. If such a CO2 molecule should interact with such an upwelling IR photon there would be at least a theoretical possibility of a stimulated emission of an IR photon from that CO2 molecule. Such stimulated emissions are predominately at the same frequency and with the same momentum, ie: in the same direction, as the stimulating photon. What I am, admittedly, conjecturing is that when the surface is warm and emitting IR photons upward, those photons will set off a cascade of stimulated emissions, also upward, which will result in an overall asymmetry between the intensity of upward IR emissions in the atmosphere, and downward emissions.

• Curious,

but we’ve measured basically equal flux in both directions, away from the surface and towards the surface from above. So stimulated emission should be working in both directions almost equally. There should be no such asymmetry.

• Stimulated emission is not the same issue than that of the origin of the excitation. Stimulated emission is significant only, when the electromagnetic fields are very strong as they are in lasers. We are many orders of magnitude further from the significance of simulated emission than we are from the significance of emission based on absorption in incoming photon. No ordinary light source or heat source can produce light or IR radiation at the level, where stimulated emission is significant, for that we need lasers with its high quality mirrors at both ends and pumping at a high power density.

CO2 lasers are based on same principles as other lasers, they are only technically different from the solid-state lasers and other types of non-gas lasers.

• Some terrible language again. My English is not quite that bad, but I forget to read, what I have written, before I post.

13. Kermit

What about the earth’s crust and core? It is measured to be hotter the further down you go. This is supposed to be due to pressure. Why is that not part of the discussion?

• hunter

because the effect on the climate energy budget by the Earth’s interior is completely trivial.
Only when the interior creates a significant volcanic eruption will the interior have any impact on the climate.

• scepticalWombat

Because the amount of heat reaching the earth’s surface from its core is minute when compared to the amount coming from the Sun. I’m no geologist but my understanding is that one of the reasons the earth’s core remains so hot is nuclear fission.

• Kermit

Fission is the Sun’s thing. The Earth is pressure.

• hunter

Kermit,
Fusion drives the sun, not fission.
The exact mix of processes that keep the interior of the Earth hot are not completely known,but radioactive decay including fission play an important part.

• Fusion is the Sun’s thing.

• Kermit

okay, my apologies.

The coldest place on the moon is 62 Kelvin according to a Discover article and is the coldest place in the solar system (apart from 2.7 Kelvin in space I presume). This is in the south pole where there is some permanent darkness in large crater shadows. It would seem that if the earth were without atmosphere like the moon that would possibly be the minimum temperature from the moon itself – whatever the process. This would indeed be a third fireplace and a fourth being the background cosmic X-ray radiation that starts us off at 2.7 Kelvin.

• Kermit

Given the size of the Earth compared to the moon, one should be able to further refine that 62Kelvin to something higher. Unless Earthshine is the cause. I’ll assume this is a common calculation and most here know that the answer, but I don’t know. Please, let me know what this base temperature of the Earth without atmosphere is (excluding the chemical and biological activity on the Earth too).

• scepticalWombat

Now that we have got the fission thing out of the way I should say something about pressure. Compression raises the temperature of a substance but continued pressure does not create heat (to do so would violate the first law of thermodynamics). This is easy to demonstrate. Let the air out of a bicycle tyre and then inflate it quickly with a hand pump. The pump and the tyre will be hot or at least warm. Now leave the inflated tyre in the shade for a few hours. The tyre will be at ambient temperature again but the air inside it will still be under pressure.

The high temperature inside the earth may in part be caused by residual heat from the original compression when the planet was formed combined with the insulation properties of the crust and mantle. However the high pressure does not provide an ongoing source of heat.

• Fusion is the Sun’s ‘thing’.

A lot of the heat in the mantle is from radioactive decay – certainly different from fission.

• scepticalWombat

As I understand it radioactive decay that results in the emission of an alpha particle ( a helium nucleus) is fission. Admittedly emission of gamma rays and beta particles is not.

• scepticalWombat

OK that was wrong too. The definition of fission requires that the daughter particles be of approximately equal mass. This is not the case in alpha decay because the alpha particle is much lighter than the remaining nucleus.

Fission does occur naturally but it is very rare.

So summarising:
Pressure does not provide a ongoing source of heat in the mantle or the core.
Radioactive decay does provide some of the ongoing heat.

• hunter

Chief,
Thank you for clarifying and correcting my statement implying nuclear fission was a significant factor in the Earth’s interior heat budget.
There is strong evidence natural fission has occurred in the distant past,
http://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor
but we have no evidence that it is more than very rare at best.
I made the mistake of placing radioactive decay in the family of fission reaction. That was incorrect.

• Ian Blanchard

From recollection of some first year geology lectures, the contribution to the Earth’s surface from geothermal heat is something like 0.3W/m2, so can be ignored as trivial in this discussion. The main reason for the inner planet being hot is decay of long-lived radioactive elements, with residual heat from accretion (and hence pressure) being long gone. Lord Kelvin’s famous miscalculation of the age of the Earth was based on an estimate of heat loss from the assumption that the heat was caused by the pressure build-up of planetary formation – he was unaware of the presence of radioactive elements that continued contributing to the heat source within the planet.

Fission is not known in the inner planet, although there is at least one location where a natural fission reactor developed in the Earth’s crust (an initially uranium-rich sandstone in Gabon iirc – the Oklo natural reactor). Irrelevant as a heat source, but an interesting aside.

14. Salamano

Alistair Fraser was a professor of mine in college. He and Craig Bohren were/are some pretty big names in the field that were teaching at the same time when I was at Penn State. Prof. Fraser was one of the early adopters of the internet and self-designed websites for use in class. His ability to communicate online was ahead of his time, and extended well beyond his retirement.

Ben Franklin was noted as saying, “You want to become famous? Write something worth reading, or do something worth writing about” … Of course, you can always stick it on the internet too.

15. Let’s get our definitions straight, OK? The term ‘back radiation’ refers to the mystical properties that must exist if fears of runaway Global warming are not to be confused with the superstitious fears of whitcbdoctors. That is, ‘back radiation’ is shorthand for reason down the swirling vortex and worshipping a golden calf on the altar of ignorance.

• Not even wrong.

• Wagathon

Yes, as Wm Starck observed climatelogy is a cargo cult science.

• So, Wm is not even wrong. Surprise Eli

• Wag

“Let’s get our definitions straight, OK? The term ‘back radiation’ refers to the mystical properties that must exist if fears of runaway Global warming are not to be confused with the superstitious fears of whitcbdoctors. That is, ‘back radiation’ is shorthand for reason down the swirling vortex and worshipping a golden calf on the altar of ignorance.”

“http://en.wikipedia.org/wiki/Backscatter”

And I will give you a practical military application, one that I’m familar with.
Let’s take a plane flying at 10K feet. The plane is hot. It radiates at different wavelengths: ( hot metal, hot gases, aero heating)

http://en.wikipedia.org/wiki/Infrared_signature

Software like this, used to be secret or TS/SAR
http://sourceforge.net/projects/osmosis-project/

Anyway, the radiation leaves that plane and then it has to travel through the atmosphere. The same way a cell phone signal has to go through the atmosphere, the same way a radar beam has to, same way sunlight has to. What happens to radiation when it transfers or propagates through the atmosphere? do we know? yes. we build things every day and use things every day that rely on a sound proven understanding of the propagation of radiation through the atmosphere. In some cases we use the fact that the atmosphere interfers with long range transmission to build short range “covert” transmission systems.
http://portal.acm.org/citation.cfm?id=1720092
Simply, we know how radiation propagates. Our soldiers lives depend upon this science.

When you shine a flashlight on a mirror, do you see light come back? Yup. that is specular reflection. You ever drive late at night in the fog?
How come the light doesnt go through the fog? That would be like diffuse reflection, or backscatter.

So back to the plane. At 10K feet what happens if I try to see the plane’s IR from the ground with a sensor? Well That IR has to get to the sensor. How does that work? well as the energy comes toward the ground some gets
‘backscattered’, some gets absorbed, and some makes it through. What if a cloud passes overhead? Well the IR gets blocked. Why? well clouds are full of water and h20 does a great job absorbing and deflecting and reflecting IR. In order to keep our pilots safe from nasty russians on the ground, the airforce decided it would be a good thing to understand how different molecules react to different wavelengths. They built a database: Its called Hitran. And, we needed tools to predict what would happen to the IR as it went through different kinds of atmospheres ( standard, tropical, etc) So we had another tool MODTRAN. That engineering tool allowed us to model and then test how IR ( say from a plane) would transmit down from a plane to the ground. It’s known physics. It works. You use it every day.

Now, That same plane radiates UPWARD as well as downward. What happens to the IR that goes from 10K upward. Well, the same thing happens. Some of the IR get scattered back, some gets absorbed and some gets transmitted. Why is this important? This is important because there might be an airplane above me at 50K feet looking down. or a space platform looking down. The person on the ground looking up will see one thing. That is driven by the atmosphere between the ground and the plane at 10K. But the plane at 50K looking down will see a different image. Why? because the IR from the plane goes through an atmosphere that may be different. With different amounts of C02 and water and clouds, the plane at 50K may see the plane at 10K, whereas the guy on the ground behind the cloud sees Nothing! And, if I’m designing at plane I might also look at trying to use C02 to hide the plane. Why? because the physics the airforce relies on tells me that C02 does a good job at backscattering and absorbing IR. I might even spend a bunch of money testing this. here is a very nice paper
http://dspace.library.iitb.ac.in/jspui/bitstream/10054/613/1/5740.pdf

So to protect this wonderful country and our individual liberty, people like me had to believe in backscatter. We had to use the very same physics ( Radaitive Transfer equations) to calculate how IR would pass through the atmosphere. So, backscatter is real. The IR that leaves the surface of the earth heads toward the sky, but along the way it gets absorbed, scattered back, and eventually it get reradiated to space.

• Wagathon

By your analogy that heat engine in the sky we call the Sun is like a hot plan dashing through the airspace. And, that is a bad analogy. When it comes to the transfer of heat we really should at least try to honor the Laws of Thermodynamics.

A study of the Earth’s albedo (project “Earthshine”) shows that the amount of reflected sunlight does not vary with increases in greenhouse gases. The “Earthshine” data shows that the Earth’s albedo fell up to 1997 and rose after 2001.

What was learned is that climate change is related to albedo, as a result of the change in the amount of energy from the sun that is absorbed by the Earth. For example, fewer clouds means less reflectivity which results in a warmer Earth. And, this happened through about 1998. Conversely, more clouds means greater reflectivity which results in a cooler Earth. And this happened after 1998.

It is logical to presume that changes in Earth’s albedo are due to increases and decreases in low cloud cover, which in turn is related to the climate change that we have observed during the 20th Century, including the present global cooling. However, we see that climate variability over the same period is not related to changes in atmospheric greenhouse gases.

Obviously, the amount of `climate forcing’ that may be due to changes in atmospheric greenhouse gases is either overstated or countervailing forces are at work that GCMs simply ignore. GCMs fail to account for changes in the Earth’s albedo. Accordingly, GCMs do not account for the effect that the Earth’s albedo has on the amount of solar energy that is absorbed by the Earth.

• Actually Mosher’s analogy is right on. Just like in Mosher’s analogy I don’t expect the IR signature of the plane, from the moon or from Betelgeuse to warm the surface of the Earth any more than I expect a -50 degree sky to warm my section of the Earth that is at about 33 C right now. I do know that when the night sky is -20 instead of -50 that clouds have moved in so the temperature here will cool down slower. Why? Because the clouds are intercepting more outgoing radiation than the clear sky. If it stays cloudy all night the temperature of the clouds will drop as the temperature of the surface drops. If the clouds were warming the surface, I would expect the temperature of the surface to increase as the temperature of the clouds decreased. So I have no real problem with back radiation other than when someone says it warms the surface. The sky does have a temperature so it emits IR like any object that has a temperature. The higher the temperature of the sky the lower the net outgoing radiation. It is only when the net is positive incoming that the surface is being warmed.

Call it semantics, but it is simpler to stick to the basic physics.

• Wagathon

You canot support a false analogy with another. A blanket of cloud cover may ‘warm’ the night but the surface of the Earth will cool all the same throughout the night.

By your way of thinking, if you put a blanket on a dead body it will warm. And, if you add more blankets you run the risk of the body bursting into flames due to runaway warming.

The problem all will run into in trying to defend delusinal and their unscientific beliefs about global warming alarmism is their failure to grasp the obvious. We know what causes global warmnig and global cooling. Nominally, it’s the Sun, stupid.

16. Vaughan Pratt
Re: “Well, moving the ice further away reduces its cooling effect on you and your warming effect on it, so presumably that number must be reconciled with the evident fact that you’re warming the ice, not vice versa.”

“Reduces its cooling effect” is due to the subtended solid angle being reduced by the finite block of ice being further away.
When radiating to the sky at 4C, the subtended solid angle of the sky does not change much when you are above the earth, so this is a confusing metaphor. May I encourage you find more helpful illustrations.

(PS For precise calculations of the global atmospheric absorbance or emission, there is some variation with angle due to the varying thickness of the atmosphere through which the radiation is transmitted. See Miskolczi’s calculations on Anisotropy in directional radiance.)

• “Reduces its cooling effect” is due to the subtended solid angle being reduced by the finite block of ice being further away.
When radiating to the sky at 4C, the subtended solid angle of the sky does not change much when you are above the earth, so this is a confusing metaphor.

It wasn’t intended as a metaphor, only as additional confirmation that it’s the ice that’s cooling you and not something else, nothing to do with the atmosphere in that case. When experimenting I like adjusting as many variables as I can in case one of them has an unexpected effect that I’d overlooked. In hindsight it would have been less distracting to skip that particular adjustment.

17. hunter

Dr. Curry,
You ask some very interesting questions.
Here are some observations from someone who has been involved in the design and manufacture of industrial insulation for pipes boilers and storage vessels that may help with understanding this. I will go through this in small steps. Please feel free to show where the steps go wrong from your perspective.
First, the primary heat source is doing the work of heating. Everything else is cooling, just at rates based on thermal properties. A steel pipe, uninsulated, will lose heat very quickly. A steel pipe insulated with a good industrial insulation will still lose energy, but at a lower rate.
If you review this technical spec sheet for a quality mineral wool industrial supplier’s pipe insulation product, you will see the HL (Heat Loss) spec at differing temperatures, along with the graph showing behavior over temperature ranges.
http://www.roxul.com/files/RX-NA-EN/pdf/Techton1200.pdf
Note the ambient temperature set for the performance tests. Do you think that very many industrial catastrophes occur if the ambient temp goes from 75.0F to 80.0F, by the way?
The Earth is entirely heated for climate purposes by the sun like any other planet.
Earth’s surface happens to be covered in an ocean of gas and vapor ice and liquid- the atmosphere. The Earth, unlike a typical industrial application, heated from the outside source of the sun, so the insulator, the ocean of air and vapor/liquid/ice and dust that makes it up gets heated as directly as the surface does. Some of that heat in the atmosphere is re-radiated down as well as out. But the net flow is always out, away from the Earth. To say the insulation warms the pipe makes no sense. Yes, as the insulation warms it radiates, but so what? It is still moving energy out on a net basis. The AGW obsession is as if someone was looking at the flow of a great river, and decided that since there are eddies in the flow, the river is not really running to the sea.
To say the insulation keeps the pipe warmer, and holds the temperature longer, makes more sense. To say the insulation is heating up the pipe in any significant way makes little sense. You will never insulate the pipe to the point of a run away boil or steam pressure rupture. Turn off the furnace or boiler, and no matter how good the insulation, the pipe cools off.
But the Earth and its atmosphere is heated by the sun, so the energy passes through the atmosphere and heats it along with he surface. And the atmosphere does pass part of its radiative budget to the Earth.
Frankly that seems trivial in terms of energy budgets. The atmosphere acts to moderate what it is given. It adds nothing. If the atmosphere was not over the Earth, the energy budget hitting Earth would be identical. It would simply, like the uninsulated pipe, lose its heat much more quickly, as does Luna or Mercury,when the sun sets or on the dark side.
Insulation, while generally manufactured to high standards, is still variable from batch to batch. The slag, the binders, the protective wrap over the insulation all influence its R value. But that seldom causes problems in the field, as long as the variation is not extreme.
When I observe the numbers offered as to how much change CO2 has made in the energy budget due to its recent increases, the word that comes to mind is ‘trivial’.
And that is what the climate record of the past 150 years shows: Trivial typical changes in climate manifestations. Nothing dangerous or dramatic or unusual.
When I see your projection of where CO2 ppm will be at the end of the century, the question comes to mind, ‘How can it grow to >800ppm in this period at an increase of ~2.5ppm per year?’
And in light of Salby’s soon to be published review of CO2 budgets, perhaps even the assumptions underlying CO2 will need to re-examined.
Sorry about the long post, but there are really better things to critique AGW with than the dead dragon.

• Jim D

I think the idea of the atmosphere as an insulating layer is better as an engineering analogy than a greenhouse. Adding CO2 increases the insulation. You may think that 4 W/m2 from doubling CO2 is trivial, but remember it is sustained and corresponds to a 1 degree increase in surface temperature, which is not trivial in climate terms and can cause feedbacks that amplify it, mostly because water vapor is a greenhouse gas that is very responsive to temperature,

• hunter

Jim D,
4watts in a multi hundreds watts system is trivial by definition.

• hunter

ooops hit submit too soon.
Additionally, the 4 watts is not additional energy to the system, it is reduced loss on the way out.
BTW, I thought the CO2 impact was different from 4W?

• Jim D

I degree in climate is by no means trivial.

• Jim D

I mean one degree, and doubling CO2 changes the radiation by about 3.7 W/m2 at the top of the atmosphere, which translates to a similar order of magnitude change at the surface.

• hunter

JimD,
1.0C in a system that has daily swings in many cases of 10’s of degrees and seasonal swings in tens is trivial.
Just as with eugenics, the AGW movement has extrapolated a crisis based on trivial data.

• Joel Shore

So, when does it become non-trivial? The global temperature difference between our current climate and the last-glacial maximum is something like 5- 6 C. I would call the effect on here in Rochester highly non-trivial, given that we were under thousands of feet of glacial ice.

• Peter317

So what you’re saying is that you’re worried that we’re going to be buried under thousands of feet of ice if the temperature increases a few degrees?
If not, then exactly what are you saying?

• Joel Shore

I am saying that global changes in temperature that might seem small to some people can lead to very large changes

• Joel Shore

…in the world in which we live.

• Peter317

I would suggest the local temperature at Rochester is now a lot more than 5- 6 C higher than it was during the last glacial maximum.
The global average says little to nothing about local temperatures, and furthermore it’s determined by local temperatures – not the other way around.

• Joel Shore

Peter,

You are probably correct about Rochester. However, the point is that the same will be true of some places for a given rise due to AGW: It will be larger some places than others. For example, it will be larger over continents than it will be over the oceans.

• hunter

Joel,
We have seen, if the current understanding is correct, CO2 go from ~280ppm to ~390ppm.
Has Rochester suffered in any way from this?
No. Are the seasons changing in dangerous ways? Is rain, drought, snow, heat or cold changing in ways that are going t make you move away?
Will 5-6 degrees put Rochester under ice?
No.

• Joel Shore

I and the flora and fauna and the agriculture are adapted to the Rochester climate the way it is, thank you very much. And, I think the people in Bangladesh are adapted to the sea level where it is.

• Jim D

OK, we have 1 nearly degree in the last century with probably three more in the next. At what point do you think it won’t be trivial? It is fine to agree with IPCC WG1 about the three degrees, and argue with WG2 about its effect, if that is your position.

• hunter

You raise the interesting question about how useful global average temperatures are in the first place.
As for the ‘probably three more’, I believe that assumption is not viable.
‘doubling’ is tossed around frequently. Doubling from what level? From 280ppm?
From the current ~390ppm?

• Edim

I agree that describing the atmosphere as an insulating layer is better analogy than a greenhouse. However, I disagree that adding CO2 increases the insulation. It affects radiation, but it also affects convective and evaporative heat fluxes and the net result is not known.

Furthermore, it seems that adding CO2 to the atmosphere does not significantly affects atmospheric CO2 – it’s driven by climatic factors.

• Jim D

The difference between having GHG insulation and not is 33 degrees C. So it stands to reason that adding CO2 would add more, unless we have suddenly hit a ceiling.

• Bryan

Jim D
That is what is said if you follow a long line of “iffy” assumptions.
Read Postma paper 1 for a more balanced outlook.

• Jim D

Postma uses a flawed argument to state that the surface temperature is the current-day surface temperature even with no greenhouse gases. He doesn’t seem to realize that the surface temperature is not determined solely by atmospheric mass. Very weird stuff.

• Bryan

Jim D
Postmas point is the 255K radiating temperature is for the Earth/Atmosphere ensemble not the surface temperature.
He does the calculations to show for instance that at the solar zenith, earth temperatures reach 80C for an area the size of the USA facing the Sun.
Given the reality of Oceans and earth atmosphere and surface thermal energy retention the 33K greenhouse effect seems a little exaggerated

• Jim D

He thinks the radiating altitude of 5 km is independent of greenhouse gases.

• Bryan

Jim D says (of Postma)

“He thinks the radiating altitude of 5 km is independent of greenhouse gases.”
Perceptive comment as usual, thank you.
Where would it be if a full contribution from the greenhouse gases was included?

• Jim D

It would be at the surface if there were no greenhouse gases. He didn’t seem to know that obvious fact.

• Bryan

Jim d says
It (-18C) would be at the surface if there were no greenhouse gases. He didn’t seem to know that obvious fact.”

You are ignoring the heat retentive properties of the Earth system.
He covers the topic of the surface at great depth.
For instance at the solar zenith a sun facing part of the earth the size of the USA is at 80C.

Is the Earths water going to instantly freeze down to -18C – get real

• Jim D

Bryan, you seem not to be skeptical of Postma. I am. His time-varying issues raise no new science regarding the energy balance and mean state. He only has to look at the Moon to see what a GHG free state would look like. Atmospheric mass wouldn’t help the Moon to be warmer if you added a GHG-free atmosphere there somehow.

• Bryan

Jim D says

“He only has to look at the Moon to see what a GHG free state would look like. Atmospheric mass wouldn’t help the Moon to be warmer if you added a GHG-free atmosphere there somehow.”
What do you think would happen to the maximum and minimum temperatures on the Moon if its rotation period was 24 hours?
Does anyone have a program model to run this test?

• SkepticalScience will have an extended breakdown of Postma’s paper, scheduled to be published there Wednesday.

• Kermit

I don’t think it’s any better. A blanket at night can keep you warm but a greenhouse in the night gets cold.

Maybe a gore-tex blanket is better example but probably not.

We left an iPod Touch in the sun the other day and it was so hot it burned your fingers but the table it was on was not very hot at all. Wrapping it in a blanket has no effect on its temperature.

• Bryan

Kermit says
“a greenhouse in the night gets cold.”
True and sometimes the temperature inside the greenhouse is less than the ambient outside temperature.

• hunter

Edim,
CO2 will, on balance, increase the insulating potential of the atmosphere.

• Edim

I am not convinced hunter. Too complex to be certain.

And even if it will, how significant is this increase?

Furthermore I think temperature determines atmospheric CO2. That means CO2 can’t really be increased at constant climatic factors. Any disturbance in fluxes (anthropogenic or not) will be removed.

• hunter

Edim,
It is not too complex.
It is established by experiment experience and physics that CO2 will act as an insulator in the Earth’s atmosphere.
As you point out, it is the size of impact that is significant.
The impact from the past ~150 years has been trivial.
Temperature certainly regulates CO2, as does biosphere activity, the availability of geologic CO2 sinks, ocean temperatures, etc.
That does not mean we cannot put in more CO2 than the system can sequester or consume in a fixed period of time.
But that said, none of this supports a catastrophe caused by CO2.

• Edim

I think it’s too complex. We agree on almost everything else. Increased atmospheric CO2 will VERY likely reduce Earth’s radiative heat loss to space, all other things held constant. But all other things can’t be held constant.

I think that we cannot put in significantly more CO2 than the system can sequester in a fixed period of time, at the anthropogenic CO2 emission rate. I agree 100% with Salby on this point, not because I am not sceptical, but because I came to the same conclusion few years ago.

• BlueIce2HotSea

Hunter –

You are correct that insulation will not increase the temperature of a pipe to greater than the temperature of water flowing through it.

Similarly, the insulating properties of the atmosphere will not increase the temperature of Earth to greater than that of the Sun.

• BlueIce2HotSea

To be more accurate, the maximum temperature would only be around 400 C at the Earth’s surface. At that point, all of the oceans would be water vapor and Earth could not get any more insulation from water vapor.

• BlueIce2HotSea

To be still more accurate. My 400C calculation was based on the temperature explicit form of the Antoine equation for boiling water.

• hunter

Surely you are not suggesting that CO2 is going to cause the seas to boil?

• BlueIce2HotSea

Hunter –

Of course, not. My guess is that with an overall albedo of ~.8 for 100% cloud cover, a complete boil off of the oceans is not possible.

On the other hand, heat from volcanism, radioactivity, plasma flux ropes, a big meteor/asteroid strike, etc. will take awhile to get to top of atmosphere. Has somebody done these calculations? Not me.

BTW, Dr. Pratt said to address what you are thinking, not what you are saying. And I imagine what you were thinking was correct. That is, I believe you correctly understand Heat flow. However, I addressed your pipe/insulation model which was not correct.

Sorry.

18. ferd berple

If the greenhouse effect from CO2 is real, the evidence must exist in the paleo record. It is simply not possible that there have not been massive releases of CO2 due to natural causes many times in the past. If the greenhouse effect from CO2 is real, then in the long history of the earth there would be clear evidence that CO2 leads temperature.

Why do we not see this in the paleo record? Why do we find that CO2 lags temperature, but not that Co2 leads temperature? Why in the long history of the earth have we not found evidence in the paleo records that CO2 leads temperature if the CO2 greenhouse theory is correct?

Is it just possible, that our knowledge of CO2 and radiation budgets is an incomplete picture of climate? That water, sun, air, earth and life are the drivers of climate on planet earth? That they interact in such a fashion that the earths temperature has remained at 22C or 11C for most of the past 600 million years, and our present 14.5 C average temperature is far from typical or average. It is simply the result of a brief warming in the middle of a series of ice ages.

A warming that is on balance a benefit rather than a danger to life. A warming that is responsible in large part for human prosperity. Is it really a coincidence that our modern prosperity began with the end of the Little Ice Age? In that respect it could be argued that warming is what drove human CO2 emissions.

• Jim D

There is a lot of evidence of CO2 leading temperature in the paleo record. Firstly volcanic periods, like the Permian-Triassic boundary that ended the Permian ice ages, and led to the warm Mesozoic Era, generally because these volcanoes increased the atmospheric CO2 concentration at least tenfold. Secondly, most of the last 100 million years since the Cretaceous has been a cooling trend, generally seen to coincide with a slow reduction in CO2. The CO2 was decreasing through natural sequestration, such as weathering, ocean sedimentation, and soil burial, and the temperature followed. No one has suggested this is the other way around.

• The latest crackpot theory is that temperature drives CO2 and the lag is 30 years. Do the ice core records have this sort of definition?

19. Bryan

A factor that occurs to me is the overemphasis on radiative transfer and a corresponding underestimation of the various thermal retention properties of the Earth system.

I picture the Earth daily heating cycle by this simple analogy.
An electric circuit with a resistor a diode and a capacitor.

The Sun facing side of the Earth changes gradually every half cycle.
This heating can be represented by the crest part of a sine wave the diode removing the trough half cycle.
The resistor represents the dissipative loss to space of degraded radiative energy.
The capacitor represents the thermal energy storage system.
The circuit is of course called a smoothing circuit.

By correct choice of resistor and capacitor the voltge across the resistor (Earth Temperature analog) is almost constant or smoothed.

I find this narative much more plausable than backradiation saving the Earth night side plunging towards -273C.

20. Chuck

I feel that Professor Pratt’s point was missed by most readers. He was trying to explain why the conventional explanations of the “greenhouse effect” (which might be easier to explain if it were named the Arrhenius effect as that would not draw in confusing analogies to real greenhouses) lack persuasive power. More details of Professor Pratt’s position are given at:
http://boole.stanford.edu/pub/lgw.pdf

Suffice to say, he accepts thermodynamics and does not dispute the resonances of the C02 molecule.

Tom said:
I agree with Charles, why on earth have you allowed an article like this to be pulished on your blog, when clearly the author doesn’t understand basic physics ?

That’s not how I read his article. I thought it was making a point about the types of explanations that would communicate best with skeptics. His knowledge and skills in math and computing are probably better than those of most (all?) who call themselves climate scientists. And, I’d be willing to bet that he got better grades in physics than they did.

His was a post from a non-skeptic. The tone of the comments on his post illustrates some of the problems with the discussion of climate issues.

Chuck

21. PMH

In your last paragraph conclusion, does not the caveat “based solely on the temperature and CO2 records to date” include the huge assumption that CO2 drives temperature rather than temperature driving CO2. Based on my experience in high school I should have graduated from Ga Tech with honors. I neglected to consider a few other variables.

• In your last paragraph conclusion, does not the caveat “based solely on the temperature and CO2 records to date” include the huge assumption that CO2 drives temperature rather than temperature driving CO2.

It’s not an assumption, it’s a calculation based on a very simple mechanism. In order to stay at the same temperature, Earth must shed as much energy as it receives. When GHGs increase, each photon leaving from each point of the planet, whether from solid, liquid, or gas, now has a lower probability of escaping to space, resulting in a decrease in radiation. The heat that doesn’t escape gradually heats the Earth, thereby increasing radiation until balance is restored. This is a simple and natural mechanism.

For each photon at any given wavelength leaving Earth from any given point of any given kind at any given temperature and altitude in any given direction through any given quantity of GHGs, we can estimate the probability that the photon will escape to space. We can further estimate the reduction in that probability resulting from increasing the GHGs. (GHGs are not independent hence one cannot analyze this independently for each GHG.) From this we can infer the net decrease in radiation resulting from the GHG increases. We can then estimate the increase in temperature needed to bring the radiation back into balance.

This is the mechanism by which increasing CO2 and other GHGs increase the temperature. It is only an assumption in the same sense that the falling of an apple from a tree is assumed to be due to gravity. It’s a very reasonable assumption once the principle has been grasped.

DLR plays no role in these calculations. It’s quite correct to say that DLR exists (that’s what my IR thermometer measured). It’s also quite correct that the extra photons that the extra CO2 prevents from escaping raise the vibrational energy of CO2 molecules. This energy is converted to translational, rotational, and vibrational energy of air molecules (of all kinds) when the CO2 molecules collide with them, by Boltzmann’s principle of equipartition of energy among all available degrees of freedom of each molecule. At STP they collide every 500/70 = 7 nanoseconds on average since air molecules move at 500 m/s and have a mean free path of 70 nm.

In this way the air is warmed.

Where the back radiation argument for global warming breaks down is the assumption that the additional warmth is conveyed to the rest of the planet by radiation. Clearly some of it is, but some of it is equally clearly conveyed around the planet by convection, eventually reaching the surface in the form of warmer air which then heats the ground by conduction via contact with the bottom millimeter or so of the atmosphere.

It is completely irrelevant what proportion of this extra warmth from the atmosphere reaches the ground via DLR as opposed to via convection and conduction. The math is independent of that proportion.

Nevertheless it is of independent interest to know that proportion. The two bottlenecks in getting an increase dT of temperature down to the surface are radiation and conduction. Given that the rate dT/dt of global warming is about a billionth of a degree per second, while the diurnal fluctuations are many orders of magnitude greater, convection cannot possibly be a bottleneck.

Ignoring feedbacks, we can estimate the rate dF/dT of change of heat flux F in W/m2/K as 4F/T (since it’s equal to the derivative of F = σT^4.) With F = DLR = 324 W/m2 and T say 270 K for the sake of argument, dF/dT = 4*324/270 = 4.8 W/K. (By all means replace this with a better estimate if you have one.)

Thermal conductivity of air at typical surface temperatures (the only place where conductivity is relevant) is roughly 0.025 W/m/K. Assuming a skin thickness of s mm at the surface, this becomes dF/dT = 25/s W/m2. In order for this to equal the 4 W/m2 of radiation rate dF/dT we would need a skin thickness of about 6 mm.

Being neither an atmospheric physicist nor a barefoot doctor I don’t know all that much about skin on the ground. However I would imagine that with even a slight breeze the skin is likely to be a couple of orders of magnitude thinner than this.

If so then we may conclude that almost all the warming of the atmosphere is conveyed to the surface by convection and conduction, and that DLR plays no significant role in global warming. In order for it to go the other way the air skin on the ground would have to be centimeters thick.

Put simply, a warmer atmosphere warms the ground by direct contact, with essentially no assistance from DLR.

While I realize this may not be the reason climate skeptics are skeptical about the role of DLR in global warming, they may derive some measure of satisfaction in the thought that for all they know their subconscious had done the math and was bugging them to speak up.

Based on my experience in high school I should have graduated from Ga Tech with honors.

What was your major? I went into physics at Sydney Uni based in part on coming 8th in the NSW external (LCE) physics honours exam (no idea what careers the 7 above me went into). Although I graduated with double honours in pure mathematics and physics (a 5-year program), computer science was just starting up as an academic subject when I graduated and I picked it as a more exciting field to get into than physics at the time.

• Jim D

Vaughan, seeing that you want a scientific rather than analogy explanation, let me give it a try. The surface has to warm before the troposphere can because the tropospheric temperature is tied to the surface by convective-radiative equilibrium that constrains the lapse rate. So your idea that CO2 directly warms the troposphere which then spreads to the surface has it backwards. (The stratosphere is unlinked to the surface, and has its own behavior). This is why DLR is so important. CO2 increases DLR as a first step in increasing surface temperature, which then increases convection and warms the troposphere.

• Jim D

In fact, suddenly adding CO2 has the immediate effect of cooling the atmosphere because it radiates more efficiently to space, but this also spurs on convection to equilibriate the lapse rate.

• Bryan

Jim D
Lets think of a solid hot surface and a solid colder surface both parallel and facing each other with an large air gap between .
Large enough for a measurable change to be detected if the composition of the air was changed.
Lets say the experiment was carried out in space so as to eliminate convection.

We change the composition of the air by adding or subtracting CO2.
We wait till each new steady state arrives.
We then measure the thermal energy flow from the hot to colder surface.

I’m honestly in some doubt as to what would be the outcome .

1. No change
2. Increased flow with trebling CO2 above atmospheric norm
3.Decreased flow with trebling CO2 above atmospheric norm

Any ideas?

• Jim D

If by flow, you mean radiative flow, I think the net won’t change, but upward and downward amounts increase with more CO2 canceling each other out in the net. I am not sure what the equilibrium profile would be, but it is either isothermal at the mid-point temperature or a linear T gradient.

• Bryan

Jim D
No H2O in mixture for simplicity
the main method of heat transfer here would be radiative for most situations.
This would be largely constant
However diffusive heat transfer (effectively collisions) best described by conduction would also be there.
Non IR active gases could only scatter any radiation intercepted.
IR gases could heat up the non IR gases thus assisting the diffusive flow
It seems that with no CO2 the diffusive heat transfer would be very small and slow.
It seems that with CO2 the diffusive heat transfer would be larger and faster.
The two processes diffusion and radiation seem then to work against each other and a balance point is reached
There must be tables made up predicting the overall flow given the gas mixture.
A bit like calling the process thermal conductivity figure but that would be the wrong term
The radiative properties of the solid surfaces and the temperatures of the surfaces would also have to be factored in
If the radiative surfaces had small emissivity its possible that the diffusive flow might be greater than the radiative.In this case adding CO2might cool the increase the overal heat flow

• Bryan

Last sentence should be
.In this case adding CO2 might increase the overall heat flow

• The surface has to warm before the troposphere can because the tropospheric temperature is tied to the surface by convective-radiative equilibrium that constrains the lapse rate.

It takes only microseconds for heated CO2 to collide with nearby molecules and warm them. Heating takes place throughout the atmosphere, somewhat more at the bottom. Furthermore global warming is around a nanokelvin per second which will have no appreciable impact on anything to do with lapse rate at this time scale.

If you’re referring to the tendency of increased environmental lapse rate to decrease to the adiabatic lapse, the requisite convection takes on the order of hours to days, not seconds, even for large changes. For changes as small as those of global warming it will take so long as to be lost in the noise of other thermal fluctuations.

• I agree that “it takes only microseconds for heated CO2 to collide with nearby molecules and warm them” but that is non-responsive to the fact that “the SURFACE has to warm BEFORE the troposphere can.” That fact invalidates your entire objection to DLR not DIRECTLY warming the surface, which is not part of the GHE model, thus it is a straw man argument on your part to claim that to be a flaw in that model.

It is in fact not any part of that model.

• I agree that “it takes only microseconds for heated CO2 to collide with nearby molecules and warm them” but that is non-responsive to the fact that “the SURFACE has to warm BEFORE the troposphere can.”

Sorry, I’m not following this reasoning. The surface is warm to begin with, quite enough to emit photons that the CO2 can then capture. Are you claiming otherwise?

• Vaughan,

As Jim D and several others have pointed out, the immediate consequence of an sudden addition of CO2 to the atmosphere is to strengthen the radiation from the atmosphere down to the surface. The surface starts to warm, and the atmosphere first to cool. The warming of the surface will then influence the atmosphere leading to a new balance, where both are warmer. The same order of influence applies also to infinitesimal increases of CO2 to the atmosphere.

The Earth system, which includes both the surface and the atmosphere starts to gain heat immediately as the IR flux to the space decreases. This happens for two reasons
– radiation from the surface and the lowest atmosphere escapes less to the space and is more often absorbed by the atmosphere
– the very highest level of troposphere and the tropopause absorb more of the radiation from slightly below and move the average origin of the radiation up tor the wavelengths of the strongest absorptivity/emissivity.

The immediate change at the top of troposphere is what is called radiative forcing.

• Pekka – The word “cool” or “cooling” is sometimes used to mean different things. In the sense that I would like to use these terms in this discussion, when CO2 increases, less radiation escapes to space and more is directed downward. This includes IR upwelling from the surface, some of whose energy is now directed downward. As you state, this increase in energy release into the surface in response to impeded release to space can be thought of as “cooling” but the net effect can be expected to increase atmospheric temperature, because photon absorption, thermalization, and subsequent energy emission is a temperature-raising process. The increase in these events within the atmosphere is thus a warming effect.

The above requires increase in emissions to have been the result of increase in absorptions. While this is probably true in the troposphere, the opposite is the case in the stratosphere. Here, added CO2 responds to ambient temperature by increasing emission rates, but because the temperature is the result mainly of UV absorption by ozone, absorption has not increased significantly, and the result is a reduction in temperature. I’m unaware of any scenario whereby the same thing could happen in the troposphere, although it seems conceivable that to some extent, water vapor could temporarily duplicate the role of ozone. All in all, though, a warming troposphere would seem to be the first response to an OLR reduction from increased CO2. The surface responds much more slowly because of its higher heat capacity, and so the warming of the atmosphere via a warmed surface is probably a lagging rather than leading event in the changing dynamics.

In response earlier to Alex and Jim D, I stated that I remain open-minded to an alternative scenario, but so far, no mechanism that would result in a temperature reduction has been described. Increased DLR is not a mechanism when it is simply a response to reduced OLR. The response of the atmosphere to an initial OLR reduction will be to increase both DLR and OLR until the latter returns to its earlier values sufficient to balance absorbed solar radiation. That increase in DLR and OLR is a manifestation of a higher temperature.

• Jim D

My next comment after the one you responded to was that adding CO2 actually cools the atmosphere at first. This is supported in parallel discussions with Alex Harvey and Chris Colose (though we haven’t quite convinced Fred yet). It is counterintuitive. The explanation is that adding CO2 enables the atmosphere to radiate and absorb more efficiently. These opposing effects cause it to warm more by absorbing surface photons better and emitting less to space, but also to cool more by emitting to the surface. The latter turns out to be more important, although the effects are within 10% of each other.
The other way to understand it, and the way I came to it, is that IR in general is a cooling influence in the atmosphere (as it is at the ground), and enhancing it by adding CO2 enhances this cooling effect.

• Jim – Chris can speak for himself, but I interpret him as saying that added CO2 increases atmospheric temperature even though with more CO2, there are more IR emissions from within the atmosphere. I haven’t yet seen any mechanism to contradict this when analyzed at the level of each atmospheric layer, but perhaps an alternative will be forthcoming.

• Jim D

Fred, as I posted elsewhere here replying to Alex, more experiments with Modtran have forced me to modify my view slightly. In a tropical atmosphere, instantly doubling CO2 would lead to a net warming effect, while in the US sounding (more like a global average) it results in net cooling. The sign of the immediate change being variable reinforces to me that the driver for further changes is the increased DLR, with the immediate atmospheric temperature change not being part of the explanation, so the rest of the argument holds up.

• My next comment after the one you responded to was that adding CO2 actually cools the atmosphere at first. This is supported in parallel discussions with Alex Harvey and Chris Colose (though we haven’t quite convinced Fred yet). It is counterintuitive. The explanation is that adding CO2 enables the atmosphere to radiate and absorb more efficiently. These opposing effects cause it to warm more by absorbing surface photons better and emitting less to space, but also to cool more by emitting to the surface. The latter turns out to be more important, although the effects are within 10% of each other.

Jim, that’s a lovely observation. I can see that it’s true by the following argument. What’s different about the incoming CO2 from the established CO2 is that the former hasn’t yet got into the routine of absorbing and emitting photons, so it’s “bank account” so to speak of vibrational energy is initially empty. It establishes itself by building up to an ongoing nonzero account, which cools the atmosphere.

Is that your argument or do you have a different one? If the former, how long would you say it take for a freshman CO2 molecule to establish itself? If the latter, does your argument estimate more or less cooling than mine?

A more important question for your point might be, if CO2 molecules come from combustion, wouldn’t they enter the atmosphere with more vibrational energy than the established ones rather than less?

• The molecules have more vibrational energy, when the gas is hotter as the flue gases usually are. That’s part of the specific heat of CO2.

• “If so then we may conclude that almost all the warming of the atmosphere is conveyed to the surface by convection and conduction, and that DLR plays no significant role in global warming. In order for it to go the other way the air skin on the ground would have to be centimeters thick…Put simply, a warmer atmosphere warms the ground by direct contact, with essentially no assistance from DLR.”

Vaughan – That is probably incorrect. Rather, DLR is the predominant mechanism whereby atmospheric warming is conveyed to the surface. At the surface, in the absence of conduction, a discontinuity exists because the air is radiating both up and down while the surface radiates only upward. Thus, if the surface radiates 2W upward in a steady state, the overlying air would have to absorb and radiate 2 W, but since it does this isotropically, its radiation per meter squared is halved and therefore its temperature must be lower by (1/2)^4 via Stefan-Boltzmann. What conduction does is eliminate the discontinuity so as to raise the air temperature at the surface – i.e., the ground heats the air by conduction. This is a change in a direction opposite that of transfer from air to ground and would counteract any air to ground heat transfer.

The KT energy budget and confirming observations of DLR indicate the very large amount of energy absorbed by the land and ocean from the atmosphere. Conduction appears to play a minor role in the opposite direction – heat loss.

• Of course, the air is also absorbing IR from above, and in that sense my explanation oversimplifies, but the discontinuity is a valid principle, as is its resolution by ground to air conduction.

• Also, I meant the 4th root of 1/2, not the fourth power.

• Fred, I believe you’re analyzing the steady state, where it’s clear that a lot of DLR is reaching the ground. The point is that it’s not raising the temperature of the ground in the steady state, it’s just holding it at its present temperature (averaged over say a year, to the extent that makes sense). Hence your analysis is fine, but says nothing about rate of warming. You need to take the derivative of what your looking at with respect to time.

When CO2 increases, both DLR and temperature increase. All this happens extremely slowly, that is, both dF/dt and dT/dt are tiny. The increasing temperature of the surface, dT/dt for the surface, is driven both by dT/dt for the bottom of the atmosphere and dF/dt for DLR. When these last two are both zero the surface eventually equilibrates and their is no further warming of the surface. When one or both is positive the surface warms accordingly. We want to know what dT/dt for the surface is, and we infer it from dT/dt for the bottom of the atmosphere, which we convert using the thermal conductivity of air to conductive dF/dt, and we have radiative dF/dt with no need of such conversion.

Having reduced the rate-of-increase contributions of thermal conduction and radiation to common units of dF/dt in nanowatts/m2/sec, we can compare them directly. My observation was that radiative dF/dt is around 5 in those units while conductive dF/dt might be 250 for a 0.1 mm skin. DLR would then be responsible for about 2% of the rate of warming because conduction would be basically a short circuit by comparison.

• Vaughan – It seems to me that you continue to make the same mistake, because you still haven’t come to terms with the fact that conduction at the air/surface interface is from surface to air rather than the reverse. This is due to the discontinuity that would create a substantial temperature drop from surface to air based only on radiative transfer.

When GHGs increase, the increase in DLR will be the predominant mechanism whereby thermal energy is transmitted to the surface. The energy balance shows that conduction plays a much smaller role, but more importantly, in the opposite direction. Increase in air temperature will of course tend to reduce the conductive flow of energy outward from the surface, but the increased DLR will tend to increase the temperature discontinuity and enhance outward conduction. Because of the small overall role of conduction, these changes in the conductive balance outward will be overwhelmed by the increase in absorbed thermal energy from the increased DLR. Some details are given in “Principles of Planetary Climate” on page 392 quantifying the increase in surface/air temperature differences as a function of back radiation.

For all these reasons, your interpretation of the role of conduction vs DLR appears to be untenable, even though it would make sense if the temperature discontinuity did not exist. Your interpretation would also predict that as atmospheric and surface temperatures rise, the conductive heat loss from the surface would decline in absolute (W/m^2) terms rather than rise. I expect that data on this will show the opposite (more conductive heat loss with rising temperatures), but if you have a data source demonstrating reduced conduction, you should cite it.

• It also occurs to me that you may be assuming that the DLR increase is exclusively a function of an increase in temperature at the bottom of the atmosphere. However, the increased DLR will come from changes at all levels of the atmosphere, and thus can increase significantly with only minimal temperature change at the bottom. To quantify this would require modeling involving the radiative transfer equations at relevant wavelengths, and is not something that could be done as a back of the envelope exercise. I don’t know the outcome, but it might turn out that the “mean conductive distance” is measured in meters rather than fractions of a millimeter.

• It seems to me that you continue to make the same mistake, because you still haven’t come to terms with the fact that conduction at the air/surface interface is from surface to air rather than the reverse.

Fred, you’re still not making the distinction between F and dF/dt. Yes there is a significant net upward flux from the surface to the air, but in my analysis this is constant and therefore contributes nothing to dF/dt at that interface. We’re talking about global warming and you’re describing a situation that has been the case for billions of years with no human intervention.

• I don’t think this makes much sense. Increasing DLR will increase the conductive flux outward for the reasons I’ve outlined. Increasing air temperature may operate in the other direction, but the balance change will be small and probably net outward.

As I mentioned in my above comment, the DLR will come from multiple altitudes, and its increase will exceed – perhaps greatly – the increase due to temperature change of air at the surface. The conduction effect will reflect only the latter, while the DLR effect will represent the entire atmosphere.

• One further point before we beat this horse to death. Consider the process of response to a radiative imbalance as though it occurred in steps instead of through concurrent mechanisms. Let’s say CO2 increases to the point of a 2 W/m^2 TOA imbalance. At this point, some IR that would ordinarily escape is redirected downward at all atmospheric levels and is absorbed at the surface as an increase in DLR. In our hypothetical stepwise scenario, this has occurred with no change in atmospheric temperature at all, simply because of the redirected energy. Step two consists of atmospheric warming from the increased IR retention.

In the real world, these events are concurrent, but the point is that DLR changes are not due entirely to changes in atmospheric temperature, and can be significant with relatively small temperature changes during the initial stages of an imbalance.

• Writing in prose won’t solve this. Without formulas and associated values there is no precision in your comments. Back up what you say with values for each of F, T, dF/dt, and dT/dt for each of DLR and conduction, specifying where, and we can then compare values for these to see where we disagree.

• I have only briefly followed the exchange between Fred, Vaughn, and Arthur, so I apologize if I repeat already mentioned things, but to highlight a few points.

— The enhanced greenhouse effect is not directly dependent on the atmosphere becoming a better emitter of DLR to the surface when you add CO2. Think of a scenario where we thicken high cirrus and cirrostratus clouds to an atmosphere optically thick in the boundary layer, or migrate them to a lower pressure so that they are colder. In this case, the cloud is, if anything, emitting weaker DLR and it is unlikely that the DLR will actually make it to the surface, under the assumption that our lower atmosphere is opaque. But such a cloud will invariably increase the greenhouse effect, reducing the OLR and forcing the atmospheric (and surface) temperature to rise.

— The DLR will increase eventually, primarily because T increases (or because it is now holding more water vapor). The tropics fall close to the scenario played out above, since the lower atmosphere is moisture-heavy and IR opaque, and the corresponding surface forcing from direct increases in DLR by making the atmosphere a better emitter is far less than in the higher latitudes (see e.g., Lu and Cai, 2009,Quantifying contributions to polar warming amplification in an idealized coupled general circulation model, Climate Dynamics, particularly Fig. 2).

— Increasing CO2 will eventually cause all the surface fluxes to change, not just the radiative ones. As explicitly pointed out in Miller, 2011 in press (http://pubs.giss.nasa.gov/abs/mi09610i.html) the result is for the TOA forcing to control the surface temperature change and the exchange of the surface fluxes to regulate the ground-lower atmosphere temperature difference.

• “Without formulas and associated values there is no precision in your comments.”

There is a good mathematical treatment starting on page 391 of Pierrehumbert’s “Principles of Planetary Climate”. What is surprising in that analysis is the magnitude of the temperature discontinuity between surface and the air in contact with it based on radiative transfer alone. In an atmosphere with significant IR opacity, such as ours, it can exceed 30 deg C. However, in reality, the difference is much smaller, because the difference generated by increased back radiation is countered by significant increases in outward conduction followed by convective and other turbulent temperature changes to eliminate the discontinuity.

• Chris, you’re absolutely right that all the surface fluxes changes. Hence you can hold any or all of them responsible, which is my primary point. Comparisons between them showing one dominates another must be done rigorously, but that’s a secondary issue.

Miller knows his stuff. The only issue I’ve ever had with him is details about resonances in Milankovitch cycles, the logic of which is tricky to get right. Outside of paleoclimate I am 100% aligned with him. (And not just as a way of getting invited to Tea Parties.)

Fred, do you feel your quotes from RPH support or weaken my account? Seems to me they support it. The bit about turbulence at the surface is what I had in mind when I said earlier that I was getting out of my depth in estimating the skin, which turbulence should decrease dramatically compared to a smooth breeze. The idea that turbulence will naturally occur as a result of the strong diurnal fluxes creating large temperature discontinuities at the surface does not surprise me.

• Vaughan – I believe the RPH treatment renders your interpretation untenable, but if you get a chance to read it, you can make your own judgments on this. The effect of DLR would be to magnify the disparity between surface and air temperature, and create a conductive gradient that is increasingly in the outward direction.

I have to leave the discussion at this point – reluctantly. It has been interesting, and readers should not mistake disagreement here for disagreement about either the GHE or the magnitude of absorbed DLR. It is only about the exact energy transfer mechanism.

• The effect of DLR would be to magnify the disparity between surface and air temperature, and create a conductive gradient that is increasingly in the outward direction.

But it’s not the DLR that matters for that purpose, it’s the net radiative flux, which is 390-324 = 66 W/m2 of cooling. This is offset during the day by 168 W/m2 of directly insolation. If the difference 168 – 66 = 98 were constant the surface and air temperature would drift into equilibrium. It is the switching on and off of the insolation at dawn and dusk that creates the disparity and the resulting turbulence on an ongoing basis.

• Oops, ignore what I said about R. Miller, whom I don’t believe I know. I somehow mixed him up with Richard Muller. Sounds like I agree with both of them. :)

• Vaughan – Insolation is critical, as you suggest, in determining the radiative gap between surface and overlying air. The important point as I see it, is that as GHG concentrations rise, DLR increases and this increased energy is absorbed by the surface as the predominant contributor to the increased heat content and temperature of the ocean and land. Net conductive flux is strongly upward, and so a conductive change serves to reduce heat loss that would otherwise result from the rising temperature, thereby permitting the temperature to reach a higher level. It is not so much the source of the temperature increase as it is a preserver of that increase. DLR is the main source, and as I suggested earlier, a CO2 increase can mediate significant DLR increase even if atmospheric temperature can be kept constant, although increased temperature also contributes to increased DLR.

It’s probably artificial to consider these phenomena as separate entities, because they work together for a final result. If DLR did not exist, a radiative imbalance would be restored to equilibrium by other means, but in our current climate, it is a predominant mechanism.

Interestingly, elsewhere in this thread, Alex Harvey and Jim D have suggested a concept somewhat antithetical to yours. They suggest that CO2 increases will cause atmospheric temperature to decline rather than rise except for the ability of DLR to warm the land and ocean, which in turn warm the atmosphere. I probably don’t agree with the temperature reduction aspect of their argument, but I do think they are correct in stating that DLR can cause a warming effect partially independent of atmospheric warming. This is simply because more CO2 molecules will result in more upwelling photon energy being redirected downward, even at a fixed temperature.

• At this point, you must start to plug in numbers to your equations and compare them to observations.

Yes there is a significant net upward flux from the surface to the air, but *in my analysis* this is constant and therefore contributes nothing to dF/dt at that interface.

To me, those words mean that your analysis differs from physical reality, aka is unphysical, and so your argument is forfeit.

We’re talking about global warming and you’re describing a situation that has been the case for billions of years with no human intervention.

No, the laws of physics are the same. One of the quantities is changing, thus, you need to start plugging in numbers and compare them to real observations. Pointing your IR gadget in two directions does not substantiate all these assumptions you’re making.

• Yes, and even the constancy argument (which I believe is false) doesn’t work. If an increase in downward conduction were to account for a surface temperature increase, then the net flux must change. That should be true whether it is upward or downward to start with. One can’t have inward conductive W/m^2 increasing at a particular rate and outward W/m^2 increasing at the same rate, and still make this the cause of a changing temperature, particularly in a system which dissipates most of a temperature increase via increased radiation. The change in net conductive flux might be small, but it can’t be zero. In reality, I expect it’s in the wrong direction to support Vaughan’s argument – that’s because an increase in DLR will increase the gap between surface temperature and the lower temperature of the overlying air.

• One of the quantities is changing, thus, you need to start plugging in numbers and compare them to real observations

Suppose that quantity is Q. If what matters is that Q is changing then the relevant value is not Q but dQ/dt. You need dQ/dt in order to know whether the fact that Q is changing is relevant: the larger dQ/dt is, the more relevant is the fact of changing.

Pointing your IR gadget in two directions does not substantiate all these assumptions you’re making.

Correct. That’s because it only measures F, not dF/dt. My point is that F is relevant only to global warmth. For global warming you need dF/dt for which I have no (immediate) instrument.

• You have just admitted that you are using the wrong tool for the job.

Pointing your IR gadget in two directions does not substantiate all these assumptions you’re making.

Correct. That’s because it only measures F, not dF/dt. My point is that F is relevant only to global warmth. For global warming you need dF/dt for which I have no (immediate) instrument.

In layman’s terms, for the linchpin of your argument, you got nothing.

• You’re overlooking that my thermometer was for the benefit of those who doubt the existence of DLR. Where did I imply it had anything to do with my argument, which deals with dF/dt, not with the F that the thermometer measures?

• I’m ignoring no such thing.

You’re overlooking that my thermometer was for the benefit of those who doubt the existence of DLR. Where did I imply it had anything to do with my argument, which deals with dF/dt, not with the F that the thermometer measures?

Granted, you never did imply that was where you were pulling your unsubstantiated assumptions about dF/dt out of. Nor did I imply that you had any basis for your assumptions about dF/dt. What I noted was what you said first. You have no basis whatsoever for your assumptions about dF/dt.

My point is that F is relevant only to global warmth. For global warming you need dF/dt for which I have no (immediate) instrument.

2x
In layman’s terms, for the linchpin of your argument, you got nothing.

• This is an excellent comment and clearly shows Dr. Pratt has quite a deep understanding of the science (more than most who seem to have responded to this article assumed – miscommunication goes many ways around here). Nevertheless, while qualitatively appealing, the discussion is not entirely correct.

That is – there is no way to quantitatively calculate the effect of a change in atmospheric composition (such as doubling CO2), at least for the problem on Earth, without accounting for the changes in DLR explicitly through a radiative transfer calculation. Thinking of it in terms of slowing down escaping photons is treating the problem in essentially a continuum manner, similar to a diffusion problem. That’s fine if radiation is absorbed quickly, in the center of the absorption bands, the problem is then essentially diffusive, and the radiative transfer problem is somewhat like a standard heat conduction problem. And in the “window” regions, where there’s essentially no absorption, you have simply a constant fraction of emission that escapes directly to space, a short-circuit between the surface and the 2K vacuum so again the result is simple. But in the “wings” of the absorption bands, where a given wavelength of radiation might be absorbed just once on the way out, you have to treat the radiative energy exchange as a discrete process linking surface temperature to temperatures all through the atmosphere. There’s no simple analogy I can think of between this radiative transfer situation in the wings of an absorption line and any normal heat transfer problem – it is fundamentally a matter of direct exchange of quantum particles over a very long distance and across large temperature differences, something you rarely see. The math for this is just different from standard heat transfer.

And then – the process of warming itself is a little different from what you describe. If you instantaneously double CO2 in the atmosphere while keeping all else fixed to start, the radiative transfers change in such a way that the largest flux gain is at the surface, with gradually reduced net energy flux changes as you go up through the atmosphere until the net flux change becomes one of *cooling* once you reach the stratosphere (and stratospheric cooling has been observed). This is because, at the start, the surface has not warmed yet, so there is no upward increase in radiation to compensate for the increased DLR. The detailed warming process after an instantaneous doubling would be quite complex, and doesn’t match the simple picture you draw here. Convection would certainly be involved in redistributing the heat – but I don’t think any atmospheric scientist would deny that!

• Thanks very much for your thoughtful and insightful comments, Arthur. Let me respond to what I’m hoping will be the easiest to answer. I’ll assume until you say otherwise that your concern is with the second half of my comment at
http://judithcurry.com/2011/08/13/slaying-the-greenhouse-dragon-part-iv/#comment-98462
and that you’re ok with the reasoning up to and including the proposition that warming the atmosphere then also warms the surface, and that the joint warming of everything then raises total radiation until balance is restored. (Or at least Earth warms fast enough to prevent any imbalance from growing indefinitely; there may be some persistent lag as CO2 and temperature continue to rise.) Let me know if not.

If that much is OK then the question becomes, is DLR the main way of converting atmospheric dT/dt to surface dT/dt?

If you instantaneously double CO2 in the atmosphere while keeping all else fixed to start, the radiative transfers change in such a way that the largest flux gain is at the surface, with gradually reduced net energy flux changes as you go up through the atmosphere until the net flux change becomes one of *cooling* once you reach the stratosphere (and stratospheric cooling has been observed).

Quite right, and what I wrote neglected this. However wouldn’t taking it into account increase the ratio of dT/dt to radiative dF/dt at the surface, by virtue of increasing dT/dt there relative to higher up? Conductive dF/dt through the skin is linear in temperature (Fourier’s law of thermal conduction) whence higher dT/dt at the surface implies higher conductive dF/dt there. If conductive dF/dt through the skin is already much greater than radiative dF/dt at the surface with my overly simplistic model, wouldn’t that be even more so in the more accurate model you’re pointing out?

Putting my argument in its simplest terms (so as to make it easier to debug), if the atmosphere is gradually warming then in the absence of DLR this warmth will still eventually reach the surface via convection and conduction. Conversely if conduction doesn’t occur but DLR does, the DLR will warm the surface.

But if both are in effect, which warms it more? Naively DLR would because it “gets there first.” But if the rate of warming is what matters, and if dF/dt is a steady nanowatts/m2/sec over decades, then the bottom of the atmosphere is warming at some equally steady dT/dt in parallel with DLR increasing at dF/dt. By Fourier’s law of thermal conduction we convert dT/dt to conductive dF/dt and then make a direct comparison of conductive and radiative dF/dt to see which is contributing more to the rate of increase of the surface temperature.

Right now it’s late at night and my logic engine is suggesting I sleep on it. Maybe this line of reasoning won’t seem so sensible in the morning, we’ll see.

I do agree with your point (if I understood it) that DLR must be analyzed to get a reasonable distribution of fluxes within the atmosphere as a function of (at least) altitude. But is a distribution really needed if one just wants to show that more CO2 means fewer photons escaping to space and hence a warmer planet. What is the simplest yet rigorous way of demonstrating this?

• That is far and away the most sophisticated, most technically literate climate science denial sophistry that I have ever seen!

But it is still just sophistry, sir.

It is completely irrelevant what proportion of this extra warmth from the atmosphere reaches the ground via DLR as opposed to via convection and conduction. The math is independent of that proportion…
If so then we may conclude that almost all the warming of the atmosphere is conveyed to the surface by convection and conduction, and that DLR plays no significant role in global warming.

False. You may conclude from your calculations that DLR does not directly warm the surface. You have convincingly argued that the atmosphere’s thermal contact with the ground by conduction and convection are the dominant factors in warming the surface, but you have already conceded that the atmosphere is warmer due to DLR than it would be without DLR, and that means that it is warmer with more carbon dioxide than it would be with a lower concentration of carbon dioxide. So, by your own admission, the conduction and convection that warms the surface has more warmth to transfer to the surface as a direct result of carbon dioxide, and therefore DLR from carbon dioxide plays a pivotal role in global warming.

Put simply, a warmer atmosphere warms the ground by direct contact, with essentially no assistance from which is warmer exactly because of DLR.

• hunter

So now the surface of the Earth, not the air, is over heating due to CO2?
Are we going to see magma puddling, or merely spontaneous combustion of forests and neighborhoods? What about the oceans? How will they react to this run away CO2 heating?

• So now the surface of the Earth, not the air, is over heating due to CO2?

Hunter, get with the program. Or are you working with the same definition of “now” as Don Easterbrook? In his demonstration that medieval warming was warmer than now, Easterbrook tacitly defined “now” to be about a decade after 1896, the date of Svante Arrhenius’s paper “On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground”. Global warming has been about the surface (land and sea) ever since that date. Given how much of the absorbed heat has been going into the ocean, it has to be for any energy budget of the planet that isn’t a travesty (technical term).

• So, by your own admission, the conduction and convection that warms the surface has more warmth to transfer to the surface as a direct result of carbon dioxide, and therefore DLR from carbon dioxide plays a pivotal role in global warming.

Are you ok with formally defining “warmth” as temperature T, and more warmth, or just “warming”, as dT/dt, rate of change of T? Without formal definitions of these informal terms it is hard to reason reliably about the underlying physics.

I don’t agree with your “therefore.” More CO2 captures more photons, thereby gaining vibrational energy and raising the temperature of the atmosphere by transferring that energy to other air molecules principally by collision. The warmer atmosphere then warms the surface by rising conduction resulting from rising air temperature as well as by rising DLR. Even though T and DLR may both be substantial, if dT/dt = dF/dt = 0 in the atmosphere then dT/dt = 0 for the surface as well. There can be no warming of the surface without warming of the atmosphere, using the above formal definitions of these informal concepts.

Global warming is not the same thing as global warmth. This distinction is constantly blurred in this and other blogs, thereby causing endless confusion.

My main claim is that it doesn’t matter how the labor of warming the surface is divided between conduction and radiative dF/dT. My less relevant (but possibly interesting) claim is that al scientifically rigorous estimates of that proportion to date show that much more of that labor is performed by conduction than by rising DLR. Perversely perhaps, I love to be proved wrong, and would therefore be very happy to see a rigorous derivation of the opposite conclusion!

the most sophisticated, most technically literate climate science denial sophistry that I have ever seen!

Thank you, but you’re too kind. I’m not denying global warming is taking place, nor that DLR is real and substantial. I’m merely denying the logical necessity of rising DLR, positive dF/dt, in accounting for rising surface temperature, positive dT/dt. Global warming understood as surface warming can be just as well or better explained in terms of rising air temperature at the surface. This denial of the logical necessity of rising DLR has no impact on either the fact of global warming or its extent, it merely fixes what I feel is flawed logic in the proof of global warming.

Unsound proofs of true propositions are common but unjustifiable. They are commonly justified on account of the truth of the proposition, but that reasoning is circular.

• Absolutely.

Are you ok with formally defining “warmth” as temperature T, and more warmth, or just “warming”, as dT/dt, rate of change of T?

We’re also agreed on how CO2 and other greenhouse gases trap IR emitted FROM THE SURFACE. I think that bit in all capitals is what you’re neglecting in your entire analysis, as well as how the surface actually gets to be warm in the first place.

More CO2 captures more (IR) photons, thereby gaining vibrational energy and raising the temperature of the atmosphere by transferring that energy to other air molecules principally by collision.

The warmer atmosphere then warms the surface by rising conduction resulting from rising air temperature as well as by rising DLR. Even though T and DLR may both be substantial, if dT/dt = dF/dt = 0 in the atmosphere then dT/dt = 0 for the surface as well.

Citation needed. What directly warms the surface? Says who?

• We’re also agreed on how CO2 and other greenhouse gases trap IR emitted FROM THE SURFACE. I think that bit in all capitals is what you’re neglecting in your entire analysis, as well as how the surface actually gets to be warm in the first place.

The surface got warm before there were humans. This discussion concerns global warming, which can start from the premise that the surface is at around 280 K or whatever it was in preindustrial times. The surface has been emitting IR for billions of years.

Citation needed. What directly warms the surface? Says who?

Let me get this straight. You’re asking for a citation proving that blowing air over the cooling fins of a CPU will cool it? Reminds me of the Wikipedia editor who asked for a citation for the claim that the human hand has five fingers.

Or did you think that the heat in the fins was being radiated into the air and then rapidly carried away?

• I think the rising threw him off. The warmer atmosphere then warms the Earth through increased conduction due to the increased air temperature as well as increased down welling radiation. That may be clearer.

• Yes, much clearer. Thank you for putting it so simply.

• Let me get this straight. (straw man argument)

You can’t understand the point of the question, unless I emphasize the last two words? Fine.

Says who?

What directly warms the surface? Says who?

What I contest is not whether conduction & convection occur. What I contest is whether anybody ever said otherwise.

You have argued that IR is not directly absorbed at the surface, and you have argued that well enough.

I am asking you, who ever said that IR is directly absorbed at the surface?

http://content.imamu.edu.sa/Scholars/it/net/trenbert.pdf

Fasullo & Trenberth don’t say that it is. Granted, page 4 says “Absorbed by Surface” and back radiation is clearly referenced in the text. But nowhere do they actually claim that at the air/surface boundary where you are obsessing, conduction & convection are not the primary modes of heat transport, do they? Does anybody? If not, you are just making a straw man argument. Is this entire argument of yours intended as rebuttal to the shorthand that fits on a diagram?

Obviously, we are not walking around on greenhouse gases. If I thought it was important to know whether back radiation is directly absorbed by solids and liquids on Earth’s surface or whether that heat transfer must be occurring via conduction and convection, I would go look up the line spectra of the relevant substances, starting with silica & liquid water. But if you want to claim that the warming must occur by conduction & convection, not by back radiation, and therefore to claim that such disproves anybody else, you must first cite who has said that back radiation directly warms the surface.

I posit that it is not specifically mentioned because it is not considered interesting to those balancing the global mean energy budget, because as you admitted from the outset, it is irrelevant to the correctness of the climate science consensus. Whether IR radiation or conduction & convection (of heat trapped by CO2, then transferred by collision to O2 & N2) directly warm the surface is not addressed in the literature to my knowledge. It is omitted, and omission is not error, particularly when, as you’ve already admitted, it is irrelevant which is the case.

So the whole case you’re making is based on your own incorrect inference, that somebody ever asserted that the surface directly absorbs IR. Or, it’s the incorrect inference of the climate science deniers on whose behalf you’re arguing. It becomes difficult, when debating the Devil’s Advocate, to know whether your errors are your own, or on behalf of your client.

• But nowhere do they actually claim that at the air/surface boundary where you are obsessing, conduction & convection are not the primary modes of heat transport, do they? Does anybody?

Well, I don’t know whether you consider the IPCC “anybody”, but they say pretty clearly in Chapter 1 of AR4:

“To balance the absorbed incoming [solar] energy, the Earth must, on average, radiate the same amount of energy back to space. Because the Earth is much colder than the Sun, it radiates at much longer wavelengths, primarily in the infrared part of the spectrum (see Figure 1). Much of this thermal radiation emitted by the land and ocean is absorbed by the atmosphere, including clouds, and reradiated back to Earth. This is called the greenhouse effect.”

I think a lot of people have taken that last “This” to include the last step, in which the absorbed thermal radiation is reradiated back to Earth. Absent mention of any other transport mechanism, the IPCC seems to be claiming that the Earth is warmed radiatively, namely by reradiation. Are you somehow reading this differently from me? And I suspect from a lot of other people?

• Vaughan Pratt

• No, that’s still just your inference. It’s not a crazy inference from that text, but it is still just an inference and I didn’t ask you for your inference, and I know I made that perfectly clear.

Fasullo & Trenberth don’t say that it is. Granted, page 4 says “Absorbed by Surface” and back radiation is clearly referenced in the text. But nowhere do they actually claim that at the air/surface boundary where you are obsessing, conduction & convection are not the primary modes of heat transport, do they? Does anybody? If not, you are just making a straw man argument. Is this entire argument of yours intended as rebuttal to the shorthand that fits on a diagram?

Obviously, we are not walking around on greenhouse gases. If I thought it was important to know whether back radiation is directly absorbed by solids and liquids on Earth’s surface or whether that heat transfer must be occurring via conduction and convection, I would go look up the line spectra of the relevant substances, starting with silica & liquid water. But if you want to claim that the warming must occur by conduction & convection, not by back radiation, and therefore to claim that such disproves anybody else, you must first cite who has said that back radiation directly warms the surface.

I posit that it is not specifically mentioned because it is not considered interesting to those balancing the global mean energy budget, because as you admitted from the outset, it is irrelevant to the correctness of the climate science consensus. Whether IR radiation or conduction & convection (of heat trapped by CO2, then transferred by collision to O2 & N2) directly warm the surface is not addressed in the literature to my knowledge. It is omitted, and omission is not error, particularly when, as you’ve already admitted, it is irrelevant which is the case.

So the whole case you’re making is based on your own incorrect inference, that somebody ever asserted that the surface directly absorbs IR. Or, it’s the incorrect inference of the climate science deniers on whose behalf you’re arguing. It becomes difficult, when debating the Devil’s Advocate, to know whether your errors are your own or your client’s.

Like all climate science deniers, the best you can do is disprove things nobody ever said. As I said, yours is the most impressive bit of such sophistry I have ever seen, but it is still just sophistry. It just takes a bit more work to identify your straw man.

What you have claimed to be untrue, is also never asserted. It may (or may not) be implied, but it is never said because, as you admit from the start, it is irrelevant. Whether back radiation warms the surface, or whether back radiation warms the air which warms the surface by conduction and convection, in either case back radiation warms the Earth. That is Settled Science.

• PS
re: “Thank you, but you’re too kind.”
Any time.

• Peter317

Vaughan Pratt

Clearly some of it is, but some of it is equally clearly conveyed around the planet by convection, eventually reaching the surface in the form of warmer air which then heats the ground by conduction via contact with the bottom millimeter or so of the atmosphere.

Two words: Thermal capacity. Look it up.

• Two words: Thermal capacity. Look it up

If you’re worried that it takes 5 exajoules to add a degree to the atmosphere, that’s very little in the grand scheme of things, as the global energy budget literature points out from time to time. It’s about equivalent to the top three meters of the ocean. Global warming is currently about 1.6 millidegrees a month adding 8 petajoules to the atmosphere. Please show with working that a mere 8 petajoules is so much that a month of global warming can’t add that to the atmosphere.

• stillcurious

Vaughan – wikipedia has US annual energy consumption at 105 exajoules in 2005.

Are you saying (with the correction below) that 1.6 millidegrees Centigrade warming of the atmoshpere would be expected for an 8 exajoule input based on atmospheric heat capacity? And that this is the average monthly global warming we are seeing?

If so, do you have any comment on the fact that the US average monthly energy consumption (2005) was 105/12= 8.75 exajoules?

Apologies if I have misunderstood – I haven’t followed the whole thread.

• If so, do you have any comment on the fact that the US average monthly energy consumption (2005) was 105/12= 8.75 exajoules?

CO2 as an agent of global warming is something like the catalytic converter in your car exhaust. The energy obtained from fuel in the process of burning it to produce CO2 has little relationship to the heat that CO2 prevents from leaving the Earth.

One can demonstrate this quantitatively, but a qualitative way of seeing it is that the energy obtained in return for emitting a given mass m of CO2 is in proportion to m, whereas the energy that mass is responsible for preventing from escaping from Earth is in proportion to mt where t is its residence time in the atmosphere. It would be remarkable if the residence time turned out to have any bearing on the energy derived from burning fuel to produce CO2.

The similarity of the two numbers you point out would seem to indicate that the forcing induced by a given amount of CO2 is roughly equal to the energy obtained in the course of burning the fuel that produced this CO2, multiplied by the residence time in months. If so that’s quite a convenient coincidence, thanks for noticing it!

• stillcurious

Thanks Vaughan but I’m still curious about the impact on atmospheric temperature of the 8.75exajoules per month liberated from fossil (and nuclear) power generation.

Had I correctly interpreted your numbers on atmoshperic heat capacity? If so, doesn’t this local heat addition equate to a monthly temperature rise of a similar magnitude to that which we are observing?

I’ve done a “ctrl-f” on the thread for “residence” and it only comes up in your comment above. If there are other comments which I should read please point them out. Thanks.

• Joel Shore

The numbers for the heat released are not hard to convert to W/m^2 and I seem to recall that, on a global basis, they come out to be about 0.02 W/m^2. This is to be compared to about 4 W/m^2 for doubling CO2 (and ~2 W/m^2 for increasing CO2 from the pre-industrial levels to the current levels). So, in other words, it is pretty insignificant. Of course, there is a lot of local variation and it may be true that on a local scale they can sometimes be more significant. (Surely, we do know, for example, that a power plant can have significant effects on the temperature of the stream that it uses for cooling.)

• stillcurious

Thanks Joel below – that number rings a bell from my sums on a global basis, but I’d still like to know what happens to the 8exajoules/month of heat US energy consumption adds at approx surface height level. If I’ve understood Vaughan correctly (no guarantee!) he seems to be saying this would be enough to generate an increase in air temp. equivalent to observation?

• Residence time didn’t come up before. You can read about it on the web, e.g. at

http://www.princeton.edu/~lam/TauL1b.pdf

which gives a range of 70-400 years as a plausible range of residence times.

Meanwhile I just realized that your monthly figure of 8.75 exajoules of energy consumption was for the US. Using a figure of 480 exajoules for annual global energy consumption, 8 exajoules is consumed worldwide every 6 days. Rounding that up to a week for simplicity, the ratio I referred to should have been expressed in weeks of residence time, not months.

However the discussion with Peter371 that you jumped into was for heat content of the atmosphere alone associated with a rise of 2 degrees/century. This is useless as a measure of total heat of the planet attributable to global warming since only a very small fraction of that heat ends up in the atmosphere.

In the 2009 paper Earth’s Global Energy Budget, Trenberth, Fasullo, and Kiehl estimate the top-of-atmosphere (TOA) energy imbalance at some 500 terawatts. What exactly happens to the difference is not clear, but less than a percent of it ends up warming the atmosphere, say around 2-3 terawatts. At that rate the above ratio should be in neither months nor weeks but hours of residence time!

By comparison the above figure of 480 exajoules per year represents 15 terawatts of world-wide power consumption. So if we take TOA imbalance as a measure of global warming, this shows that global energy consumption is a mere 3% of global warming, in case that addresses what you were asking. Hopefully that turns out to be a more reliable number than anything we might base on CO2 residence time.

But don’t trust my numbers, which for one thing haven’t been vetted by anyone and for another are almost sure to have calculation errors, unwarranted assumptions, misunderstandings of the literature, etc. etc. Google Trenberth on energy, he has a number of papers, some with Kiehl and/or Fasullo, that have a lot of numbers of the kind you’re like to be interested in and that are likely to be a lot more reliable than much of what you’ll read on this blog.

• stillcurious

Thanks again Vaughan, I’ll continue looking into it. Apologies for jumping in – your specific heat comment caught my eye.

• Vaughan Pratt, 8/14/11, 7:18 pm, Vaughan Pratt

The residence time of CO2 in the atmosphere is taught in 11th year public school physics as the leaky bucket problem. IPCC’s formula in its TAR and AR4 glossaries are correct, but, alas, used nowhere in those IPCC Reports. It’s 1.5 years if you include IPCC’s leaf water, but if you ignore leaf water as IPCC does, it’s 3.5 years.

• Joel Shore

Jeff – Wow, that time keeps getting shorter and shorter! You do know that there is a difference between the residence time of a single molecule of CO2 in the atmosphere and the decay of a perturbation in the atmosphere? Willis Eschenbach does. You’re really hard-core on denying the science, aren’t you?

• Joel Shore, 8/15/11, 4:01 pm, Vaughan Pratt IV

Residence time is not getting shorter. It’s staying the same.

We’ve had this argument on WUWT, where you ganged up with Eschenbach to write, as you like to call it, nonsense. (If I created a spam filter to block Joel Shore’s posts with the word “nonsense”, my email flux might be halved.) Why you didn’t bother to quote your own, joint blather is explained after the blather:

Jeff: Willis’s criticism is exactly right and what you are saying is confused and incorrect. The mean lifetime of a CO2 molecule in the atmosphere is short because of the large exchanges that occur between the atmosphere, the biosphere + soils, and the mixed layer of the ocean. However, the decay time for a pulse of CO2 such as by the burning of fossil fuels is governed by the much slower rate at which CO2 can be removed from these reservoirs into the deep ocean.  So, what happens when you add in some new CO2 from burning of fossil fuels is that it rapidly partitions itself between the atmosphere, biosphere + soils, and the mixed layer…and now all three of these reservoirs have an elevated level of CO2. And, the decay of this elevated level is very slow. Bold added, Joel Shore, WUWT, 6/12/10, 7:59 pm.

Residence time is defined, and precisely by an equation. None of this talk about slow uptake applies to the formula. The uptake by the ocean from the atmosphere is about 92 GtC/yr for all species of CO2. That is the rate of depletion of CO2 from the 760 or so GtC in the atmospheric reservoir; it is the number to use in the leaky bucket formula along with about 120 GtC/yr to terrestrial sinks, plus another 150 to 270 GtC/yr for leaf water unless you want to repeat IPCC’s erroneous omission. 760/(92 + 120) = 3.6 years; 760/(92 + 120 + 270) = 1.6 years. The notion that the uptake is slower as IPCC claims for ACO2 (about 2.2 GtC/yr) violates physics on at least five counts.

(1) No mechanism exists by which the ocean can distinguish between ACO2 and nCO2, which are different mixes of 12CO2:13CO2:14CO2, and no absorption coefficients can be assigned to create a bottleneck just for ACO2.

(2) The surface ocean is not only not in equilibrium to make the equilibrium chemical equations applicable, but it is never in such equilibrium, which is the bottleneck conjecture.

(3) Dissolution of CO2 in water is instantaneous on climate time scales.

(4) That Henry’s coefficients might depend on sea water pH is novel science, and even if true, far down in the noise of any measurements. No such measurement has ever been made. They depend on pressure, temperature, and salinity, two tied for first order effects, and the other a distant third.

(5) When IPCC climatologists tried to measure the bottleneck, called by the previously defunct name the Revelle Buffer, they measured ordinary, temperature dependent solubility according to Henry’s Law. IPCC removed that analysis and suppressed it so as not to confuse the reader.

Residence time is another bulk parameter. The lifetime of a single molecule has no meaning, and consequently is unmeasurable. That fiction does not appear in the formula. The decay time of a slug of CO2 above a solvent is the information that yields the average life time of a molecule.

We do recognize that you need ACO2 to accumulate in the atmosphere in order for the AGW model to even have a remote chance, so do continue to fantasize about the bottleneck.

• Joel Shore

Jeff: No system is ever in equilibrium. It is an ideality that is never actually obtained. Therefore, fundamentally, one can never define a temperature of anything. And, yet, we do so.

The fact is that the atmosphere, the mixed layer of the ocean, and the biosphere constitute a subsystem that exchanges CO2 very rapidly between each other but only slowly with the deep ocean. As a result of this separation of timescales, a new slug of CO2 introduced into the atmosphere will rapidly partition itself between the different reservoirs of the subsystem but then the decay of this perturbation from this subsystem is governed by the much slower rate. All these things about the ocean being unable to distinguish between anthropogenic CO2 and other CO2 are a red herring. The important distinction is between CO2 that is just sloshing around between the three different reservoirs vs CO2 that is released from another source.

There are nice analogies with fountains and so forth, but I am too tired dealing with all the sophistry in this thread to write that down in more detail.

• Henry’s law applies directly to the solubility of CO2 as dissolved CO2 molecules and non-dissociated H2CO3 molecules. Henry’s constant defined in that way depends only on temperature, not on the composition of the seawater.

When the water is not strongly enough acidic, H2CO3 dissociates to a major part to HCO3- and CO3- – ions and H+ ions. The ratio of H2CO3, HCO3- and CO3- – depends on pH and the dependence is strong, when pH is well above 7, i.e. the water is basic. With the pH of seawater around 8.1 the amount of HCO3- is roughly 100 times that of CO2 and H2CO3, for neutral water (pH = 7) the ratio is roughly 10. Thus the solubility including HCO3- and CO3- – is really strongly dependent on pH in this range and even more strongly for pH > 8. (The amount of CO3- – depends even more strongly on pH, but is relatively small still at pH = 8.1.) When CO2 is dissolved in pure water like in rain drops without extra acidification the pH = 5.5 – 6.0 is clearly on the acidic side. Under those conditions the share of HCO3- is small and CO3- – negligible.

The ratios are fixed for fixed pH. Thus Henry’s law remains valid for fixed pH. The Revell factor is 1.0 in that case. The larger values of the Revell factor are based on the fact that additional CO2 raises pH and lowers the ratio HCO3-/CO2. How much additional CO2 affects pH depends on the chemical composition of seawater. The largest values are obtained, when carbonates are the only buffering component and all other ions are of the type that remain as ions over a wide range of pH (e.g. Cl- and Na+). The Revell factor is lower, if there are other buffering components than carbonate and bicarbonate ions, but the share of other buffering components is not large in oceans. Therefore the Revell factor is rather large, of the order of 10, but varies from one part of the oceans to another.

• Well, that’s a change, for me to be preferring Jeff Glassman’s side over Joel Shore’s.

Joel, the “leaky bucket” argument as I understand it has nothing to do with individual molecules. If we’re adding 9 GtC a year to the atmosphere but only 55% of it stays there, then I would interpret the other 45% to be “leaking” into the land and ocean. The identities of the molecules is irrelevant.

You seem to be assuming that if we stop emitting, the leaking stops instantly. My understanding of how leaky buckets work is that if you’re adding water faster than it leaks, the bucket gradually fills up. But if you stop the filling the leaking doesn’t stop, though it slows down as the bucket empties.

In the case of the atmosphere, “empty” should correspond to the preindustrial level of CO2. Since the leaking is currently running at around 4 GtC a year, if we shut off CO2 then the atmosphere should drain starting at that rate and gradually slowing as it approaches the preindustrial level.

Since the carbon cycle is a lot more complex than a leaky bucket, some flows may well decrease faster than others. In particular if we’ve inadvertently encouraged weeds to gobble down CO2 faster than they used to, they may not see a need to stop doing so at the preindustrial level.

If you have a technical objection to the leaky bucket model (as distinct from the “everyone knows the residence time of CO2 is many decades” argument) I’d be very interested in understanding your objection.

• Joel Shore

Vaughan,

You probably want to read through the CO2 residence time thread and the various references (e.g., to David Archer’s work that have been brought up there). The short answer to why the “leaky bucket” picture is not correct: Let’s take first the mixed layer of the ocean. What happens when you add a slug of CO2 to the atmosphere is that the partial pressure of CO2 in the atmosphere increases. This upsets the equilibrium between the ocean and atmosphere and drives an increase in the CO2 in the ocean mixed layer until the equilibrium is restored. The timescale for this, however, is pretty fast (on the order of a months to a few years at most), so what you then have is an overall higher partial pressure both in the atmosphere and the ocean. [Eventually, the CO2 will get mixed down to the deep ocean but this is a quite slow process.]

For the case of the biosphere: What an additional slug of CO2 does is increase the amount of biomass that can be supported, so again some of the CO2 partitions into the biosphere but it doesn’t just keep increasing endlessly.

• Joel,

“For the case of the biosphere: What an additional slug of CO2 does is increase the amount of biomass that can be supported, so again some of the CO2 partitions into the biosphere but it doesn’t just keep increasing endlessly.”

It doesn’t need to keep increasing endlessly, just to the end of our carbon based fuel availability. Research shows that the nitrogen fixation that was thought to be a limit isn’t. Apparently the microbes and other little dickens increase nitrogen fixing with increased growth of many plants. Natural processes will reclaim huge areas of deserts under higher CO2 levels. If we can just keep pumping the CO2…

http://www.co2science.org/subject/n/summaries/nfixherbaceous.php
(10 different papers referenced)

• Joel Shore

kuhnkat,

Your should first be aware that CO2Science is hardly an unbiased look at the literature.

However, regardless of that, you are addressing a different question than I am talking about: You are addressing the question of whether or not sinks will eventually saturate as we continue to increase CO2 levels. That is, if you are right, what it means is that about half of the CO2 that we emit will continue to partition into the oceans and biosphere. If you are wrong, that fraction may go down in time.

But, even if you are right, that does not challenge my point, which is that what is occurring is such a partitioning and not a “leaky bucket” scenario as Vaughan has proposed.

• Joel,

did you at least look at the abstracts of the 10 papers they quoted in the article?? Yes, they are biased just like Pierre Humbert is biased about ice cores and CO2. We have to look at it all and make up our own minds.

Again, it does not need to increase endlessly unless you believe we will increase population endlessly (we seem to be tapering off), hydrocarbons are abiotic (unknown), and we will NOT find better sources of energy in the next 100 years (unlikely as thorium is already available).

• Joel,

“But, even if you are right, that does not challenge my point, which is that what is occurring is such a partitioning and not a “leaky bucket” scenario as Vaughan has proposed”

MY bucket has more than one hole in it.

• Joel Shore

kuhnkat: Ray Pierrehumbert is a very well-respected scientist in the field. Those who publish CO2 Science are not. Even if they didn’t spin those particular articles too badly, they may have omitted articles that don’t agree with their favored point-of-view. It puzzles me why the same people who would likely scream bloody murder if we linked to Greenpeace and Sierra Club for our scientific reviews are so comfortable with reviews carried out by people with very clear advocacy views on the other side.

However, the most important point is even if you are right and the sinks don’t saturate with increasing CO2 levels, that doesn’t address the issue that Vaughan and I are talking about…i.e., it is irrelevant. It is a different issue.

• Joel,

y’all are funny. You claim that CO2 site only presents one side of the argument. Uh, well, I probably shouldn’t bring it up, but, y’know, those IPCC reports y’all are so fond of don’t exactly play sceptic either!! They are the epitome of biased Science complete with their own Cult sections filled mostly with NON-PEER Reviewed papers from EnviroWhackjobs. I won’t bother going into the rest of the argument of gatekeeping and blog sites that restrict posters… I do believe the CO2 site actually references peer reviewed papers that are so important to you?? In fact, it is run by SCIENTISTS who actually have PUBLISHED ORIGINAL PEER REVIEWED PAPERS. That was even BEFORE they started their blog. Interesting that anyone who has a different take on the science becomes marginalized in so many ways by you believers.

But enough of the usual whining. You claim my point is not apropos to the argument. In that case, why did you make the point that the reservoir was not infinite if it wasn’t appropriate to your argument? Just an arm wave trying to get some traction?

• Bryan

kuhnkat

Of course Joel can give you an unbiased lead to a”well respected scientist”
Read what another well respected scientist thinks!
pielkeclimatesci.wordpress.com/…/a-response-to-ray-pierrehumbert’… – Cached

• Bryan,

I’ve read some of Ray Pierrehumbert, Jaworowski, Segalstad, and Velikovsky. Old Ray tends to disagree with the other three about the useability of ice core data so he is the odd man out!! 8>)

Did you mean to direct me to this:

“Ray is quite simply wrong — and the reviewers of our paper (Piers Forster and Isaac Held) agree with me. It matters a great deal whether radiative fluctuations are the result of feedback on surface temperature, versus the myriad other variables that control cloudiness. Piers Forster was honest enough to admit that their neglect of the internal variability term in Eq. 3 of “The Climate Sensitivity and its Components Diagnosed from Earth Radiation Budget Data” (Forster and Gregory, J. Climate, 2006) was incorrect, and that it indeed can not be neglected in feedback diagnosis efforts using observational data. He also stated that the climate modeling community needs to be made aware of this.”

http://pielkeclimatesci.wordpress.com/2008/05/22/a-response-to-ray-pierrehumbert%e2%80%99s-real-climate-post-of-may-21-2008-by-roy-spencer/

and

http://pielkeclimatesci.wordpress.com/2008/05/23/follow-up-to-the-response-to-ray-pierrehumberts-real-climate-post-by-roy-spencer/

• Joel Shore

I’ve read some of Ray Pierrehumbert, Jaworowski, Segalstad, and Velikovsky. Old Ray tends to disagree with the other three about the useability of ice core data so he is the odd man out!! 8>)

Yes, in a group consisting of 3 crackpots and one serious scientist, Ray is most assuredly the odd man out!

y’all are funny. You claim that CO2 site only presents one side of the argument. Uh, well, I probably shouldn’t bring it up, but, y’know, those IPCC reports y’all are so fond of don’t exactly play sceptic either!!

There is no comparison between the CO2science site and the IPCC reports, particularly the WG1 (Scientific Basis) part of the IPCC reports.

But enough of the usual whining. You claim my point is not apropos to the argument. In that case, why did you make the point that the reservoir was not infinite if it wasn’t appropriate to your argument? Just an arm wave trying to get some traction?

What I said was: “For the case of the biosphere: What an additional slug of CO2 does is increase the amount of biomass that can be supported, so again some of the CO2 partitions into the biosphere but it doesn’t just keep increasing endlessly.” That was a statement about what happens when CO2 increases by a certain amount and then stops. You are now asking a different question, which is whether if CO2 continues to increase, will the amount of biomass that can be supported continue to
increase with it or will it start to level off at some point?

Do you see how this is a different question?

• “Yes, in a group consisting of 3 crackpots and one serious scientist, Ray is most assuredly the odd man out!”

Well Joel, since I doubt you have the education of any of these gentlemen in their own fields, I would ask you by what right do you call any of them Crackpots?? I would tell you that I didn’t read Velikovsky until I found out that he was actually a friend of Einstein due to the interest Einstein had in his work. No, Einstein didn’t agree with everything Velikovsky claimed. The fact that he agreed with a lot of it should make you consider how closed minds have affected the progress of civilization and especially science. Velikovsky made a lot of predictions that were later confirmed. Many, probably much like you, thought he was just guessing. You need to know Velikovsky was quite intelligent, widely read with an excellent understanding of the latest science at the time, and exchanged ideas and depended on experts in the fields he dealt with. In some cases those people did NOT want the general public and their colleagues to know this because of attitudes like yours!!All in all, a man that very poorly fits the term Crackpot that seems to fall so easily from the lips of the ignorant.

You again ignore the discrepancy between CO2Science, that uses Peer Reviewed Literature, and writes it, and those who use Botique Literature from Agenda Driven Organizations that has never been Peer Reviewed. The IPCC uses the latter. There is no comparison.

You repeated what you claimed. OK, apparently I am not understanding your point. Of course, my point is that these interminable discussions about CO2 have already been shown to be moot. The levels we can push CO2 to in the atmosphere is very unlikely to be a problem temperature or biosphere wise. So, what are you trying to say within this?

“What happens when you add a slug of CO2 to the atmosphere is that the partial pressure of CO2 in the atmosphere increases.”

Lemme see. I have actually stated this and been told the increase in partial pressure due to the few PPM of ACO2 is too small to be significant. My thought was that the contribution by man is simply inhibiting some of the natural CO2 release. So, is there a signicant suppression of natural CO2 release or not?? Someone who could run some rough numbers would be good.

Back to the original statement. I think you are trying to over evaluate a relatively simple situation. While the ocean chemistry and plant biology is quite complex, the large fluxes really don’t care about the details and will not change by large amounts based on the Anthro flux being there or not over single decades. I am sure Vaughan would be interested in detailed arguments showing it DOES, and, if I can follow them so would I. Leaky bucket is a reasonable image until facts show different. Whether that bucket is leaking into one or 100 pans doesn’t affect the rate of the leak that is from above the level of the pans. You need to show that something would cause a significant change in the hole or the pressure so to speak.

• Kuhnkat continues to champion the kook Velikovsky as a planetary scientist and great thinker, disregarding all facts to the contrary.

A while back, I pointed out to him how false his claims are that Einstein supported Velikovsky’s crackpot ideas about Venus and that Velikovsky had made many predictions that were later confirmed. Alas, correcting Kuhnkat’s errors and falsehoods is like shoveling water uphill — the labor yields absolutely no practical effect.

However, it does help us to know that Kuhnkat’s “scientific” understanding comes from the crank who claimed Venus was spit out of Jupiter as a comet about 5500 years ago by a mysterious, unknown force and that it then careened around the solar system for a while, pushing earth out of its orbit, flipping it over on its axis, shoved Mars out of its orbit into earth’s path to wreak additional havoc on our ancestors — while pouring trillions of tons of oil and other hydrocarbons from its tail onto them so that their descendants could fuel their trains, ships, planes and automobiles.

And then just as mysteriously through forces yet to be discovered, the comet settled itself peacefully in the most circular orbit in all the solar system to become the planet Venus.

To explain how Venus overcame all the laws of physics to accomplish those miracles, Velikovsky proposed an imaginary electromagnetic force for which there is absolutely no evidence.

The great Carl Sagan said of the Velikovsky, “There is not one case where [Velikovsky’s] ideas are simultaneously original and consistent with simple physical theory and observation.” Indeed, few of his ideas turned out to be either original or consistent with physical theory and observation.

To be wrong is bad enough, but to be Velikovskian wrong is an honor for which Kuhnkat needs to be earnestly recognized.

On nearly every page of his books, Velikovsky demonstrated a profound ignorance of both astrophysics and basic science. For example, in just the first pages of his Worlds in Collision, he explains how planets are pulled toward the sun by gravity, which is balanced by forces that “push” (his word) it outward — which of course is nonsense. What balances the sun’s gravitational pull is the planet’s inertia. If you could switch off the sun’s gravity, the planet’s inertia would send it, not outward, but in a straight line perpendicular to the gravitational pull. There is NO force pushing planet’s away from the sun. Velikovsky had very little education in basic science, as almost every pages of his writings show. That he should become the patron saint of astronomical crackpottery is therefore hardly a surprise.

Velikovsky’s predictions about Venus are so hilariously wrong that it’s a wonder why Kunhkat isn’t rolling in laughter himself instead of holding the kook up as a “brilliant” authority. Take for example Velikovsky’s prediction that Venus’ atmosphere is rich in hydrocarbons — which he “deduced” by his “discovery” that our planet’s wealth in oil and natural gasses came from collision with Venus’ “tail” several thousand years ago!!!!

No, there’s almost no hydrocarbons in Venus’ atmosphere. Even more hilariously embarrassing, Velikovsky didn’t know the difference between hydrocarbons and carbohydrates!!! He used those words interchangeably — which is something no bright 7th-grade schoolchild would every do. Both classes of compounds contain carbon and hydrogen — but that’s where their similarities end. Carbohydrates also contain oxygen and can combine in far more complex compounds than hydrocarbons. Carbohydrates are hydrophilic while hydrocarbons are notoriously hydrophobic.

Yes, Velikovsky said Venus is hot — but he wasn’t the first to guess this and he didn’t make any prediction how hot. Any idiot could have guessed that a planet 1/3 closer to the sun would be hotter than Earth. He NEVER predicted that Venus would be hot enough to melt tin and lead!

And some Velikovsky idiots say he correctly predicted Jupiter emits radio waves. But all bodies above absolute zero emit radio waves. Jupiter turned out to be a surprisingly powerful emitter of radio waves because charged particles from the Sun are trapped and accelerated by the planet’s powerful magnetic field — which Velikovsky never predicted. Velikovsky predicted Jupiter emits radio waves because it is very hot. His prediction was clearly wrong. The temperature of Jupiter’s atmosphere is more than 200 degrees F below zero.

Velikovsky’s ignorance was so profound it provided considerable amusement to even his friends — of which he had many who found him charming. Unfortunately, his followers — as well as many of today’s supporters of crackpot science — use his friendship with Albert Einstein as evidence that he was a credible scientist instead of a crackpot. Alas, Einstein’s letters, tell a different story:

July 8, 1946
Dr. Immanuel Velikovsky
526 West 113 Str.
New York City
Dear Mr. Velikovsky:

There is much of interest in the book which proves that
in fact catastrophes have taken place which must be
attributed to extraterrestrial causes. However it is
evident to every sensible physicist that these catast-
rophes can have nothing to do with the planet Venus and
that also the direction of the inclination of the
terrestrial axis towards the ecliptic could not have under-
gone a considerable change without the total destruction
of the earth’s entire crust. It were best in my opinion
if you would in this way revise your books, which contain
truly valuable material. If you cannot decide on this,
then what is valuable in your deliberations will become
ineffective, and it would be difficult finding a sensible
publisher who would take the risk of such a heavy setback
upon himself.

script, since I will not be free on the considered days.

With friendly greetings, also to your daughter,
Your
Albert Einstein

In his previous panegyric to Velikovsky’s “brilliance” as an authority on the planet Venus, Kuhnkat concluded with an obvious understatement: “I simply glean the best ideas from other people. I don’t claim any personal brilliance other than a pretty good BS detector, and that isn’t perfect either.”

I said then anyone who has a BS detector so utterly worthless should return it to the store and then shut up.

Anyone who would cite Velikovsky as a “brilliant” authority on Venus is a virtual tar baby for ridicule and fun poking. Now that we know Cumquat’s view of our solar system has been shaped by the “brilliance” of that kook, it’s our civic duty to mock his foolishness and utter disregard for reality.

• Oops, scale all that up by 1000, I was calling 10^18 kJ an exajoule but overlooked the k so that’s 10^21 J hence a zettajoule. 8 petajoules should have been 8 exajoules.

• Peter317

No. You were saying that the atmosphere warms the surface by conduction. The massive difference in thermal capacity alone should tell you that this doesn’t happen. And then there’s the fact that warm air rises, and is displaced by colder air cooled by the ground beneath.

• Actually the thermal capacity of the atmosphere is not terribly different from that of the portion of the surface capable of sensing diurnal fluctuation.

Global warming on the other hand is by a vastly smaller amount than the diurnal fluctuation at the surface, as well as on a vastly longer time scale, so there is nothing unreasonable in the idea that the global warming of the atmosphere could be transmitted to a volume of surface with a thermal capacity many times that of the atmosphere.

Luckily it’s irrelevant to the question of the respective values of dF/dt for respectively radiation and conduction at the surface, which both face the same obstacle of getting that heat below the top millimeter of the surface. Hence I don’t need to compute how deep global warming can go. But if you compute it I’d be interested in your answer, especially if it proves me wrong.

• Peter317

I’m afraid I’m not at all sure that I follow what you’re saying – perhaps it’s just me suffering the effects of the weekend.
Do you have something akin to an example?

• Let’s start with the most important point first. I claim that thermal capacity of what’s below the surface (if that’s what you’re referring to) is irrelevant to the question of whether the surface is being heated by the atmosphere conductively, radiatively, or both. I would have thought this was clear, but if you doubt it I’ll be happy to take a shot at arguing it.

It it’s not what you’re referring to then you might like to expand on your point about thermal capacity.

22. Ed Forbes

hunter | August 13, 2011 at 11:00 am |

Thank you for the post. Very nice.
Practical engineering vs theory. Stuff that we know works vs stuff that “may” work.

• hunter

Ed Forbes,
Thank you.
Notice that none of the AGW believers really dealt with it.
The more I observe the alarmists, the more I am certain I am observing people who are trapped in their beliefs.

• simon abingdon

Hunter, just look a little closer at the dialogue between Fred Moolten and Vaughan Pratt. And realize that you (and I) are nowhere near playing at their level.

23. son of mulder

Currently according to Trenberth’s diagram on average 80 W/M^2 of Latent heat from evapotranspiration and 17 W/M^2 due to thermals leaves the surface. ie about 5 W/M^2 for each degree above 0 deg C for Latent heat (at 0 deg C there would be no latent heat transfer). Say there was a 4 W/M^2 increase in downward radiation from doubling CO2 then combining increase outward radiation and increased latent heat the surface rise in temperature looks to me like it will be fairly small before equilibrium is regained and that’s before debate about clouds begins. Where does this simple view fall down?

• Jim D

It is not quite right to say latent heat flux goes away below 0 C, as ice surfaces can also have a latent heat flux. However, yes, a warmer surface has more latent heat flux leading to more water vapor in the atmosphere leading to more GHG effect, leading to more warming. This is a positive feedback.

• son of mulder

But what empirical evidence is there that this faster hydrological cycle acts a a positive feedback vs latent heat removed?

• what empirical evidence is there that this faster hydrological cycle acts a a positive feedback vs latent heat removed?

That’s a very reasonable question. It is possible to apply radiative transfer principles to water vapor to compute the magnitude of warming for a given concentration, and then use observational data to determine whether the expected atmospheric water concentrations are occurring. In general, the observations confirm expectations, but there is latitude for considerable variability. The estimates constitute the positive water vapor feedback.

It is also possible to compute the energy associated with latent heat release at various altitudes, and calculate how much cooling will result from the transfer of energy from lower altitudes to altitudes closer to space. The estimates comprise the negative lapse-rate feedback.

The difference is the net feedback from these two processes, which based on climate models utilizing the observational data, is net positive. In fact the difference between the water vapor and lapse rate feedback estimates tends to be smaller and less variable than the magnitude of either one alone.

Cloud feedbacks are subject to more uncertainty. They entail very powerful greenhouse effects, but also the ability of clouds to scatter sunlight back to space, which is a cooling phenomenon. Most models estimate cloud feedbacks as positive, but that’s a topic for a thread of its own. Trying to address it here would be unwise, in my view, because the subject is so vast that introducing individual pieces of evidence is almost always an exercise in cherry picking.

• son of mulder

Thanks Fred, so how does the increase in latent heat transfer increase vs temperature, straight line, logarithmic or what?. As I understand it like CO2 the increase in back radiation due to increased water vapour is logarithmic but with the speeding hydrological cycle how does the actual amount of atmospheric water vapour grow, linearly, logarithmic or what. eg at one extreme it could be like a pipe ie water can flow faster but there is no actual increase of water in the pipe? Is the physics of these processes really empirically tested when integrated over the earth system? What are the acsdemic references to answer these questions? And yes let’s ignore clouds for now.

• Based on the quasi-exponential Clausius-Clapeyron equation, water vapor is expected to increase at about 7% per degree C warming, at least within the range over which current climate is operating. For more on observational data of water vapor increase, see Comment 98441.

24. I have added a post on my blog on Judy’s confession that “back radiation is a phrase”
http://claesjohnson.blogspot.com/2011/08/what-judy-curry-suddenly-understands.html

• Well I assume that you included the rest of my comment as well, or did you take my statement out of context?

• Oh, Prof. Curry, you know he took it out of context. But don’t feel too bad. He has also taken Maxwell, Planck and Einstein out of context. So you’re in good company.

• well going over to the meta-expertise thread, that kind of tactic doesn’t get you many points. (hint hint Claes)

• Well, that was a demonic comment, max.

• What do you mean by “out of context”. What is it that you want to say about “back radiation” that I did not get right? I just want to you express your standpoint. So what is it? Is back radiation a phrase or real physics.
I think your blog readers want you to tell, and also I.

• Luis Dias

The problem is that you are going for sound bytes instead of participating in a more rational discussion. And when people notice that this is what you are going from, you’ll become ignored and avoided. I, for one, have enough of politics already.

No, no. Not sound bites. Claes doesn’t speak in sound bites. He speaks in parables, he says. Like Jesus, I say.

Cleas is pretty good at debating Maxwell, Planck, and Einstein, since they are not inclined to correct his misstatements. But he’s not so effective with authorities like Dr. Curry, who will trouble themselves to correct him, until they give up in frustration

A key point that should not be overlooked is that if Claes’ “science” had any validity to it, he would have published it in a peer reviewed science journal instead of in this book by an obscure publisher of right-wing diatribes — which recently put out a press release announcing the sale of its 5000th book!

In making that decision, Claes chose not to join the great physicists he wishes to replace. Rather, he joined the ranks of self-publishing crackpots like Martin Fleischmann and Stanley Pons (of “Cold Fusion” infamy), Immanuel Velikovsky, and TV infomercial quack, Kevin Trudeau.

Consider how closely Claes Johnson’s conduct fits Wikipedia’s “universal characteristics of cranks”:
http://en.wikipedia.org/wiki/Crank_%28person%29

1. Cranks overestimate their own knowledge and ability, and underestimate that of acknowledged experts.
2. Cranks insist that their alleged discoveries are urgently important.
3. Cranks rarely, if ever, acknowledge any error, no matter how trivial.
4. Cranks love to talk about their own beliefs, often in inappropriate social situations, but they tend to be bad listeners, and often appear to be uninterested in anyone else’s experience or opinions.

Some cranks exhibit a lack of academic achievement, in which case they typically assert that academic training in the subject of their crank belief is not only unnecessary for discovering “the truth”, but actively harmful because they believe it “poisons” the minds by teaching falsehoods. Others greatly exaggerate their personal achievements, and may insist that some achievement (real or alleged) in some entirely unrelated area of human endeavor implies that their cranky opinion should be taken seriously. …

[Cranks] seriously misunderstand the mainstream opinion to which they believe that they are objecting, stress that they have been working out their ideas for many decades, and claim that this fact alone entails that their belief cannot be dismissed as resting upon some simple error, compare themselves with Galileo or Copernicus (or in a religious context, Noah), [or in Claes’ case, Maxwell, Planck, and Einstein!] implying that the mere unpopularity of some belief is in itself evidence of plausibility, claim that their ideas are being suppressed, typically by secret intelligence organizations, mainstream science, powerful business interests, or other groups which, they allege, are terrified by the possibility of their revolutionary insights becoming widely known, appear to regard themselves as persons of unique historical importance.

I think this could very well have been written for Claes Johnson.

• bob droege

I think it’s been clear that no matter what you call it, it is real physics.

• hunter

Claes,
You are hurting skeptics everywhere by your silly crap and I wish you would stop. You are actually hurting AGW because your silly arguments are giving the believers more excuses to cling to their apocalyptic clap trap, and the sooner AGW finishes imploding, the sooner we can get on with things that matter.

25. While I do agree that sitting next to a block of ice will cool whatever is around that block of ice, it’s not a very good comparison and I wonder if it will do more to confuse the real physical issue here.

One becomes cold next to a block of ice because some water molecules are sublimating (going from solid to gas phase) and will have smaller translational energies than other molecules in the air. As these sublimated water molecules collided with you, your body transfers energy to them and you become cooler.

But that entire time your body is also radiating a good deal of IR radiation. As is the block of ice. And by putting that block of ice there one is slowing down the rate of radiation loss, which is effectively what the atmosphere does.

So there are two physical processes going on. One is the energy transfer via collisions between cold sublimated water molecules and your body. This causes your body to cool and the water molecules to heat up. The other process is the radiation loss by both your body and the ice block. These sources of radiation will slow down energy loss via radiation independent of the temperature of each body.

To me at least, it’s not a good idea to confuse these two processes, as gets done almost ubiquitously on these threads. The greenhouse effect or ‘back radiation’ or whatever anyone wants to call it does not occur via collisions. It occurs via radiation. And that’s what matters.

• Luis Dias

exactly.

• Maxwell, your point that the ice block cools one by both convection and radiation is an excellent one that I overlooked. However I don’t see how to calculate the proportions, do you? However you’d have to have pretty still air before convection became significant, any little breeze would blow the cold air molecules away before they could diffuse across to you.

But does it matter?

The same point can be made of an atmosphere that is warmed by absorbing more radiation on account of more CO2. Some of that additional warmth will warm the ground by radiation and some by convection followed by conduction (in the final millimeter or so). But in what proportions? Perhaps it’s all DLR because it’s instantaneous and convection would take far longer. Or perhaps not.

But does it matter?

Answer: no, as I argued above at http://judithcurry.com/2011/08/13/slaying-the-greenhouse-dragon-part-iv/#comment-98462

I also argued that, although it didn’t matter to whether global warming was happening, DLR was highly unlikely to play any significant role in transferring the global warming of the atmosphere to global warming of the surface. I argued this via a simple calculation showing that much more heat can reach the surface via conduction than via radiation, under the assumption that convection offers no thermal resistance at all based on the mind-bogglingly slow rates of warming involved: about a billionth of a degree per second.

• Vaughan,

I’ve seemed not to convey my point in the comment above.

Generally there are two mechanisms in play as I sit next to a block of ice. Cold, sumblimated water molecules are gaining energy from my skin and clothes via collisions and I am absorbing the radiation that the block of ice emits as a blackbody. One of those mechanisms cools me while the other heats me up because one process is transferring energy away from me mechanically while the other transfers energy to me electromagnetically.

As to the relative magnitude of these contributions, the devil is in the details. You’re right that any breeze would be a significant factor to account for. If it’s blowing to me from the block, I’ll likely get colder. If it’s blowing away, not so much. And we could go on and on and on describing what type of situation would result in which process ‘winning out.’

But that’s really the issue here.

Your main point seems to me that one can create a simple, intuitive physical model to account for surface warming via a greenhouse effect that does not necessitate a meaningful role for radiation transfer processes. Once we’ve done so, there is no need to discuss ‘backradiation’ because we don’t need it to understand that increasing atmospheric CO2 concentrations will increase surface temperatures.

It’s a very logical argument, but, like others here, I’m not sure it’s the most physically correct argument. I don’t think you do either, which coming from someone who has admitted some ignorance, is completely understandable.

What I struggle with not only in this situation where we are trying to find a way to talk about accepted science, but in many others is the extrapolation from the simple model to reality. And others like Pekka and Fred who have discussed this topic here ad nauseam continue to struggle to convey the most important physical aspects of these situations in a way that we can all agree upon in a blog comment box while trying to explain to less willing participants that the Stefan-Boltzmann law is real.

It’s not easy.

But I think we can say this: the transfer of energy between the atmosphere and the surface of the earth is very complex. It can happen via a handful of processes which also have intermediate physical process that affect where and how the energy ends up at the surface (condensation is a good example of this idea). Electromagnetic and mechanical mechanisms for energy transfer are both important and likely vary in importance in both time and space. It is very difficult without specifying spatial and temporal conditions (air pressure, humidity, altitude, etc.) to determine which process is more important in warming the surface due to the greenhouse effect. But both play a role.

How does that sound?

I’m going to be in the bay area for the APS Laser Science conference later this fall if you’d like to take some time and sit and chat about this face to face. They make very fine adult beverages in that part of the world.

Cheers.

• John Carpenter

“Generally there are two mechanisms in play as I sit next to a block of ice. Cold, sumblimated water molecules are gaining energy from my skin and clothes via collisions and I am absorbing the radiation that the block of ice emits as a blackbody.”

Max,

I don’t think water sublimation is the right way to look at how the heat transfer is occurring. If you look at the phase diagram of water, you will note that at 1 atm and at 0 deg C, the pressure necessary for sublimation is at the triple point, is much lower than 1 atm. Even if the temperature was at 25 C, the pressure for solid to vapor phase transformation is still well below 1 atm. The phase transformation has to be from solid to liquid at room temperature and 1 atm pressure. The energy used to melt the ice cools the air molecules around the ice, which in turn cool your skin. Water sublimation is not the correct vehicle for that description. As you know, when an ice cube melts, it leaves a puddle, it does not disappear into the atmosphere like solid CO2, which does sublimate at 1 atm and 25 C.

• What I struggle with not only in this situation where we are trying to find a way to talk about accepted science, but in many others is the extrapolation from the simple model to reality.

Yes, we’re stuck theorizing when we’d like to be experimenting. But it seems to me that the question of which of conduction and radiation dominates surface warming (in the dT/dt sense) is intrinsically academic in two senses.

1. It doesn’t really matter so long as the net effect of the increasing DLR and increasing temperature of air at the surface combine to warm the surface.

2. The values of dF/dt and dT/dt for global warming are so many orders of magnitude less than the diurnal fluxes as to render them beyond the reach of any conceivable instrumentation that might have a prayer of measuring the difference.

For the purposes of arguing that global warming is happening, sense 1 is sufficient reason to ignore the comparison question. That’s really all I care about. Unless you see a way round sense 2 I think that makes it truly academic, somewhere on the level of string theory or quantum error correction perhaps. That wouldn’t stop me from writing about such things if I had something new to contribute to them though.

It is very difficult without specifying spatial and temporal conditions (air pressure, humidity, altitude, etc.) to determine which process is more important in warming the surface due to the greenhouse effect. But both play a role.

Sounds like we might be in agreement.

I’m going to be in the bay area for the APS Laser Science conference later this fall.

Great. My email address is on my web site.

• hunter

maxwell,
No, the ice block is radiating a good deal less energy than the human body, unless the ice block is very large.

• hunter,

I think I did make a statement that causes confusion.

That is, I say,

‘These sources of radiation will slow down energy loss via radiation independent of the temperature of each body.’

which can be interpreted as the radiation each body emits being independent of its temperature. That is obvious physically incorrect. The amount of radiation each body emits is directly proportional to the fourth power of its temperature, as per the Stefan-Boltzmann law.

By making that statement, I was saying that my body will absorb the radiation emitted by the ice block independent of the fact that the ice block is at a lower temperature of my body. This is being said to buffer against the Dragon Slayer’s theory that this process is not possible for some reason.

Thanks for pointing that out though. I had seen it last night and thought it might create some confusion.

All clear now?

• hunter

well,
Thank you for clarifying that.
I am in agreement with you.
The practical effect of the block of ice and its radiation budget will be very small. The net flow, the heat, will flow away from the warmer body, and the ice, in its response, will not stay ice for long.
The lack of recognizing that in a universe evertyhing is radiating is one of the more frustrating aspect of the dragons.
A cool body in the presence of a warmer body does not stop emitting.
A warmer body that is radiating will still continue to absorb.
This effect, however, is going to be quite small, until you get to special conditions like an igloo that combines covection and reflectivity to the situation.

26. RobB

If greenhouse gases reduce the rate that LWR radiation is emitted to space then there must be warming (if the rate of incoming radiation remains constant). If you can accept this then you don’t need to confuse the issue by talking about back radiation. Please address this specific point, Slayers.

• I’m curious about the rate you mention, Rob. Are you talking about milliseconds? If so, then you won’t get any argument from the Slayers. If you integrate over a longer cyclic period, like 24 hours, then what do you expect to happen? The peak temperature is reduced a little bit and the minimum temperature is increased a little bit…but all of the GHG energy stored (or blocked or retarded or whatever) gets to space with no problem. There’s small thermal mass (compared to ocean water) and there’s a short thermal time constant (compared to our 24 hour rotation cycle). How do you get higher and higher record temperatures out of this?

• Joel Shore

Because the earth’s surface temperature is determined by the balance between the rate at which it receives energy from the sun and the rate at which it emits energy back out into space. So reducing the rate at which it emits energy back out into space means temperatures must raise until it is again emitting back out into space as much as it is absorbing from the sun.

One might as well make the statement, “Some people claim the Hoover Dam will raise water levels behind it dramatically producing a lake but my calculations show it will only delay the flow of a water molecule to the ocean by a few hours. How do you get higher water levels out of this?” In other words, it is sophistry.

• “Some people claim the Hoover Dam will raise water levels behind it dramatically producing a lake but my calculations show it will only delay the flow of a water molecule to the ocean by a few hours. How do you get higher water levels out of this?”

This is one of the entertaining issues of global warming analogies. The dam or tub analogy illustrates the level rises without the direction of flow changing. Down welling longwave would be like increased random reverse motion of water molecules or eddy currents that move opposite the direction of flow, but the net direction of flow does not change. Some have problems with the dam analogy because it is not perfect, but it is useful. The greenhouse analogy is not perfect nor is the blanket or space blanket, but they have some usefulness.

The issue with down welling radiation to me is that photons can warm an object without being locked into whether the object emitting the photon is warmer or colder than the object emitting the proton. So some go into great detail attempting to show that night time down welling longwave “warms” the ocean, which implies to many that the sea surface temperature increases at night or that you could build down welling longwave collector to heat your bath water. Be it sophistry or not, warming and heating have firm definitions, at least to engineers, that down welling longwave advocates tend to ignore.

• Joel Shore

Dallas,

I wasn’t addressing details about what is the best terminology to use in regards to the word “warming” or “heating”. I was addressing the fact that Ken Coffman said something that was complete nonsense.

• Sorry, I wasn’t try to correct you, just an observation.

• If you integrate over a longer cyclic period, like 24 hours, then what do you expect to happen? The peak temperature is reduced a little bit and the minimum temperature is increased a little bit…but all of the GHG energy stored (or blocked or retarded or whatever) gets to space with no problem

This analysis is quite different from the usual one, which is that Earth is a body in space radiating away its heat in all directions and that additional CO2 reduces all of that radiation lying in the bands of wavelengths susceptible to CO2. Ignoring the Sun for the moment, there is no obvious problem with this reasoning.

You’re proposing that the motion of the Sun around the Earth (using the geocentric frame for this analysis) changes this effect. Well, what it does is to raise the temperature of the portion of the Earth visible from the Sun. This results in increasing the radiation from the heated region of Earth. As the Sun moves on that region cools back down again.

This extra radiation is just as susceptible to trapping by additional CO2 as the base (night time) level of radiation. The only difference is that there’s more total radiation being decreased by the additional CO2 when hot than when cold. A steady increase in CO2 results in a steady decrease in what the radiation would have been without that CO2 increase, across the whole planet, day and night.

• ferd berple

H2O is the dominant GHG. Here is the million dollar question. Does this GHG make temperatures warmer or cooler?

We know that when it is overcast, that days are cooler and nights are warmer. If it is fully overcast for 1 month, is the average temperature of that month more or less than it would have been if the skies were clear?

AGW tells us that since there is more GHG (H2O) in the sky, average temperatures are increased. The real world says otherwise. With increasing clouds you get a decrease in average global temperatures, not an increase as predicted by AGW. This is the negative feedback observed in the satellite data.

Don’t take my word for it. Compare the highs and lows for sunny and cloudy days and average them out over a year. Increased warming leads to increased H2O which leads to increased cooling which means there is no tipping point.

• Joel Shore

ferd,

You continue to be profoundly confused about pretty much all aspects of climate science and your contributions to this thread have all been riddled with errors. Here, you are confusing H2O in its vapor and condensed (i.e., cloud) forms. And, you don’t even understand what the basic arguments are.

Clouds have both a warming and cooling effect but it is indeed generally agreed that on a global scale the cooling effect dominates somewhat. However, jumping from that to it being a negative feedback is incorrect because determining the feedback requires understanding how cloudiness changes as the climate warms. This is not such an easy thing to assess because although the warming causes more water to evaporate, it is also true that the saturation pressure of water vapor (“how much the atmosphere can hold”) increases with temperature too…and it happens in such a way that the relative humidity (the ratio of the amount of water vapor to the amount at saturation) is expected to remain roughly constant. So, it is not easy to predict how cloudiness changes. Also, not only the overall change matters but also how each type changes. In particular, high clouds generally have a stronger warming effect (due to their greenhouse effect) than cooling effect (due to blocking solar radiation) while low clouds have the reverse.

Perhaps you need to be reading more and contributing less…Or at least asking questions rather than just stating incorrect things. You don’t make AGW “skeptics” appear to be very knowledgeable.

• Joel, you are making a very big assumption, that the people you are responding too know anything about clouds aside from that are puffy and pretty.

• ferd berple, 8/11/11, 6:11 pm, Vaughan Pratt IV

fb: H2O is the dominant GHG. Here is the million dollar question. Does this GHG make temperatures warmer or cooler?

Good question. Latest estimate is that it’s a \$30 trillion question, making it an even better question, and the answer is even better. In the snowball state, this gas morphs into ice and snow, locking Earth at about -10ºC compared to the present warm state. Today, this gas neither warms nor cools, but regulates the temperature so that it slowly follows the long term average solar radiation, mitigating against all forcings.

Pay no attention to the little men behind the curtains. H2O is the dominant, powerful feedback in all of climate, negative in the warm state and positive in the cold state, and by a wide margin.

• hunter, 8/15/11, 12:04 pm, Vaughan Pratt IV

Whoops!

Correction: Water vapor is a powerful, dominating feedback, positive with respect to the Sun and negative with respect to surface temperature. In the cold state, it is negative with respect to the Sun and not responsive to surface temperature.

• Joel Shore

How convenient! And, the amusing part is that there are “skeptics” out there who complain, “Why do scientists assume that the water vapor feedback amplifies CO2 forcing but not any other forcing?” Of course, that’s not true but that doesn’t stop them from thinking this is the case.

Now, you’ve invented a way (no doubt shown in the peer-reviewed literature, with lots of accompanying evidence…Ha! Ha!) to have water vapor act to magnify what you want it to magnify and to not de-magnify what you don’t like! I guess the water vapor feedback is really magical in that way!

27. Nullius in Verba

While I would agree with the conclusion that back-radiation does not properly explain the greenhouse effect (or whatever you want to call it) as I’ve said previously, I see a few problems with this approach.

First, if you sit beside a block of ice, whether you are warmer than you would be otherwise depends on the temperature of the rest of your surroundings. In a room with walls of frozen hydrogen, near absolute zero, standing near a block of ice would make you feel warmer, as the rate of heat loss was reduced. Compared to a warm room, it would make you feel colder. We are familiar with the difference between a warm room and a cold one, but in both cases our surroundings are far cooler than we are. How can standing between walls at 20 C make us feel warmer than standing between walls at -20 C? At 20 C, they are still a cold object to our warm 37 C.

Second, a cold sky can supply more energy than a hot sun because the sun only covers a tiny fraction of the sky, while the sky occupies half the view. It is, as noted, more than balanced by the upward radiation.

The main miscommunication here is the logical difference between saying the temperature of the sky warms the surface, and saying the temperature of the sky makes the surface warmer than it otherwise would be, had the sky been at absolute zero. In some ways it’s a purely semantic confusion – if a thing is warmer than it otherwise would be because of another entity, it’s not entirely unreasonable to say in a colloquial sense of the word that the other entity has “warmed” it. It doesn’t mean any (net) heat has gone from the warmer of the two to the colder. It hasn’t.

Admitting that back-radiation exists and is absorbed doesn’t mean that the conventional back-radiation explanation is correct, though. I’ve given an example where back-radiation is even stronger, the greenhouse effect magnified 100,000-fold, and yet no surface warming occurs. It would not be a surrender.

Good luck to Judith in trying to deal with this argument so we can move on, but I have little expectation that it will work.

• “While I would agree with the conclusion that back-radiation does not properly explain the greenhouse effect (or whatever you want to call it)”

NIV – Your earlier post was interesting, and I agree with the “whatever you want to call it” phrase as telling us that “back radiation” and the more formal “downwelling longwave radiation” are terms used to denote the same very real and measurable phenomenon

Your water analogy in your previous comment does not, in my view, invalidate the conventional understanding of the greenhouse effect mechanism, but rather reinforces it. The actual analogy would be to an atmosphere that is almost completely IR opaque at all wavelengths. In that circumstance, the Earth’s surface would reach intolerably high temperatures, and even convection and conduction could not preserve life as we know it. In the case of water as in your analogy, we know that convection is a major mixing mechanism that dissipates solar heating at depths. (We also know, of course, that back radiation, or whatever we wish to call it, is an even greater source of thermal energy into the oceans, and this latter source introduces energy from above the water downward into it).

• Nullius in Verba

“In that circumstance, the Earth’s surface would reach intolerably high temperatures, and even convection and conduction could not preserve life as we know it.”

If the conventional back-radiation explanation was correct, liquid water could not exist. If the conventional back-radiation explanation is not invalidated, then a pool of water would also inevitably reach “intolerably high temperatures” within millimetres of the surface. It doesn’t, and therefore the explanation is wrong.

Water doesn’t boil in the sunlight because the conventional back-radiation explanation omits convection, just as it omits discussing it when talking about the atmosphere. Convection dominates (not in the sense of being bigger, but in the sense of entirely controlling the outcome), and back-radiation, while it certainly exists, has (in the case of water at least, and I would argue in most circumstances for the air too) no net effect.

If you want to say that the back-radiation argument still works for air, you have to say why greenhouse gases like water vapour in the atmosphere behave (radiatively) differently from liquid water.

• The reason is in the fact that air expands when the pressure drops and that it cools, when that expansion happens adiabatically. In other words, the adiabatic lapse rate is very much larger in the atmosphere than in water.

• Nullius in Verba

Yes, exactly.

But you don’t see the essential role of the adiabatic lapse rate set out in the conventional back-radiation explanation, which was my point.

It’s all about the (albedo-modulated) insolation, the lapse rate and the average altitude of emission to space. Back-radiation doesn’t enter into it.

• We have so many people trying to explain the atmosphere in simple terms that having a huge number of bad explanations is unavoidable. Some of the people who err in that way know correctly the full physics, but cannot simplify it in a reasonable way, others don’t know any better the full physics than they understand the simplifications.

• Explanations that do not violate the Laws of Thermodynamics are an appropriate beginning to understanding.

• Joel Shore

We can’t help you if you do not understand the Laws of Thermodynamics to know when they are violated or when they are not. (Well, we can try to help you, although in my experience, it will likely do little good.)

• Wagathon

You might start by understanding why any serious scientists understands that believing in possibility of runaway global warming is believing in the possibility of a perpetuum mobile.

• Wagathon,

There are a few people that can explain down welling radiation where everyone understands there is no violation of the laws of physics. Spencer for one and Pratt as well since he is catching it from both sides. The heat transfer from object A to object B is proportional to the difference in temperature and the net transfer is from the warmer object to the cooler object. If both objects are above 0 K they both emit radiation. An object doesn’t do a background check on the individual photons in the radiation, so radiation flows both ways, net heat though moves the way it is supposed to, from hot to cold.

A colder object can cause a warmer object to be warmer still by decreasing the temperature difference between the objects. Space is at 4K and the Earth is at 280 K. Between Earth and space the tropopause is at 230K. If enough CO2 gets to the tropopause, it can increase the temperature to 231K if there is enough outgoing 15 micron radiation. So we now have an object, layer really, that decreased the apparent temperature between the surface of the earth and the heat sink of space. The Earth now loses heat to space a little slower so the Earth is now a little warmer.

It is only around the tropopause that photon exchange between gas molecules, CO2, a tiny trace of H20 and a few other trace gases is significantly due to radiation, up or down. Below the tropopause, water vapor increases and the density of the atmosphere increases so most of the energy transfer between molecules is due to collision and the impact of convection, latent heat and conduction increase in importance, decreasing the impact of molecule to molecule transfer of energy via radiation. Water vapor, CO2 and other “greenhouse” gases still are excited by radiation, primarily rising from the surface the closer to the surface you go. At the surface skin layer, collisions dominate the heat transfer between molecules which means that conduction is the main heat transfer path between the surface skin layer and the atmosphere at that point. Warm air means more collisions which means more heat transfer. Still the net transfer is from the warmer to the colder. It is pretty rare that the air is actually warmer than the surface, but as the temperature difference between the surface and the air decreases, the rate of heat flow decreases.

Since there is a little more going on than adding an object to block part of the heat flow from a heated object in a vacuum chamber, the down welling radiation term or back radiation leaves a little to be desired. It is a simple way to calculate or measure changes in the net heat flux, with some limits. The main limit is that the accuracy of the measured net from comparing up to down sucks. The second is it confuses the heck out of people, but it doesn’t violate the laws of physics, just the sensibilities of normal engineering type folks.

• Wagathon

–>”A colder object can cause a warmer object to be warmer still … So we now have an object, layer really, that decreased the apparent temperature between the surface of the earth and the heat sink of space. The Earth now loses heat to space a little slower so the Earth is now a little warmer.”

Sorry Dallas but that is just not the way of the world we live in. The Earth does not get ‘a little warmer’ because it ‘loses heat to space a little slower’ and a colder object cannot make a warmer object warmer.

But, let’s cut through the injection of mysticism need to invent properties we do not observe in nature. Let’s get real and look at the world we actually live in.

“A market garden greenhouse is not warm because the glass cover is transparent for visible light, but opaque for infrared radiation [IR]. The greenhouse is warm because a closed roof does not let out the warm and humid air. A greenhouse with a roof that is IR transparent is only a little bit lower in temperature.

“The standard theory, in contrast to this experience, teaches us that the earth surface radiates into space through the IR absorbing atmosphere, and therefore, if IR absorbing gases increase, the surface temperature increases. Cooling through radiation becomes more difficult.

“FM’s [Ferenc Miskolczi] theory, in agreement with this experience, teaches us instead that the heat transfer from the surface is by non-radiation processes: vertical & horizontal convection, water evaporation, cloud formation, rain and snow. And FM teaches us more: Our atmosphere has, in the global and time-averaged mean value, a constant optical thickness, so, when more CO2 is injected, the atmosphere compensates this by increasing its water vapor content to regain the equilibrium.

“The atmosphere makes itself just that optimal optical thickness that allows for the maximum heat transfer to space, by adjusting its IR absorbance.”

~Dr. Ir. E. van Andel,

• Joel Shore

Wagathon: You really haven’t a clue what you are talking about. You are just throwing around phrases about the Laws of Thermodynamics and perpetuum mobile that seem to be as ignorant as when a Young Earth creationist says that evolution violates the Second Law. It’s hard to know where you are getting tripped up since you just make these pronouncements of fact that seem to be based on nothing other than your own lack of knowledge about these laws. Would you care to enlighten us about how you in your immense brilliance have discovered these violations of the Laws of Thermodynamics that have alluded all the scientists in the field, authors of some of the most commonly used introductory university physics textbooks, etc.? Do you understand the nature of the Second Law and the its underlying grounding in statistical physics?

• Wagathon

Your condescending nature probably is your biggest hurdle to acquiring knowledge Shore.

The global warming alarmists’ fersome trace gases reguire even more energy to get them excited than the air that surrounds them which they instantly radiate in all directions at light speed–i.e., they actually increase the efficiency of an air mass to transfer heat from the surface of our water planet, which is exactly what we expect given the first and second laws of thermodynamics.

It is not surprising that you do not understand this. But it is amazing that you think everyone else believes as you do.

• Joel Shore

Can you explain why you think your picture is in better agreement with the Laws of Thermodynamics than the accepted picture?

It is not surprising that you do not understand this. But it is amazing that you think everyone else believes as you do.

So, who exactly disagrees with me on these points? All mainstream climate scientists agree…but even ones like Spencer and Lindzen do too. Heck, even some of the quite nutty skeptics like Monckton agree with me.

In terms of physics textbooks, I’ll toss out two major ones that incorporate a discussion of the greenhouse effect and global warming (by no means meant to be an exhaustive list, this is just the two we happen to use):
University Physics, 13th edition by Young and Freedman
College Physics, 2nd edition by Knight, Jones, and Field

Do you know of any that say it violates the Laws of Thermodynamics or even question its correctness in any way?

• Wagathon,
>”A colder object can cause a warmer object to be warmer still … So we now have an object, layer really, that decreased the apparent temperature between the surface of the earth and the heat sink of space. The Earth now loses heat to space a little slower so the Earth is now a little warmer.”

Sorry Dallas but that is just not the way of the world we live in. The Earth does not get ‘a little warmer’ because it ‘loses heat to space a little slower’ and a colder object cannot make a warmer object warmer.

If the Earth did not have a fairly constant heat source, that would be true. There is no magic heat being created. If you wear a coat you feel warmer because you are losing less heat. If you are dead and wearing a coat, it ain’t going to help. Even the simplest of analogies requires some common sense or a desire to understand.

• Wagathon

Shore can be condescending and Dallas can indulge in the comfort of analogies that support his preconceptions—we have come to expect that from proponents of global warming alarmism—but, that will never put the broken theory back together again.

“…the greenhouse models are all based on simplistic pictures of radiative transfer and their obscure relation to thermodynamics, disregarding the other forms of heat transfer such as thermal conductivity, convection, latent heat exchange et cetera. Some of these simplistic descriptions define a ‘Perpetuum Mobile Of The 2nd Kind’ and are therefore inadmissible as a physical concept. In the speculative discussion around the existence of an atmospheric natural greenhouse effect or the existence of an atmospheric CO2 greenhouse effect it is sometimes stated that the greenhouse effect could modify the temperature profile of the Earth’s atmosphere.”

~Gerlich and Tscheuschner

• Joel Shore

Oh…Okay, so now you tell us that you are basing your claims in regards to a violation of the Laws of Thermodynamics on the completely discredited work of Gerlich and Tscheuschner. No wonder you are so confused!

• Joel Shore

Just to be clear on why G&T are wrong: As near as anyone can figure, their claim that the greenhouse effect violates the Second Law is based on the notion that the greenhouse effect proposes that the warmer atmosphere warms the cooler surface. However, this is simply a confusing regarding the word “warm”.

What the Second Law says is that you can’ t transfer heat from cold to hot. All models of the greenhouse effect, be they simple models you can solve on an envelope or the full radiative-convective models used for quantitative calculations, show that the heat (i.e., net energy) flow is from the hotter earth to the colder atmosphere. The reason why this still results in “warming” the earth…in the sense of raising the average temperature of the earth…is that the average temperature of the earth is determined by the balance between the energy it receives from the sun and the energy that it radiates back out into space.

In the case where there are no greenhouse gases (more technically, no IR-absorbing elements…i.e., no condensed water vapor [clouds] either), none of the energy that the earth radiates out into space is returned to it. So, if some gets returned, even a small fraction, that results in the temperature of the earth being higher than it would otherwise be.

A more complicated picture also considers the effects of convection, which enforces the stability requirement that the lapse rate in the atmosphere not exceed the adiabatic lapse rate…and then it turns out that the best thing to look at is the radiation budget at the “top of the atmosphere” because we know that the only communication of energy that occurs between the earth + atmosphere and the sun and space is via radiation. But, these more complicated considerations do not change the basic qualitative result.

• Joel Shore | August 15, 2011 at 11:26 am |:
“Just to be clear on why G&T are wrong: As near as anyone can figure, their claim that the greenhouse effect violates the Second Law is based on the notion that the greenhouse effect proposes that the warmer atmosphere warms the cooler surface.

Uh, the greenhouse effect proposes that the cooler atmosphere warms the warmer surface.

Joel then goes on to say “What the Second Law says is that you can’ t transfer heat from cold to hot… this still results in “warming” the earth”

That pretty much clears it up

• Wagathon

Sadly, reality refuses to conform to the expectations of the modelers of runaway global warming alarmism. I say sadly as I can only imagine how difficult it must be for global warming alarmists to give up the specter of the ‘greenhouse analogies’ and IPCC-approved fears of runaway global warming that underlie the prognostications of doomsday-warmanists that SUV-driving soccer moms will cause rivers to run red. “[G]reenhouse” theory creates a perpetual process in violation of the conservation of energy.” ~Gerlich and Tscheuschner:

“…our falsification paper discusses the violation of fundamental physical and mathematical principles in 14 examples of common pseudo-derivations of fictitious greenhouse effects that are all based on simplistic pictures of radiative transfer and their obscure relation to thermodynamics, including but not limited to those descriptions (a) that define a ‘Perpetuum Mobile Of The 2nd Kind,’ (b) that rely on incorrectly calculated averages of global temperatures, (c) that refer to incorrectly normalized spectra of electromagnetic radiation… We take the opportunity to clarify some misunderstandings, which are communicated in the current discussion on the non-measurable, i.e., physically non-existing influence of the trace gas CO2 on the climates of the Earth.”

• Joel Shore

Hockey Schtick says:

“Just to be clear on why G&T are wrong: As near as anyone can figure, their claim that the greenhouse effect violates the Second Law is based on the notion that the greenhouse effect proposes that the warmer atmosphere warms the cooler surface. ”

Uh, the greenhouse effect proposes that the cooler atmosphere warms the warmer surface.

Joel then goes on to say “What the Second Law says is that you can’ t transfer heat from cold to hot… this still results in “warming” the earth”

That pretty much clears it up

Ah…To clear it up, you have to read the words in between. Your “…”.

• Here we go again…

Joel Shore correctly states “What the Second Law says is that you can’ t transfer heat from cold to hot.”

He then goes on to say heat is transfered from cold to hot, but just not as much as hot to cold.

So Joel, which statement is correct:

1. you can’t transfer heat from cold to hot

OR

2. you can transfer heat from cold to hot, just not as much as hot to cold?

• Wagathon

Something that has been happening on Earth for billions of years is by definition, reality. And, for as long as humans have been able to describe reality in words, they have called it ‘nature.’

For the last couple of decades, a relatively few number of Western scientists have created a fictional world based on global climate models (GCMs) that defy reality. They call it the `greenhouse effect,’ which they say is the physical basis for their claim that “CO2 emissions give rise to anthropogenic [man-made] climate changes.” Real scientists call that science fiction.

There is only one independent variable. It’s the sun, stupid.

• Joel Shore

Hockey Schtick: I thought that I explained it pretty clearly but let’s try it again. Heat, which is DEFINED as the net energy flow must be from hot to cold. However, this heat flow in the case of radiation is produced by two countervailing energy flows, one from hot to cold and one from cold to hot. The statement of the Second Law is then that the amount of energy from the cold object that is absorbed by the warm object is always less than the amount of energy from the warm object that is absorbed by the cold object.

If you don’t like this idea of two countervailing energy flows (despite the abundant evidence that downwelling longwave radiation really exists), you don’t have to think about it that way. You will get exactly the same result as long as you accept that the flow of heat from an object depends not only on the object’s temperature but also on the temperature of the surroundings. (If you don’t accept that, well, there is very little that we can do except say that the Laws of Radiative Physics that say this are so well-tested that you are simply being ridiculous.)

Radiative balance between the earth, the sun, and space requires that the amount of heat that the earth emits back out into space equal the amount of heat it receives from the sun. Reducing the amount that the earth radiates back out into space (by increasing levels of greenhouse gases) thus causes the earth’s temperature to increase until such point that the amount that it is radiating back into space once again balances the amount that it receives from the sun.

Not that complicated, really.

• Joel Shore says: “Heat, which is DEFINED as the net energy flow must be from hot to cold. However, this heat flow in the case of radiation is produced by two countervailing energy flows, one from hot to cold and one from cold to hot. The statement of the Second Law is then that the amount of energy from the cold object that is absorbed by the warm object is always less than the amount of energy from the warm object that is absorbed by the cold object.”

Wikipedia article on the 2nd law: Thermodynamically, energy can only be transferred by heat between objects, or regions within an object, with different temperatures, a consequence of the zeroth law of thermodynamics. This transfer happens spontaneously only in the direction to the colder body, as per the second law of thermodynamics. The transfer of energy by heat from one object to another object with an equal or higher temperature can happen only with the aid of a heat pump via mechanical work, or by some other similar process in which entropy is increased in the universe in manner that compensates for the decrease of entropy in the cooled object, due to the removal of the heat from it…Spontaneously, heat cannot flow from cold regions to hot regions without external work being performed on the system.

Joel Shore misstates the 2nd law claiming -in the case of radiation only- [hmmm maybe that’s why we’ve never heard the words ‘back-conduction’ or ‘back-convection’] that heat transfer happens spontaneously without work input from cold objects to warm objects, just not as much as warm to cold. That is not what the second law says. Clearly, the 2nd law says heat transfer is one way – only to maximize entropy. Transfer of heat from cold to hot REDUCES ENTROPY and is therefore forbidden by the 2nd law.

• Wagathon

What the global warming alarmists who live in their fictional ‘greenhouses’ fail to appreciate is that the big actor in Earth’s climate change drama is water, oceans of it. The energy of the sun falls on the oceans and lakes, causing evaporation and resulting in water vapor. The water vapor mops up heat and rises, leaving a cooler Earth behind. As water vapor rises the atmosphere becomes cooler, thinner where it eventually condenses and gives up its heat to the cold emptiness of space as the vapor returns to water and forming clouds or freezing and ultimately falling back to earth as rain, sleet, hail and snow.

The global warming alarmists cannot change this process. They can only program GCMs depicting runaway global warming by treating water vapor as a contributor to global warming, i.e., a positive feedback by collecting heat like a greenhouse. In actuality, water vapor is a part of a holistic process that results in a negative feedback because the amount of solar energy that is reflected away by clouds during the day more than offsets the suppression by clouds of cooling during the night.

The work of Gerlich and Tscheuschner clearly shows us that to believe otherwise is to believe that the Earth’s atmosphere acts like a perpetual motion machine. The secular, socialist Western academics’ greenhouse gas theory is based on conclusions about reality that contradict the basic laws of thermodynamics and do not correspond to observational evidence. The global warming alarmists’ GCMs have no forecasting ability because they erroneously calculate a doomsday scenario for one purpose only: to blame capitalism and Americanism for a non-existent problem.

• simon abingdon

Joel “Not that complicated, really”. But what about the rotation of the Earth? Seems to me that the period between the time of maximum cooling (sun overhead) and the time of minimum cooling (the moment before sunrise) is a significant complication.

• Joel Shore

Joel Shore misstates the 2nd law claiming -in the case of radiation only- [hmmm maybe that’s why we’ve never heard the words ‘back-conduction’ or ‘back-convection’] that heat transfer happens spontaneously without work input from cold objects to warm objects, just not as much as warm to cold. That is not what the second law says. Clearly, the 2nd law says heat transfer is one way – only to maximize entropy. Transfer of heat from cold to hot REDUCES ENTROPY and is therefore forbidden by the 2nd law.

(1) Like I explained to you, heat is a macroscopic quantity which is defined as the net flow of energy. Saying the heat flows from hot to cold does not mean that there is no radiative energy going from cold to hot, just that there is more going in the other direction. You seem to believe in some sort of “magical form” of the Second Law. What do you think happens…Do you think the colder object detects the hotter object there and refuses to radiate toward it or do you believe that the hotter object posts a little sign that says “No photons from colder objects allowed”?

(2) There is indeed the equivalent of “back-conduction” and “back-radiation”. For example, if you imagine two boxes of gas at different temperatures separated by a flexible membrane, then heat is transferred by collisions between the molecules on the cold side and the molecules on the hot side. On average, the result of many such collisions will be the molecules on the cold side gaining kinetic energy and those on the hot side losing it. However, in any given collision, it is possible for a molecule on the cold side to lose energy to a molecule on the hot side.

(3) This would all make a lot more sense if you actually read up on the modern understanding of the Second Law as deriving from the statistics of large numbers of microscopic events (the field of statistical physics). Then you would understand that the Second Law is not some magical construct but actually something that makes intuitive sense. At an elementary level, one of the better approaches I have seen is that of the textbook “College Physics: A Structured Approach”, 2nd edition by Knight, Jones, and Field. The relevant section is 13.8 Entropy and the 2nd Law of Thermodynamics.

• Jim D

HS, if you are saying a photon can’t go from a colder object to a warmer object you need to say that, and then we know what we are arguing about. The language here is very imprecise.

• Joel Shore

What the global warming alarmists who live in their fictional ‘greenhouses’ fail to appreciate is that the big actor in Earth’s climate change drama is water, oceans of it. The energy of the sun falls on the oceans and lakes, causing evaporation and resulting in water vapor. The water vapor mops up heat and rises, leaving a cooler Earth behind. As water vapor rises the atmosphere becomes cooler, thinner where it eventually condenses and gives up its heat to the cold emptiness of space as the vapor returns to water and forming clouds or freezing and ultimately falling back to earth as rain, sleet, hail and snow.

Really. Thanks for informing us that this is left out of climate models. I will have to call up those modelers right now and suggest that they add this in. I am sure they will be very grateful!

By the way, here’s a little hint for you: Evaporation/condensation is indeed a very important mechanism for moving heat around in the atmosphere but it just doesn’t do that good a job at transporting the heat out to space. There is just something about conduction and convection through a vacuum that isn’t very effective. That is in the field of climate science, the easiest thing to focus on turns out to be the energy balance at the top-of-the-atmosphere (TOA). The energy balance at the surface turns out to be quite a bit more complicated but if you think about the energy balance at the TOA and then work your way down from there using the lapse rate, you are able to determine what happens at the surface more easily.

In actuality, water vapor is a part of a holistic process that results in a negative feedback because the amount of solar energy that is reflected away by clouds during the day more than offsets the suppression by clouds of cooling during the night.

I’ve already explained to you that you are misusing the term “negative feedback”. The fact that clouds block more solar energy than the amount of greenhouse warming they cause is correct. However, the difficult part is figuring out what happens to clouds in a warmer climate. It is not as simple as saying, “warmer temperature = more water vapor = more clouds” because the air’s capacity to hold water vapor also increases with temperature.

The work of Gerlich and Tscheuschner clearly shows us that to believe otherwise is to believe that the Earth’s atmosphere acts like a perpetual motion machine.

The work of G&T is garbage for the reasons I have explained. Every credible scientist agrees about this, including Roy Spencer and Richard Lindzen.

The secular, socialist Western academics’ greenhouse gas theory is based on conclusions about reality that contradict the basic laws of thermodynamics and do not correspond to observational evidence. The global warming alarmists’ GCMs have no forecasting ability because they erroneously calculate a doomsday scenario for one purpose only: to blame capitalism and Americanism for a non-existent problem.

How’s the tinfoil hat working out for you?

• Joel, you are the believer in a magical 2nd law that, in your mind says heat is transferred from cold to hot to REDUCE ENTROPY.

Of course, all objects above absolute zero radiate, but the 2nd law forbids radiation from colder to warmer to have the effect of reducing entropy, and that is why heat only flows one way from hot to cold, that radiation from colder objects cannot heat warmer objects.

There is a reason why the term “back-conduction” is not used and that is because it is trivial in the statistical sense.

• simon abingdon

Yesterday I read hunter saying “Everything radiates” and then Dallas saying “If..objects are above 0 K they..emit radiation” and suddenly (very late in the day) I realized:
If you can see it (or passively detect it) it’s radiating. Thanks guys.

• Peter317

Joel,

You wrote:

Like I explained to you, heat is a macroscopic quantity which is defined as the net flow of energy.

Not quite. Heat is not the net flow of energy.
While the net flow of energy to a body is positive, the heat content of the body will increase until the net flow of energy reduces to zero.
While the net flow of energy to a body is negative, the heat will decrease until the net flow of energy increases to zero.

• Jim D

HS, you are saying that because a photon from a colder to warmer object reduces entropy it is not permitted. The 2nd law doesn’t apply to individual photons, only the net of large numbers of photons which do go from hot to cold. You forget that the 2nd law is a concept of statistical thermodynamics (dealing with large numbers) not of quantum mechanics (dealing with individual particles).

• Joel Shore

Peter317: You will really piss off the thermodynamics terminology enforcers if you use “heat” in the way that you have. Heat is a flow of energy. You can’t talk about the “heat” in a body. Better to use the term “thermal energy”.

• Peter317

Joel,

I’m afraid you would also fall foul of the enforcers. By saying that heat is the net flow of energy, you’re also saying that heat reduces to zero when the net energy flow reduces to zero.
But the body still contains joules, and still has a temperature.

• Peter317

Besides which, by your definition you could tell KT where his ‘missing heat’ is hiding – it just stopped flowing! ;-)
(sorry, couldn’t resist)

• LOL, Wag I am about as far from being a CAGW proponent as it gets. Just because I understand the basic physics doesn’t mean I believe that a doubling of CO2 will cause more than a “warming” of about a degree or two over the general trend from 1900. The unforced variations is what will likely bite the butt of the alarmists, not nonsense with no basis in the reality of physics. You can add another blanket on a cold night or throw another log on the fire, it is the net flow of heat that counts.

• Joel Shore

No, Peter. You are still mistaken. It makes no sense to talk about the “heat” in something. That is terminology that you might use in colloquial speech but it is not used in thermodynamics. You would use the term “thermal energy”.

The technical statement is that “heat” is a process variable, not a state variable. I.e., you never talk about the heat of an object in state A; you just talk about the heat absorbed or emitted in going from state A to state B.

I know that these conventions may seem somewhat arbitrary…and, as I have noted elsewhere, the convention about only using “heat” for the net flow has screwed me up before…But, I am trying to be more rigorous about the terms now.

• Joel Shore

Hockey Schtick,

If you want to believe Claes’s nonsense then there is little that I can do to help you but at least you should be aware that Claes’s new interpretation does not change one single calculation of the greenhouse effect, since Claes does not dispute the equation but just the meaning of the terms…and it is the equation that is used in any models of the greenhouse effect.

• Peter317

Joel, I think we’re just going to have to agree to disagree on the terminology – my definition being more widely accepted in engineering circles.

• Joel Shore

Peter317: Yours is certainly not the terminology that was taught to the engineers when they took their physics course but maybe some revert back to this! At any rate, I am using the terminology as I have described it.

• Joel Shore, 8/15/11, 8:11 am, Vaughan Pratt IV

When you refer to the accepted picture and mainstream climate scientists agree, you are no longer talking science. Consensus and appeal to authorities violate the principles of science. A model advances to a theory or law based solely on its predictive power. Absent predictive power, a model can be no better than a hypothesis even if every living sole is a believer, including the Guru of all gurus. When a model fails to satisfy all facts in its domain, it is invalid and no longer science. AGW is such a model.

Since you talk about the accepted picture, no one can parse your observation or answer your question who exactly disagrees. Regardless, the violation of the Second Law is pervasive in AGW. No part of Earth is ever in equilibrium, yet that is the foundation of the AGW model, formerly a conjecture and now no longer even science. Global temperature, atmospheric gas content, the background natural state, and the surface layer of the ocean have never been in equilibrium. Earth has no preferred state. The arguments about acidification and extraordinary resident times for CO2 are based on this repeated error, and faulty mathematics. The Second Law applies only to an isolated and closed system. A proper 2d Law model including Earth would have to include the Sun and Deep Space.

The arguments presented here about back radiation warming things arises from an error in thermodynamics, violating the definition of heat and implications of the Stefan-Boltzmann law.

• Joel Shore, 8/15/11, 1:51 pm, Vaughan Pratt IV

I sort of liked your novel interpretation of the Second Law. It rehabilitates the notion that radiation is heat. Would anyone else in the world agree with us?

Now you ask, Do you think the colder object detects the hotter object there and refuses to radiate toward it or do you believe that the hotter object posts a little sign that says “No photons from colder objects allowed”?

It sort of does. All those things sort of happen.

Radiation and temperature are statistical. Photons are emitted from all objects with a temperature, which as you will see is a bit of a tautology. Consider the classical model of an object in a cavity, the cavity being a second object. The space between the first and the walls is filled with radiation. When in thermal equilibrium, the net radiation for both is zero. If the walls, say, are cooled, then the flow from the first object will increase! Or heat the walls, and the reverse happens.

One way to look at it is that while photons are always emitted, they are statistically going nowhere without a temperature difference, filling the cavity and being replaced at their source. Another way is that the radiation in the cavity exerts a back pressure and the objects exert a forward pressure. Energy flows only in response to a pressure difference, which is caused by a thermal disequilibrium. Yet another way to look at it is the Stefan-Boltzmann law with temperature as the independent variable, but temperature doesn’t exist (isn’t defined) except during thermal equilibrium.

The temperature of a system is a property that determines whether or not a system is in thermal equilibrium with other systems. Zemansky, M. S., Heat and Thermodynamics , Fourth, 1957, p. 7.

Thermodynamics is neither easy nor forgiving.

• Joel Shore

Jeff Glassman says:

When you refer to the accepted picture and mainstream climate scientists agree, you are no longer talking science. Consensus and appeal to authorities violate the principles of science. A model advances to a theory or law based solely on its predictive power. Absent predictive power, a model can be no better than a hypothesis even if every living sole is a believer, including the Guru of all gurus. When a model fails to satisfy all facts in its domain, it is invalid and no longer science.

That is a red herring. The argument is not about how a scientific theory should be judged but who should be doing the judging. I think the judging should be done by the scientific community and the institutions set up by the scientific community. They have generally performed that service well and have kept us from going back to the Dark Ages.

You guys seem to think the judging should be done by a few scientists with little or no publication record in the field and the right-wing think tanks that they are usually closely allied with.

While there are some legitimate scientific issues about exactly how severe the warming is going to be and its impacts, most of this is not about science at all. It is simply an attack on science that is inconvenient for some people to accept, just as is the case for evolution…and was the case for the dangers of smoking. And, the techniques of you guys are cribbed from them, perhaps not surprising in that some of the same actors are even involved.

• Errata re 8/15/11, 4:24 pm, Vaughan Pratt IV

My statement, The Second Law applies only to an isolated and closed system, is incorrect. Strike isolated

Turning to Zemansky, Heat and Thermodynamics, 4th:

When a system is not influenced in any way by its surroundings, it is said to be isolated. Id., p. 24.

Zemansky does not define closed, but the Second Law is applicable to a system that is closed in the sense that work but not mass may cross its boundary. That is consistent with Zemansky’s diagrams.

Zemansky defines a thermodynamic system to be influenced by surroundings, hot and cold reservoirs and work, all necessary for the Second Law. The problem with a thermodynamic model of Earth is that the solar constant is variable, neither constant nor sufficient. A modeler is free to model the Sun as a hot reservoir, but the problem that poses is that the surface temperature changes on the scale of decades vary with the fine structure of solar radiation models. On the scale of centuries, Earth’s evident hot and cold states may be due to solar variations beyond today’s best models.

Modeling the Sun as a constant will cause a misattribution of climate effects. IPCC already made that mistake by initializing GCMs as of 1750, zeroing on-going increases in temperature and CO2. Those natural effects evident in the Vostok record became wrongly attributed to humans. It compounds that initialization error by considering solar variations insignificant, and failing to model the atmospheric TSI amplifying effect reported even in the peer-reviewed literature.

The problem that involved the Second Law here was that without it, investigators have no basis in physics for modeling climate in equilibrium. They would have been led to the Second Law and the effects of the Sun if they had simply tried to justify their equilibrium assumption.

• suricat

Wagathon.

I concur, but the ‘definition’ of ‘the process’ can be confusing to individuals of different ‘teachings’.

The terms ‘back-radiation’ and ‘back-conduction’ can conjure violation to the second ‘law’ for intellects aligned to ‘macroscopic’ teachings, but this is because the microscopic ‘back-‘ point of the statement isn’t fully realised as the macroscopic ‘negative conduction’ term of ‘insulation’ for the macroscopically educated.

Perhaps ‘radiative insulation’ and ‘conductive insulation’ would be better understood by all factions of educational teaching?

It would also promote a discourse for the tipping point between negative and positive of conduction/insulation for all forms of energy transport.

Best regards, Ray Dart.

• Joel Shore

Hockey Schtick: You are not reading what I wrote. Heat does not flow from cold to hot but that does not mean that no radiative energy flows from cold to hot because heat is defined as the net flow of radiative energy between the two objects.

Just look at the equation that I just showed to mkelly, the last equation here: http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/stefan.html See the lefthand side, that is the amount of heat flowing. See the first term on the righthand side, that is the radiative transfer from hot to cold. See the 2nd term on the righthand side, that is the radiative transfer from cold to hot. If you don’t want to call that 2nd term “back radiation” despite the fact that this radiation can be measured, then you can call it “afkgihkrgjewowfweoognerogthn3rihoghipwergf It won’t change anything because once you accept that equation, you have the greenhouse effect. (If you don’t accept that equation, well, you have a heck of a lot of experimental evidence to argue against.)

• Joel Shore

Hockey Schtick says:

It matters because…

No. It doesn’t change anything. The physics is expressed by the mathematics. The computers don’t really care if you call one term in the equation “back radiation” or not. You are still going to get the same answer.

Joel then changes the subject to an unrelated topic and makes a series of unsupported ad hominem attacks against Claes. Typical.

“Unrelated topic”…”ad hominem attacks”?!?! This is unf-ing-believable. I am talking to you about Claes’s “theory”, which you, who I presume (in the biggest Orwellian doublespeak possible) call yourself a skeptic ,have bought into even though you haven’t a clue how it was derived, what evidence supports it, what evidence it neglects to address…just because it gives you the result that you want to believe.

Apparently, evidence is something that only needs to be presented for science that you are ideologically opposed to. Pathetic!

• And here’s why that equation is correct, but your interpretation that this proves the GHE and the effect of “backradiation” is wrong:

http://claesjohnson.blogspot.com/2011/08/how-to-fool-yourself-with-pyrgeometer.html

• Joel Shore

Hockey Schtick,

If you want to believe Claes’s nonsense then there is little that I can do to help you but at least you should be aware that Claes’s new interpretation does not change one single calculation of the greenhouse effect, since Claes does not dispute the equation but just the meaning of the terms…and it is the equation that is used in any models of the greenhouse effect.

• Joel – In your arguments with HS and others, I believe you have forgotten to account for the hydrostatic effect.

• Joel Shore says ” Claes’s new interpretation does not change one single calculation of the greenhouse effect, since Claes does not dispute the equation but just the meaning of the terms…and it is the equation that is used in any models of the greenhouse effect.”

Joel, apparently you didn’t follow the simple algebraic error Claes is pointing out that happens to be the pathetic basis of climate alarm. Here it is again with a few notes added to help you out:

“We see that a pyrgeometer does not measure DLR directly but invents it from the formula

E_in = E_net + E_out,

which is supposed to result from E_net = E_in – E_out expressing a Stefan-Boltzmann law of the form

E_net = sigma Ta^4 – sigma Te^4, [the false equation of climate alarm]

where Ta and Te are the temperatures of atmosphere and Earth surface.

But Stefan-Boltzmann’s law is not described this way in physics literature, where it instead takes the form

E_net = sigma (Ta^4 – Te^4) [i.e. the equation you linked to]

which does not allow extracting DLR as sigma Ta^4.

DLR and backradiation is thus fiction invented from an ad hoc formula without physical reality, which is not described in the physics literature.”

http://claesjohnson.blogspot.com/2011/08/how-to-fool-yourself-with-pyrgeometer.html

I see you’ve now entered the climate scientist default ad hominem mode to defend the religion, apparently the best course of action at this point.

• Joel, how dare you think a(B+C) = aB+aC!!!!!!!!!!!!!

Take an algebra lesson!!!!!!!!!

• Joel Shore

Fred: That’s a very depressing effect if correct! And, I worry that it may be correct.

Hockey Schtick: I have spent a lot of time patiently explaining all of this to you but it is apparently time wasted. I think it is you who does not understand basic algebra if you actually believe what Claes says. Do you not understand that the two things that Claes writes down are mathematically-equivalent?!?

Look, if you believe any nonsense that anyone writes down as long as it agrees with what you want to believe, then it is useless for us to argue with you. I only request that you go out and spread your arguments as far and wide as possible and tell others that this represents the best thinking of the “skeptic” community. That will do a better job of discrediting “skeptics” than could be done any other way.

• “The algorithm used in GEOLAND computes DLR by (in principle)
DLR = sigma Ta^4

where Ta is the measured atmospheric temperature (more precisely a frequency spectrum characteristic of the temperature). The algorithm to compute DLR reflects a Stefan-Bolzmann’s radiation law (SB) of the form

(1) Q = sigma Te^4 – sigma Ta^4,

where Te is the Earth surface/instrument temperature, expressing the net heat transfer Q as the difference between two-way gross heat transfer back and forth. DLR is then identified with the second term, see also the The Atmospheric Radiation Measurement Program.

But this form of SB is not found in the physics literature, where instead SB is written as

(2) Q = sigma (Te^4 – Ta^4),

which expresses net heat transfer from warm to cold. In this version it is impossible to single out the term sigma Ta^4 and claim it to represent DLR. In this version of SB there is no DLR, no back radiation, only net heat transfer.

We now see the trick: Rewrite (2) as (1) by an algebraic manipulation and then interpret
the miraculously appearing term sigma Ta^4 as DLR:
By a purely algebraic manipulation a massive physical flux of energy DLR has been created.
With massive DLR it is possible to stir up CO2 alarm.
This trick has fooled a whole world of climate scientists. Does it fool you?

Recall that CO2 alarmism is based on making the effect of something small (CO2) into something big (increase of global temp by 3C), and this inflation is based on replacing small one-way net heat transfer by (the difference of) gross two-way transfer.

It is like creating something out of nothing by writing 0 = 100 – 100, which miraculously creates 100 out of 0.

But this inflation is fictional and is based on an incorrect interpretation of the SB law in the literature. It is surprising that so many people get fooled by the simple algebraic trick used.

PS Measuring temperature by recording frequency spectrum is possible by using SB. But to measure two-way transfer of heat energy is a different issue.

• Jim D

HS, it makes no physical sense to prefer to combine these two terms when Ta and Te are independent of each other. Johnson is suggesting they are not independent? Unbelievable.

• HS, you do realize that eq 1 and eq 2 are mathematically equivalent?

• Joel Shore

Hockey Schtick: I suggest that any physicist or mathematician that you meet, you should point out Claes’s brilliant insight about writing Q = sigma Te^4 – sigma Ta^4, rather than Q = sigma (Te^4 – Ta^4). I am quite sure that they will all be duly impressed by that and will immediately abandon any belief that they might have had in the greenhouse effect!

• Joel Shore

Rattus: But you are missing thewhole point…We physicists write it the other way and that clearly shows something deeply profound and significant that nobody noticed until the very wise Claes Johnson made it apparent to us! ;-)

• Yes, eq 1 and 2 are mathematically equivalent and instead of saying ‘algebraic error’ I should have said ‘algebraic trick.’ The point Claes is making is that instead of implying there is a massive transfer of heat both from cold to hot and vice versa, there is (per the 2nd law) only a one way transfer from hot to cold. Joel Shore, etc. assume a massive heat transfer from cold to hot is taking place, overwhelmed by an even more massive transfer from hot to cold. Claes is showing that instead there is only a transfer of heat one-way of a much smaller magnitude. Yes, 0 = 100-100, but so does 0=1-1.

• HS, the only way there would be a “massive transfer of energy from cold to hot” is if Tc (the temp of the cold body) was greater than T (the temp of the warm body). This is impossible by definition — a body can not be both colder and warmer than a reference body at the same time.

• Joel Shore | August 15, 2011 at 9:41 pm | Says
Hockey Schtick says:

Joel Shore, etc. assume a massive heat transfer from cold to hot is taking place, overwhelmed by an even more massive transfer from hot to cold. Claes is showing that instead there is only a transfer of heat one-way of a much smaller magnitude. Yes, 0 = 100-100, but so does 0=1-1.

(1) And, that matters why exactly?

It matters because

1) DLR does not heat the Earth (which Vaughn Pratt also explains via different means in the header of this post)
2) DLR measurements of heat energy from GHGs are fictional
3) The “backradiation” concept is fictional [there is radiation, but it does not cause any heat transfer from cold to hot]
4) Ergo, the TK energy budget is fictional
5) The NASA energy budget derided on this site many times over is in fact correct [note complete absence of GHG “backradiation”]:

6) The energy from the Sun cannot be recycled or “trapped and re-used” to create a perpetuum mobile
7) No heat is transfered from cold to hot (negligible in a statistical as well as macro sense)
8) all the arguments we have been stomaching from you for years that ‘G&T don’t understand the 2nd law’ and that the 2nd law really says there is a massive 2-way transfer between cold & hot are false
9) As Claes says, “Working with fictional differences of massive gross flows feeds alarm, while physically correct net flow does not.” In other words, implies that the climate is much more sensitive to changes in greenhouse gas concentrations than it actually is.

Joel then changes the subject to an unrelated topic and makes a series of unsupported ad hominem attacks against Claes. Typical.

• Bryan

To Jeff Glassman above
Your understanding from Zemansky (excellent textbook) above is quite correct.

‘On radiative exchange he says (from memory)
The difference between the radiation that a body absorbs and what it emits is called heat.
Then some pages later
Thus we can say for radiation as for conduction and convection;
heat will only move spontaneously from a higher temperature object to a lower temperature object.’

One quality of genius is to express things as simply as possible.

• So Joel, do you now understand that while Eq 1 and Eq 2 are mathematically equivalent, the implied magnitudes and directions of heat flow (including massive transfer from cold to hot) implied by Eq 1 are fiction, the basis of the false claims of 333 W/m2 DLR heating the Earth, and of climate alarmism? As Claes says, “the distributive law of algebra does not create physics.” Same question to Chris Colose.

Rattus Norvegicus says:
HS, the only way there would be a “massive transfer of energy from cold to hot” is if Tc (the temp of the cold body) was greater than T (the temp of the warm body). This is impossible by definition — a body can not be both colder and warmer than a reference body at the same time

Correct, yet all the “experts” here are claiming there is a massive 2-way transfer.

David N | August 15, 2011 at 6:22 pm | Reply
So you’re (still) saying that the rate of radiative heatloss of an object is independent of the temperature of its surroundings.

Claes Johnson | August 15, 2011 at 6:29 pm | Reply
No, I say that it depends on the temp of the surrounding medium according to the SB Q = sigma (Te^4 -Ta^4) with Te and Ta the temp of the Earth and atmosphere.

• Jim D

HS, do you agree with Claes’s 7:25 pm claim, or has he finally gone off the rails with that remark? If you want to talk about magical effects, it is right there. Maybe you can find a way to defend it within the realm of physics.

• Joel Shore

Hockey Schtick says:

Joel Shore, etc. assume a massive heat transfer from cold to hot is taking place, overwhelmed by an even more massive transfer from hot to cold. Claes is showing that instead there is only a transfer of heat one-way of a much smaller magnitude. Yes, 0 = 100-100, but so does 0=1-1.

(1) And, that matters why exactly. [By the way, I would avoid saying “heat transfer” instead of “energy transfer” as the latter is more correct…and the former will get Bryan really mad at you.]

(2) Claes has not shown ANYTHING. What Claes has done is write down a bunch of mathematics that noone has even bothered to check as far as I know because it starts from such a flawed premise. He basically wants to displace an entire field of physics (statistical physics) because he doesn’t understand it. He wants to replace it with a new axiom which basically states that…got this…the world has dissipation in it because a numerical method of solving partial differential equations has dissipation in it that everyone else in the world but him interprets as a numerical artifact of the method and not a new fundamental principle of the universe. (So, basically, he can get dissipation out by putting it in explicitly! Well, isn’t that a surprise!?!) He has given exactly zero proof for this new idea, has to do somersaults to try desperately to get around all the experimental evidence against his notion, and has made no attempt to rederive an entire century’s worth of physics that has been explained by statistical physics. This really ought to appeal to the “skeptic” crowd who claim that they don’t trust models and want empirical data. Here, you have a new theory with no experimental support based on the premise that numerical models describe reality better than reality itself!

P.T. Barnum was really an optimist!

• Joel Shore

Hockey Schtick says:

So Joel, do you now understand that while Eq 1 and Eq 2 are mathematically equivalent, the implied magnitudes and directions of heat flow (including massive transfer from cold to hot) implied by Eq 1 are fiction, the basis of the false claims of 333 W/m2 DLR heating the Earth, and of climate alarmism? As Claes says, “the distributive law of algebra does not create physics.” Same question to Chris Colose.

This claim isn’t even true. Do you know what would happen to all the calculations and models of the greenhouse effect if Claes’s point-of-view were adopted? Well, guess what, I have just magically gone and changed all the models and calculations in the universe and it makes no difference. It wasn’t that hard really since the models are based on the EQUATION; they are not based on whether or not you choose to call one of the terms “back-radiation”.

So, even if Claes was correct and all the wealth of experimental data that we have that objects really do radiate on the basis of their temperature and independent of the objects that they are radiating to was wrong, it would not change one calculation.

• Once again, Joel Shore misunderstands and/or misquotes what Claes is saying

Joel Shore August 15, 2011 at 9:59 pm: “So, even if Claes was correct and all the wealth of experimental data that we have that objects really do radiate on the basis of their temperature and independent of the objects that they are radiating to was wrong, it would not change one calculation.”

David N | August 15, 2011 at 6:22 pm | Reply
So you’re (still) saying that the rate of radiative heatloss of an object is independent of the temperature of its surroundings.

Claes Johnson | August 15, 2011 at 6:29 pm | Reply
No, I say that it depends on the temp of the surrounding medium according to the SB Q = sigma (Te^4 -Ta^4) with Te and Ta the temp of the Earth and atmosphere.

Joel Shore fails to understand that the difference between Eq 1 and Eq 2 DOES make a difference when looking at perturbations of forcing, as perturbations of net one-way flow of energy (small) vs perturbations of gross two-way flow of energy (big). This is the origin of CO2 alarmism: how to make something small into something big.

Joel Shore fails to address any of the 9 reasons listed why the difference between what the real 2nd law says [heat is transfered one way only] and his fictional 2nd law [massive heat transfer is 2-way between hot and cold] matters, saying “it makes no difference.” Eq 1 is analogous to Joel’s fictional 2nd law, and Eq 2 analogous to the real 2nd law.

• Joel Shore

Hockey Schtick:

Calculations of the magnitude of the greenhouse effect are based on the equations of radiation transfer, not how one interprets them, including how large a percentage perturbation it happens to be.

As for the rest of what you say about the Second Law: I teach the Second Law and I have published papers in statistical physics, which provides the underpinnings of thermodynamics. I have also worked in industry doing practical radiation transfer calculations. What exactly is your background that causes you to believe that you understand the Second Law so well?

• Wagathon

What we see with you Shore is global warming alarmism simply means never having to admit you are wrong and then toss a personal attack grenade on the way out as you turn your back on reason.

• Joel Shore

No…What we see is your total inability to comprehend anything that disagrees with what you want to believe. If you want to believe nonsense about physics, then go ahead. I’ll just ask that you do the same thing as I told Hockey Schtick to do: You should go far and wide spreading your beliefs and telling them that this is the way “climate skeptics” understand the science. You’ll do more to discredit the skeptic movement than could be done any other way.

• Wagathon

Your explanations reveal a fundamental ignorance of thermodynamics and this is not surprising considering what amounts to the global warming alarmists’ unconscious incompetence if not outright deception in their absolute loss of ‘official’ raw data upon which the AGW True Believers’ faked snapshot of the world rests, and the hypocrisy and corruption of all of those who engage in the ideologically-motivated global warming political movement.

• Bryan

To Jeff Glassman above
But note he was careful NOT to say that both radiations were heat.

Only the difference.

This (as you probably know) is the part that can be turned into some other energy form or to do work.

• The adiabatic lapse rate in the atmosphere varies with temperature, salinity, and pressure. For typical values of ocean salinity and for a temperature of 20C and pressure right near the surface, the ocean adiabatic lapse rate is 0.185 K/km (compared to 9.8 K/km in the atmosphere).

• suricat

curryja.

“The adiabatic lapse rate in the atmosphere varies with temperature, salinity, and pressure.”

???

I think you’re confusing your definitions here Judith. :)

Best regards, Ray Dart.

• the adiabatic lapse rate in the OCEAN varies with temperature, salinity and pressure

• NIV- I think your description is incorrect. The warming effects of GHGs involve radiative transfer that is then modified by convection, and rather than being ignored, this is a fundamental calculation in all analyses. Without the radiative effect, however, there would be little for convection to operate on. It does not “control the outcome” but merely adjusts it. Ultimately, the greenhouse effect is responsible for Earth’s temperature being what it is.

There is no fundamental difference in principle between the IR-absorbing behavior of water vapor and liquid water, but there are enormous quantitative differences. Even so, water would certainly boil in the circumstance you describe in the absence of convection, but again, this has nothing to do with the validity of the “greenhouse” mechanism and its ability to distribute energy in all directions, so I’m not sure what your point is.

There is one additional distinction between the atmosphere and oceans that is also critical – atmospheric lapse rate and the decline of pressure and molecular concentrations with altitude. This means that IR can always escape to some extent by moving to a higher colder altitude where there are fewer intercepting GHG molecules – this can’t happen in water.

In summary, the greenhouse effect, including the downward radiation (colloquially “back radiation) is a critical determinant of surface temperature, with no serious challenges to its validity as stated, but a universally acknowledged understanding of the role of convection in adjusting the temperature response toward an adiabatic lapse rate.

• Nullius in Verba

“The warming effects of GHGs involve radiative transfer that is then modified by convection”

Yes, but the “modification” is such as to render the radiative transfer entirely irrelevant. What you say is true of liquid water too. Radiative transfer is involved, and convection “modifies” it. Internal back-radiation in a pool of water certainly exists, but has no effect on the temperature at the bottom, and the same applies to the atmosphere.

Once you have enough of a vertical gradient to get convection, only convection enters into the answer. It’s like trying to explain why a pot of boiling water is at exactly 100 C by going into a long energy-balance calculation involving the heat supplied by the stove, the air temperature, the radiation from the sides and lid of the pan, the radiation from the kitchen, the colour of the paint, and so on, and then only as an afterthought mentioning that all of this is “modified” by the latent heat of the boiling water. I would argue that the explanation of the water’s temperature is that 100 C is the boiling point of water, and all other considerations are secondary. Yes, the pan lid radiates IR to and absorbs IR from the water’s surface. So what? It’s true, but not explanatory.

• In troposphere the convection makes indeed many details of radiative energy transfer irrelevant as the convection reaches automatically that strength that is required for getting to the stability limit of adiabatic lapse rate. Thus less radiative heat transfer is automatically compensated by more convection and vice versa.

That’s not any more true, when radiative heat transfer by itself is strong enough to produce the adiabatic lapse rate, but at that point we are out of troposphere by definition.

The radiative heat transfer is also important near the surface, because it provides one of the two main mechanisms for energy transfer from the surface to the atmosphere. The other one is latent heat transfer.

• Yes, but the “modification” is such as to render the radiative transfer entirely irrelevant

I’m afraid that’s completely wrong. The radiative transfer is what dictates the temperature change, and in the atmosphere, convection adjusts it in the direction of an adiabat. However, the new temperature profiles, while adiabatic (or approximately so) are now higher at any given altitude than without the radiative transfer, all the way down to the surface.

If you want to understand this, perhaps the best exercise would be to calculate the change in radiative balance at the top of the atmosphere due to a change in CO2 (for this exercise, we can neglect feedback effects of water vapor, clouds, lapse rate, albedo, etc.), and then calculate how this affects surface temperature after convective adjustments have occurred. The effect is significant. Feedbacks are a different subject, of course, but as you know, most estimates put them in the positive category, and arguments on that topic can’t be resolved in a few comments here.

• To add to the above, remember that the temperature before the CO2 change also involved convective adjustments, and since convection is only a response to a temperature change, the before/after difference must have started with a temperature change to which convection then responded. That change was initiated by radiative transfer effects. If they had not changed temperature, convection would not have had anything to respond to.

• Basically the temperature difference is created by heating of the surface by solar radiation and reduced by both radiative heat transfer and by convection as well as latent heat transfer.

What’s essential is that the radiative heat transfer cannot proceed unhindered from the surface to the space but is reduced by atmosphere to a level that would still lead to higher lapse rate than the adiabatic stability limit.

• Nullius in Verba

The radiative transfer to outer space does affect the answer. Radiative transfer internal to the atmosphere (where it is convecting) does not. Back-radiation is internal to the atmosphere. More back-radiation would simply be cancelled by more convection, leading to the same lapse rate.

The surface temperature is the effective radiative temperature (controlled by insolation and albedo) plus the average altitude of emission to outer space (controlled by GHGs) times the lapse rate (controlled by pressure and humidity).

Back-radiation purports to affect/cause the lapse rate in this picture. Where the lapse-rate is convectively limited, which is most of the troposphere, it doesn’t. The exceptions are a minor modification to the lapse-rate mechanism, not the other way round.

I’m not arguing the physics, I’m arguing which part of the physics constitutes the better explanation.

• The details of back radiation are important in the determination of the energy transfer from the surface and thus also of the surface temperature. I don’t think there is any way of bypassing these details, when one tries to reach quantitative understanding of those physical phenomena.

• Nullius in Verba

“The details of back radiation are important in the determination of the energy transfer from the surface and thus also of the surface temperature”

Just as the IR radiated from the pan lid is important in the determination of the energy transfer from the boiling water, and hence it’s temperature.

This, I suggest, is like saying if you painted the pan lid black, the water would boil at a different temperature.

• Radiative transfer internal to the atmosphere (where it is convecting) does not. Back-radiation is internal to the atmosphere. More back-radiation would simply be cancelled by more convection, leading to the same lapse rate.

I believe you are continuing to confuse yourself. Radiative transfer internal to the atmosphere is critical in linking surface temperatures to radiative imbalances at the tropopause or at the top of the atmosphere.
Convection does not “cancel” back radiation. Rather, during a radiative imbalance, surface temperature rises in response to back radiation until incoming absorbed energy and IR flux to space again balance. Convection is part of the restoration process, which also includes radiation, latent heat transfer, and conduction. In most cases, convective adjustment maintains a near-adiabatic profile by redistributing some heat upward so that the lower altitudes are not too hot and the higher ones too cold for an adiabat The adiabat is restored, but at a higher temperature, so there is no canceling of the radiatively induced temperature rise or the contribution to it from back radiation.

• Nullius in Verba

“Radiative transfer internal to the atmosphere is critical in linking surface temperatures to radiative imbalances at the tropopause or at the top of the atmosphere.”

The only thing linking temperature at the tropopause to the surface is the adiabatic lapse rate. The temperature at the tropopause plus the height of the tropopause times the lapse rate equals the surface temperature. Same for any other lower altitude. Unless you are saying that back-radiation can affect – increase or decrease – the adiabatic lapse rate, it cannot have any effect.

I suspect we’re not going to get anywhere with this – we seem to be going in circles. Good debate, though. :-)

• Fred,
The point is that back radiation is one expression of the fact that the IR radiation from the surface cannot escape unhindered to the open space.

If the IR would be completely blocked, the temperature of the surface would be much higher. The stronger the radiative heat transfer is the weaker is the GHE. The sum of convection, latent heat transfer and radiative heat transfer must be at the level that corresponds to the adiabatic lapse rate. That equality is guaranteed by the convection, which adjusts automatically to the required level given the same state at the bottom and the same radiative processes at the top.

It’s true that GHE is needed, but the radiative heat transfer acts to weaken the GHE, as does convection.

When radiative heat transfer alone is sufficient for stability, convection stops and the lapse rate is something less than adiabatic.

• NiV,

Adiabatic lapse rate is internal to the troposphere. What happens at the interface between the surface and the troposphere is affected by IR. That determines, how much radiations escapes directly to the space and that affects also the temperature of the surface and the rate of evaporation, which affects the humidity of the atmosphere. These details affect the outcome and they are not compensated by changes in convection.

• Nullius in Verba

“These details affect the outcome and they are not compensated by changes in convection.”

In what sense? Do you mean convection doesn’t change, or that it doesn’t change by the right amount to compensate?

What happens to the lapse rate, in that case?

• Unless you are saying that back-radiation can affect – increase or decrease – the adiabatic lapse rate, it cannot have any effect.

That continues to be wrong, NIV. Back radiation changes the temperature at which any given lapse rate operates, and so it can increase surface temperature in response to CO2 without a change in lapse rate. This is the result of a rising mean radiating altitude, with the lapse rate then translating the temperature increase at all lower altitudes down to the surface. Again, I suggest you do the calculations in order to understand this.

Pekka – Radiative transfer within the atmosphere operates in all directions, and it is this isotropic feature that creates the GHE. At higher temperatures, there is an increase in upward emissions (via Stefan-Boltzmann), but at higher GHG concentrations, there is an increase in downward emissions. The enhanced upward rate “weakens” the effect of the GHGs that act to reduce net upward emissions, but not until the surface temperature has increased, at which point a balance is restored. Without that upward transfer (aided by convective processes), the planet might become intolerably hot. I don’t think we disagree on this point, so we are discussing differences in the way of looking at it.

Regarding convective adjustments, the effect of latent heat transfer is to reduce the slope of the adiabat away from the dry adiabat at about 9.8 C/km and in the direction of a moist adiabat at about 5 C/km.

• Nullius in Verba

“This is the result of a rising mean radiating altitude, with the lapse rate then translating the temperature increase at all lower altitudes down to the surface.”

I just said that. Like I say, we’re going in circles.

• NiV,

The surface presents a discontinuity. There’s no lapse rate at a surface of discontinuity. The energy balance at this discontinuity depends on several components, whose relative sizes are determined by properties of each of them.

There’s no convection through the surface. The convection builds up over a layer of some finite thickness, and the thermodynamics of that layer is not so simply determined by the lapse rate and convection as the ultimate process that guarantees it.

The size of the net IR flux has a real influence on the outcome under those conditions.

• Nullius in Verba

Pekka,

Oh, I see. You’re talking about microclimate/UHI/albedo stuff, yes? If you mount your thermometer over black tarmac, you’ll read a different temperature sort of thing…

Yes, I agree. The surface skin layer is non-convective, so the above considerations don’t apply. Is that the part of the atmosphere that people are supposed to be measuring, though?

• Fred,

I have said it before. Correct physics can often be expressed in many ways. If they are all correct, they are equivalent, but it may also happen that some of these descriptions have more limitations than others.

The role of IR radiation in GHE can be described by considering all radiation at all stages, but it can also be described by considering the net energy flux. In the discussion with NiV we both consider the net IR energy transfer within the troposphere. That’s perfectly correct and equivalent with the approach, where back radiation is considered separately.

I don’t seem to agree with NiV on, how the interface with surface must be handled to get it correct. On that point I seem to agree with you.

You emphasize the role of back radiation in GHE, but that’s not the only way of describing it. Many people have recently expressed acceptance to the alternative description based on insulating effect. In that approach only the net energy transfer is considered. Having the back radiation is considered as a reduction in the net transfer. When a flow is automatically and unavoidably canceled in part by an opposite flow, that situation may be considered as counteracting the energy flow exactly as an insulation does for energy flows in other connections. This is not only a superficial analogy, but there is much similarity with thermal insulation even on the microscopic level, but I’m not going to that now.

Mostly we agree on the actual physics, but I’m not certain, whether there are some disagreements even on that. The most obvious difference is in any case your willingness to stick to one description of at least two equivalent, but different ones, while I feel that the other one might be even better as an understandable description, and perhaps also more acceptable to some skeptics of the non-denialist group.

• NiV,
Not specifically micro climate, and albedo was not in my mind.

The effects that I meant are present everywhere and they affect also averages.

• Nullius in Verba

“Not specifically micro climate, and albedo was not in my mind.”

I’m not sure I understand, then.

Let’s try applying it to my pond example. I would agree that if you get close enough to the black plastic sheet at the bottom of the pond, convection is suppressed. Are you saying that in these circumstances, back-radiation from the water could affect the temperature of the sheet itself, and that if the water was to be magically made more IR-opaque, that the temperature of the sheet could increase?

• We do agree that in the troposphere convection is the mechanisms that adjusts to guarantee adiabatic lapse rate as long as other mechanisms would lead to a larger gradient. That happens independently on the extent of this extra gradient. We understand that large gradient results when energy flow is large in comparison with the heat transfer mechanisms, and that convection reacts very strongly to excess gradient. Thus the gradient with convection depends very little on the size of the convective flux. All that is based on thermodynamics and dynamics of gases.

On the surface we don’t have any single mechanism that reacts much more strongly to the temperature difference of the water near to the skin (say at the depth of 1 mm) and the air close (say 1 m) to the surface. When one of the components changes, downwelling IR as the point considered, that is not compensated by one change only, but many things change having each a significant share in returning the balance. The relative size of these changes varies depending on the particular circumstances, but typically more than one factor is important. The changes include the temperature difference between water and air, evaporation, humidity of air, emission of IR by the surface and convection, most certainly not only convection.

That’s the difference. Many things change, not only net IR and convection as in the middle of troposphere.

To be precise something else changes also in the middle of troposphere. That’s absorption and emission of IR at wavelengths than can penetrate through a large fraction of atmosphere unabsorbed. That has also other consequences, which are not compensated by changes in convection. It’s quite important as it influences directly the radiation escaping up from the troposphere as well as the balance at the Earth surface that I discuss above. Convection cannot balance fully anything that’s not internal to the troposphere.

• Nullius in Verba

“On the surface we don’t have any single mechanism that reacts much more strongly to the temperature difference of the water near to the skin (say at the depth of 1 mm) and the air close (say 1 m) to the surface.”

First, I’m surprised that it takes as much as a metre before convection starts in air. I didn’t know it was that viscous. Are you sure?

And given the complexity you describe, and how specific it must be to properties of the surface other than the albedo, I’m astonished they can model it well enough to predict it! For the whole globe!

We are directed to radiative-convective models that estimate the magnitude of the greenhouse effect – but none that I saw said very much at all about the detailed surface properties – transparency, heat capacity, thermal conductivity, frequency response, roughness, etc. Surely the effect must be very different over water, grass, sand, forest, etc. And yet, the simple models I saw all seemed to think average albedo and input power were sufficient. Clearly, we have a whole new list of things to question, and be sceptical about! Like, have they got their models for each of these factors, and the frequency of their occurrence on the surface of the Earth, correct? How carefully are they documented?

And indeed, one now has to question whether measurements taken down in the boundary layer – with all this complex dependence on local conditions – is meaningful for the climate as a whole at all.

Hmmm…

• NiV:
The surface temperature is the effective radiative temperature (controlled by insolation and albedo) plus the average altitude of emission to outer space (controlled by GHGs) times the lapse rate (controlled by pressure and humidity).

Specific humidity near the tropopause is mainly controlled by changes in levels of solar activity. A pretty clear indication that the Sun’s variation has a much larger effect on ‘climate change’ than co2 levels IMO.

• Perhaps I should add that the situation may differ from the above also at high latitudes, where the lapse rate is often significantly less than adiabatic.

• I haven’t had time to absorb the whole of this PP/FM/NiV debate, though I certainly agree with NiV’s sentiment:
Good debate, though. ;)

I think the argument I make at
http://judithcurry.com/2011/08/13/slaying-the-greenhouse-dragon-part-iv/#comment-98462
most closely corresponds to NiV’s position, which I take to be that it doesn’t matter how the heat in the atmosphere gets to the surface so long as it gets there. That is, DLR should not matter, regardless of whether it is the main conduit to the surface of atmospheric warming.

To that I would add my argument at the end of that post that not only doesn’t it matter, it isn’t true that DLR plays any significant role in global warming.

Although this has seemed intuitively obvious to me for some time, it’s only now that I’ve got around to doing the requisite math to prove it, based on the skin effect (for air in contact with both land and sea — for sea there is also skin effect under the surface but water has 24 x the thermal conductivity of air).

Certainly the estimate of 4-5 W/m2 for radiative dF/dT in my argument should not bother anyone. And the value of 25/s W/m2 for surface conduction seems fine to me. Although s is not so clear, I would expect it to be less than 0.1 mm given any breeze at all but surely no more than 1 mm.

The only quantity I didn’t calculate was dF/dT for convection. However I don’t see why convection should be relevant at all so long as there is a constant exchange of air between the surface and all altitudes. This is because the whole of this constantly moving column will be heating at essentially the same dT/dt rate from top to bottom at all times on average. Furthermore that heating is so slow as to be entirely masked by diurnal fluctuations at all altitudes though of course most strongly at the bottom kilometer.

If DLR is to play any role at all it would be smoothing out these fluctuations between altitudes. It’s not clear to me that this is needed for a working theory of global warming however.

• Vaughan – Your conclusion that DLR plays little role in global warming appears to be incorrect for the reasons I described at Comment 98474. DLR is almost certainly the predominant mode of transfer of atmospheric warming to the surface.

• Some of the precise mathematical details are described in Raypierre’s book starting on page 391.

• I agree completely. Down welling long wave radiation due to CO2 would have to run the same gauntlet down as it does up. If the infrared thermometers were tuned to the CO2 spectrum and showed high down welling in that band, then down welling 15 micron infrared radiation due to CO2 would indeed warm the surface. I haven’t seen that published anywhere.

As it is, the impact of CO2 is its absorption of a narrow band of IR, transferring that absorb energy to another molecule and so on back to the surface where it has to compete with convection, latent cooling and more CO2 molecules.

DWLR is a convenient tool for measuring or modeling changes in the net radiation, but not so good for explaining a slightly more complex process.

• Nullius in Verba

“I think the argument I make at […] most closely corresponds to NiV’s position, which I take to be that it doesn’t matter how the heat in the atmosphere gets to the surface so long as it gets there. That is, DLR should not matter, regardless of whether it is the main conduit to the surface of atmospheric warming.”

There’s a better explanation of my position at http://judithcurry.com/2010/11/30/physics-of-the-atmospheric-greenhouse-effect/#comment-16901 in case you haven’t seen it before.

It can be summarised as saying that in a convective atmosphere, the lapse rate is (to a good approximation) fixed, so temperatures at all altitudes move up and down in unison. Internal transfers between one part of the atmosphere and another that would tend to upset this lapse rate (like back-radiation) trigger fast-acting convective changes to cancel them out. Only transfers outside the system can have an effect – radiation direct to space, insolation, energy transfer to the deep ocean, etc. and these will shift the whole system up or down together.

There’s another prediction it makes. Because surface temperature is effective radiative temperature plus average height of emission to space times lapse rate (Ts = Teff + z * MALR), the theory predicts that if the lapse rate were negative, then adding more greenhouse gases would cause cooling! This would be intuitively hard to explain using any sort of “trapping heat” or “blanket” analogies.

The pond thought experiment was another attempt at a counter-example. If the lapse rate is near zero, you get no greenhouse effect, no matter how strong a greenhouse “gas” you use. (As a bonus, you can also prove that convection is responsible by considering the way a solar pond works.)

It’s true I hadn’t really thought about skin effects and the discontinuity at the surface as being involved. My thinking was based on looking at the radiative-convective models the mainstream scientists used, and figuring out for myself what they really meant physically, rather than what the scientists said they meant. No descriptions or models I’ve come across mention the GHE being specifically a skin effect. Nevertheless, I’ll have a think about it.

• The so called ‘skin effect’ is negligible. Even at very moderate windspeeds the water surface is constantly broken and differentials maintained. This was experimentally demonstrated by Japanese oceanographers years ago. Not that experimental evidence will convince those committed to the AGW hypothesis.

• Some effects are broken, some persist.

Conservation of energy is one of the laws that are not broken. That tells that all the solar energy absorbed by the atmosphere, which occurs mostly at depth of a few meters must either remain in the atmosphere and heat it or be transferred to the skin and be lost from the skin to the atmosphere (or to a small extent directly to space). Therefore we are guaranteed to have on the average an upwards energy flux in the topmost layers of the atmosphere and this must extend almost as far down as solar energy penetrates. Otherwise the ocean would warm much more rapidly than it does.

The energy balance tells also that the change in DLR will have many effects on the various fluxes at the skin. Those will all be intermediated by the skin temperature, which is the only thing directly influenced by DLR.

28. Vaughan Pratt
“When I measure the DLR by pointing my Microtemp MT250 infrared thermometer at the sky it registers 20 degrees below zero, icy indeed and corresponding to 2.534 * 5.67 = 232 W/m2 of DLR. Pointing it at the ground, it registers 20 °C or 2.934 * 5.67 = 418 W/m2 of upwards longwave radiation. . . . I’ve been unable to persuade myself that back radiation is anything more than a computationally unusable extrapolation from John Tyndall’s insightful experiments in the 1850s.”

I think a major problem is confusion over the multiple meanings of “warming”.
The major impact of downward atmospheric IR emission is that it reduces the heat loss to space.

Instead of a “block of ice”, you would be much better to use an igloo” Any Eskimo, Arctic explorer, Alaskan native, or Boy Scout can tell you that building an igloo can save your life, even though the ice is much colder than you are. First the Downwelling Longwave IR Radiation (DLR) or ice emission provides a major reduction in heat loss compared to direct radiation to space. Secondly it provides a convective trap to reduce heat loss.

Ignoring the convective contribution, the igloo will give some semblance of the benefit of the atmosphere in reducing the heat loss to space.

• Vaughan Pratt
Regarding “(ii) Clouds. Water droplets that scatter, absorb, and radiate differently from GHGs.”

May I suggest “radiate differently from water vapor and other GHGs” to clearly indicate that water vapor is the most important GHG rather than a possible miss interpretation that it is excluded from GHGs.

On your comment on 2 Acidity, “Consumes carbonate faster than coasts can replenish it,” may I encourage you to include the other very large sources of carbonate as well as other even larger chemical buffers.

See papers by Tom Segalstad See CO2 Web info
http://folk.uio.no/tomvs/esef/ Especially
4. Chemical Laws for Distribution of CO2 in Nature http://folk.uio.no/tomvs/esef/esef4.htm

The geochemical equilibrium system anorthite CaAl2Si2O8 – kaolinite Al2Si2O5(OH)4 has by the pH of ocean water a buffer capacity which is thousand times larger than a 0.001 M carbonate solution (Stumm & Morgan, 1970). In addition we have clay mineral buffers, and a calcium silicate + CO2 calcium carbonate + SiO2 buffer (MacIntyre, 1970; Krauskopf, 1979). These buffers all act as a “security net” under the most important buffer: CO2 (g) HCO3- (aq) CaCO3 (s). All together these buffers give in principle an infinite buffer capacity (Stumm & Morgan, 1970).

• Leo G

David, , the easiest way to “see” this in my experience is looking at house roofs after a good snow. You can tell which were built with good insulation values compared to those that weren’t, by the obvious melting of snow from the lousily insulated roofs.

The attic insulation does not stop the home from loosing heat, but it does slow down this loss dramatically. Also, if we have two similiar built homes side by each, one with good insulation values, one with lesser insulation, and both occupants like to keep their homes at 20*C during the winter, I will guarrantee, that the insulated house will take less energy to maintain that temperature. Therefore, if we were to apply the same amount of energy to both houses, such that the under-insulated house was kept at 20* C, again, I will guarrantee, that the better insulated home would be much warmer inside.

To me, this is the easiest way to understand what effect CO2 has on our planet.

• Bruce

However, if someone opened a window, or left the damper open in the fireplace without a fire …

I believe there is a recent paper that suggests someone has left a window open to space.

• Leo G

Nice catch Bruce.

Thanx.

29. Jim D

165 comments in 6 hours. I think Judith has put this thread up to guarantee pushing over 100000 posts for Climate, Etc., by the end of the week.
Only 1700 to go. :-)

• Yes, we are getting close to 100,000 comments, comments are currently accruing at almost 500/day, so it should be a few days yet, we will have a blogospheric celebration :)

30. Jim2

Where I live in Texas we have been having 100+ days for what seems forever. Today, it is overcast. My IR thermometer tells me the clouds are at 70 F. But the air temp near the ground it 90 F. The ground itself is 100 F. If atmospheric or cloud radiation heats air near the ground, why isn’t today in my neck of the woods 110 F instead of 90 F?

• Jim2

(I’m just putting this out there for discussion, btw.)

• Jim2 – In general, during the day, the ground is heated (literally – i.e., its temperature is raised) by a combination of solar radiation and radiation emitted downward from the atmosphere. It sheds some of that energy by radiation and latent heat transfer (from evaporation), with a small contribution from conduction. Convection enhances the upward transport but requires the heat to enter the atmosphere via one of the other mechanisms. At night, the ground cools because the energy shedding exceeds the downward radiation, which is now unaccompanied by sunlight.

Without the downward radiation, the ground would be cooler than it is. However, because temperature declines with altitude, it will still be warmer than air or clouds at higher altitudes (except in cases of temperature inversions, which are unlikely in Texas on hot days). This altitude effect does not mean that the air and clouds are not sending energy downward. They emit energy in all directions as long as they have any temperature at all above absolute zero.

• Like a pitbull Fred clings to the notion that the cooler atmosphere warms the Earth because some programmer used the term downward radiation as a variable in his climate model radiation kernel.

• Dallas – Calm down. The cooler atmosphere in combination with solar radiation does warm the Earth. Without the sunlight, the Earth cools. Do you disagree? If not, I thinks it’s unfair to confuse Jim2 by implying that I answered his question incorrectly.

• I am calm Fred, just attempting some humor. Without sunlight the Earth would be colder. The issue is the down welling infrared radiation from the atmosphere, “by a combination of solar radiation and radiation emitted downward from the atmosphere”. While I understand where you are coming from, the atmosphere does not physically warm the Earth, it reduces the rate of cooling or it helps retain heat if you like. It is still the net that counts.

To go further, as Eli stated water vapor and other greenhouse gases are doing their thing, but in both directions as I added. Since the thread is based on the misunderstanding of the radiative effect and its terminology, it just seems right to focus on the confusion caused by “down welling radiation”, “back radiation” and the atmosphere “warms” the Earth.

• Let me use Eli’s words, “in the lower atmosphere the hold time for longwave in the water vapor and CO2 spectrum is forever”, or words to that effect. In the lower atmosphere, 15 microns is optically opaque. That is both up and down, it is not a trick window. While CO2 is excited by 15 micron longwave, it releases its energy packet by collision. Since that part of the spectrum is nearly if not saturated at the surface it limits the impact of CO2. Where there is less competition with other CO2 molecules and water vapor, the additional CO2 begins to have a greater impact.

• Jim2

The air still has a net cooling effect on the ground temperature. It’s just that the ground is a little hotter than it would have been without the CO2 (and water vapor).

• hunter

Jim2,
As someone who is also in Texas, I think what you are describing is a great example of what I attempted to explain above.
The atmosphere is not adding any heating. It can only enhance or weaken cooling. When a nice sized thunderstorm developed just east of my house yesterday, we benefited from the cooling effect of the storm, even though we were on the sun ward side. But clouds can act in multiple roles, after all.

• Jim2

hunter – That is exactly correct. The atmosphere cools the ground (and ocean also). A little more CO2 will retard the cooling, but the net effect is still cooling.

I’ve been playing with my IR thermometer some more. One thing is clear, there is no way clouds can cause an increase in ground temperature, net-net. My IR thermometer tells me the Sun is quite hot even in infrared. The clear sky about 37 F. The clouds about 60 F. So while the clouds are hotter than clear sky, they are way cooler than the Sun they block. The net result of this has to be a cooler ground.

31. Sean Houlihane

I’m confused by the purpose of this thread. I am unable to read the primary post, since to me it is only exposing the author’s inability to use words in a context that has meaning to me. Is he saying this is a good argument to swing people with, or that it is an example of why people are not persuaded? My argument would be that this weakens the sceptic case because it makes them easier to dismiss as idiots (and ones who are not easy to educate, because they deny the physics that some of us have learnt)

• The reason is that many are confused by the language. The phrase “back radiation” implies the atmosphere warms the Earth when actually it reduces the rate of cooling. Some grab that phrase believing that the greenhouse theory violates the laws of thermodynamics, when it does not.

Even the professionals have screwed up trying to explain the “greenhouse effect”. Gavin Schmidt tried to post a simple explanation years ago with embarrassing results, so don’t feel like the Lone Ranger if you have some issues understanding.

• steven

I agree. It would cause a lot less confusion if the phrase slows the cooling were used instead of causes warming. I still like the lid on a pot analogy the best.

32. manacker

We are all debating the correct wording to be used for as well as the impact on our climate of the greenhouse skydragon.

This is all very interesting, but shouldn’t we be spending some time talking about the monstrous superskydragon up there?

As we all know, this is clouds and their impact on albedo and reflected incoming energy.

That’s where the action is.

Max

33. Back to the essential question Judy: Do you say that you don’t think “back radiation” is real physics, just a phrase, but that “downwelling longwave radition” is real physics and not just a phrase? In what sense would then the two concepts differ? I am asking you to come out and tell and do not want to cite you out of context. I want to cite you in proper context, because you are an important player in a debate in which very few real scientists participate. Parents should not leave to the kids to fight about the family economy but carry their responsibility, right?

• The concept of interest is the spectral infrared emission/absorption (nearly isotropic emission) of gases with a dipole moment (permanent like H2O or fluctuating like CO2). That is the quote from me that you can use. You can play games with naming things and then finding misleading connotations of the name to try to discredit the basic physics, but this is no longer convincing anyone here.

• Judy: You say that back radiation is a phrase, but indicate that DLR is real phyiscs and when I ask you to confirm, I do not get answer but a riddle that “the concept of interest is the spectral infrarred emission/absorption” of CO2. I would like you to answer my question: Is DLR real physics? Is back radiation real physics? If, yes who showed this?

• Claes, you really don’t get it. You are using words and then twisting their meaning. The physics is in these words: “the concept of interest . . .”

• Judy: You are speaking in riddles, but this not science. I ask you to clarify your standpoint on back radiation and DLR, and you simply refuse. Answer my question, please, so that we can move forward the real concepts of interest, like climate sensitivity. No more riddles.

• Joel Shore

To put it another way, saying that something is just a phrase and saying that it represents really physics are not contradictory. It is a phrase that represents real physics. There may be other phrases that would be better (particularly since those practicing sophistry seem to be able to make so much hay out of the phrase “back radiation”), but this is a debate more about semantics than physics.

• Actually both. My original post focused on semantics as a valid concern for those bothered by the idea that the atmosphere could warm the Earth. However my comments have been moving away from the semantics and towards the physics, with a strong emphasis on the distinction between F vs. dF/dt, and likewise T vs. dT/dt.

These are related by dF/dt = dF/dT dT/dt = 4F/T dT/dt, and since F and T are varying by only minute amounts over a year, one can use 4F/T = 4*324/270 = 4.8 to arrive at dF/dt = 4.8 dT/dt. Well-known stuff.

This ignores feedbacks of course, but positive feedbacks have the effect of reducing 4.8 and hence further strengthen my argument that conduction dominates radiative dF/dt at the surface.

• Claes- Her position or anyone else’s is not difficult to follow.

The surface receives a large quantity of longwave radiation, due primarily to the presence of greenhouse gases in the atmosphere. You can call this “back radiation” or “fuzzy bananas” but the physics is the same. Gravity is just a “phrase” too, but the phenomenon is not fiction. Without GHG’s, sensors which routinely measures downward longwave energy would only see a small amount for the sun, and virtually nothing at night; inverting the Planck function would yield temperatures much closer to the ~2 K emission of space than to atmospheric temperatures.

• The surface receives a large quantity of longwave radiation, due primarily to the presence of greenhouse gases in the atmosphere. You can call this “back radiation” or “fuzzy bananas” but the physics is the same.

No question about that. Let’s call this the radiative flux F in W/m2 and associate it with climate.

Climate change concerns dT/dt, rate of change of temperature T with time t. Using dF/dT = 4F/T for radiation we can associate this with dF/dt, rate of change of flux with time, by the formula dF/dt = dF/dT * dT/dt = 4F/T dT/dt = 5 dT/dt roughly. Well known stuff of course.

F = DLR itself has been with us for billions of years, not always at the same value of course but preindustrially with dF/dt far smaller than today.

Suddenly we are faced with large dT/dt and hence large dF/dt. It is not DLR = F that global warming should be talking about but its derivative with respect to time.

We can then start comparing radiative and convective/conductive fluxes on the basis of dF/dT, a quantity that is meaningful for both radiation from sky to ground and for conduction through the skin on the ground, the bottom millimeter or less of atmosphere. (I should probably start using F_r and F_c to distinguish these.) The former as noted above is 4F/T or around 5 W/m2/K. We find that the latter ought to be one or two orders of magnitude greater than the former, say 250 W/m2/K assuming a 0.1 mm thick skin.

And on the premise that dT/dt for global warming is pretty much independent of both altitude and day of the month, being about a billionth of a degree per second in recent years or 2 degrees a century, we can use this common factor to convert the dominance of conduction over radiation as measured by dF/dT to the same dominance for dF/dt, just by moving the decimal point left nine places.

The comparison then becomes 5 nW/m2/sec for increasing radiative global warming of the surface (the “back radiation” contribution to global warming) vs 250 nW/m2/sec for its conductive counterpart via direct contact of the atmosphere with the ground.

• Your numbers don’t make any sense here. For a start, surface flux changes under an increase in CO2 are very different (several times larger) than the changes at the “top of the atmosphere”, where radiative forcing is defined. And your dF/dT formula is based on the Stefan-Boltzmann relation with absolute temperature and total flux, and yet you use marginal F and T changes?

Like I said in a previous comment here, proper accounting of radiative transfer is essential to understand these effects quantitatively, there really are no simple short-cuts, and attempts like this one just make a hash of things.

• Vaughan – You have now repeated several times what appears to be an error in your interpretation. I’ve addressed it in response to your previous comments that implied the unimportance of DLR in heat transfer from the atmosphere, and you should review these. I’ll simply repeat here that conduction (followed by convection) operates from the ground to air rather than air to ground. This is because the air in contact with the ground would have a lower temperature than the ground if based only on radiative transfer, and conduction is necessary to warm the air from below. The reason, as I mentioned previously, is that the ground emits only upward, but the same wattage absorbed by the air is emitted both upward and downward, and so its temperature will be less than ground temperature by a factor of the fourth root of 1/2 unless heat from the ground is conducted upward to remove the discontinuity.

In essence, DLR must be seen as the predominant mechanism for surface warming.

• And again, as I mentioned elsewhere, you can consult Raypierre’s “Principles of Planetary Climate” starting on page 391 for a more precise mathematical formulation that adds in the complexity of atmospheric radiative transfer down to the surface air but doesn’t change the general principle that the surface must heat the overlying air rather than the reverse.

• surface flux changes under an increase in CO2 are very different (several times larger) than the changes at the “top of the atmosphere”, where radiative forcing is defined.

Yes, you made essentially that point in your previous comment (if not in so many words) and I agreed to it, I also pointed out that it strengthens my argument that conduction at the surface dominates the impact of increasing DLR on the surface

And your dF/dT formula is based on the Stefan-Boltzmann relation with absolute temperature and total flux, and yet you use marginal F and T changes?

Yes, but that’s routine. Calculus provides tools for relating these, namely

dF/dt = dF/dT dT/dt

That is, the absolute quantity dF/dT, which is 4F/T and hence 4.8 in the relevant units when F = 324 and T = 270, provides the scaling factor between the marginal F and T changes.

• Incidentally, on the bit about strengthening my point, my argument was based on 324 W/m2 at the surface, so the fact that the TOA flux is several times less is irrelevant. The strengthening results from your point leading to a slight increase in dT/dt at the surface, which increases conductive dF/dt without affecting radiative dF/dt. That’s why it strengthens my point.

• Vaughan – I apologize for my previous comment, I had misunderstood what you meant by “F” and “T”, or somehow thought you were using them in two inconsistent ways, but it seems you were at least not being inconsistent in the way I thought you were. It does help to define symbols precisely! I believe what you mean now is:

F = downward IR flux to Earth’s surface (you write F = DLR above)
T = average temperature of Earth’s surface

Correct? However, I don’t understand why you think there is a T^4 relation between F and T – can you explicate? There *IS* a T^4 relation between T and *upward* flux from the surface because Earth’s surface emissivity is essentially 1 (black body) and T’s relative variance across the surface is not large. But the upward flux and your F = DLR are two different things – upward is about 390 W/m^2, not 320, for one thing.

More importantly, when CO2 changes in the atmosphere, F = DLR necessarily changes because that’s a change in the atmosphere’s emissivity at the wavelengths where CO2 is strongly absorbing and emitting. But that doesn’t necessarily entail any change in T. Certainly not immediately.

I’m also confused by your insistence on looking at dT/dt as if it mattered that it’s changing only very slowly. The actual response to a change in forcing (as usually defined at the top of atmosphere) is a time-dependent function – Hansen uses a Green’s function formulation in this recent article:
http://www.columbia.edu/~jeh1/mailings/2011/20110415_EnergyImbalancePaper.pdf

That is, dT/dt = an integral over earlier time s up to t of G(s-t) dforcing/dt

so the relation between surface temperature is not a dT proportional to dF immediate response, but rather a response integrated over time. To the extent it’s linear it doesn’t matter whether the change in F is small or large, the Green’s function is the same.

In particular, looking at an abrupt doubling of CO2 should give you essentially the same information as looking at a very gradual change over time, though the responses are different because dF/dt has a different time dependence, the response function itself is the same thing. Your formulation of the problem seems far too simplistic – if I understand what you’re trying to get at at all.

• Claes:

Just read your paper, ‘climatethermoslayer’. If you are at a university and want to discuss radiant energy effects in the atmosphere with someone other than a climate person, amble over to the mechanical engineering or metallurgical engineering faculties. Find the resident heat transfer prof. He or she will happily explain that Dr. Curry’s understanding of the physics is correct. They will explain to you why 0.028% is pretty large, in terms of thermodynamics. They will explain how an intervening gas between a high temperature energy source (the surface of the planet) and a cold exterior (space) will absorb energy in proportion to the CO2 content. They will explain that when something absorbs energy, it will warm up until the amount of energy it radiates is in balance. They will show you time tested methods of estimating this absorbance and even show you how to come up with the temperature increase that can be calculated, measured and confirmed. They will show you that this temperature increase can be correlated to CO2 concentration in a very predictable method. It isn’t advanced physics. It’s just engineering.

You can pick nits, and play semantic gotcha, but everything I understand about radiant energy jives fairly well with Dr. Curry. Your math doesn’t work in a blast furnace. If it doesn’t work there, you have a flaw in one of your assumptions. My blast furnace math jives nicely with climate estimates. As it must. Radiant energy absorbance by CO2 does not depend on who is doing the calc or the purpose of that calc.

• Bryan

John Eggert
You mention blast furnaces and CO2
You must therefore have heard of Schack who did pioneering work in this field.
he concluded that a CO2 heating effect was significant at blast furnace temperatures but insignificant at atmospheric temperatures.
http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.1161v4.pdf

• Bryan:

Nope. Never heard of Schack. Based on the paper you linked to, he did his work in the 1920’s. As such, for the purposes of heat transfer work, it would have been superceded by Hottel in the 1950’s and subsequently Leckner. Leckner’s work is relevant to 0 celsius. If you use Leckner’s curves, you can generate a curve very similar to F=a ln([CO2]/[CO2-0]) Where [CO2-0] is 278 ppm and [CO2] is whatever forcing you are trying to calculate and a is a constant (5.35 if memory serves). This equation is from AR4. Some paper by Ramanathan and Hansen if I’m not mistaken.

Cheers

JE

• John – The 5.35 figure is correct from the work or Myhre et al, but each of the models derives its own value, which generally are close to Myhre.

Off topic, but possibly of interest to you, I visited your website. As someone much interested in climate change, I thought you should be aware that CO2-mediated climate change entails two phenomena that are probably of equal importance. The first is global warming. The second is ocean acidification, which is not a global warming consequence. To equate climate change with global warming alone would be to misrepresent the totality of the potential impacts of anthropogenic CO2 emissions.

• Brian H

Fail. The Schack work was published in 1972.

• How is this a fail? Here is the reference from the article, page 71. First publication in 1929.

[95] A. Schack, Der industrielle Warmeubergang [The industrial heat transfer] (Verlag Stahleisen m.b.H., Dusseldorf, 1. Au age 1929, 8. Au
age 1983).

• You repeat standard material which is precisely what I find reason to question.

• John Eggert

Standard material indeed. So standard, it has moved from the realm of theoretical physics to engineering. Sometime in the 1940’s, long before anyone cared about climate.

Sooo.

You’re saying that Hottel was wrong? Really?

Can your math explain his (very detailed and easily reproduced) results?

Cheers

JE

34. Schrodinger's Cat

All of the molecules in the atmosphere are blackbodies in their own right, (since they are at temperatures much higher than absolute zero) so they radiate IR radiation in all directions, including downwards towards the earth.

Now, if there is more CO2 absorbing gas in the atmosphere, it follows that there may be more molecules energised by the blackbody IR radiation from the earth.

But this is not the full story. More downwards radiation may result in negative feedback through evaporation from the oceans and cloud formation to block the sun. [ OK, it could also be positive feedback through water vapour.] This is one big can of worms, so let’s move on.

The more enegetic molecules in the atmosphere (i.e. hotter molecules) rise due to convection so that more of the extra heat is eventually lost to space.

The water vapour formed by IR absorbence may quickly re-condense due to lower environmental temperature, leading to cloud formation and all the uncertain consequences of that.

As the heat dissipates upwards in the atmosphere, the proportion lost to space must increase.

I’ve mentioned some possibilities, and I guess there are a number of others. The real importance of the GHG effect is an analyses of the consequences. I have yet to see a report that descibes all of them (a) qualitatively (b) quantitatively and (c) the net result with a discussion of the statistical significance and uncertainties.

Dr Curry, as far as I can deduce, is promoting a discussion of commonly misunderstood concepts. That is ok with me. I think I understand these, but no doubt others will correct me if I’m wrong. I would argue that the assumptions at the next level of detail are the problem with the AGW community.

I believe that changes, e.g. the level of IR radiation from the atmosphere, will result in numerous other changes, some warming and some cooling. I am sure that that the net result of increased CO2 is fairly insignificant, but that is a debate of the next level of detail.

• I am sure that that the net result of increased CO2 is fairly insignificant,

SC – I think your overall perspective is reasonable, but “insignificant” is a matter of judgment. The effect of doubling CO2 is a 1 deg C increase in temperature from a rough calculation that involves differentiating the Stefan-Boltzmann equation, or a 1.2 C increase based on more sophisticated modeling that includes regional and seasonal heterogeneity. The difference between the two estimates is rather small. The greater effect would come from feedbacks that either amplify or diminish the direct CO2 effects. As you know, feedback estimates are a matter of contention, but my purpose here was simply to suggest that instead of “insignificant”, we apply a particular value to the CO2 effect. – a value that is not necessarily insignificant in its climate change potential, depending on what level of change we are concerned with.

• ‘The overall slight rise (relative heating) of global total net flux at TOA between the 1980’s and 1990’s is confirmed in the tropics by the ERBS measurements and exceeds the estimated climate forcing changes (greenhouse gases and aerosols) for this period. The most obvious explanation is the associated changes in cloudiness during this period.’
http://isccp.giss.nasa.gov/projects/browse_fc.html

The satellite data shows relative cooling in the IR band.

‘Earth’s global albedo, or reflectance, is a critical component of the global climate as this parameter, together with the solar constant, determines the amount of energy coming to Earth. Probably because of the lack of reliable data, traditionally the Earth’s albedo has been considered to be roughly constant, or studied theoretically as a feedback mechanism in response to a change in climate. Recently, however, several studies have shown large decadal variability in the Earth’s reflectance. Variations in terrestrial reflectance derive primarily from changes in cloud amount, thickness and location, all of which seem to have changed over decadal and longer scales.’ http://www.bbso.njit.edu/Research/EarthShine/

Since ‘since the climate system is complex, occasionally chaotic, dominated by abrupt changes and driven by competing feedbacks with largely unknown thresholds, climate prediction is difficult, if not impracticable.’ http://www.biology.duke.edu/upe302/pdf%20files/jfr_nonlinear.pdf

The application of simple ideas to the complex Earth system is unlikely to be of any value. The TOA flux data suggests that CO2 is of less influence than clouds in recent warming.

• BlueIce2HotSea

Schrodinger’s Cat-
I do agree with you in the sense that the ‘full story’ seems missing; the explanations are not wholly satisfactory.

For example, explanations of how GHG absorption of IR results in increased surface temperature are quite plausible. Yet, what is missing is a quantitative number on what percent of direct incoming solar IR is back radiated (into space) as a result of GHGs and what is the subsequent contribution to the reduction in surface temp. Bookkeeping numbers, anyone?

All of the molecules in the atmosphere are blackbodies in their own right, (since they are at temperatures much higher than absolute zero) so they radiate IR radiation in all directions, including downwards towards the earth.”

Not even close. None of the molecules in the atmosphere are blackbodies since they adsorb very little radiation. By definition, blackbodies adsorb all radiation that fall on it. The gasses in Earth’s atmosphere are very unlike blackbodies because they are transparent to visible light, infrared light, and microwaves (although CO2, H2O and CH4 do adsorb certain frequencies of infrared light).

“The more enegetic molecules in the atmosphere (i.e. hotter molecules) rise due to convection so that more of the extra heat is eventually lost to space.”

You seem to be implying that heat loss into space is due to convection. It is not. All the heat lost by earth is lost solely by radiation.

35. David N

Imperfect terminolgy may confuse anyone momentarily, but the permanently confused are working hard at it, because it is to their advantage. There’s no reason confusion about a term like “backradiation,” (an reasonable term IMO), can’t be dispatched with a simple explanation and linkage to a “superior” term, like Dr. Curry’s above, unless you intend to deny it no matter what it’s called. If that’s your intent you should state it and stop wasting everyone’s time with semantic games.

Also, everyone, including “Slayers,” has a right to their own terminology. That comes with a duty to be respecttful of other’s terminology. An “insulation” analogy may help some understand and accept what’s occurring but that doesn’t make it a more useful analogy than “greenhouse.”

And for the umpteenth time, sometimes people say “warms” instead of “keeps warm” or, “reduces the heat loss rate of.” They shouldn’t do it in a scientific thread, but we all should be ignoring the imperfect speech to get at the heart of the matter, not making speech the focus.

36. Schrodinger's Cat

Apologies, I should be more careful with the use of words which have different meanings in science and general conversation, eg “insignificant”.

I believe that the changes to our climate will not result in large disasters and may even have some benefits. I accept that changes may be significant, statistically. I also believe that our climate is always changing in a significant manner and that it may be difficult to prove that any particular change is due to CO2 or any other factor in the current belief system.

37. Jim D

To Vaughan, who asks how “back” radiation fits into his picture of CO2 causing warming, I would use the blanket analogy that I have seen above, and modified. The surface heated by a constant solar input is like the human body that has its own heat source. The atmosphere which is cooler than the surface is like a blanket, which is cooler than body temperature. The room at a fixed temperature is like space. Even this blanket can make the body warmer than without the blanket while not itself rising to body temperature but it should be warmer than room temperature due to the body heat. Adding CO2 is like adding another blanket. We know intuitively this makes you feel even warmer, even though the room is at the same temperature, and your body is trying to maintain the same temperature. It is not a perfect analogy, but gives the right idea. “Back” radiation in this analogy is part of the blanket’s insulating effect that works by resisting heat transfer from the body.

• simon abingdon

Jim, you spend a dozen lines polishing your analogy, but finish up by saying ““Back” radiation in this analogy is part of the blanket’s insulating effect that works by resisting heat transfer from the body”. Nothing comes “back” from the blanket as far as I can see.

• simon abingdon

Further thoughts. Suppose your blanket is made of material which is a perfect insulator. However, a particular area of the blanket is made of a special material called “agent greenhouse” which has the peculiar property of being able to absorb heat before retransmitting it in all directions. Half the time it will be radiating heat back towards you, but the other half it will be radiating away heat that the insulating blanket would otherwise have kept trapped. Result? No difference. What you lose on the swings you gain on the roundabouts.

• hunter

simon,
A blanket, heated up by a nice toasty person, is radiating more than a blanket left outside on the clothes line some frosty night.

• simon abingdon

OK, but the blanket isn’t a source of radiation; you’ve already said it’s the “nice toasty person”. I can’t see how adding radiations together when there’s only one source can be correct. It’s like my claiming I’ve given away £70 if I give you £40 of which you give £20 to someone else who then gives £10 of it to a third person.

• Jim D

The blanket can be a source of radiation as any solid object with a temperature can.

38. Frank

Vaughan: I think your sensible post deserves a sensible response to the confusing issues you raise.

If you recognize these facts about the earth’s energy balance, then you are probably struggling with the difficult concept that the colder atmosphere is “warming” the warmer surface by DLR. Is it appropriate to use the word “WARMING” to describe DLR’s role in balancing incoming and outgoing energy at the surface? We all know from basic science courses that cold things do not warm hotter things and that the second law of thermodynamics requires heat to flow from hot to cold.

The problem is that DLR is mediated by photons and therefore controlled by the laws of physics on the atomic scale, not the macroscopic scale of thermodynamics. When two molecules collide, sometimes kinetic energy is transferred from the slower-moving molecule to the faster-moving molecule (when the slower strikes the side of the faster), but far more often the opposite process occurs. This process of random collision produces the familiar Boltzmann distribution of energy. Superficially, it therefore appears as if some collisions transfer energy from hotter molecules to colder molecules, but this is incorrect because concept of temperature doesn’t apply to individual molecules – temperature is defined only for a group of molecules that collide often enough to be in local thermodynamic equilibrium. (If you are unfamiliar with this aspect of temperature, Wikipedia has discussions under temperature and thermodynamic equilibrium.) Since we live in the macroscopic world, we don’t usually experience energy flowing from slower/”colder” molecules to faster/”hotter” molecules and vice versa. We experience the net result of trillions of such molecular collisions and energy always flows from hot to cold under those conditions.

When energy is transferred by radiation and that radiation travels over macroscopic distance, the chaotic world of atomic physics intrudes on our comfortable macroscopic world. When ONE molecule of a greenhouse gas emits a photon downward that is absorbed by the surface of the earth, we can’t say that energy is being transferred from the colder atmosphere to the warmer earth because the concept of temperature is not defined for the INDIVIDUAL emitting and absorbing molecules. However, you can measure the total downward and upward flux with an IR detector. The second law of thermodynamics demands that the NET flux must be from warmer to colder, but it doesn’t place any limits on the number of photons going each direction.

• Sam NC

Frank,

I hope Vaughan and the likes could learn from your clear explanation here. Excellent post.

• Frank 8/13/11, 7:34 pm, Vaughan Pratt IV

Frank: We all know from basic science courses that cold things do not warm hotter things and that the second law of thermodynamics requires heat to flow from hot to cold.

In my book (Zemansky, 4th) heat by definition is what flows form hot to cold. No Second Law is involved, necessary, or recommended.

The Second Law has to do with perpetual motion machines, entropy, and equilibrium. Zemansky, honored for his mastery in the teaching of thermodynamics, develops the theory all in proper order. In sequence, he defines heat on page 57; radiant heat on page 106; and the Second Law on pp. 139 ff. The Kelvin-Planck statement of the Second Law is on p. 147; the Clausius statement on p. 148; and both entropy and the mathematical statement with entropy on p, 171.

Posters on this blog are populated mostly by laymen in thermodynamics, and of the rest, the most prolific. if not the most numerous, are advocates for AGW, who willingly, necessarily, or unwittingly distort or ignore the ample contrary physics, e.g. principles of science, and especially, the Second Law and equilibrium. A hallmark of the latter is their lack of explicit citations. For the point at hand, what the rest of us need to do is teach both types, the laymen and the conspirators, that back radiation is not thermal radiation to warm the surface. And that is so by definition.

39. Well two things.

First, while backradiation is a common and useful description, downward (or down welling) longwave radiation, DLR, is a more technical description and many links to measurements and models thereof can be found at Science of Doom

Second, Vaughn Pratt makes a very common error which we often see in discussing equilibrium processes and rates

Well, what do you know, the exact same fallacy. At the same time as 324 W/m2 is entering the surface from the atmosphere, 390 W/m2 is leaving the surface. The net flux is 66 W/m2 upwards. The atmosphere is not warming the surface, it’s cooling it!

The sun warms the surface. Without greenhouse gases the surface would heat up until it radiates an equal amount of energy, just as the moon does. When some of the energy is absorbed by greenhouse gases and radiated back to the surface you get a storage loop. This limits the speed at which the incoming energy from the sun can be sent back to space, the equilibrium is upset and the surface must react by warming up further to restore balance with the solar input.

What is being balanced is the solar input with the longwave output.

A more wordy but perhaps better statement of “The atmosphere is not warming the surface, it’s cooling it!” is that “The atmosphere limits the rate at which the earth can radiate energy to space and to restore the balance the surface warms.”

The rest is detail, detail that Prof. Fraser can/has provided, and folk like Pratt would do well to listen

• A pithier way presented itself after posting. Greenhouse gases in the atmosphere insure that the surface is warmer than it would be without them.

• Bravo! I am into pithy.

• Greenhouse gases in the atmosphere insure that the surface is warmer than it would be without them.

Eli, that must have been someone else since that’s one step pithier than what I said. Greenhouse gases in the atmosphere insure that the atmosphere is warmer than it would be without them, and the atmosphere then cools the ground. While it is immaterial how the latter happens, a strong case can be made that most of that cooling of the ground is via direct contact of the atmosphere with the ground, with DLR being the runner-up by one to two orders of magnitude depending on whether the skin on the ground is 0.5 mm or .05 mm. Higher winds should mean a thinner skin but that’s getting me into territory I’m not familiar with.

• Vaughan – DLR warms the ground. It does not cool it. I think you might want to step back and review the actual set of mechanisms in operation to get a better sense of the both the direction and magnitude of each of them. Radiation cools the ground (but not DLR). So does latent heat transfer. Conduction plays a smaller role, but is also a cooling rather than a warming factor, with convection enhancing the effect of all the other cooling mechanisms.

• I build two boxes that are insulated with 1 inch of styrofoam on the sides and bottom with a salt glass top. After placing one liter of water in each, I set one on a space blanket and set a space blanket on top of the other. With a measured DWLR of 250 W/m2 a measured up welling long wave radiation of 300 W/m2 and an ambient temperature of 10 C on a calm night, can I measure a difference in the temperature of the water in box?

• Roy Spencer did essentially this about a year ago. Confirmed the greenhouse effect.

• I think you might want to step back and review the actual set of mechanisms in operation to get a better sense of the both the direction and magnitude of each of them.

Fred, I’m sorry you feel I don’t understand these mechanisms. If you can’t tell the difference between my mispeaking on occasion and being confused about the mechanisms here then you’re going to offend people left and right and we’ll be wasting time talking about trivial syntactic and semantic distinctions and miswordings instead of focusing on the logic, which is what’s really at stake here.

In this case the obvious fix to what I presume you’re complaining about, my tossed-off phrase “with DLR being the runner-up”, is to replace “DLR” with “DLR minus ULR” or just “net downwards flux.”

There can be no question that the atmosphere is almost always colder than the ground, and generally a cold body