by Chris Colose
There has been a lot of blog interest recently on feedback theory and climate sensitivity (e.g., Isaac Held, ClimateAudit, Science of Doom, Nick Stokes, one on control theory here at Climate Etc.).
A lot of this interest surrounds the debate between Roy Spencer and Andrew Dessler on cloud feedbacks, of which I have little to add. However, this general topic stands out as perhaps the most important focus of study in climate research, and my impression from reading the various entries (and a lot of comments) is that a lot of people are thinking about the issue in a very different manner. I’d therefore like to take a step back from some of the discussions on how well observations (such as the co-variability of the net radiation and global temperature, accounting for noise, ocean heat uptake, etc) constrain climate sensitivity. While the previous article on control theory by Richard Saumarez was enlightening, I’d like to do a climate sensitivity/feedback primer from the perspective of how a climate scientist thinks, and on how this framework can be applied to larger planetary climate problems. Various perspectives are always insightful, and physics is universal, but a lot of the definitional framework differs across disciplines.
For climate sensitivity, we are interested primarily in how a coarse variable such as global mean temperature responds to a radiative perturbation. This is a useful metric since we can treat the surface temperature in terms of the top of atmosphere energy balance in a convecting troposphere (and this balance is relatively simple, being purely radiative), and the surface temperature change is relatively uniform field over the globe- with the usual caveat that land will warm more than oceans, or Poles more than the tropics.
Consider a parameter G which represents the net top of atmosphere energy balance (outgoing thermal radiation – incoming absorbed radiation) so if G > 0, the planet cools, and if G < 0, it warms. Now, think about applying a radiative forcing to the system, such as an increase in carbon dioxide or sunlight. Climate sensitivity is then related to the slope of a line in a G vs. T plane (where T is the surface temperature). In particular, higher climate sensitivity implies a weak slope (see figure 1), so that the planet is more sluggish at changing its outgoing radiation in response to perturbations. This allows for larger temperature changes.
Figure 1: Net TOA energy balance (G) vs. surface temperature. For a low climate sensitivity (solid lines) the slope is large. For large climate sensitivity, the slope is more shallow (dashed lines). Starting at T0 in either case, applying an increase of CO2 decreases the outgoing longwave radiation, shifting the blue curves down to the corresponding red curve positions. The new intersection point (equilibrium) is T1 for the low sensitivity, or T2 for a higher sensitivity. From Climate Stabilization Targets: Emissions, Concentrations, and Impacts over Decades to Millennia (NAS, 2011)
In order to think about feedbacks, it is necessary to define a baseline (or reference system). One reasonable reference system would be to consider a naked planet (with no atmosphere) which radiates energy at a rate of σT4 (so that if the planet became twice as hot, it would radiate sixteen times as much energy away, allowing it to relax to this new equilibrium temperature). In models, this is actually calculated with a full radiative transfer code for each gridpoint on the Earth; this so-called “Planck feedback” amounts to about an extra 3.2 Watts per square meter (W/m2) power emitted for every 1 K temperature increase (Soden and Held, 2006). Climate sensitivity is often taken as the ratio of the temperature change to the radiative forcing; so for example, a doubling of CO2 which constitutes a forcing of ~3.7 W/m2 would produce a temperature response of 3.7/3.2 = 1.2 K. You can get a similar answer with a simple back of the envelope calculation. Note that while the Planck restoring mechanism might be thought of as a “negative feedback” it is simply a baseline “no-feedback response” in climate lingo.
Now, consider a positive feedback, for example the increased water vapor associated with a warming climate. What impact does this have on Earth’s radiation budget? From the perspective of Figure 1, the increased infrared absorption from water vapor makes the outgoing radiation response more linear than a T4 dependence, so it takes a greater surface temperature rise in order to accommodate the necessary infrared emission change required to re-establish equilibrium. Note, however, that the slope of outgoing radiation is still positive and so it is possible to re-establish equilibrium without “running away.” In the case where we double CO2, feedbacks being net positive simply means the global temperature rise is larger than 1.2 K.
Non-linearities, bifurcations, and extreme atmospheres
Armed with this definitional framework, we can now think about some larger applications in the context of climate. The reason positive feedbacks don’t cause runaway warming on Earth is often explained in terms of a converging power series which can easily be shown to take the form ΔT=ΔT0/1-f (where ΔT0 is the Planck restoring response defined before, and f is a feedback parameter that depends on how a particular feedback variable like water vapor changes with temperature, and on how much that change impacts Earth’s radiant energy balance). In a linear worldview, f being greater than zero but less than one implies a positive feedback, yet still one that allows the system to relax at a stable temperature. f being less than zero means the feedback is negative. The table below shows estimated values of f for individual feedbacks.
Fig. 2- Values of f based on various studies (taken from Roe, 2009)
What does it mean when f = 1, or for that matter, what if f is greater than one?
It is sometimes argued that this scenario mandates a “runaway greenhouse/icehouse” scenario; in reality, when f gets close to one, this linear analysis breaks down. There are certainly many feedbacks that are not linear over a large enough range, so rather than thinking of f =1 as a runaway point, we can think of it as a bifurcation point (or loosely some sort of “tipping point”) but what resides on the other end of the bifurcation requires more information than just a local analysis around the base climate. This point is argued further in a great talkby Dr. Ray Pierrehumbert at the Society for Industrial and Applied Mathematics (SIAM) conference this year, entitled “Climate Sensitivity, Feedback and Bifurcation: From Snowball Earths to the Runaway Greenhouse.” See slides 24-31 for some examples of this, including energy budget structures that have various regimes of “f” values. Non-linearity appears to be of small significance for the modern climate change problem (Roe and Baker, 2011, Nonlin. Processes Geophys)
The extreme hot end of a planetary bifurcation is indeed a runaway greenhouse, provided the planet in question has a large enough liquid ocean. A runaway greenhouse requires a large enough supply of solar radiation to sustain (some speculations, some of which Jim Hansen provided in his “Storms of my Grandchildren” book, that a large amount of CO2 could trigger a Venus-like syndrome, are not actually possible).
Current climate sensitivity estimates generally yield a coherent picture of ~2-4.5 C per doubling of CO2, with very little chance of sensitivity at the low end of this. Current methods of estimating climate sensitivity do not completely rule out high-end values of climate sensitivity for various reasons (Knutti and Hegerl., 2008); perturbed physics ensembles tend to exhibit distributions of sensitivity with a skewed tail toward higher values (e.g., Stainforth et al., 2005), much in the same way as thinking about climate sensitivity being proportional to 1/1-f would yield a skewed distribution (assuming a symmetric and broad uncertainty distribution in the total feedback strength, e.g., Roe and Baker, 2007). Moreover, if one is interested in the forecast out to hundreds of years or longer, climate sensitivity is likely even higher than these estimates when including “slow feedback” processes, like the decay of ice sheets (Lunt et al., 2010; Pagani et al., 2010; Royer et al., 2011).
Whether or not this is “significant” is ultimately a social, economical, and political question although it is very likely a geologist a million years from now would view the “Anthropocene” in the same light as a glacial-interglacial change, except on a much more rapid timescale, and with settled global populations nearing 7 billion.
1) Talking about “positive” and “negative” feedbacks requires defining the reference system, in this case, the Planck radiative response. Changing the reference system changes the feedback.
2) In the end, it is possible to have positive feedbacks without causing a runaway warming/cooling. In this case, these feedbacks reduce the efficiency of the Planck restoring effect, so the system can accommodate a larger temperature change before a new equilibrium is established.
3) Climate sensitivity, after accounting for “fast feedback processes” (like water vapor, sea ice, clouds, etc) is probably within a range of ~2-4.5 C, and higher when including slower feedbacks (ice sheets, vegetation)
JC note: My own essay on climate feedbacks was posted [here].
…and lower considering the unknowns about clouds, and lower in light of obvious and excessive activism (hence, bias) on the part of the authors of many studies …
Legitimate questions about the science of global climate change are “hot news” today:
I dont really understand the science here although I get the general drift; but I am just reading Laframboise’s book on the IPCC http://tiny.cc/rc9c7 and she claims that conventional systems theory assumes the most likely effect in general is negative feedbacks rather than positive ones- this is made as a critique of the IPCC which assumes there will be positive feedbacks on warming. Is this true and if so why is it that most systems have negative feedbacks?
I found a good general introduction online (http://statpac.org/walonick/systems-theory.htm) that may help.
In stable systems, negative feedbacks must overwhelm positive feedbacks overall, to bring the system toward some central or equilibrium state, otherwise the system runs away from the center until it becomes so unstable it breaks down.
We believe the Earth climate system is somewhat stable (within a wide band) for a number of reasons: some animals and many plants have existed virtually unchanged within their niche for so many generations that we must expect the climate was stable enough for the animal and everything it depends on to survive through every generation; the ice core record gives us information about some properties of the climate for 800k years; other evidence seems to agree with these two sets of data.
This assumption requires no one to throw a monkey wrench into the system to fundamentally change the strength or direction of important feedbacks.
Where there is substantial disagreement is over the size and power of the monkey wrenches due human activity.
Aaahhh! now I get it. I’ve been at this climate subject all this time and I haven’t been able to see this simple theory in all it’s glory.
So let me see if I got it right.
This planet has been through ice ages, climatic optimums, CO2 ranging up to 1000s ppm, mini ice ages, warm periods, biblical floods, meteor asteroid strikes, solar flares, thousands of nuclear strikes, world wars, millions of bush fires, billions of giant critters munching their way through all the vegetation, sea level rises of hundreds of metres and yet the grass is still green, the sky and oceans are still blue until………..
I idled my SUV for an extra 3 minutes per day in winter. THAT WAS THE MONKEY WRENCH THAT STUFFED THE SYSTEM.
Though I can’t comment on how many nuclear strikes, pretty much.
LOL! Nicely expressed. I heard your words in the tone that the late, great George Carlin might have used.
I could not fathom Chris’ “non-technical” post, until you used the missing technical jargon — “monkey wrench”
In nontechnical terms: 2.14 EJ is the rough amount of energy released by all nuclear tests up to the end of the last millennium.
While you’d think that would be a big monkey wrench..
That’s about the energy of a 9.3 magnitude earthquake, or about the energy the Sun delivers to the Earth in a 22 seconds. (Please feel free to independently verify.)
The USA uses almost 100 EJ a year, much of that from fossil sources.
The amount of heat trapped by CO2 and feedbacks, expressed in how long before the monkey wrench of CO2 is a million times the monkey wrench of all nuclear tests combined?
Well, that’s the question, isn’t it? (Or is it?)
“The amount of heat trapped by CO2 and feedbacks, expressed in how long before the monkey wrench of CO2 is a million times the monkey wrench of all nuclear tests combined? ”
You are absolutely wrong. GHG’s TRAP nothing. They are conductors and absorb and emit freely. Exactly how does this TRAPPING y’all are always on about happen again???
Just think, if they actually trapped anything we would have the fabled Hot Spot++++!!! (by the way, RealClimate talks about a Bottleneck and not Trapping!! 8>)
That doesn’t even make sense.
How can a question (well, two questions) be ‘wrong’, much less ‘absolutely’?
Now, since I don’t read much a RealClimate much, I don’t care much whether you want to die on the hill of ‘trapped’ vs. ‘bottlenecked’, but what are we, twelve? Tch.
By the way, it’d be around 27 years of 390+ ppm CO2 that’d be a million times the monkey wrench of all the nuclear tests ever that I’d be ‘absolutely wrong’ about, if I’d answered the question you’re so sensitive over.
“Exactly how does this TRAPPING y’all are always on about happen again???”
Did you really even say that? It implies I have the attention span to be always on about anything, which is silly in itself. And, if you haven’t figured out from all the many explanations (some of them even consistent with each other) floating around, then how likely is it you’ll understand it if I explain it to you one more time, when you can’t even understand my explanation of what a monkey wrench is?
Oh, and the Hotspot thingie, I’d ignore it until research like http://journals.ametsoc.org/doi/abs/10.1175/BAMS-87-3-291 is resolved, as it’s meaningless to talk about something so ill-understood. Its presence or absence proves nothing either way, at the current state of understanding of the data.
Try not to cut yourself on any shells while eating soft-boiled eggs.
Well Bart R,
Thanks for TOTALLY sidestepping the issue. I won’t need to come up with any more childish arguments to rebut your childish pronouncements. You are apparently wrong and offered nothing to rebut my questioning your use fo the term.
As far as the paper you linked, it is an interesting correlation. Do let us know when there is something more won’t you?? This could be more evidence for the Electric Universe theoreticians.
Did it ever occur to anyone that Hansen’s scenario “A” is based on a rate of CO2 emissions of just over 30Gt for 2010 and with actual CO2 emissions for 2010 standing at over 33Gt and with the world cooling instead of warming as Hansen predicted; perhaps feedback has nothing to do with it and Hansen just made the whole thing up!
He understated emissions overstated CO2 concentration and stated that we should now be warming at a level over 0.6°C above our current global temperature which is now in the tenth year of a cooling trend that started in 2002.
Hansen’s climate sensitivity for the 1988 projections was also 25% greater than IPCC mean estimate. Scenario B was closer to reality for CO2 emissions. See;
That was terse. Basically, what you get when you leave dynamics out of feedback is this simple linear analysis that can cause stability for all feedbacks from negative infinity to 1. Also correct that real nonlinear systems don’t behave like this. But a few steps were left out getting from there to “Current climate sensitivity estimates generally yield a coherent picture of ~2-4.5 C per doubling of CO2, with very little chance of sensitivity at the low end of this”.
The Earth only radiates a limited amount of energy in the 14.77micron band that is affected by CO2 and at current concentration well over 80% of the energy possibly accessed by CO2 in this band has already been accessed.
If we calculate the greenhouse affect at 33°C and properly attribute 90% of it to the reflection from Earth’s 50% variable cloud cover and to the Earth’s 10,000ppmv to 40,00ppmv concentration of water vapour this only leaves 3.3°C even possibly attributable to CO2.
Since there is only 20% of the energy left to access the maximum possible further effect from even a ten fold increase in CO2 is just 20% of 3.3°C which is 0.66°C.
The maximum possible effect from a doubling of CO2 from our current 390ppmv to 780ppmv is less than half this amount at at the currentm rate of increase of just 2ppmv/year it will be 195 years before this doubling occurs with its catastrophic 0.33°C pleasant global warming.
Physics and physical measurement tell us the sensitivity to a doubling of CO2 is less than 0.33°C so wher does the 2 to 4.5°C come from?
This is a good post. Just wanted to review the history of sensitivity estimates. In 1988, Hansen had 4K. The latest GISS model has 2.6K. In AR4 the model range is 1.5-5K. If you look at Judith’s plot of the NCAR model AR4 vs. AR5, you will see that with pre-industrial initialization and best estimates of forcings, it overestimates warming since 1900 by 50%. In short, there is a lot of evidence that there is overestimation of the feedback by scientists and by the models.
Lindzen makes a great point and that is that a small uncertainty in the feedback factor yields a large change in the climate sensitivity. This explains the uncertainty and the fact that historical estimates have been revised a lot. It also makes me suspicious when even the IPCC says that the scientific understanding of clouds and aerosols is low, that we need a lot more work. I think we must also now say the solar forcing is also something where the scientific understanding is low.
What is not inspiring of confidence is that some mistakes by Svenmaark seem to have caused the climate community to dismiss out of hand any of his statements.
By the way, Chris, what’s the basis for the statement that the current climate regime is within the linear feedback range?
Actually, very little change has been made in the estimated range of equilibrium climate sensitivity over the last few decades (it’s always been about 3 C +/- 50%). I suppose you can either interpret that as a lack of progress or it can be interpreted as many different methods converging on a similar ballpark figure.
Various methods have inherent limitations in how well they allow us to constrain sensitivity or unskew the upper bound. For example, volcanic eruptions don’t really say anything about the bound on the high end of climate sensitivity because the transient response to a volcano has very weak dependence on different equilibrium sensitivity possibilities, with the peak cooling shifting only slightly for larger ECS values.
A model “over-estimating” warming is not a clue that it is getting ECS too high, especially since the latter has independent constraints (e.g., paleoclimate); it could be a problem with the heat diffusion or the forcing (a lot of model runs don’t have an aerosol indirect effect for example).
There are many studies suggesting that df/dT is a small term (the higher-order terms in a Taylor expansion are not a big deal)…see some of Gerard Roe’s work on this.
“Actually, very little change has been made in the estimated range of equilibrium climate sensitivity over the last few decades (it’s always been about 3 C +/- 50%). I suppose you can either interpret that as a lack of progress or it can be interpreted as many different methods converging on a similar ballpark figure. ”
Yes the idea that doubling CO2 would increase warming temperature by about 5 C is over a 100 year old:
“Svante Arrhenius (1859-1927) was a Swedish scientist that was the first to claim in 1896 that fossil fuel combustion may eventually result in enhanced global warming. He proposed a relation between atmospheric carbon dioxide concentrations and temperature. He found that the average surface temperature of the earth is about 15oC because of the infrared absorption capacity of water vapor and carbon dioxide. This is called the natural greenhouse effect. Arrhenius suggested a doubling of the CO2 concentration would lead to a 5oC temperature rise. He and Thomas Chamberlin calculated that human activities could warm the earth by adding carbon dioxide to the atmosphere.
The global warming hypothesis originated in 1896 when Svante Arrhenius, a Swedish chemist, developed the theory that carbon dioxide emissions from the burning of fossil fuels would cause global temperatures to rise…”
Arrhenius thought such warming would be a good thing, not sure who first thought it would be bad thing.
The Arrhenius Graph
Green trend – HADCRUT record prior to his 1896 paper. His world got colder.
Purple trend – the Max-Girma-style take on things
Brown trend – HADCRUT since his paper
A lucky guess?
Yeah. He then refined his estimate down to 1.6°C for 2xCO2 (which appears to be roughly confirmed by observations since 1850)
Chris, Thanks for replying. +-50% seems large to me.
One bottom line here that I think is quite striking is what Andy said, viz., that internal variability will continue to have large uncertainty for the forseeable future. Any attempt to infer sensitivity from historical data that doesn’t include this seems to me to be pretty questionable. I think paleoclimate data even less trustworthy than studies of current responses.
In any case, I see your point that overestimating Delta T does not imply an incorrect sensitivity. The models overestimating warming is a problem for us laymen who see the IPCC basing its scenarios for the next century on them.
Basically, a lot of this boils down to “we don’t know.” And that means to me that we’d better get serious about finding out. My concern is that the scientific establishment is too busy defending their work (and worrying about some imaginary secret cabal of fossil fuel interests) to really get serious about it or to be open minded enough to pursue it.
Ditto!! There has been too much grant money available from government and special interests for climate researchers to focus on the CO2 warming theory, when the science needed a much broader and in-depth research program nailing down the physics of natural mechanisms which caused all the temperature cycles before 1850. We have 800K years of data in the ice cores to try to develop good models that explain these variations based solely on natural mechanisms which are still active today and will be active in any climate predictions into the future.
I won’t be very interested in climate change model predictions (other than to debunk them) until they can explain the available empirical data on global temperature cycles, polar ice cap cycles and global sea level cycles that had nothing to do with human related CO2.
Well then get busy buddy, and try to lift a finger. The other day, I took the Vostok Ice Core data and placed it in the context of climate sensitivity and the positive feedbacks of CO2 outgassing. The results are here:
This link is a heck of a lot more interesting than most of the comments I have been reading on this post.
I’ve left a fairly long response here.
As J C said the overall system is strongly negative feedback [proportional to t ^ 4]. The climate community has defined the no atmosphere feedback to be the dividing line between positive and negative feedback.
The British Royal society estimates that the no feedback sensitivity of the earth is .4 ° C for a doubling of CO2. To get even the lowest end of the range the warming must be multiplied by 5.
The ice albedo effect while a positive feedback it is small as the amount of surface is small and at a low angle and for a couple of months a year. The big gorilla is water vapor which may be positive or negative on balance.
Feed-backs operate on any source of warming not just CO2.
The case for huge feedbacks is very weak since that would imply that small differences in sunlight or other forcings would cause massive temperature changes and Dr Mann thinks he has proven that the temperature has been flat for 1 thousand years. [Shot himself in the foot on that one didn’t he?]
“The British Royal society estimates that the no feedback sensitivity of the earth is .4 ° C for a doubling of CO2”
Since that value is completely implausible based on simple physical principles without a need for models, I suspect you’ve misunderstood something you heard or read. If you link to a reference, we can figure out where you got that figure, which is certainly wrong.
Fred glad to oblige !
From the PDF. 
“Application of established physical principles shows that, even in the absence of processes that amplify or reduce climate change (see paragraphs 12 & 13), the climate sensitivity would be around 1oC, for a doubling of CO2 concentrations.
A climate forcing of 1.6 Wm-2 (see previous paragraph) would, in this hypothetical case, lead to a globally averaged surface warming of about 0.4 ° C [Seems pretty clear to me — NetDr]”
Read it more carefully. It specifically says that the no-feedback sensitivity would be 1.2 C for a doubling of CO2. They then scale that to a 1.6 W/m2, which is much less than you get from a doubling. In any event, amplifying this response by 2-4 or so is not physically problematic whatsoever, and no one thinks the last millennium is a contradiction of this statement (though the last millennium is not a very good constraint on this).
As I suspected, you misinterpreted what you read. The no-feedback sensitivity, as your quotation, suggests, is about 1 deg C per CO2 doubling – actually it’s closer to 1.2 C, but the 1 C figure is often used as an approximation. Your error was to use the 1.6 W/m^2 figure as the forcing for doubled CO2. It’s actually about 3.7 W/m^2, which leads to the 1 C (or !.2 C) figure for no-feedback sensitivity, depending on some of the small modifications that can be employed in the calculation. The 1.6 W/m^2 forcing is not for doubled CO2 but for the estimated forcing due to the rise in CO2 since pre-industrial times, which is much less than a doubling.
You got me.
Even with that the argument is still valid. If each slight perturbation was multiplied by from 2.5 to 6 the temperature would e wildly unstable.
The good Dr Mann has assured us that the temperature has been very stable for a thousand years. It seems he has shot himself in the foot.
The factor 2.5 to 6 is given as the stable outcome that results ultimately from the feedback that is f = 0.6 for the factor 2.5 and f = 0.833 for 6:
1/(1-0.6) = 2.5,
1/(1-0.833) = 6.
You have a misunderstanding here as well.
So, 0.4 degrees is what the low-sensitivity models of Lindzen and Spencer would have predicted for the last century when actually it was 0.8 degrees warming. They may want to reconsider their sensitivity model in light of this failure.
or you may want to reconsider the accuracy and the way the observations are compiled.
Watts, Muller, Spencer, et al. have tried to disprove the warming, but have not succeeded.
Jim, could they ever — c’mon seriously!
No misunderstanding except you own. The amplification factor is what I said it was.
If the atmosphere has only changed .8/10 ° K out of about 300 ° K that is
.2 % in 120 years. That is ultra stable.
If the feedback was as high as has been used in the climate models the whole system would be wildly unstable.
The alarmists want it unstable but the earth won’t go along with it.
The sun was 25 % cooler in the distant past but the temperatures were about the same because of the negative feedbacks.
Why would it be wildly unstable?
You made a strong claim. Try to substantiate it.
Dear Dr Curry,
Here is a copy of a query to Chris Colose, which was posted on his blog. It contains his explanation of the effect of CO2 as far as I can see.
He has not answered me yet. I didn’t finish high school, but I have never received an answer to the same sort of question from anyone who promotes the “greenhouse effect”. It doesn’t seem to me that you can get “something for nothing”.
In the interest of brevity, I will post my question here : –
I posted a comment on your old blog at WordPress. I didn’t realise it had been retired.
I hope to can help me to understand a problem I have with your explanation of the greenhouse effect. I have cut and pasted the relevant part of your post; –
“For example, if 10x units of solar radiation hit the surface, then
10x solar in, 10x infrared out establishes radiative equilibrium
Now suppose that the solar is 10x to the surface, but only 6x of infrared escapes to space, and 4x is absorbed by the atmosphere. Of that 4x, 2x is re-radiated back to the surface, and 2x radiated back out to space.
12x in the surface
8x back out to space
This is a case of where the surface is not in radiative equilibrium, and what is happening is that the surface cooling is inhibited . Ultimately, the surface is warmer than would otherwise be in a no atmosphere case because it is heated by both the sun and the atmosphere. ”
Now my problem is that if 6 x leaves the surface, the surface temperature will drop by 6/10 of the increase caused by the 10x in. Obviously, the temperature cannot rise, nor can it remain the same if the surface is emitting infrared. Now if 2x is reradiated back to the surface, then the temperature is raised by 1/3 of the drop which occurred when the 6x left.
In no case can the surface temperature be higher than that caused by the radiant energy absorbed from the Sun. The atmosphere as you have stated acts as a fairly poor insulator, which retards the escape of heat from the surface, and retards the absorption of radiation from the Sun.
This would explain why the max day temp on the Earth’s surface is lower than that on the Moon (same distance from the Sun as the Earth, on average) and why the min night temp on the Earth is higher than that on the Moon.
I have seen other explanations of the greenhouse effect, and all of them seem to overlook the fact fact that the temperature of a body losing heat actually drops.
Thank you in advance.
This is straying away from the topic but I don’t understand where your conclusion that “In no case can the surface temperature be higher than that caused by the radiant energy absorbed from the Sun” comes from. It’s just as nonsensical as saying that the only way you can get more toasty in your bed at night is by turning up the house furnace, and that the number of blankets over your body is irrelevant.
Dear Chris Colose,
No, it’s about as nonsensical as saying that the only way to heat a non heat generating body (a corpse for example), is by piling blankets on it, rather than turning up the furnace.
My body generates heat. Put me in a Dewar flask or other suitable insulating medium, and the heat I generate will kill me. Your “back radiation” at work, if you like. In fact, my temperature will actually rise, because heat generated by the cells internal mechanism is actually greater than 37C – at least 42C.
The Earth, on the other hand, is not, unlike my good self, capable of heating its surface to 37 C by means of its internal heat generating capacity.
Now as for your lack of understanding – I am uneducated, so I will have another try.
If the Earth intercepts 10x incoming radiation from the Sun (all wavelengths, total energy we are talking about, and using your terminology), then it cannot under any circumstances magically create any more than the 10x the “disc” of the Earth intercepts.
It doesn’t matter whether the Earth has no atmosphere (assuming this does not change the area of the disc as seen from the Sun), or whether the Earth is covered with water, soot, or leftover tinfoil from the hat factory.
The maximum radiation available to be absorbed is that which was emitted by the Sun and prevented from travelling into outer space because the Earth got in the way. As to the final surface temperature, that of course will depend on how much of the intercepted radiation is actually absorbed, and reaches the surface. In no case can the Earth “generate’ any more than the 10x it received (once again, your figure and usage), from the Sun.
Do you understand now? If not, if you have access to a reasonable lab, set up a calibrated heat source with an power supply – red heat will do, and a passive body distant from the heat source, in a vacuum chamber. Ensure external heat sources remain the same in all runs.
Once the passive radiator’s temperature has stabilised (you will see this from the stabilisation of the power input to your heat source – make sure it is adjusted to be the same as the first run), measure it. Now flood the vacuum chamber with CO2 at STP (gently tends to be a good idea). Once again, wait for the power output to stabilise.
Measure the temperature of the passive body again. Interesting isn’t it?
Choose another experiment, if you like – I am no scientist.
The come back and tell me how you increased the temperature of a body by surrounding it with carbon dioxide, compared to a vacuum.
If you still cannot understand, why I cannot understand your posting, I cannot see how 10x in magically turns into 12x in.
No new energy is created, but the rate of escape is now inhibited. From the perspective of the the whole planet, the same amount is coming in, but less is going out (for a given temperature, when you add GHGs). From the perspective of the surface, it is now receiving energy from both the atmosphere and sun.
I am a skeptic and I believe in science. I also believe CO2 does cause some warming.
The best analogy I know is a pan of water on a stove with the burner on low so it doesn’t boil. Let it come to a steady temperature.
Put a lid on the pan and it warms.
Put a different lid made of animal fur and it heats to a higher temperature.
The basic CO2 warming makes perfect sense to me. It is the feedbacks which don’t seem to be happening. Give them 100 more years ?
Dear Chris Colose,
Ah. I agree – the rate of escape is now inhibited.
From the perspective of the surface, less is going out – I agree again.
Now you may have overlooked the fact that if the same amount is coming in (and hitting the surface is implied in your closing sentence), the only way the atmosphere receives energy, is if it is radiated from the Earths surface. If you are saying that the atmosphere is warmed by the Sun, then that energy is subtracted from that available to reach the surface .
Now if the atmosphere or part of it is warmed by radiation from the Earth’s surface, the energy came from the Earths surface, and the temperature will drop – no ifs, buts, or maybes. Energy re-radiated from the atmosphere will reinstate some, but not all of the drop.
As you say, the result is that the rate of cooling will decrease. The temperature will not rise.
As you introduced analogies, I will continue.
My house furnace is set to 30C.
I have died.
My skin temperature is now 35C.
Your task: –
Your task, should you accept it, is to raise my skin temperature to 36C.
You have two choices –
1. Pile blankets on my cooling corpse.
2. Turn up the thermostat.
Your “reply” thingy has vanished.
With respect, and meaning no offence, maybe you have a different stove. I just tried your experiment. I didn’t have lid made of animal fur, so used white plastic foam about 50 mm thick, as well as standard lid.
I noted that my stove has a radiant element which turns on and off to maintain the temperature of the sensor, which obviously induces hysteresis.
My stove appears to maintain a temperature rather than a set energy input. The energy input appears to vary, depending on the overall rate of heat loss from the pan (all directions.)
I don’t want to waste your time, but I was unable to draw the same conclusions from my amateur attempts.
I can now confidently that the adage “A watched pot never boils” is not true.
I’m not much of a physicist, but I am a pretty good cook – and I use a gas stove. I do notice that when I use a lid on pots, water in them they reaches a boil more quickly and boils faster thereafter.
I’ve also noted that adding salt to the water makes the food cook more quickly – presumably because adding salt makes the water retain more heat.
All of that happens even if I don’t adjust the flame on my stove.
Could you explain that for me?
Re cooking. Without necessary equipment, I can only guess. The first (but not necessarily the only or best) explanation that springs to mind is that the lid acts somewhat like a regular real greenhouse, and restricts the loss of heat by convection.
I have observed steam rising from an uncovered pot, which I assume indicates convection. I can’t be bothered setting up an experimental situation. Would you be able to find the answer to your question on the Internet?
Apologies if my answer does not help. If your Internet such is fruitless, I suggest a person with a knowledge of thermodynamics and fluid dynamics may be of assistance.
So Ozzie –
You’re saying that putting a lid on a pot of boiling water, or adding salt to the water, aren’t analogous to adding a GHG in the atmosphere?
The rate of heat being introduced into the system is constant, yet changing those factors either makes the heat increase more quickly or causes the fluid (air is kind of like a fluid, isn’t it?) to retain more heat. I thought you were saying that such a situation is impossible? Wouldn’t that be analogous to the effect of adding GHG to the atmosphere?
I guess if you can’t answer that question, so I should just try looking on the Internet for an answer.
Yes that is exactly what I am saying (at least about the lid, and I can’t think of a single reason to think about the effect of adding salt, except it occurs to me it may raise or lower the boiling point of the solution vis a vis pure water.)
I’m not sure about the rest of what you say.
If rate of heat introduced into the system is constant, how could the heat increase more quickly? The heat of what? If you have a fixed amount, you can’t magically create any more. Obviously I don’t understand your meaning.
Air is not ” . . .kind of like a fluid . . .”. It is a fluid as far as I am aware. How do you cause it to retain more heat? As far as I know we, are not talking about a pressure cooker.
I am not sure why you would think that a real greenhouse doesn’t work. Your pot is no different to my eyes. If you say it is analogous to the effect of adding GHG to the atmosphere, then I would disagree.
The real greenhouse works. The “greenhouse effect” does not exist. No amount of waving pots, blankets, magic filters, or fur covered lids at me will make it so.
So, it appears that you do have answers for my questions. And here I thought that you said that you didn’t. Sorry for my confusion.
Because as opposed to a pot without a lid, the rate of heat escaping the water is reduced. Wouldn’t that be true? And wouldn’t that be similar to CO2 introduced into the atmosphere reducing the rate of heat loss?
Why, the heat of the water. In this case, the water would be analogous to the Earth’s climate.
But ozzie – I wasn’t talking about “creating more heat.” I was talking about creating heat faster – or perhaps I should say slowing down the rate of heat loss.
By putting a lid on the pot. I don’t own a pressure cooker – which is why I never mentioned anything about a pressure cooker. Why are you bringing up the subject of pressure cookers?
Yeah – I see that – although I’m not sure why you would disagree. I guess it’s because I have a limited background in studying physics?
Oh, and ozzie –
Because adding salt changes the chemical composition of the water, which in turn changes the physics of how the water responds to heat. My guess was that it might be analogous to changing the chemical composition of the atmosphere – which in turn would change the physical properties of how the atmosphere responds to heat. But I guess that’s not possible, eh? No matter how we might change the chemical properties of the atmosphere, we wouldn’t change the physical properties of how it respond to heat – right? Sorry, again, for my confusion.
I do have answers, maybe. You would prefer that I didn’t?
As I indicated at 6:47, I guessed that sealing the pot would create a real (as opposed to not real) greenhouse effect.
I stated it was a guess. If you don’t agree, maybe seeking facts from another source might be an appropriate course of action. Your call.
I respond to your questions to me: –
“Because as opposed to a pot without a lid, the rate of heat escaping the water is reduced. Wouldn’t that be true? And wouldn’t that be similar to CO2 introduced into the atmosphere reducing the rate of heat loss?”
1. Not necessarily. Given the same convective heat transport away from the water, temperature will not increase. I can give you an example if you wish, but I assume you would argue that because you haven’t specified any number of measurable parameters, I am somehow cheating if the answer doesn’t favour you.
2. Not at all. I cannot see the connection.
“Why, the heat of the water. In this case, the water would be analogous to the Earth’s climate.” Firstly, the heat of the water (I assume you are talking about heat content), will obviously be maximise by restricting heat losses. Wrapping insulation around your pot will certainly help, as will minimising convective loss from the surface.
Why is the water in a pot analogous to the Earth’s atmosphere? Why not just discuss realities rather than these ridiculous and irrelevant analogies that everyone else seems so fond of?
I have no idea of your background. I disagree based on my observation of facts, and measurements if they are available. In the specific instance of your pot, I guessed. I suggested if you disagreed, you might like an expert opinion. If you wish to ask me for a guess, and then complain that I guessed, then I guess that is up to you.
I am bamboozled by your response, which starts off as follows ; –
I may err in my judgment, but there have been too many cases of one specific model among participants. That model includes:
– Starting by some basic questions.
- Continuing with new questions that go to surprisingly deep details, which are often chosen among those, where answering is difficult, not because there would not be a perfectly valid and well confirmed answer, but because the issues cannot be understood without fair knowledge of physics.
– Dismissing all statements on such need of basic knowledge and insisting that nothing can be true unless someone with no relevant education can understand it.
- Being formally very polite, but in content arrogant and even insulting.”
I haven’t had the benefit of your standard of education. I believe you are Finnish. This would explain why your response is, to put it mildly. somewhat less than would be expected of an educated English speaker, as I understand the term.
One the one hand you claim I possess more knowledge than I admit. On another, on another you accuse me of “. . .Dismissing all statements on such need of basic knowledge . . .”. Either you made a typographical error or two, or you need brush up on your English expression. If you find that insulting, I have no control over your hurt feelings.
I get a strong impression that you feel you can insult me, cast whatever aspersions you feel like, leap to invalid conclusions, make unfounded and insulting allegations without a shred or evidence or proof.
I don’t care one or the other about your “reaction” in my “case”.
You don’t have to accept anything.
I asked a simple question on Chris’s blog. I did not get the courtesy of a response. I asked again here when I saw he had authored an article.
The response included an inappropriate analogy, and an implication that I had asked a “nonsensical” question – at least that is my take.
I have still not received an answer.
I thought maybe the whole issue was too complicated for me to express more than one sentence at a time. I asked you a simple question which I thought had three possibilities, two of which seemed to me to be wrong.
Your final response ” . . .Agreeing with you would mean agreeing with a statement, which is at least misleading, if not strictly wrong.. . .”
So, you appear to agree that I am right, but a simple answer based on simple physics, would mean that agreeing with me ” . . .is at least misleading. . .”, without any evidence to that effect.
So truth has been supplanted with “no agreement unless it supports my argument, whether it is factual or not”.
I guess by now that the assumption that the Earth’s surface temperature remains the same in spite of emitting enough radiation to warm the atmosphere etc. fails if you answer yes to my query, even though you acknowledge that the answer to be correct.
I can see why one of the climate researchers in the Climategate affair did not want to release information in case someone wanted to examine it, with a view to discovering errors.
In my opinion (admittedly amateur) the CO2 “greenhouse effect” does not exist. You can produce no experimental evidence to demonstrate it. Instead you rely on analogy, obfuscation, magic, pretending that many years of study are required to “understand” the effect, and generally hand-waving and trying to bully those outside your tribe.
So good luck. If you think I am arrogant, insulting, condescending, patronising, and generally thoroughly obnoxious – give me a single rational reason why I should give a rodent’s rectum about what you think.
I normally try to be polite. In your case, I am prepared to make an exception. You seem to think that common courtesy is a “trick” of some sort. I feel sorry for you. You appear to be an amateur masquerading as a professional, and expecting the unknowing to bow before.
I am honest – I am an amateur. Facts are facts, whether you like them or not.
As we say in my part of the country “may your chooks turn into emus and kick your dunny down”.
As I already wrote, I may have erred in your case. If so, I apologize for that.
In my previous message I tried to explain the logic that I apply based on earlier experience with some other contributors. On the net all of us can make judgments based on, what we see written. Only seldom do we have other information to help making judgments. Such judgments are often correct enough, but sometimes not.
If others (including me) err in their judgments that may be just bad luck, but it may also give a hint on, what to change in the style of writing.
Pekka Pirila 9:41.
Thank you for your comment. I should perhaps apologise to you. My language was a little intemperate, and I must admit purposeful.
I have difficulty in consciously writing that way.
I am now somewhat diffident about pointing out some awkward phrasing in your most kind response. I think I understand what you mean in your last para., so I will proceed on that assumption.
Thank your for your forbearance.
Mike – It may help you to understand the greenhouse effect by analogy with a situation you described:
“My body generates heat. Put me in a Dewar flask or other suitable insulating medium, and the heat I generate will kill me. Your “back radiation” at work, if you like. In fact, my temperature will actually rise, because heat generated by the cells internal mechanism is actually greater than 37C – at least 42C….The Earth, on the other hand, is not, unlike my good self, capable of heating its surface to 37 C by means of its internal heat generating capacity”..
The key word in your description is “internal”. The greenhouse effect is similar to internal heating for a simple reason – the atmosphere is fairly transparent to sunlight, and absorbs only a small fraction. Most is absorbed by the Earth, heating it. This is equivalent to internally generated heat. When the Earth emits that heat, it is in infrared wavelengths, which are well absorbed by the atmosphere. That is the equivalent of the Dewar flask you mention, or a blanket, or an overcoat, all of which return some of the heat back to the you (or the Earth) so that the Earth warms until the amount of heat it releases catches up with the amount it is accumulating. Notice that the important element here is that the atmosphere is rather transparent to sunlight but more opaque to the heat the Earth emits – that’s why the effect occurs. If the atmosphere were opaque to sunlight, the Earth wouldn’t heat much in the first place, you wouldn’t have the equivalent of an internal source, and you wouldn’t have a greenhouse effect.That would be the equivalent of wrapping a dead body in a blanket.
I agree with your first sentence absolutely. Now tell me, “When the Earth emits that heat, it is in infrared wavelengths, which are well absorbed by the atmosphere.”, what does the surface temperature do after it emits the heat – rise, fall or stay the same.
Now you say that if the atmosphere were opaque to sunlight, the Earth wouldn’t warm much in the first place. Take your Earth model, smoke it all over with a candle or similar, and expose it to a heat source. The surface under the layer of carbon black doesn’t heat up much? It did for me. Even if you wrap the body in left over tinfoil with a high reflective index, it will eventually get as hot as the remaining incoming radiation will make it, after subtracting the amount reflected away. I haven’t any left over tinfoil, unfortunately.
So we are faced with a conundrum – the opaque atmosphere of carbon black actually “traps” more heat than any transparent atmosphere you can devise. (I assume.)
The Earth doesn’t have the “equivalent” of an internal heat source. If the external heat source goes off, the Earth cools down really quickly.
Actually, if you go back to the Earth’s creation, and assume it was a molten blob, since than it appears to have cooled rather nicely. So over a really long average – “global cooling”?
Yes, Mike. If the sun goes dark, the Earth will stop warming, and if you die, you will stop warming. The analogy is very good. Think of it this way. The atmosphere is like a magic blanket that lets heat in so that the Earth doesn’t need an internal source to heat itself, but the atmosphere doesn’t let heat out very well, which is how a blanket behaves.
Think about it overnight, because it’s the correct answer
Now you, Chris Colose and myself are agreed. The atmosphere acts like a blanket, albeit a pretty pathetic one, if my experience of desert nights is anything to go by.
The main difference is that you and Chris use a “magic” blanket that acts as a one way insulator. Mine is more prosaic, and obeys the laws of physics.
May I inject a bit of humour (no offence intended)?
Do you keep your magic blanket next to your Maxwell’s Demon?
Please don’t wander off into spectrometry. Your whole premise, (even with the magic blanket), is based on the Sun emitting no heat radiation (longer than visible wavelengths).
Now the last time I looked (a long time ago) the Sun acts like “black body”, with a temperature so high it starts emitting shorter wavelengths like visible light, UV, and even ionising radiation.
But for your “magic blanket” to work, the black body of the Sun does not emit heat.
If you could point me to a physical manifestation of your “magic blanket”, I would be most grateful. One way mirrors, double glazing, Dewar flasks, and such like are not one way insulators.
To finish, the Earth’s equivalent internal heat source at night is . . .?
(And I don’t need a “magic blanket”. An ordinary old “physical” one is a good enough explanation for me.
Mike – You didn’t do what I suggested – think about it overnight. If you do, you’ll probably get it. If you don’t, you’ll waste everybody’s time here, including your own. Try it – don’t do any more commenting until you’ve thought about it for 12-24 hours.
And you didn’t do what I wanted. We’re even.
I hope you will understand I have thought about the matter of the “magic blanket”, and it sounds nonsensical, to put it bluntly. I don’t believe in “magic blankets” any more than I believe in phlogiston, or the luminiferous ether.
I don’t need to “think about it” for any more than a few seconds. I hope you will pardon me for disregarding your admonition.
I might be older, I might be more experienced, I might even be smarter.
I don’t know about you, and I assume you don’t know about me. You may have overlooked the fact there are a few others that may agree with me rather than you.
So, if you want to waste your time admonishing me rather than providing me with some physical evidence of your “magic blanket”, fine.
I suggest you give the matter of the conservation of energy some thought, and cogitate upon the albedo factor in the normal calculations of the Earths so-called “black body” temperature. Here’s a hint – the albedo only works to reflect solar radiation on the side that faces the Sun.
Please learn a bit about the greenhouse effect in some basic textbooks first (I have many posts floating around the web on the matter, but most basic climate books will describe it). This post is about feedbacks, not the operation of the greenhouse effect, which has also been discussed endlessly on this blog and others.
I would suggest ozzieostrich studies the Kiehl-Trenberth energy diagram. Note that the energy budgets are satisfied at the surface, in the atmosphere and at the top. Having studied that, let Fred and Chris know which of those numbers you disagree with and why, and how you would match up those three budgets.
The “magic blanket” is not really so magic at all. It’s like a colored filter that lets some colors pass through and stops other colors. In the case of atmosphere it lets through the visible light as well a little UV and some IR. Because sun is so hot, it’s radiation is mainly in wavelengths that the atmosphere passes through, but the IR from the Earth surface is in wavelengths that the atmosphere stops to a major part.
“Because sun is so hot, it’s radiation is mainly in wavelengths that the atmosphere passes through, but the IR from the Earth surface is in wavelengths that the atmosphere stops to a major part.”
Interesting, Do you mean the atmosphere SLOWS the emission of IR?? I seem to remember that we currently are close to an equilibrium where everything coming in is also going out. It would be difficult to have an IN=OUT if a major part of the OLR is being STOPPED!!
Words and their meanings are important. One of my problems with climate science is that the concepts seem to often be couched in terms that imply things that are NOT happening!!
The atmosphere “stops” most photons leaving the surface by absorbing them. The atmosphere emits as well. The emission would be so strong that the flux would not change, if the temperature of the atmosphere were the same as that of the surface, but a lower temperature of the atmosphere leads to reduced flux with altitude.
The more effectively the atmosphere absorbs (and emits) radiation the more it acts as an insulator for the radiative heat transfer. The heat transfer is slowed down by frequent absorption and reemission of the photons. Due to compensating convection that makes little effect inside the troposphere, but the change is significant for radiation that escapes to the space, because that occurs the less from the surface and lower atmosphere the more CO2 there’s in the atmosphere. The Earth as whole must be warmer to emit as much to the space when the point of emission is moved up in the troposphere.
Cannot work out this threading thing. Sorry.
I have looked at the diagram before. If you cannot see the problem, I see you have accepted this “greenhouse gas effect” on faith.
I never argue with faith. Chris Colose has not deigned to assist with an explanation of his 10x in creates 12x on the surface
You propose a filter that transmits the full spectrum of a black body at about 5500C in one direction, stops part of that spectrum in the other direction.
I am unaware of any filtering material which possesses this property. Could you point me in the general direction of such a one-way filter? If you can’t, I will assume it is made out of the same material as the magic blanket, and as useful.
Did you really misunderstand my message so badly, or are you just pretending?
If you did, please read again. If you are just pretending, then I cannot expect any progress in the discussion.
Interposing a passive filter of any sort (no Fresnel or other lenses allowed) will not magically increase the temperature. A filter absorbs the wavelengths it does not transit, and heats up because of this. I thought you were talking about a “one way” filter with theoretical properties
My bad. If I misunderstood, I apologise.
You made another point about the warming of the atmosphere. And I agree. Radiation from the Earth (and at over 250K there will be lots) will indeed heat the atmosphere.
As you say, the atmosphere “stops” photons by absorbing them, and heats up. Where do these photons radiate from? The Earth. Now if the temperature of the atmosphere is raised by absorbing these photons, what do you think happens to the temperature of the body that emits those same photons? Rise? Fall? Stay the same?
You tell me.
Hi Mike – I just visited your website and found this:
If you throw 15 heads in a row, does this mean the odds of another head are more than 15,000 to 1? Rubbish! The coin has no memory, and I strongly suggest that you don’t buy a used car from anyone that makes this claim. The odds are still even money – more or less.
Even money? Wanna bet?
Your knowledge of probability seems to equal your knowledge of the greenhouse effect (named after greenhouses, which heat the surface below by interposing a substance between them and the sun, although the convective mechanism differs from the radiative mechanism involved in climate greenhouse effects).
Yes indeed, I do wanna bet. I have in my hand a coin that has come down heads 15 times in a row. I will sign a statutory declaration, or a notarised declaration or whatever to this effect.
I am prepared to bet a reasonable amount that a tail will appear on the next toss. An “honest broker” will hold the stakes. I assume you are offering me odds much greater then even money.
Say 10,000 to one? Tell me how much cash you can give the stakeholder, and I will put up 1/10,000 of that amount.
I think this coin doesn’t know what it’s supposed to do. I don’t think it’s got a memory. However, a bet is a bet. You offered, I accepted.
Over to you.
This question gets near to the core of the GHE. At the wavelengths were the GHG’s are effective each photon gets absorbed soon after it has been emitted. That means also that the temperature difference between the points is small, and that means further that there is almost as much radiation from the cooler point to the warmer than from the warmer to the cooler. One more way of putting this point is that there’s only little net energy loss from the warmer point related to IR radiation towards the cooler point. The Earth surface cools the less the closer to the surface the radiation from the surface gets absorbed as the radiation in the opposite direction compensates the emission the better the smaller that distance is.
Adding GHG’s shortens the distance discussed above and reduces the heat loss. At the same time it doesn’t affect significantly the radiation from the sun to the surface. Thus heating of the surface is not changed, but cooling is reduced. That leads to warming of the surface until it’s warm enough to loose again as much energy as it receives. The warming of the surface leads to a warming of the whole troposphere up to tropopause, which is shifted a little higher up. An energy balance is obtained, when the warming of the surface and the whole troposphere has reached the point, where the total radiation to space is again as large as it was with less CO2. In the new situation the radiation to the space directly from the surface is limited to a narrower band of wavelengths, because CO2 absorbs more at the edges of this band. Similarly the radiation upwards from lowest atmosphere is also absorbed more, while a larger part of the spectrum reaching the space is emitted from the top layers of troposphere. The stronger radiation from the warmer surface and low troposphere at wavelengths that penetrate best through the atmosphere make the rest of the balance.
Am I correct in assuming that your answer to my question is that it falls?
We can proceed to discuss the magnitude of the fall as soon as you acknowledge that when heat leaves the surface, the temperature does, indeed fall.
That’s why it’s called equilibrium. The temperature consequence of 10X out is accounted for in the equilibrium. So is the temperature consequence of 10X in.
You buy a planet that has no sun. It’s xx degrees cold, and it is in equilibrium. So you buy it a sun. Is there new equilibrium temperature? Good luck.
There is no point in continuing discussion with you as you seem to be one more case of those, who know much more than they admit and use that knowledge to mislead the readers as far as they can.
Hey Mike – You’re the one who said that heads on the next toss (after 15 consecutive heads) was an “even money” proposition, because a coin “has no memory”, so if we’re going to bet, that should be the condition. Don’t you think that’s fair, or are you backing down from your “even money, no memory” claim?
(For anyone who thinks this is off-topic, I would argue that an understanding of probabilistic estimates is important for efforts to evaluate climate sensitivity and other relevant values)
Just curious, is your point that a coin that comes up heads in 15 consecutive flips is not likely equally balanced?
Or some other factors related to the conditions of how the coin is flipped?
Joshua – No fair! You’ve just ruined my chance to win a lot of money from Ozzie, or at least to have him admit that he’s just as ignorant about probability as he is about climate.
Of course his claim that if a coin comes up heads 15 consecutive times, it’s “even money” to come up heads on the next toss because “a coin has no memory” is nonsense, and you get the feeling from his latest reply that he was already trying to back down from that claim.
What are the odds of heads on toss number 16? Well, I don’t know, but they are greater than 50/50. A completely fair coin (one that would yield a ratio of heads to tails that approaches 1/1 as the number of tosses increases) will yield 15 consecutive heads with a probability of 0.5^15, which is one chance in 32768. A two-headed coin will do it with probability 1.0, and a coin unbalanced toward heads will perform somewhere in between. To calculate the probability that the coin in question will come up heads on toss number 16, one has to know something about the frequency of two-headed coins and the frequency and behavior of unbalanced coins. Once that’s done, the numbers can be entered into a standard Bayes formula to estimate the probability of heads on toss 16. Without all the numbers, one can only say that the probability is greater than “even money”.
It seems that Two-headed Coins may not be that rare, in case someone asks you to place an “even money” bet on tails from a coin that came up heads 15 times in a row, claiming that “a coin has no memory”.
I don’t want to belabor the point because it’s not directly relevant to feedbacks per se, but the Bayesian principle, that one can update probabilities based on observed behavior, is a critical element of many climate estimates, as evidenced in the recent thread on probabilistic estimates of transient climate sensitivity.
According to the laws of thermodynamics, you are exactly correct. We are in agreement.
And the relevance to the alleged greenhouse effect is . . .?
Pekka 10:27 am
I haven’t heard that particular ad hominem argument (if that’s what it is) before.
I admit to knowing very little. I did not finish High School. I have no University Degree, Diploma, Certificate or anything of that nature. I have not attended a Trade School, or Technical College. I don’t have anything that would be acceptable as a formal qualification as far as I know.
If knowledge is a crime, then on your evidence (based on precisely nothing, as far as I can see), I plead guilty, your Honour.
Fred 12:10 I think.
Yes, I did say I was willing to bet, as you seemed to take exception to a statement on my blog wherein I said something to the effect that regardless of prior history, the odds of a coin coming down heads or tails (given a fair coin and a fair toss) were pretty much even money, and you seemed to be prepared to offer significantly better than even money odds.
I may have misunderstood your challenge, as I inferred from it that you thought I was wrong, and you said to someone else that “. . . You’ve just ruined my chance to win a lot of money from Ozzie, or at least to have him admit that he’s just as ignorant about probability as he is about climate.. . . ”
How am I supposed to take it?
If you are now telling me that you accept that I was right that the odds are even money, do you still believe that I know as much about climate as I do about probabilities?
I thought offering you odds of 10,000 to 1 against the 30+ thousand you calculated (and remember this is before your subsequent demonstration of your knowledge of the odds) was more than generous.
I am not sure what the purpose of this discussion. I did not invite it, so don’t blame me if you have thought about, and you are now not so sure about the accuracies of your related postings.
Of course, I am still willing to take the bet. Of course I haven’t changed my mind about the odds. If you still believe the odds are greater than even money, give me your assessment. If you trust me, drop your stake into my bank account (at your expense – you wanted to bet) . Tell me what you call. You may nominate a coin tosser.
Please do not take offence. None is intended.
Hi Mike – Some of the participants here get frustrated and angry at you when they can’t get you to admit you’re wrong, as though that’s a personal failing on their part. I just think you’re funny.
As usual, you missed the point about the 15 heads. It’s evidence against the coin being “fair”, a word that now mysteriously appears in your comment but wasn’t in your blog.
Mike, it’s true you don’t understand climate and you don’t understand probability. That’s OK with me. You can go through life ignorant about both those things. You shouldn’t go through life unwilling to learn. You might want to start by considering the possibility of going back to get a high school diploma.
not nice. You are assuming a bias in the system. Where did the terms state a BIASED system??
With an unbiased, random system you are wrong.
I may err in my judgment, but there have been too many cases of one specific model among participants. That model includes:
– Starting by some basic questions.
– Continuing with new questions that go to surprisingly deep details, which are often chosen among those, where answering is difficult, not because there would not be a perfectly valid and well confirmed answer, but because the issues cannot be understood without fair knowledge of physics.
– Dismissing all statements on such need of basic knowledge and insisting that nothing can be true unless someone with no relevant education can understand it.
– Being formally very polite, but in content arrogant and even insulting.
I have become perhaps too sensitive to such a behavior, because it’s not always intentional.
Whatever the reason for such behavior, I have seen that it’s really useless to continue long, when the pattern appears. I have seen that both in responses to my own writings and in many discussions, where I haven’t participated.
The following comment from you was the final reason for my reaction in your case:
Why should I accept such conditions from your side? Agreeing with you would mean agreeing with a statement, which is at least misleading, if not strictly wrong.
You are assuming a bias in the system
Kuhnkat – Maybe no-one else is paying attention, but this is a situation where you might learn something about probability you didn’t know before. The entire point is that one assumes nothing about bias or lack of bias. Rather, we let the behavior of the system give us quantitative information about the probability and magnitude of bias. If you do a series of coin tosses, you start off with the presumption that heads and tails will occur with about the same frequency, because that appears to be the behavior of coins in general, and you have no further information about this particular coin to change that. If the first 15 tosses come out heads, however, you now have information that you didn’t have previously that tells you that the coin might be biased. If you ignore that information, you will make inaccurate estimates of the future behavior of the coin. Quantifying the change in probability is the province of Bayesian statistics, which is one of the most powerful tools in science, including climate science.You should probably Google this for more details.
Just to reinforce the point – if you have a coin that is going to be tossed, how will you know whether it is a “fair coin” or very unfair? There is no label on it. The answer is that you test it to see how it behaves. Even a fair coin might give you 15 heads on the first 15 tosses, but that outcome should very much alert you to the alternative possibility – an unbalanced or double-headed coin.
we are not talking about just probability. We are talking about ASSumptions around the computation. You are claiming it is most likely biased due to its having flipped fifteen times the same in a row. you know this result is within possibility so have no reason to automatically assume that it is biased, yet, you DO make that assumption anyway without investigating to find whether there is a bias.
This means you should NOT be making a bet, not that you should be going with a situation that you can only compute probabilities without having any way of determining whether the computations have meaning for the situation. This is what real statisticians call being too sure of yourself.
Since you are betting based on a bias you should have no problem giving the odds. Since you really do not KNOW whether it is biased or not you will refuse to give odds and spout off about others not understanding statistics when you are really talking GAME THEORY.
Spare us your rationalizations.
“if you have a coin that is going to be tossed, how will you know whether it is a “fair coin” or very unfair?”
Try measuring the properties to a high confidence, which we cannot yet do with our earth system. Tossing it a few more times will not prove anything unless it is grossly biased such as having two heads. Ask any pit boss with a gambler 12 hours into a winning streak. Have the odds changed? Probably not, yet the person keeps on winning so they change decks, balls, dealers, whatever anyway!!!
Kuhnkat – If you don’t want to learn, I can’t force you, but you’re wasting an opportunity. You are also, I’m afraid, making yourself look very foolish in the eyes on any knowledgeable individual who happens to be reading these exchanges, although there probably aren’t many readers left. Rather than arguing, why don’t you think about it for a few days, and also look up some of the material on Bayesian statistics via Google?
kuhnkat, since Fred Moolten has decided to berate you while making a claim partially regarding me (I am a knowledgeable individual), I’d like to take this opportunity to disagree with him. He claims:
I don’t think you’re making yourself look foolish at all. In fact, I think you are absolutely correct. Given this, Fred Moolten’s claim here is necessarily false, unless one intends to argue I am not knowledgeable. However, even if someone wishes to argue such, it is clear I am more capable of reading simple sentences than Moolten is, and that makes me infinitely more qualified to offer an opinion on this dispute. To demonstrate my point, he recently said:
Take special note of the part I made bold. What he says there is true. If the first 15 tosses of a coin come out heads, this does change the probability of the next toss landing on heads. However, this isn’t what was being discussed. This dispute started with this sentence:
You’ll note there is nothing in this which indicates the 15 tosses in question are the first tosses observed. Fred Moolten has simply changed the scenario being discussed, without saying so. Every single one of his criticisms has been predicated upon using a scenario nobody else is discussing. It is only by grossly distorting what has been said he is able to effectively insult you.
Brandon – If you have a coin that has been known to show tails on previous occasions, you are discussing a different scenario from the one described by Mike Flynn, where the only observation reported is 15 consecutive heads. Since that was the only knowledge available, what I said was completely accurate, because probability depends on available information. As I mentioned, if you toss a “fair coin” enough times, it will eventually show 15 consecutive heads (it’s a one in 32768 occurrence if I recall correctly), so obviously I was not referring to a coin with a known record of heads and tails. I doubt that other readers would have trouble understanding the meaning of what I was saying, because it’s a standard paradigm in discussing probability to postulate a set of coin tosses with a specified outcome, and in all these cases, it’s implicit that the observer doesn’t have any previous history of how the coin behaved – otherwise the paradigm would have no meaning. Again, the important concept is that probability depends on available information. If you are aware only of 15 consecutive heads and someone else knows of additional information that is different, that person’s probability and yours must differ – that’s an essential ingredient of probability theory.
I also think you’re going to confuse kuhnkat, who misunderstands this aspect of probability and whom I was trying to help by pointing out how probability is a function of observed behavior..
Fred Moolten, first I’ll note you didn’t dispute my refutation of the claim you made. I’ll take this as you tacitly agreeing you misspoke unless (or until) you decide to offer some counterargument in the future. This means you were wrong in your criticism of kuhnkat. That leaves only one issue to discuss, an issue best summarized by your statement:
This is a misleading statement. It is necessarily predicated upon the assumption one is using a Bayesian approach to probability, an unjustified assumption. If one uses a different probability approach, your claim is false. This means everything you’ve said is dependent upon an unstated and unjustifiable assumption.
But it gets worse. It is perfectly clear from Mike Flynn’s blog post he was not referring to a subjectivist view of probability, but rather a physical view of it. This means your assumption is not only unstated and unjustifiable, it is in direct contradiction to what the person you responded to was using.
Added on top of this, you’ve now flatly denied the existence of the probability approach he was using even though it is extremely well known. I know you probably favor Bayesians over Frequentists, but that doesn’t mean you can simply pretend the physical view of probability doesn’t exist, or that it wasn’t what he was using in his post.
You’ve gone from misunderstanding/misrepresenting what he said to flatly making things up. Nothing you’ve said in your latest response is true due to the fact you’ve hand-waved away a common approach to probability which everybody but you was using.
For those who aren’t well-acquainted with different views of probability, let me give a brief description of the issue here. There are two main approaches to probability, subjectivist and physical. Physical views of probability state the probability of things is determined by the physical nature of what’s being considered. This is what most people instinctively think of when they hear “probability.” In this view, a fair coin will always have a 50% chance of landing on heads, no matter how many (if any) flips have been observed. This is obviously the view Mike Flynn subscribed to.
A subjectivist view of probability is quite different. In it, the physical nature of what’s being considered is irrelevant, except insofar as one knows it. Instead of relying on some absolute sense of probability, it determines probability by what has been observed. This means it will say a fair coin does not have a 50% chance of landing on heads until it has been observed to have that chance. If one sees 15 heads in a row, these observations will have one say the chance for heads is greater than 50%.
Now then, there are a lot of disputes over which of these views are “correct.” However, there is no dispute that both views exist. There is also no dispute most people are acquainted with the idea of a physical probability, and it’s almost certain more people think of probability in that view than in a subjectivist view.
If one only uses a subjectivist view, Fred Moolten’s comments would be correct. However, there is no justification for limiting the discussion in such a way, and it is abundantly obvious other people (including the writer of the original comment) were not doing so
Brandon – Either I explained the situation unclearly or you have been unable to be receptive to a rational explanation. Or both. But you are simply wrong, and it has nothing to do with philosophical differences between Bayesians and frequentists, who in this case I expect would agree with my point (their differences relate more to the subjective element in Bayesianism). The point I made was correct, unambiguous, and consistent from one comment to another. I’ll try to make this clearer now in hopes you’ll understand, but I won’t waste more time if you continue to argue.
Probability is a function of your information about a circumstance. In the case of 15 consecutive heads, if that is all the information you have about this particular coin, then from the perspective of a probability estimate, 15 consecutive heads is informationally equivalent to heads on the first 15 tosses. Stating it one way is the same as stating it the other, which is why the distinction you make is without substance. If you fail to grasp this point, then you are missing a critical element in the understanding of probability, and so I hope you will think about it carefully..
In the real world, it wouldn’t take any particular philosophy to convince a rational observer confronted only with the knowledge of 15 consecutive heads and no other information that the probability of heads on the next toss has risen. That conclusion would be even more evident if he or she had money riding on it. No matter how many different ways you look at it, my point is completely accurate, and is designed to correct kuhnkat’s misunderstanding. I hope you take some time to reflect, because although I won’t deem you foolish for arguing, your argument has been foolish, and that will be recognized, I think, by others familiar with coin toss scenarios used to illustrate the principles of probability. No such scenario can be useful without the understanding that the observer starts with no information about the coin and then observes the sequence specified in the scenario – for that observer, N coin tosses means the first N tosses.
(Here’s another way to grasp the point. Imagine the first 15 coin tosses you see are heads. You know the coin has been tossed before but the results are unavailable to you. As long as you can’t have that information, does knowing that previous tosses have occurred change your probability estimate? I hope not.)
The problem is that in an effort to quibble that is unwarranted, you will confuse anyone actually trying to understand these concepts.
Brandon – The comment I wrote last was posted before yours immediately above mine and was in response to your comment above that. Reading your latest comment, it seems to me that you completely misunderstand probability by confusing physical properties with the opposite of subjectivism. They are not opposites. I won’t take time here for the details, but you are welcome to email me. All I’ll say is that physical behavior depends on the physical nature of whatever it is that is exhibiting behavior, but probability involves an effort to know what that behavior will be. As I said, email me if you want more details.
Fred Moolten, I’m not going to e-mail you over a point anyone could figure out for themselves by spending five minutes on Wikipedia. This is especially true as while your responses have been long-winded, they’ve responded to my points only in the most indirect of ways, if at all.
Ultimately, this entire dispute can be judged on a single statement you’ve made. You say:
The comment in question is this one. The contents of it are fairly simple and extremely easy to judge. If one reads those contents and decides they indicate I “completely misunderstand probability,” you must be right. If, on the other hand, one reads the contents and decides they indicate I understand probability, I must be right.
For anyone who is still uncertain whether or not you are full of it (or conversely if I am), I advise looking at this Wikipedia article and comparing what I said to what it says. As Fred Moolten might say, any reasonably intelligent person who did so would think Moolten has made a fool of himself.
Hi Brandon – Against my better instincts, I’ll make one more attempt to continue this discussion here despite the thread inconvenience. I should know by now to expect quibbles from you based on your quarrelsome nature, and not get annoyed, particularly when you have something interesting to say, which is often the case.
In this case, though, I truly think you have confused yourself in distinguishing “subjective” from “physical” probability in regard to the 15 heads problem. The wikipedia article may have misled you if implies that Bayesian inference must be subjective. That’s wrong, because it can be subjective but needn’t be, and in the problem we’re discussing, it isn’t. My own appreciation of Bayesian inference comes from a highly objective application – medical diagnosis – where the values of Bayesian priors can be ascertained from data and don’t require subjective judgment. In fact, the subjectivity of some Bayesian applications makes me uncomfortable, even if it can’t always be avoided. In the 15 heads scenario, however, we could in theory derive a probability value on completely objective grounds, provided that we knew the frequency of fair coins, unfair coins, and the nature of how the latter behaved. For a simplistic example, we could divide coins into fair coins and two-headed coins, in which case only the frequencies would be needed. In the problem at hand, we don’t have that information, but we don’t need it to conclude that 15 heads, with no other information available, signifies a greater than even money probability for heads on toss 16.
There is no doubt that the physical properties of objects determine their behavior. However, I think you have misconceived this point in the following statement:
“A subjectivist view of probability is quite different… it will say a fair coin does not have a 50% chance of landing on heads until it has been observed to have that chance.”
That’s not correct. No matter whose philosophy is operating, a “fair coin” by definition is one whose physics cause it to split heads and tails about 50/50 on average. But that’s not the problem here. We aren’t interested simply in whether a fair coin is exhibiting unusual behavior (1/32768), because if it’s a fair coin, it will come up heads on the next toss about half the time. What we want to know is whether the coin we are observing is a fair coin. If it is, it will have fair coin physics, and if it isn’t, it will exhibit unfair coin physics. If no unfair coins existed, it wouldn’t matter how many consecutive heads we’ve observed – the next toss would be a 50/50 proposition, but since unfair coins exist, we have to ask how likely it is we’re observing unfair coin physics. Bayesian inference allows us to do that – in a quantitative manner when we know the value of the priors, and in a qualitative manner when we can only say the odds are no longer even money.
I’m a frequentist by instinct, with a strong inclination to base probability estimates on objective data. I don’t know of anyone with those characteristics who would make an even money bet on tails when the only available information is 15 consecutive heads, no matter how much additional history on prior tosses exists but is unavailable. Subjective belief is not involved, but only rational common sense. I believe the difference between schools of thought lies somewhere else than where you have attributed it for this particular problem.
Fred Moolten, your comments about my character are as baseless as ever, but I won’t dwell on that. Instead, I’d like to point out that despite all of your verbiage, you’ve failed to comment on the extremely simple standard I offered for judging this dispute. You didn’t question the fairness of the standard, and you didn’t make any effort to show you “win” based upon that standard. This is remarkable. When provided simple and direct points which could lead to resolution, you choose to ignore them. I cannot see any reason for your continued refusal to address simple points which wouldn’t require making far worse comments than you’ve made about me, so I’ll simply point out your behavior is almost perfectly suited for avoiding resolution.
Aside from that inescapable point, there’s little to say about your latest comment. The first half of it discusses subjectivity, but nothing you say in it has any relevance to anything I’ve said. Since you don’t quote anything I said or state which arguments you’re responding to, I have absolutely no idea what you think you’re responding to, but it seems to be something which doesn’t exist. In fact, the only thing you discuss which is relevant to my comment is the issue of a “fair coin.” Unfortunately, everything you said was just based upon you misunderstanding what I said.
I referred to a “fair coin,” but that does not indicate I say the coin is known to be fair to the person testing it. It merely indicates the coin being tested is fair. I could understand your mistake, except immediately prior to the sentence being discussed, I said:
This sentence clearly indicates everything you said misses my point. I obviously agree a subjectivist would say a fair coin has a 50% chance of landing on heads, if he knows it to be fair. He could know this by observing a large amount of flips, or just by observing the physical characteristics of the coin, but “until it has been observed to have that chance,” a subjectivist will not say it has that chance.
So this leaves us in a strange situation. Your latest comment was almost 600 words. About half of that had no bearing on anything I said, and another half stems entirely from you misunderstanding something I said. At the same time, you’ve failed to address a number of simple, outstanding points, including a single sentence standard with which this dispute could be resolved. All it would take to show you’re right on this issue is to point to what I said which indicates I don’t understand probability. A single quote with a two sentence explanation is all that’s needed.
Once again, let me try to offer a simple resolution. You claim I (seem to) “completely misunderstand probability.” Prove that point and you “win.” Convince people, maybe even myself, I don’t understand basic concepts involved in probability, and you’ll show how much of a fool I am.
If you’re right, it should be an extremely simple task.
thank you for your for your support. I am experienced at looking foolish though!!
Fred, yes I have seen discussions of statistics and what you are referring to any number of times in the climate blogs and one statistics blog I read. Technically you are correct if you subscribe to that form of stats. I don’t.
The odds on the flip each time when a fair coin and method is used is 50/50. The fact you decide to use the previous 15 throws as evidence of bias is your choice, not a fact. Suggesting it is a 2 headed or biased coin doesn’t fly because Ozzie is betting on a tails. “I am prepared to bet a reasonable amount that a tail will appear on the next toss.” YOU are betting on another head. Why would he bet on a different outcome if the coin or throw was biased? Of course, if you are suggesting that he deliberately cheats that is also a non-starter with so many witnesses. Realistically the data you have does not lean toward bias.
I will reiterate, you are ASSUMING that there is bias because of how long the odds are against flipping 15 in a row. You make your computation on this assumption. The odds are still 50/50 because there is no bias.
Now, after all that BS, I do believe that Ozzie said ABOUT 50/50. “The odds are still even money – more or less. ” What was the number you computed again Fred??
kuhnkat, I won’t weigh in on how foolish as you may be at times, or as a person. I only responded because Fred Moolten said any knowledgeable would find your comments foolish, and I didn’t. This means he either misrepresented me, or said I wasn’t knowledgeable. Either way, it was something worth responding to.
Aside from that, I think it’s appropriate to defend anyone from false criticisms, no matter who they are, or what they may be like.
Brandon – I’m sorry my previous responses to your arguments haven’t convinced you. I don’t think repeating them will help, but I hope that anyone else who has followed this long discussion will find my explanations useful. Probability is a fascinating concept, but an elusive one. If you want to delve deeper – up to a point – my email invitation still stands.
Kuhnkat – How much you want to pursue this depends on how much you want to understand the concepts I’ve mentioned. Maybe not at all, but if you wade through all the foregoing and are still struggling, you are also welcome to email me. I don’t want to waste more column space here on something that may now interest only a few of you. The bottom line, though, is that for the problem at hand, anyone who think the odds remain at even money stands to be on the losing end of a bet.
Useful, yes. Probability has this wonderful utility of serving to quantify a belief system as well as quantifying natural random processes. If you have reason to believe that the coin flipper can generate a desired outcome (which can be done based on the way the coin is launched), or that the coin itself is biased, then one can add that belief as a probability. It’s really as simple as that.
Fred Moolten, you’ve consistently and adamantly refused to respond to the simple points I make. Rather than address what I say, you have instead rambled on about things which had no bearing on anything being discussed. You have also given lengthy discourses about mistakes I have supposedly made which ultimately showed nothing more than your failure to understand what I’ve typed. Even worse, when these inescapable points have been explained to you, you’ve simply decided to leave the discussion.
There is much more I could say about your behavior here, but ultimately, it boils down to one simple thing. Despite everything you have said about me and my comments, you have not responded in any way to the points I have raised. Ultimately, all you have done is show yourself incapable or unwilling to understand simple sentences or participate in a reasonable discussion.
while I don’t pretend to be an expert on statistics Bayesian or otherwise, you don’t appear to be willing to accept that piling layer on layer of uncertainty by making ASSumptions about the facts in the computations are not helpful. Try pursuing that angle for a few minutes of thought.
Why would I ask you questions and prefer you didn’t have answer? I fail to understand the logic in your speculation.
lol! A Brandon-type post.
Let me try again:
Why would I ask you questions and prefer you didn’t have answer? I fail to understand the logic in your speculation.
What is a “real” vs. “not real” greenhouse effect? How do you create a “real” greenhouse effect with no greenhouse – only a stove, a pot, some water, and some salt?
Your namesake achieved fame using his extremely loud voice. He destroyed rather than created – if my recollection is correct.
Now to my responses:
You have stated you fail to understand my logic. I cannot assist you if you fail to understand that a closed question requiring either a yes or no answer, should be answered either yes or no. OK, so you fail to understand. I must be stupid.
If you want to treat my “guess” about convective heat vis a vis your mythical pot (in the sense that you have not produced anything other than anecdotal evidence provided by yourself for me to examine) as fact, then OK.
If you don’t want me to answer questions you direct to me, then say so.
Absolutely. Just because every swan you have seen in your life is white, do you deny that black swans might exist? If you wish to deny heat transfer by convective flow away from an object, then OK. It must be so.
I can assume anything I like. And I have. Fair enough.
I am in agreement with you and you are in agreement with me. Insulators work by slowing down the transmission of heat. I’m pretty sure you know that, and you are just trying to trick me. OK.
As an example of where that wouldn’t happen
Yes you did. I believe I understand how insulators work.
Thank you for your expressions of sorrow.
Your background might be relevant, but because I have no knowledge of it one way or the other, I said I have no idea of your background. OK.
I have not asked a single question, as far as I can see. Please correct me if I am wrong. If you wish to continue to discuss the question I asked Chris Colose as his accredited representative, continue.
You are again asking me to answer a question to which I have already told you that without an exact physical description of the parameters involved I can only guess at, in view of the imprecise nature of your question. If you cannot accept the notion that a guess means I don’t know (otherwise I wouldn’t have to guess), then fine.
I shall not respond further to inane analogies.
Finally, if you don’t think you complained, then I accept your statement.
I rather expected that you would know whether you were voicing a complaint or not. No matter. You have clarified the matter by stating explicitly that “. . . I would never complain about one of your posts. I find them to be uniformly quite amusing. . . .”
I will hold you to that. I am pleased that I have bought some humour into the discussion.
Please note I have asked no questions.
Chris Colose, it’s odd you would single that sentence out as “nonsensical.” All he said in that sentence is Earth can be no warmer than caused by the sun. I think you must have misunderstood the sentence as it is completely non-controversial.
“No warmer than caused by the sun” If that was all there was to it: ie the distance between the Earth and the Sun, then the Moon and the Earth would have approximately the same average temperature.
They don’t. The Earth is much warmer on average.
tempterrain, your response makes no sense. You seem to be disputing something I’ve never said while not responding to what I did say. In fact, you implicitly agree with what I did say.
Whatever other effects may be at play, the Earth is no warmer than caused by the sun.
And the earth never gets as hot as the moon or as cold as the moon. The atmosphere with GHG’s and the ocean is a wonderful MODERATOR of the radiation.
You ultra-literal interpretation that “All he said in that sentence is Earth can be no warmer than caused by the sun.” is disingenuous. You know very well the natural GHE was being questioned. That should be on a other thread BTW.
tempterrain, you are being ridiculous. You have effectively accused me of dishonesty without any basis. What is my dishonesty? I read a sentence for what it says, nothing more. Apparently you would have people believe I knew (and know) that sentence didn’t mean just what it said, but acted otherwise just to mislead people.
Do you think you’re so obviously right it would be impossible for me to disagree with you, or do you just like making things up about people?
Do you not see the fallacy in your question regardng blankets?
The pattern with many believers, when asked uncomfortable questions, is to either ignore the question or reduce their answer to “because I say so”, or to declare it is all part of a plot by the ‘fossil fuel industry’.
By the way “fossil fuel industry” is a term fabricated by climate extremists. There is no such industry as “the fossil fuel industry”. There is no association by that name, no lobbyists being paid by it, no political action committees representing it,
There are industries that are involved with coal, with oil, with gas, with gas liquids, but as a great tell of how the extremists rely on ignorance and misdefining issues, they have to create an ominous name to label everyone involved with energy from sources they do not approve of.
Demonization of one’s opponents is an important step for extremists and con-artists.
I wonder why the AGW community, from its leading scientists to blog warriors depend so much on phony and insulting names?
Mike Flynn, I think you’re making a simple mistake, and it has nothing to do with “magic blankets.” In fact, as far as I can tell, the magic blanket talk is completely irrelevant to anything you said, so I don’t know why Fred Moolten and Chris Colose have talked about it. I suspect they’ve just been confused about what you’re saying. There are two comments of yours I think need to be addressed to clarify matters. First:
The part I made bold is especially important. It is true if 6x leaves the surface, the surface temperature will be lower than it would be otherwise. However, this does not prevent the planet from getting warmer. If that 6x had previously been 7x, things would be warmer than before. This leads to the second part:
The reason you cannot see how that would “magically” happen is it wouldn’t make sense. However, that isn’t what is happening. The input value isn’t changing. It is always 10x. This means the equilibrium value will also be 10x. All that is changing is the energy absorbed and reradiated by the atmosphere. When the atmosphere changes, the system won’t be at equilibrium, so you will temporarily have a greater input than output. After a period of time, the system will reach equilibrium again, and at that point, input and output will both be 10x again. However, this new equilibrium will be at a higher total energy than before.
Increasing greenhouse gases temporarily causes the planet to shift out of equilibrium so it absorbs more energy than it emits. This causes it to warm. It isn’t complicated, and it doesn’t require a magic blanket.
You are absolutely correct when you say the temperature will be lower – if you stop there. There is no ” . . . than it would be otherwise. . . ”
Regardless of what you think, when you lower the temperature, that means the surface cools, in absolute terms.
Now I merely copied Chris’s educational material from his blog.
He said 10 – 6 + 2 = 12.
Look for yourself – if he meant something else, he should have said so.
I asked Chris to check my reasoning, or maybe say what he really meant, in case of typos or missing words. No joy.
Chris merely admonished me to learn basic greenhouse effect. I would, but his basic arithmetic doesn’t add up.
As for “magic blankets”, that is Fred Moolten, not me.
He said 10 – 6 + 2 = 12
Actually it’s, 10-6-2+2 which clearly equals 4, which means that the earth is receiving 4x more than it is emitting so it heats up.
You say in your original comment
I have seen other explanations of the greenhouse effect, and all of them seem to overlook the fact fact that the temperature of a body losing heat actually drops.
But you are only looking at once side of the energy balance. At the same time as the earth is radiating heat out to space it is receiving it from the sun. As Fred pointed out above if the sun were switched off then the earth would still radiate heat out to space without receiving and incoming radiation so would indeed cool down.
Dear andrew adams,
To summarise and to quote Chris directly
“12x to the surface
8x back out to space”
This apparently comes from ” . . .10x solar in, 10x infrared out . . . “. Note the “10x solar in”. Chris’s words, not mine.
No matter how you slice it or dice it, there is nothing you can wrap a body in, (at the same or a lower temperature than the body), that can cause the body to raise its temperature above that achieved without the wrapper. Not CO2, not anything.
If you believe you can, please let me know where I can obtain this wondrous material. Limitless pollution free energy will ensue. Of course you can’t. Another perpetual motion machine that doesn’t work.
This is obviously a matter of faith with you. I shall desist.
“No matter how you slice it or dice it, there is nothing you can wrap a body in, (at the same or a lower temperature than the body), that can cause the body to raise its temperature above that achieved without the wrapper. Not CO2, not anything.”
You can if there’s an independent heat source inside the wrapper. Then the heat source raises the temperature, because the wrapper slows its escape.
No matter how you slice it or dice it, there is nothing you can wrap a body in, (at the same or a lower temperature than the body), that can cause the body to raise its temperature above that achieved without the wrapper. Not CO2, not anything.
If you believe you can, please let me know where I can obtain this wondrous material.
In your attic?
Many apologies. I meant a body without an internal heat source. My bad.
OK fair enough, but what if instead of an internal heat source we have an external heat source and a “one way” insulator. In other words your “magic blanket”, except that it doesn’t have to be magical at all, it just has to work only at specific wavelengths.
I agree with you. If there was such a thing as a perfect (and it would have to be perfect, or it would eventually cool down) “one way insulator” in the context of Soar radiation and its interaction with the earth’s surface, it would indeed be the same as a “magic blanket”.
Demonstrate one, and I will immediately become a believer.
That’s what “greenhouse gases” are. They are not perfect in sense you mean but then theydon’t need to be, the extent to which they are determines the extent of the greenhouse effect. Or do you deny that GHGs absorb outgoing LW radiation but not incoming solar radiation?
So you say. I don’t believe in the “greenhouse magic” any more than i believe in ghosts.
What you are saying that I should accept your assertion that GHGs act in a manner that cannot be demonstrated, because you say it is so.
I hate to point this out, but the Sun radiates heat, just in case you didn’t know. Yes, CO2 and some other gases absorb heat, and their temperature rises. If they then lose that heat, their temperature reverts to that which existed before the heat absorption. Do you deny this to be a fact? Are you denying the fact that the temperature of the earth’s surface drops after it radiates LW radiation?
Here’s something you can no doubt explain to me.
The Moon is at the same distance from the Sun as the Earth for the purpose of this question.
Why is the maximum temperature of the Moons surface during its day higher than anything that can be achieved on Earth by an object as the same absorptivity as the Moon’s surface, by direct radiation from the Sun?
Shouldn’t the wonderful “greenhouse effect” make the Earth’s surface hotter than the Moon, when they are the same distance from the same heat source?
Additionally, the albedo of Luna is much higher than that of Earth.
I’m not asking you to simply accept any assertions of mine. The radiative properties of GHGs are well known and have been demonstrated – if you’re not even prepared to accept that then we’re not going to get anywhere.
The temperature of the earth’s surface depends on both energy which is emitted and energy which is received. The earth emits LW radiation and simultaneously receives SW radiation from the sun and LW radiation from the atmosphere – if the earth emitted LW radiation and no solar radiation was being received then yes the surface would cool. This goes back to the original comment by Chris which you objected to – if the surface receives 12x and loses 10x it heats up, if it receives 8x and loses 10x then it cools down.
As for the moon, well I’m guessing the reason it gets hotter than the earth is that only about half of the solar radiation received by the earth at TOA actually reaches the surface, the rest is absorbed by the atmosphere or reflected.
So you “guess” that half the solar radiation hitting the atmosphere is absorbed or reflected before it hits the surface. That seems on the face of it to contradict the warmist view of the atmosphere being effectively a “magic” blanket or filter.
In any case, I agree with you, although I might assume a lightly smaller absorption factor.
So now, you disagree with Chris, and say that the 10x reaching the surface results from (your guess) 20x hitting the atmosphere.
Given your figures, 20x in, 10x to surface, Chris would say 12x to surface.
You fight it out with him. In both cases, radiation received by the surface is less than that impinging on the atmosphere surrounding the Earth.
As you state, the Moon’s maximum surface temperature is due to the Earth’s atmosphere preventing all the Solar radiation from reaching the Earth’s surface.
No greenhouse effect involved or needed.
So you “guess” that half the solar radiation hitting the atmosphere is absorbed or reflected before it hits the surface.
No, I’m in no doubt about this. I’m “guessing” that this is the reason the moon can get hotter than the earth – it’s not something I have actually looked into.
That seems on the face of it to contradict the warmist view of the atmosphere being effectively a “magic” blanket or filter.
No it doesn’t, the “magic” blanket does not to work perfectly in either direction. The atmosphere is far more transparent to SW radiation from the sun than to LW radiation from the surface. Do you deny that?
So now, you disagree with Chris, and say that the 10x reaching the surface results from (your guess) 20x hitting the atmosphere.
That doesn’t contradict what Chris said. He was talking about the amount of radiation hitting the surface, not what was received at TOA, and his figures were not supposed to reflect the real world they were for illustrative purposes.
As you state, the Moon’s maximum surface temperature is due to the Earth’s atmosphere preventing all the Solar radiation from reaching the Earth’s surface.
No greenhouse effect involved or needed.
Absolutely correct. This has nothing to do with the greenhouse effect. Now why does the moon get so much colder than the earth at night?
Andrew Adams 8:45 am
You are in no doubt about your unproven assertion that half the solar radiation hitting the atmosphere is absorbed or reflected before it hits the surface. OK. You are obviously aware of the implications to the “greenhouse theory” implicit in this statement. If you say this is true, it must be so.
You haven’t “looked into” the reason the Moon can get hotter than the Earth? OK.
Magic blanket? I have never “denied” a fact in my life. If you wish to deny the fact that heat (LW as you put it) from the Sun reaches the surface, then OK. It must be so.
If you are claiming that Chris’s figures were not supposed to reflect the real world, then OK with me.
Why does the Earth get so much colder than the Earth at night? I will provide the answer since you can’t be bothered looking into it. The lack of dense atmosphere on the Moon allows surface to lose heat more quickly than if an atmosphere capable of having insulating properties existed.
Thank you for your interest. I am not interested in arguing. You may think what you like. Any further discussions between us will either relate directly to the question I asked Chris Colose, or will not occur.
Mike Flynn, it makes no sense to tell someone to look for themselves when you haven’t indicated what they should be looking at. You haven’t provided any sort of actual reference (other than saying it is somewhere on Chris Colose’s blog), much less a link. Even worse, you claim he said, “10 – 6 + 2 = 12.” You didn’t actually quote him, but rather, have apparently “paraphrased” sentences (or paragraphs) into a simple arithmetic statement.
Since I lack any way to verify what you claim, and since what you claim seems extraordinarily unlikely, I suspect you’ve somehow misunderstood him. This is especially true seeing as you’ve also said:
This is untrue. The clause, “than it would be otherwise,” is absolutely vital to what I said. You cannot simply say it will be cooler because energy left the system. If energy is coming into the system at the same time, the system can stay at a constant temperature, or even get warmer. Energy leaving a system only causes cooling if no energy replaces it. You’ve simply ignored or hand-waved away what I said on this point.
This comment is peculiar. Obviously I’m aware the magic blanket talk didn’t come from you. That would be why I said:
In any event, while I’d be happy to look at whatever it was Chris Colose supposedly said if you provide a link to it, nothing he could possibly say would affect the validity of the greenhouse effect. The basic concept behind the greenhouse effect is quite simple, and I’ll note when I explained it, you did not dispute what I said.
Read what Chris said in my comment to his post. It was a direct quote.
If you think that it is unclear that 10x solar to the surface becomes 12x at the surface, you and I see things differently.
I did simply say that if energy leaves the system it will become cooler. Unless you can demonstrate a passively radiating system that does not drop in temperature, or indeed, raises its temperature, I will cleave to my view.
You say that nothing Chris could say could possibly affect the greenhouse effect. You are right. Where matters of faith are concerned, facts are often meaningless.
Your explanation has a system absorbing more energy than it emits, due to greenhouse gases. Unfortunately, if you surround an object with any substance at all, including CO2, you will find the object increases its temperature more slowly, and decreases its heat loss more slowly than without the surrounding substance.
Do the experiment. You may be surprised.
Mike Flynn, again you tell me to read something without actually indicating where I can read it. You claim what you said “was a direct quote,” but it certainly wasn’t quoted from this page. If it is a quote, it must be on some other page you have simply refused to provide reference or link to. There is no reason to do this, and it simply ensures we cannot make progress. This is also true of other things you’ve done, such as this comment:
This comment is completely bogus. It simply ignores what I said, and even reality itself. Practically everything radiates energy, including all those things which are currently warming. Place a rock in the sun, and it will start receiving energy, some of which it will radiate out. That doesn’t change the fact it will warm. It all depends on how much energy the object radiates compared to how much it receives. You’ve avoided this simple fact by repeatedly focusing on only a part of the radiative balance.
If you’re going to continue to behave like this, there’s no way anyone can have a reasonable discussion with you. However, in case you are actually listening, I’d like to point out the “magic blanket”0 isn’t an surprising phenomena. All it takes to create a one-way insulator is polarized glass and a refractive surface. You can shine a light through the glass, but when the lights hits the refractive surface, it will bounce back at a different wavelength, one the glass blocks. What happens with Earth’s atmosphere is basically the same thing.
Not “practically anything”. I may be straying a bit here, my knowledge of quantum physics could be a lot better, but for practical purposes anything and everything with a temperature radiates heat. As far as i know, it has not been possible to cool anything to 0K. Not close, or nearly, but to 0K precisely.
Now what happens in your example when the “bounced back” light is “stopped” by your example? If it is absorbed, then the temperature of your “filter” is raised due to the increased energy the body now possesses. Or maybe it is a magic perfect one way filter and reflector combined?
I assume you mean a reflective surface rather than the “refractive surface” you wrote.
In any case, you now need another mechanism to prevent the heat leaving your polarized filter assembly in any direction than away from the Earth. Possibly a “magic blanket” would work?
Mike Flynn, it seems you’ve dropped a number of points, so I’ll assume my comments stand on those, and leave it at that. As for what you have responded to:
I said practically everything because I didn’t want to have to think about possible exceptions. For what it’s worth though, if you count small enough objects as things, there are some things which don’t radiate energy. That would technically have made what I said wrong if I said “everything” instead of “practically everything.” There might be some other exceptions which don’t come to mind, but really, the point is moot. However, you did remind me of something I find interesting. While we may not be able to cool things to absolute zero, there are actually systems which are below absolute zero. Completely irrelevant, but I find it interesting.
I know you said “. . . I didn’t want to have to think about possible exceptions. . . ” Pity. The not wanting to think part.
Now I confess you really me have me at your mercy. Are you saying that you must have a transparent object that your polarising filter surrounds?
I’m unaware of “refractive surfaces” as such, although refraction obviously occurs when the light rays proceed through the surface boundary at less than the critical angle. But of course, you know that.
So do you propose a transparent sphere, surrounded by a spherical polarising filter? How would it both bounce heat off and refract heat at the same time? Does your idea depend on total internal reflection, and would rays impinging at less than the critical angle for your transparent medium affect the result. This would overcome the refracting and “bouncing’ problem, but would of course introduce other physical problems.
I am puzzled as to the orientation of the “filter” as the polarising plane would rotate as you progressed around the surface of your filter. There would seem to be “poles” where the polarising effect would vanish. Is this a conceptual filter, or do have an example that actually exists?
Otherwise, I would be inclined to the view that your “one way filter” would be physically impossible. If it does exist, you will find that all the radiation passed by the filter would eventually be absorbed by said filters structure, and eventually radiated away to space.
There are no perfect filters, insulators or reflectors. i don’t understand your idea. Please enlighten me.
Why not just explain what happens when the Sun shines on the Earth?
Mike Flynn, I’ve decided there’s no value in responding to you further, You’re asking all sorts of questions to which the answers are obvious (the sphere I described would obviously not be made of a single pane of glass, but rather an array of glass panes) and have no relevance to the issue which was being discussed (the existence of one-way insulators). Added on top of this, you’re ignoring large amounts of what I say, even while claiming the exact opposite of what I said.
Ultimately, the point I made can be proven with two polarized lens and and a lens with a refractive coating (or any other object capable causing refraction). I suspect you know this, and are intentionally avoiding the point as you’ve done with much of what I said, in some dishonest attempt at trolling. I further suspect your attempts at trolling include intentionally trying to bait people into giving simplistic answers which are not fully accurate simply so you can argue meaningless points.
My suspicions may be wrong, but I suspect they’re shared by many people reading this blog.
“Now my problem is that if 6 x leaves the surface, the surface temperature will drop by 6/10 of the increase caused by the 10x in.”
I think that’s where your misunderstanding is. According to the example, it’s not 6x leaving the surface, it’s still 10x.
Before adding atmosphere, you get 10x from the sun hits the surface, 10x radiates from the surface, and heads straight out into space.
After adding atmosphere, you get 10x from the sun hits the surface, 10x radiates from the surface, some of it being absorbed by the atmosphere and some of it passing right through. The 6x is just the part that escapes from the surface direct to space.
The 4x absorbed by the atmosphere causes it to warm too and re-radiate. Half of that goes up, and half goes down. So actually the surface is now getting 12x radiation – 10x from the sun and 2x from the atmosphere – and outer space is seeing 8x of radiation, 6x from the surface and 2x from the atmosphere.
The surface is now getting 12x in and radiating 10x out, warms up, radiates more, warming the atmosphere more, and so on until balance is restored.
The physics does actually work so long as radiation is the only means of heat transfer considered. The primary problem with this model is that it doesn’t work for a convective atmosphere, because as soon as you get any excess heat building up near the surface, the hot air rises and carries the heat away. It is the bounds set on when convection can occur that control the warming of the surface. For a compressible medium like air, convection is limited and you can still get warming near the surface, although with different physics. If the air was incompressible, like water, then convection would be able to carry all the excess heat away and you would get virtually no greenhouse warming, even though the “trapping” of radiation by liquid water is immense.
For a more detailed alternative explanation taking convection into account, search Judith’s blog for “Best of the Greenhouse” and scroll down to my explanation there (under “radiative-convective perspective”).
Since this article is supposed to be about feedbacks – I’ll leave the discussion there.
Dear Nullius in Verba,
Read what you said.
“After adding atmosphere, you get 10x from the sun hits the surface, 10x radiates from the surface, some of it being absorbed by the atmosphere and some of it passing right through.”
What happens when the 10x is radiated from the surface? If the surface temperature increased due to absorbing 10x from the sun, would the surface temperature not change when it radiates the same amount of energy?
If you still feel the need to waste your time, I don’t mind. It’s a free world.
The instant after adding atmosphere and before the surface temperature starts to change, 10x is being absorbed, 10x radiated, and the surface temperature is constant.
The surface temperature doesn’t increase because of receiving 10x from the sun. It increases because it is still at the the equilibrium temperature for 10x in and 10x out, but is receiving 10x from the sun plus 2x from the atmosphere. 12x in and 10x out leads to a rise in temperature.
It’s like Tetris. No matter how many I knock down, I know the objections will keep on coming. But it’s fun, anyway.
Hang on a moment. And the 2x from the atmosphere comes from . . .?
You set ’em up . . .
The 2x from the atmosphere comes from the atmosphere.
You misunderstand me. The energy in the atmosphere, which it is radiating to the surface has to come from somewhere. If 2x comes from the surface, and is radiated back to the surface, no change in temperature.
If the 2x comes from the Sun, only 8x left to heat the surface. Still no temperature rise.
The energy to raise the temperature comes from . . . ?
Thanks. And now I have some serious loafing to do.
“The energy in the atmosphere, which it is radiating to the surface has to come from somewhere.”
The energy in the atmosphere which is radiating to the surface comes from the atmosphere. Because it it warm. What I think you are trying to ask is where does the energy *absorbed* by the atmosphere come from, to which the answer is the surface.
You are then trying to lead on to the claim that because the surface radiates 4x which is absorbed by the atmosphere, and the atmosphere radiates 2x downwards which is absorbed by the surface, that considering these two parts alone, the net heat flow is from surface to atmosphere and with no other inputs or outputs the surface will cool as a result.
But when you consider both air and surface together, the external flows have changed. They still get 10x from the sun, but instead of losing 10x direct to space, as when there is no atmosphere, jointly they only lose 8x to space because 2x is bouncing back and forth in between them. It’s the reduction in the loss of energy to space that causes the pair taken together to warm.
Enjoy your loafing.
you just fell into the same mistake that Climate Scientists fall into. Adding the atmosphere means the atmosphere absorbs some of the input and also reflects some of it reducing the heating of the surface. The DLR is also not as large as claimed as in the lower atmosphere much of the energy absorbed by GHG’s is transmitted to non-GHG’s through collisions BEFORE it can be emitted up/down/sideways… That energy is then convected away from the surface. More heating means that ALL the processes, evapotranspitation, convection, radiation… increase in speed.
Not saying that ozzieheadinthedark is right, but, two wrongs…
“you just fell into the same mistake that Climate Scientists fall into.”
Mmmm. Now try reading the second half of my first reply to Ozzie above.
I’m trying to explain the bare physics for the non-convective case, without worrying about how the actual atmosphere works, because Ozzie evidently isn’t quite ready for that yet.
“I’m trying to explain the bare physics for the non-convective case, without worrying about how the actual atmosphere works, because Ozzie evidently isn’t quite ready for that yet.”
No, you are stating something that is incorrect to attempt to move to something that is closer to reality. That is ALWAYS a mistake. He has obviously either read or been involved in this type of discussion numerous times. I would bet he could write some of your responses himself.
Thanks for the support. You may care to ask him what warmed the atmosphere, and after he has explained, point out that his answer contradicts what he said previously.
There is no evidence for the global warming rate of 0.16 deg C per decade for the period from 1970 to 2000 to continue into the future.
If a continued global warming of 0.16 deg C per decade had been assumed in the 1940s, the global mean temperature predictions for the 2000s would have been wrong as shown in the following graph:
As shown in the first graph above, there is evidence for long-term global warming of only 0.06 deg C per decade.
IPCC projection of continued warming of 0.16 deg C in the next decades corresponds to a climate sensitivity of 3 deg C for doubling CO2.
As a result, what the data so far shows is a climate sensitivity of only 1.1 deg C (=3*0.06/0.16)
There is early evidence of global cooling like those after the 1880s and 1940s as shown in the following graph.
According to this early evidence, climate sensitivity is only 1.1 deg C
Take a square meter of Earths surface, measure the temperature over 24 hours at the equinox. Measure Tmin and Tmax, and all photon fluxes, up and down.
Now, if the square meter is sea water, or sandy desert, or rain-forest, or grass land or corn, then even if the the amount of incoming radiation is the same, the Tmin/Tmax’s will be different. Using a gridded average of (Tmin+Tmax)/2 gets you nothing. It is not a measure of heat content. The idea that there is a, singular, ‘climate sensitivity’ is nonsense. The incoming heat may be transformed into latent heat, potential energy (protein/cellulose or suspending water in the sky) or a change in air pressure.
You know you are using a ‘rule of thumb’, you know roughly how many compromise you make in calculating a climate sensitivity, so why not state just how fussy this number is?
Why pretend that this is a traditional constant, in that it is a real robust number?
Good post by Chris. On this topic, I’d recommend reading the review article by Gerald Roe, which Dan Hughes linked on another thread.
Chris, nice to see you posting here.
I have a couple of items I would address.
The first is the use of paleoclimatology as a boundry on climate sensitivity. This assumes climate sensitivity is a constant or near constant value and that the forcings are well understood. Normally anything that starts with paleo I think interesting but speculative.
The second is the large values for equilibrium sensitivity. The world didn’t start warming in the latter half of the 20th century. It has been warming since the little ice age and all the forcings that caused that warming would have the same equilibrium values as current forcings. Where has this been attributed? In other words, how much of the more recent warming can and should be attributed to a warming towards equilibrium from earlier forcings?
I mainly lurk on these technical threads, but as an interested observer I would be very interested in your response to Steven’s second point. Thanks
Ditto. His first point is also very interesting. I would love some discussion of this.
“Non-linearity appears to be of small significance for the modern climate change problem (Roe and Baker, 2011, Nonlin. Processes Geophys)”
Considering nearly all of the underlying thermodynamics of water are non-linear in temperature at initial conditions found on earth could you expound on this?
Regarding the above:
This is a response to RB07, I can find no reference to an RB11.
“To summarize, RB07’s arguments are only as good as their
two main assumptions:
a. linear climate response with constant, temperature- and
time-independent slope; and
b. a broad and symmetric distribution of errors in the
feedback factor f .
These assumptions are dubbed in RB07, p. 630, “far more
fundamental” than the physics of clouds, the complex
interaction among individual climate processes, and the
chaotic, turbulent nature of the climate system. We leave
it to the interested reader to decide whether s/he agrees.”
The reference to RB11 was a reply to Zaliapin and Ghil, and is at
“While the ZG statement is trivially correct as an algebraic
exercise, we are interested in the application of Eq. (1)
to climate simulations, where we are not free to pick
arbitrary values of the parameters.”
Does assuming the models are correct when we know that they do result in linear or near linear feedbacks make any sense? The issue is the models accuracy to the “physics of clouds, the complex
interaction among individual climate processes, and the
chaotic, turbulent nature of the climate system.” It is nonsensical to me to conclude that a dynamical system dominated by non-linear processes will result in a linear “gain” to any input parameter.
Doug – If I have a chance tomorrow, I’ll try to reread the debate between RB and ZG, which is probably not yet resolved. It’s probably fair to state, however, that the non-linearity issue relates primarily to the fat tail at the high end of the sensitivity pdf, and that the lower limits are relatively unaffected. If you have a different take on this in the meantime, please comment.
The debate between RB and ZG (see also Hannart et al. 2009, Roe and Armour, 2011, etc) revolves around the asymmetry in dT distributions as a function of uncertainty in the feedback factor. I tend to agree with more of Roe’s points on the matter, but there are valid points (and what I think are flaws or irrelevancies) on all sides. I’m not quite convinced that there is an a priori reason to expect the uncertainty in the strength of the feedback to be symmetric. I also don’t particularly think that the bistable behavior or large values in the df/dT term are of large importance for the range of climate change we are most interested in here, although it becomes of a larger concern over a larger temperature range; the asymmetry in the climate sensitivity estimates does not appear to be something that can be easily removed, and I think that has important policy implications.
Firstly the arguments of ZG10 on RB07were correct insofar as RB07 so called nonlinear equation was indeed linear a point admitted by RB11.
That this point was not noticed by the so called CS community or the reviewers and editors of science is telling of the level of skill of said participants.
Secondly that the arguments of both RB07, are telling eg the impossibility of determining climate sensitivity and hence its random consequences ie the irreducibilty problem .
The use of more ” unfortunate ” inconsitencies in RB11 seem to have been overlooked by the author of this post ,would be more likely to his undereducation.see ZG11
ZG11 however take the positive view eg
To conclude, we believe that – paraphrasing a famous
quote, attributed to Mark Twain – rumors about the
death of climate science have been greatly exaggerated.
What researchers need to do is to stop panicking and
continue, aggressively but calmly, the quest for predictive
understanding of natural and anthropogenic climate change
(Ghil, 2001; Held, 2005; McWilliams, 2007) .
Nice to see you posting here.
When do you believe the Earth started generally warming?
Instead of increasing the surface temperature, is it not more reasonable to assume the increase in CO2 delays the cooling of the globe?
How is the fact that 50% of the time the globe is not exposed to incoming solar radiation taken into account in estimation of climate sensitivity?
Absolutely. At this rate, there will be more than six of us to challenge the deniers of physical laws.
Maybe we can sell them some Mythbusters T-shirts that read “I reject your reality and substitute my own.”
How is the fact that 50% of the time the globe is not exposed to incoming solar radiation taken into account in estimation of climate sensitivity?
Surely you mean that at any particular time only 50% of the globe is exposed to incoming solar radiation. I don’t know why this would have any impact on climate sensitivity, which is caculated over rather longer timescales than one day.
n Chris’s terminology, when you calculate G, the outgoing thermal radiation exists for 24 hours, while the incoming solar radiation exists only for 12 hours. If every 12 hours the globe can release its thermal energy with out receiving any solar energy how does the blanketing effect of the CO2 comes into the picture?
As long as the earth’s surface is emitting radiation within the absorbtion bands of GHG’s then the greenhouse effect will come into the picture and, as you say, this happens constantly over 24 hours regardless of how much energy is being received from the sun at the particular time. Calculations of the earth’s overall energy budget fully take into account the fact that only half of the surface is receiving energy from the sun at any moment in time.
One question I have is if we have CO2 saturated in the atmosphere and if we have a starting global mean temperature of, say, 20 deg C (all the atmosphere, land and sea) and assuming solar radiation has stopped to reach the globe, will the temperature drop below 20 deg C?
If the temperature drops below 20 deg C, how does the temperature escape into space? Or is it the case that CO2, even at full saturation, does not block all infrared radiation?
I’m probably not the best person to be answering these questions but I’ll do the best I can. CO2 only absorbs radiation at certain wavelengths so it can never block all outgoing infrared radiation. Therefore if there was no solar radiation reaching the globe the temperature would gradually fall, albeit more slowly than in the absence of GHGs in the atmosphere.
two reasons why CO2 does not block *all* radiation, even if saturated at the surface:
1) Co2 only absorbs in bands and there are gaps between them. Try running MODTRAN (available online) to see this effect modelled.
2) Emission from CO2 is ultimately from the top of the atmosphere, not the surface. At the top of the atmosphere, CO2 by definition is *not* saturated. So one explanation of the greenhouse effect is not that more CO2 prevents emssion of IR, but rather that it increases the height at which emission occurs. The effect (as the lapse rate stays constant) is that the surface temperature increases.
Try Science of Doom for this stuff, it’s a great resource.
Thanks Andrew VeryTallGuy.
Now if we have two different concentration of CO2 in the atmosphere in the above case, the difference would be the cooling rate decreases with increasing CO2 concentration. Is this not the case?
Sorry Girma, but don’t understand your response.
Do you mean there are different CO2 concentrations in the atmosphere at the same time, or a change in CO2 over time?
And do you mean the instantaneous flux at a given CO2 and temperature, or a cooling curve over time?
Also why do you think my name is Andrew?
Yes, the cooling rate would decrease with increased CO2.
Thanks for the post. I found the discussion on Plank feedback very easy to understand. But a couple of questions on climate sensitivity itself.
From Dr. Ray Pierrehumbert’s slides that you provide a link to is the following (slide #3): “What is climate sensitivity? An instance of the general problem of how the solutions of a nonlinear PDE depend on a parameter; coefficients are a smooth function of the parameter.”
Do you believe (as, apparently, Dr. Pierrehumbert does) that determining climate sensitivity is a difficult engineering calculation-type problem rather than a difficult experimental science-type problem?
And from slide #5 is a graph where the horizontal axis is “Climate Sensitivity (Warming per doubling, K) and the vertical axis is labeled “Number of Simulations”.
You didn’t mention it in your post, but this seems to imply that our confidence in our estimates for climate sensitivity are entirely dependent on our confidence in the correctness of the global climate models, and not in our confidence in the correctness of actual scientific experiments.
So how should I respond to the claim that until the global climate models software has been formally verified and validated as appropriate for climate sensitivity estimation such sensitivity estimates are formally unverified and unvalidated?
You can read the climateprediction.net work and their methodology that resulted in an asymmetric sensitivity distribution and determine the degree to which you think it is useful (e.g., Stainforth et al. 2005). These do go through a calibration and control phase. As Ray noted, it is customary in this case to admit members to the ensemble only if they pass through a “keyhole” requiring that the basic climate of that member is realistic enough to serve as a basis for predicting the future. Ray also noted that there were many different ways of going about estimating climate sensitivity, and the results of climateprediction.net were the only one he really focused on. There are people who work on this from an observational perspective, from a paleoclimate perspective (and at different timescales), etc
The most recent ten thousand years has been extremely stable in a narrow range. That can only happen if there is powerful negative feedback to temperature. There is powerful negative feedback. When the oceans are warm it snows more and earth cools. When the oceans are cool it snows less and earth warms. Oceans are warm now and it does snow more and we will cool.
So what happens when you take that stable climate and hit it with more CO2 than it has had in 20 million years (as we have so far, and counting)? The clue is that 20 million years ago it was significantly warmer.
In the last 20 million years, we are much closer to the lowest amount of CO2 and very far from the highest amount of CO2.
Herman A (Alex) Pope
I hate to contradict you on so slim a pretext as mere facts based on evidence, however, the best estimates of CO2 levels from the very records I have seen you to have used in past presentations interpolated with the geochemically derived 50 million year (Miocene) CO2 figure do contradict your claim.
Certainly, the odds are CO2 has not been so high within 10-15 million years as it has become in the past 250, to the point we can make such a statement with high confidence. (http://www.paleolands.com/pdf/cenozoicCO2.pdf for just one presentation of the evidence, it has 50 references supporting it, and they have hundreds of further references.)
Perhaps you have more authoritative new sources of information than I have seen?
I am encouraged to find that Chris Colose (a very brash young scientist) has softened the edge of his arrogance and sarcasm. Nevertheless he is still mistaken when he states:
“Current climate sensitivity estimates generally yield a coherent picture of ~2-4.5 C per doubling of CO2, with very little chance of sensitivity at the low end of this. ”
He should be aware that in the past, the CO2 concentration in the atmosphere has never been a dominant factor in relation to global temperature. The atmospheric CO2 concentration has consistently lagged temperature so the hypothesis “Temperature drives CO2 concentration” is more credible than Colose’s contrary hypothesis.
He will counter by saying “correlation does not imply causation” and I will not disagree. However, cause does precede effect so it is nonsense to suggest that CO2 concentration is the primary cause of our current warm climate.
Actually I don’t find it surprising in the slightest that temperature modifies the carbon cycle.
Thanks for your post.
I seem to remember reading that the best estimate for long term climate sensitivity, and which includes all the feedbacks, can be obtained by looking at glacial / interglacial periods and noting that a ~7W/m^2 climate forcing causes a warming of ~6 degC giving a climate sensitivity of 0.85 degC/W/m^2.
This would be consistent with a 2 x Co2 sensitivity of just over 3 degC
How accurate would say this was? Do you know how forcing , 7W/m^2, is calculated from Milankovitch cycle data?
I think they must have factored the ice albedo change in because the CO2 alone accounts for only 2 W/m2.
still haven’t figured out the causality thingie I see.
There’s different ways of going about this, I’d read Kohler et al (2009, QSR) for a review. (this emphasizes the last 800,000 years, though a number of authors like looking at deep-time warm climates as well. The NAS report I cited in the post is a good read on this). Several of Hansen’s recent paleoclimate-based papers talk about this, and Knutti and Hegerl (2008) provide a good review on the general subject too.
I stopped by before my lecture on human-caused climate change in a class on climate science and policy for non-scientists. I wanted to see if there was anything new on these topics in the blogosphere. A tip of the hat to Chris C. for his persistence and diligence in dealing with unphysical arguments of folks who find AGW to be incredible for whatever reasons. It turns out that a simple line of argument often fails to carry the day in these discussions. It is often necessary to establish an entire intuitive framework encompassing thermal radiation, cloud formation, internal energy, etc before one can actually link them together into a coherent narrative. In my class we do experiments with a heat gun, infrared camera, CO2 fire extinguisher, blackened machine screw with embedded thermocouple to try to get the idea of emission of thermal radiation from solids and gases. “What part of sigmaTtothefourth don’t you understand?” does not work in class and does not work at a Libertarian Convention. I am grateful to my university for the scheduled lab and lecture hours that permit me to present this stuff one step at a time. Hershel’s 1800 experiment is a good place to start – instead of a prism and blackened thermometers, my students use an overhead projector + plastic diffraction grating + solar collector gets to the idea of IR energy in a region of the spectrum that they can not see.
In the realm of feedbacks, it is interesting to see that the proponents of low-sensitivity are squeezed into the corner currently occupied by Dr. Spencer. I find it useful to define the edge of the flat-earth by reading Dr. Lindzen’s 2007 E&E paper on “Taking AGW Seriously”. He allows up to 30% of the recent warming to be anthropogenic. In his argument with Andy Dessler on Utube, he allows up to ~1 C sensitivity. The long-lived GHG forcings are pretty well known. The amount of energy that they added to the climate system since 1950 is plotted in Murphy et al. 2009. Its large compared to that needed to explain observed warming in the atmosphere, oceans and increases in OLW over the period. Its the First Law. If Lindzen and Spencer right, they need a negative feedback in perpetuity (in addition to sigmaTtothefourth). So far they can not find it. Lindzen and Choi seems to have been pretty thoroughly criticized and its revised version does not seem to address the criticisms. Dr. Spencer’s clouds cause El Nino argument does not seem to be carrying the day. Has the gunfight at the OK Coral taken place and no one noticed? Of course, the IPCC-acknowledged uncertainty (sensitivity>2C and <4.5C) is too large, but has never been a secret.
The Motivated Reasoners will never get AGW. Scans show that they are using the same part of their brains that drugs take over in addicts. But the problems will still be huge even if they loose interest in subverting the science.
Thanks for fighting the good fight, Chris.
So you teach AGW for Dummies 101. Don’t worry about it. Everybody has to make a living.
I am privileged to teach this material to these students. They are not dummies. It is a good way to make a living. I have taught physics, mathematics and engineering to science/engineering majors for most of my career. The basic ideas of climate science are quite challenging and clear thinking is required to get this material across. It is fun.
““What part of sigmaTtothefourth don’t you understand?””
“In my class we do experiments with a heat gun, infrared camera, CO2 fire extinguisher, blackened machine screw with embedded thermocouple to try to get the idea of emission of thermal radiation from solids and gases.”
Do you explain to them that all gases dissipate heat such as your heat gun?
Do you tell that that the 15 micro, that CO2 absorbs at, is equal to a T of -73 C or 200 K?
Do you show them Hottel’s charts of emissivity of an H2O/CO2 mixture and put that in a radiative heat transfer equation?
Do you ask them why 168 W/m^2 on the KT diagram can heat my sun tea but the 341 W/m^2 of DWLR (IR) from the GH effect can’t?
Do you tell them that since Hershel didn’t have plastic and used a glass prism that it puts lie to the IR won’t go thru glass line?
Do you tell them that if all W/m^2 are equal then the bottom of a 50000 W AM radio antenna is the hottest place on earth?
Do you ask them why the air in the mircowave does not get hot even though you are putting in near 4000 W/m^2?
Do you tell them the ability to do work is lacking in the diffuse IR from CO2 in the atmosphere so no heating can be done with it?
Do you tell them of the specific heat of H2O as compared to CO2 and explain that that is the real GH gas coupled with the phase change at atmospheric/surface temperatures?
Look up the irradiance of direct sunlight (perpendicular to the rays) on a clear day. It has nothing to do with the 168 w/m^2 you cited. The 168 w/m^2 figure you cite is the average over day-night, over all latitudes and includes an average albedo. It has nothing to do with making sun tea. On a good sun tea day, you would start with the the (approximately) 1370 watts/m^2 that arrive at the top of the atmosphere perpendicular to the sun’s rays and take out the absorption in the atmosphere (67 w/m^2) and some clear air albedo. It will vastly exceed your 168 w/m^2 figure. Your downwelling long wavelength figure of 341 is also an average figure. When camping in the mountains, you may have noticed that it cools off much faster on a clear night than it does on a cloudy night. That is downwelling long wavelength. It is nice on that cloudy night, but direct sunlight will win every time!
Your post has many more errors concerning radiation heat transfer. You do not clearly state your point, but I infer that you are trying to refute AGW by tossing around lots of radiation terms. But you are not using them correctly and the result is not convincing. I suggest that you learn the science before getting mad. The radiation heat transfer of AGW is pretty well understood. There are lots of books on it. Read one.
Thanks for the post and for pointing to Ray Pierrehumbert’s SIAM talk. I especially like his discussion on that f=1 means bifurcation rather than runaway warming. I’d think this implicitly points out the limitation of the sensitivity (or feedback) analysis: delt T = delt F / (1 – f). The existence of bifurcation means the possibility that even without forcing ( delt F = 0), the delt T could be non-zero (for example the possible abrupt climate change without external forcing).
However, even under this extreme case (bifurcation, or f= 1, or abrupt climate change), the linearized perturbation method still holds and can be used for climate sensitivity analysis, but the linearized perturbation method should decompose the delt T into different and addable terms related to perturbation in TOA radiative balance ( Note: the external forcing delt F could be zero) as suggested in the CFRAM ( and its TOA version TFRAM) by Lu and Cai (2009). In the last paragraph of our paper, we did discuss on the limitation of the f-based analysis as in Roe and Baker (2007).
Physically speaking, the bifurcation may be related to the change in the WAY how the climate reaches the balance between energy input and output, or from the 3-D viewpoint, the energy flow in the climate system.
Another example I like to use is that suppose the rotation rate of the earth suddenly reduced by 20%, then will the global surface temperature be changed? The answer is definite yes. In this case, there is a mechanic forcing, but the radiative forcing is zero, the equation [ delt T = delt F / (1 – f) ] will not work, but the TOA – based radiative perturbation equation as in the TFRAM of Lu and Cai (2009) could still lead to the estimate of non-zero delt T.
Chris, the ERBE data on net cloud forcing shows that the clouds cool the earth in the summer, and that they warm the earth in the winter.
Could you please discuss how this ERBE data either fits (or doesn’t fit) with your analysis of simple linear feedback? Because I can’t see any way that your simple linear feedback as diagrammed and detailed above could explain that ERBE result. What am I missing here?
Willis – using phrases like “the earth in the summer” suggests that there’s a time when it’s summer all over the earth. People might misunderstand you.
My lack of clarity, Simon, but I think most people would understand that I was speaking of the hemispheres independently. If not, well, that’s the meaning.
In order to think about feedbacks, it is necessary to define a baseline (or reference system). One reasonable reference system would be to consider a naked planet (with no atmosphere) which radiates energy at a rate of σT4 (so that if the planet became twice as hot, it would radiate sixteen times as much energy away, allowing it to relax to this new equilibrium temperature).
So we have earth size planet at earth distance from the Sun. No atmosphere. Let’s powdered carbon 6″ thick on surface- so blackbodyish.
Earth receives 174 petawatts of solar energy. Our black planet receives
Earth and black planet will radiate 174 petawatts.
Earth and black planet are rotating and tilted on the axis the same.
At any one time the amount energy [watts per meter] from the Sun on the sunlight side will varying due the angle of sun. If the planet was a disc in instead of a sphere of same diameter it would receive 174 petawatts of total energy and uniform amount energy per square meter.
[A disc would receive higher average energy per square meter and with same 6″ of powdered carbon [with good insulating properties] we could ignore the back side of the side- it will be close to background temperature of around 4 K. Therefore that means in addition to receiving more energy on average per square meter there less area [compared sphere] to radiate that energy. Both these factor will make the surface hotter then if it was a sphere. Though if it’s average temperature which includes the cold darkside could be quite low. And if disc was merely a sheet of metal it would have much higher average temperature. And since it would hotter on dark side and would radiate more energy [it has twice the surface area to do this].
With high conductivity of metal the sheet of metal would absorb more of the sun energy than the insulated nature of carbon powder.]
Returning to the black planet as a sphere it has 4 times the area to radiate energy as the one side disc and twice the area sheet metal disc.
Area of circle:pi R squared. Area sphere: 4 pi R squared.
In terms of receiving the sun’s energy near equator at noon at will be around same solar energy per square meter as the disc per square meter and same location at morning dusk it will receive far less energy per square meter. In temperate regions the angle of sun will always be lower, and winter it be lowest- and towards polar region is more extreme- having constant low angle sunlight or constant darkness.
It seems this black planet will fairly different than Earth. Like the earth most of the warming will be in the tropics. Unlike earth in the tropics the surface temperature should drop a fair amount during the nite and as approaches dusk and will cold at dawn. The temperate and polar zones during the winter should colder, though might warmer during the summer days as compared to earth’s surface temperatures.
So is this correct in terms of defining the baseline before I think about feedback?
“In models, this is actually calculated with a full radiative transfer code for each gridpoint on the Earth; this so-called “Planck feedback” amounts to about an extra 3.2 Watts per square meter (W/m2) power emitted for every 1 K temperature increase ”
Hmm. How about put greenhouse on the black planet which has vacuum.
And let’s say the greenhouse is the same size as a gridpoint.
I believe the gridpoint are somewhere around 100 km square- as I recall.
This would make an unreasonable large greenhouse- but making earth size planet with 6″ of carbon is probably more unreasonable.
So I skip worrying about how the greenhouse is built and just it a hemisphere 100 km in diameter and has the same 6″ carbon dust on it’s floor. And put nitrogen gas in it.
And it will be made of thin single pane glass.
It will have height of 50 km. And 50 miles on earth has very little air.
The surface area of the greenhouse dome part is twice the area of it’s base area.
The dome is far higher than the troposphere on earth, and up to the top of troposphere has about 80% of earth atmosphere and convection of heat is rather insignificant above the troposphere on earth.
Though it’s completely unrealistic that a thin pane of glass dome could contain 14.7 psi of air in a vacuum, we just say it does.
The amount of air in this dome in terms of mass is very roughly area of the base in square meter times about 30 tons.
50,000 times 50,000 times pi times 30 tons, which is 2.355 times 10^11 tonnes. Earh’s atmosphere has 5.1 x 10^18 kg or 5.1 x 10^15 tonnes
so it around 20,000th of dome [seems like my number is somewhere in ballpark].
So got my grid, so then we have the- “this so-called “Planck feedback” amounts to about an extra 3.2 Watts per square meter (W/m2) power emitted for every 1 K temperature increase ”
I don’t know what to do with that. Oh yeah need greenhouse gases.
Let’s skip part for moment.
Without greenhouse gases what would the temperature of the gas in the greenhouse?
It seems it would fairly warm during the day, and the freezing 2.355 times 10^11 tonnes isn’t going to happen in 12 hour nite- that’s a lot of energy.
nitrogen boiling point: 77.36 K, -195.79 °C,
Specific heat capacity = 1.341j/g/K
And water is Specific heat water – 4.187 kJ/kgK
So around 1/3rd of the energy.
Or 1000 kJ per tonne, so all of nitrogen would 10^17 watts [100 petawatts] per 1 K.
So need to have idea of how many petawatts could be radiate every second. But it does seem like it will get as cold as the black carbon on rest of surface.
gbaikie, your line of thinking about the disk is similar to mine. Here are links back to a discussion with Fred Molton In Planetary Energy Balance 8/19/2011 where Fred discounted latent heat as important mechanisms, whereas I’m not so sure.
Rasey 8/19 18:21 – Not a binary world. Capture the uncertainty in all components of GHE.
Molton 8/19 18:54 – Latent heat discussion
Rasey 8/19 20:00 Basic Thesis:
Let me back up to first principles: There are heat trapping mechanisms in the daily cycle of the earth’s heat flow. I have been lumping them all as GHE.
GHE certainly includs
1 — back radiation from GHGs, of which CO2 is only one and not the most important one. Agreed?
The following heat trapping mechanisms are also in play.
2 — Heat Capacity of water and air in the ocean and atmosphere.
3 — Heat of Fusion as water turns to ice.
4 — Heat of Vaporization as water vapor condenses into water.
5 — Adiabatic physics of the atmosphere.
6 — Thermal conductivity of the air and water in the ocean.
Here I make an observation that I invite your comment:
The Toy model [no day-night, only average insolation] is a static, single temperature model, and as such the contribution of 2 through 6 are zero. The whole answer is in 1, the GHGs.
But in Postma’s model, which I find far more realistic than the Toy, Temperature MUST vary by lat, Long, h, [and Time]. Heat is trapped by all mechanism 1 through 6. and as a result, the contribution of the GHG to GHE might be smaller that implied by the toy model.
Here is my crucial set of questions:
Does GHE include A) 1, the back radiation? or B) all heat trapping mechanisms 1 through 6.
If A), what then do we call 2, 3, 4, 5, and 6?
If B), then what are the units or dimensions of GHE to capture its strength? [with so many factors?]
Fred Molton 8/19 20:25 Regarding some of your other points, GHGs are heat trapping molecules, but I wouldn’t call the other phenomena trapping mechanisms, although all are important for the rate and location of heat changes.
Molton 8/20/00:02 Coin Flip Examples [day-night disk -without latent heat]
Rasey 8/20 00:38 The test is whether the energy received in the daylight can be stored in non-temp radiating means (2,4,maybe 5), and blead back at night to keep H2O liquid. Later.
Much later as it turns out. End of vacation and all that.
I’m working up 4 boundary-condition disk models:
1) Thin iron plates separated by an insulator. Instant heating and cooling, little heat capacity. Would this be any different from the Toy?
2) Thick iron sheets, thick enough that deep down they are at stable temperature. Heat capacity limited to Specific Heat of iron and high Thermal conductivity.
3&4) Thick black, soot laden, ice, so as not to change the albedo, but here, solar insolation melts ice to water (absorbing energy) without a change in temperature. 3&4 are different based upon what happens on the night side with cooling, with and without a sheet of ice forming over the melt water so that heat of fusion, thermal conductivity of water and ice, and emissivity all come into play.
Stipulating that all 4 models have the same atmosphere, it is possible they have the same mean temperature? I say no. But how different might they be?
“gbaikie, your line of thinking about the disk is similar to mine. ”
It’s basic stuff. I was merely following directions from article of this post,
I assume no one disputes it. Though I would find very interesting if someone could find something to dispute regarding it- other than objecting to it’s lack of brevity.
“Let me back up to first principles: There are heat trapping mechanisms in the daily cycle of the earth’s heat flow. I have been lumping them all as GHE.
GHE certainly includs
1 — back radiation from GHGs, of which CO2 is only one and not the most important one. Agreed?”
But few people would assume CO2 causes much warming, especially when one talking about a quantity of CO2 which less than .1% of the atmosphere.
Generally the people worried about CO2, worry that a small change in global temperature could lead to some kind of disaster.
Their concern is runaway or feedback.
So again most people would agree with this, but some people would say BUT….
Whereas I say simply, yes. CO2 could warm by some amount.
Though I am open to idea that it’s possible that CO2 may [counter intuitively] cool the planet.
If CO2 does cool the planet, it might be dangerous, but I require a lot proof to be convinced it actually does this. More than simply having ice core data showing whenever CO2 levels are high the climate tends to cools afterwards.
“The following heat trapping mechanisms are also in play.
2 — Heat Capacity of water and air in the ocean and atmosphere.
3 — Heat of Fusion as water turns to ice.
4 — Heat of Vaporization as water vapor condenses into water.
5 — Adiabatic physics of the atmosphere.
6 — Thermal conductivity of the air and water in the ocean.”
-Heat Capacity of water:-
I would say the heat capacity of water is the most significant “greenhouse affect”
The oceans in the Tropics are the highest average temperature and the most significant surface area of the planet in terms of averaging the global temperature. And Tropics is 40% of surface area of the world. Between 23 1/2 latitude North and South. Or about 1/3 of the world is to the north of it and 1/3rd to south
Ocean area dominate the planet. Most of land area on earth is in the northern hemisphere- but ocean area still dominates in Northern hemisphere.
Southern hemisphere has highest percentage of ocean area in comparison to land.
Other than the ocean the most significant aspect of southern Hemisphere is the Antarctic which is Earth’s most significant refrigerator. But in terms of average temperature the Antarctic takes only relatively small area ocean to counterbalance the Antarctic very cold average temperature. Antarctic isn’t significant in terms of average temperature of the planet but it’s very significant in terms controlling the climatic.
The Antarctic is significant but tropics rules/dominates climate.
Suppose there was as much percentage of land at tropical zone as in the northern hemisphere- earth average temperature would lower [have less so called greenhouse affect].
Not sure what degree this affect world climate very much, but I am sure it would affect the temperature global average temperature measurement.
So the tropics and the oceans in tropics have great affect upon world’s climate and the tropical ocean has greatest effect upon a measurement called global average temperature.
-Heat of Fusion as water turns to ice.
Heat of Vaporization as water vapor condenses into water.
Adiabatic physics of the atmosphere.-
These important in regard to keeping non tropical areas from getting very cold at night. So generally for land dwellers very important.
-Thermal conductivity of the air and water in the ocean-
Important for land dweller, particularly “on the west coast”- whether if in America or Europe.
Robert G. Brown (Duke University) wrote several good articles in WUWT in early Jan. 2012 that explore the issues of heat trapping and heat flow.
Earth’s baseline black-body model – “a damn hard problem” (Jan 12, 2012)
What we don’t know about Earth’s energy flow (Jan. 6, 2012) with 233+ responses, including several lengthy embellishments from RGB in comments worthy of articles in their own right:
1/7 09:10 “Well, heck…”
1/7 15:57 “We’ll have to discuss fitting multivariate nonlinear functions sometime. Especially in systems with substantial covarance,….”
1/8 07:45 “The Navier-Stokes equation all by itself is a marvel of complexity so great that …..”
1/8 08:18 “The Earth is … not just bistable, it is multistable. ….
1/9 08:57 “as different as Glacial Earth and Interglacial Earth. The point is that both of these latter possibilities can be “stable” states for exactly the same insolation, etc, because feedbacks in the global system can themselves reconfigure to make them stable.
QUESTION: In the global mean temperature (GMT) data of the last 160 years, why does not the GMT ever exceed its upper boundary line (pink line) of 0.06 deg C per decade shown below for long?
There has been discussion above of the Roe&Baker vs. Zaliapin&Ghil controversy about the significance of the unlinearities on the predictability of climate and there has been discussion about the bifurcation as discussed by Pierrehumbert, but I haven’t noticed the observation that these points are closely related.
They both are about the shape of the relationship between OLR at TOA and the surface temperature. The bifurcation is a nonlinear phenomenon that occurs when the OLR has a maximum at some temperature, a minimum at a higher one and then grows again at still higher temperatures as it does in the slides 27-29 of Pierrehumbert.
The other possibility that corresponds to the views of Zaliapin&Ghil is that the relationship is monotonous for all relevant T and that the nonlinearities manifest in the way that the slope gets steeper with increasing T. The possible maximum of OLR would occur at a so high level that it cannot be reached in any plausible scenario. My interpretation of their paper is that there’s still a possibility that such a basic form of the relationship can be proven with high level of confidence. That would make the climate more predictable and contradict the basic claim of Roe and Baker of it’s fundamental unpredictability.
Zaliapin and Ghil is a very interesting paper, I’ve flagged it to discuss here at some point. Here is link
Zaliapin and Ghil respond to Roe:
Thanks for link to Zaliapin and Ghil paper, as well as the “back and forth” rebuttals.
The mathematics behind the conclusions are not that easy to follow for the average non-mathematician, but the conclusion seems fairly straightforward (bold face by me):
The RB07 paper, to which Z+G refer, had concluded
As I understand it, the Z+G paper finds that these conclusions cannot be supported by the mathematics.
The R+B rebuttal and the ensuing rebuttal by Z+G do not seem to resolve the question.
The Z+G conclusions would seem to raise serious questions regarding the earlier statements before US Congress of James E. Hansen with regard to “the likelihood of extreme warming resulting from small changes in anthropogenic forcing”, which were made at the time “to support political proposals”:
as well as the conclusion reached by Hansen in the same statement:
It is reassuring to read that the mathematics behind these alarming postulations and conclusions (plus the proposals to “phase out coal” made by Hansen during the same testimony) may be flawed.
But it might be interesting to run a thread on this discussion, as you have suggested
Sorry, Prof. Curry, I duplicated your links here below responding to a discussion above before I finished reading the rest of the updated thread (from last night). I’m particularly interested in you view regarding the point I made in my last para:
So we had bad statistics and now bad math.
It seems that there many who still cling to bad stats, I wonder how long it takes before the basic math is accepted.
I assume for most part it will quite fast.
I generally agree with Z & G.
I thought that the cold was something we fear more.
And I think understanding exactly why we got the Little Ice Age would
be quite useful- and vital for our future.
Thank you for this interesting post. Since my post created a large amount of heat and possibly less light, could I make a couple of simple points?
1) The climate sensitivity is a steady state position. The basic thermodynamic derivation as a set of functionals of internal variables are not functions of time. This means that the delays in the feedbacks are negligible when compared to the speed of the process in going from one state to another. I feel, but I don’t know, that this is correct and in long term changes they can be ignored.
2) Looking at short term dynamics, i.e.: how does temperature, radiation and cloud interact, delays and phase response may be important, particularly as it has implications as to how you analyse data. The time scale is, I think, days or weeks, and different to that of long term changes implied in climate sensitivity calculations. If these are homeostatic they can be treated as converging to a steady state as the period of the changes increases.
3) Generally, linearisation is helpful and, as you say, the climate sensitivity equations result from a linearised thermodynamic model. The implication is that one is dealing with small fluctuations and the non-linearities do not predominate. If one is dealing with dynamic systems, linearity vastly simplifies the problem but proper analysis of observations should allow one to tell if the system is genuinely linear or not. What I do not know, because I am well out of my field, are ice ages an example of a bifurcation, i.e.: when non-linearity predominates?
Richard, I think that in the climate system some of the so-called feedbacks, actually causal loops, have scales of decades, centuries, and longer. Ocean circulation and biospheric changes for example.
Ice ages may be an example of a two eyed attractor, like the Lorenz attractor, but we do not know, It is a central question. I think non-linearity dominates the climate system because the footprint of chaos permeates the data at all scales. But this is another central question.
“so-called feedbacks, actually causal loops, have scales of decades, centuries, and longer. Ocean circulation and biospheric changes for example.”
David, I have been thinking about this for some time. I would love to see some break down of a feedback/forcing ensemble that is thought might explain climate change/warming cooling over various units of time – decadal, centennial, millennial, and longer. I don’t know if it is even possible given the non-linearity and interconnectedness of feedbacks but it would be interesting to see. For example, something that explains early 20th century warming as opposed to overall warming since the LIA as opposed to the gentle decline in temperatures since the end of the younger dryas.
Do you or any one else know if something like that exists – something pithy and quick to digest?
After having read through both, I’d say your conclusions (earlier post) on the validity and pertinence of “feedbacks” as being used in “conventional” climate science make a lot more sense to me, from a practical viewpoint, than those of Chris Colose, which pretty much follow the “party line”.
During daylight hours the energy input that generates a recorded temperature is a combination of solar light flux and heat reradiated from the atmosphere. At night, temperature declines and its rate is a function of heat reradiated from the atmosphere. Thus, Tmin should show greater sensitivity toward a putative change in atmospheric reradiation than Tmax.
Thus, a plot of Tmin vs. Tmax would have a slope less than one if the increase in atmospheric [CO2] is a potent greenhouse gas. Should the plot of Tmin vs. Tmax generate a positive slope, it would suggest an increase in solar flux.
So, put my mind at rest. What is the slope of the global Tmin vs Tmax over the last 40 years? Do we see a differential increase in Tmax or in Tmin?
Is the rate at which the Earths cools during the night slowing or is the rate at which the Earth warms during the daytime increasing?
DocMartyn, I think you raise a very important issue with your focus on Tmax & Tmin. But where can one get the individual global data for Tmax & Tmin from, most data is the anomoly of (Tmax+Tmin)/2? From all I know and understand anthropogenic CO2 means it’ll be a little warmer at night, big deal. Daytime insolation is a massive perturbation to the system and no runaway happens I suspect because of Boltzman (T^4) and latent heat of evaporation/thermals/clouds.
Actually SOM, there is more to it than that. There is a differential response in Tmin/Tmax, resulting from either an increase in photonic recycling, resulting from an increase in a ‘greenhouse gas’, OR from an increase in incoming solar flux.
Increased IR flux from the atmosphere will have a disproportionate effect on Tmin, compared with Tmax.
An increase in solar flux will have a disproportionate effect on Tmax, compared with Tmin.
If one were to plot Tmin vs Tmax over a decade or more long period , then if the slope was less than 1, that is Tmin changes were greater than Tmax changes, then one would have identified an increase in the IR influx. However, if the slope were less than 1, that is Tmax changes were greater than Tmin changes, then an increase in solar flux is the culprit.
The hypothesis is both falsifiable and viable.
DocMartyn, I agree what you say but where is the Tmax & Tmin data available from?
Doc – I think you’ve asked this question several times, but Google would have helped you even without a response from us. A quick search turns up this paper on Diurnal Temperature Range as one example. The cloud data are outdated, but the paper has useful references. DTR has tended to diminish in association with the warming of recent decades, with clouds possibly playing a significant role, although current data are less clear on that role.
The topic is not as straightforward as you might assume. The greenhouse effect – redirection downward of infrared radiation – is a function of absorbed solar radiation, and so the more solar energy that is absorbed, the greater will be the GHE, which is why one sees an increase in the daytime as well as at night. On the other hand, one might predict that as a percentage of baseline values, nighttime temperatures (and winter temperatures) might increase more than daytime/summer temperatures, but it’s not obvious that this must be so, since the enhancement of the GHE by more solar absorption only operates when the sun is shining. In any case, the decline in DTR is consistent with this effect, but as the paper indicates, the role of other factors such as clouds makes it difficult to disentangle separate effects, and regional effects are also complex because of circulation of air and water between regions.
I think it’s fair to say that if the DTR had been increasing significantly as an accompaniment to warming, an important role for the GHE would be unlikely. In any case, this is a complicated topic with many variables, and the above only gives a rough idea of the principles involved.
Regarding a separate comment you made, I would not be happy with a mean blood pressure of 115.
I should add that an extreme case is easier to predict. Without any greenhouse gases in its atmosphere, the Earth would become very much colder at night while not experiencing as much cooling in the daytime. What happens under current climate conditions is harder to predict.
A brief comment on the ‘Planck’ sensitivity of 3.7W/m2. One may also derive a sensitivity by dividing a flux of 250W/m2 by a 70K tropospheric temperature difference and get the same value. The equivalence happens because the differential is 1/4 the absolute temperature. As the latter approach incorporates convection and the former doesn’t, caveat emptor. A correct answer doesn’t always prove the argument.
I asked Chris to explain something he wrote.
Either he can’t explain it in lay terms, or I am particularly dense.
In any case, he has assisted me not at all.
I have been assailed by a number of people offering unsolicited information. I thank them one and all.
I have lost track of the comments, so if I have failed to respond to anyone, I aplogise. I am not sure why you thought I would appreciate your input, but thanks anyway.
Chris already explained it in lay terms, and we all have enough experience at this game to know that if somebody doesn’t understand, it’ll take hours of back and forth to get the message through, if ever.
Chris wrote an article about feedback, and this is off topic. He’s not going to spend any time on the distraction. If you want help, listen to the other people who understood what he meant and have the time to spare try to explain it. If you don’t want help, why ask the question?
It’s not an especially difficult bit of physics, but it requires a long-winded explanation to get all the bits in place, and people either skip bits for brevity, assuming you can fill in what was meant, or they do it by building the explanation up layer by layer, the early stages being incomplete explanations to be corrected by later stages. Either approach can lead to confusion, especially if the person arguing is determined not to agree.
And it’s entirely irrelevant to the actual way the greenhouse effect works in a convective atmosphere, so it’s not even as if arguing with it achieves anything real.
I know what he meant, and so do several others. Do you want to know?
Your “reply” button has gone away.
My stove is gas which is a better analog for the sun anyway.
When I put the lid on the pot it got hotter even though the heat going in didn’t change.
The basic concept of CO2 causing slight heating makes sense to me it is the feedbacks which haven’t happened yet ! Since water vapor has gone down since 1950 I don’t see how it could possibly be working as hypothesized.
I am a staunch skeptic, and I appreciate what you’re trying to do by putting this into more accessible terms. However I think that there is an important point here which are you not quite getting (and to be fair, I think it could have been more clearly explained). It is my understanding that CO2 (and other GHG’s) will increase the temperature a bit for the following reason.
Imagine the earth’s atmosphere as a balloon and the inflation(i.e. diameter) of the balloon corresponds to the temperature.
Imagine that you are inflating the balloon with your mouth, but there’s a tiny hole in the balloon such that air is leaking out the other side. As the balloon inflates, air leaks out the hole faster and faster. Eventually, equilibrium will be reached when the air leaking out of the hole is equal to the air entering the balloon from your lungs (let’s ignore the messy physics of backwards pressure from the balloon reducing the efficiency of your lungs) and the balloon’s size will stabilize at a particular level.
Now imagine that someone makes the hole on the other side smaller. What will happen is that the balloon will now get even larger until the outgoing airflow again equals the incoming air flow. Voila, same energy coming in but a larger amount of inflation. Obviously there are some flaws with this analogy, as I’ve noted above, but it makes the basic point that blocking the release of stored energy leads to an increase in the amount of stored energy as long as there is a continual input of energy.
The reason this analogy with two different holes is valid stems from the fact that the energies coming into and leaving the atmosphere have different wavelength spectra, and the atmosphere is more permissive of some wavelengths than others. This has nothing to do with magic blankets; the blanket has the same effect in both directions. However the energy heading outwards is different than the energy coming inwards, and thus the blanket blocks outward energy more than inwards.
The analogy I’ve described above does not lead to runaway inflation ( heating), in that it has no feedback loops. Making the hole smaller (adding CO2) will raise the equilibrium level, but it will not lead to accelerated inflation (heating). I believe that this understanding is held even by most skeptics. The primary debate concerns other internal dynamics (i.e. feedbacks) within the balloon that would cause the hole to reduce in size even further as the balloon became more inflated.
Does that help your understanding? Personally I find this a clearer analogy than the boiling pot.
the primary problem with all these wonderful analogies is the terminology and actual word pictures. For example, you use the term BLOCKING. In the atmosphere GHG’s absorb, collide, and emit transferring energy. There is no BLOCKING, there are energy fluxes in various modes.
When you use incorrect terms and concepts you come up with invalid conclusions. The Climate Scientists came up with the idea from their models that there would actually be a BOTTLENECK in the upper atmosphere. This was based on modelling where they instantaneously DOUBLED the CO2 in the atmosphere. In that case the temperature profile is the same and there is more CO2 magically scattered throughout the atmosphere. In this situation there is alledgedly not enough warm CO2 to emit the increased energy as some of the lower, warmer, GHG emissions are “blocked” by the extra higher up GHG’s. Of course, the sun has not changed and there is no extra energy to emit so that is the first problem. There is a slightly increased delay in the energy leaving the system, but, it is constant after the first “wave” of IR.The system would not warm unless that delay was enough to keep extra energy in the system over night so it started from a higher level the next day…
IF the system actually warmed the atmosphere would expand and the earth and the GHG’s would all emit more based on this. Of course, in their instantaneous doubling the system has not warmed so there would be a possibility of an increase in emissions height due to the minor increase in GHG’s. This is such a small physical amount in the atmosphere I have a hard time believing that it happens. Of course, if it did, it would be temporary as the atmosphere would warm slightly, expanding, and allowing the original levels that are now warmer to emit at their new higher temperature.
Basically these amounts are so small that we simply haven’t measured them. The fact that there is no Hot Spot shows that their hypothesis has not been confirmed in 30 years. Without this BOTTLENECK the extra CO2 has negligible effect from its radiative characteristics. It primarily speeds up the convective cycle slightly.
If we were going to see a Hot Spot proving AGW we should have seen it at the peak of one of the major El Ninos. We may have, but, if so it was transient meaning it was not an issue as the wind patterns move that heat to the higher latitudes dispersing it. Without a large permanent change in circulation patterns it simply is not possible.
The hotspot has nothing to do with there being a “bottleneck”. It’s a consequence of their proposal that water vapour increase, which both acts as a GHG (a positive feedback) and reduces the adiabatic lapse rate (a negative feedback). The hotspot is a direct consequence of the adiabatic lapse rate change.
(A good illustration, incidentally, of the value of understanding the role of lapse rate in the GHE mechanism.)
The missing hotspot is an indication that the water vapour feedback isn’t working as they predicted. It neither confirms nor contradicts the greenhouse mechanism itself, but as 2/3rds of the anticipated warming is due to the feedback, of which water vapour feedback is the biggest component, its absence is significant.
The “hotspot” (tropospheric amplification) is actually a consequence of a negative feedback – the lapse rate feedback – in that the upper tropospheric heating is due to the latent heat released by water vapor condensation, which is the cause of the reduced lapse rate. It is true, though, that it also depends on the water vapor concentration that is there to start with, and so it’s hard to assign responsibility for less tropospheric amplification than predicted. If upper tropospheric relative humidity (RH) remains constant with warming, its feedback effects might be expected to have the estimated magnitude, regardless of the presence or absence of amplification. There are conflicting data on the constancy of upper tropospheric RH – Minschwaner and Dessler (J. Climate 2004) found that while specific humidity increased, it did not keep pace with temperature, and so RH declined. Soden et al (Science 2005) estimated a constant RH. The resolution of this disagreement will affect the magnitude of net feedbacks, but probably to only a limited extent.
it is straightforward physics, if more CO2 adds more energy to the system there should be more water vapor from at least a portion of that extra energy. The energy moved to the upper trop and dumped by that extra water vapor warms the upper trop. The bottleneck prevents it from all being radiated away, voila, hot spot.
Oh yeah, what causes the bottleneck? The extra water vapor and CO2 blocks the emissions from the warmer levels so they are emitted from higher cooler levels. Their models show that the average emissions altitude is cool enough that they cannot emit all the radiation causing more warming etc.
My problem is that as soon as the atmosphere starts to warm it causes more space between the particles offsetting the masking of the extra water vapor and CO2 I don’t have a model so it is my arm wave..
Of course, since we don’t see a hot spot, or even a warm spot, we know that the feedback is not happening as they expected meaning we can’t trust the models for this and many other reasons. I would have thought it would have been apparent during the Super El Ninos. It apparently wasn’t or someone would be pointing that out.
Other problems are that ANY warming should be able to cause this feedback, yet, we don’t see a hot or even a warm spot so it would seem there has not been enogh warming to “trigger” this straightforward basic physics.
This also highlights that only the feedback puts us into a position where there is a problem. Without this feedback there is no large warming. This reflects in the fact that Venus is cooling even with its massive amount of CO2.
I understand that this analogy isn’t perfect, but I think it gets across one essential point of the greenhouse theory, which is that retaining extra heat causes increased warming.
Please believe me that I understand the climate is so much more complex than inflating balloons.
you just did it again, “retaining extra heat.” The atmosphere has energy fluxes. The energy is continually moving between particles by collisions and radiative transfer. The only thing that can retain heat are the non-ghgs and they are just magnitudes slower in radiating their energy. They can still collide with a cooler GHG and transfer their heat to it, say, at night as the atmosphere cools. The GHG’s emit it or transfer it through collision within milliseconds. The energy does leave the system or we would be measuring an increase in temps. Right now we have seen no increase in temps for about 15 years while the CO2 has been steadily rising. Where is the BLOCKING, RETENTION…?
There is slowing due to a more convoluted path to exit, but, there certainly has been no proven BLOCKING or RETENTION by GHG’s!!!
It could be the case that CO2 isn’t a strong enough presence to have a very large impact. I’m not trying to be a poster child for AGW here, just pointing out that there is merit in the classic greenhouse-effect theory. One can believe in it without believing in the IPCC scenario.
I had stopped, but thank you for your response.
One of the problems I face is that nobody seems to be able to demonstrate the increase in surface temperature of a body by interposing anything at all between a body with no internal source of heat, and an actively radiating source of heat. My experiments from years ago failed to show anything other than a decrease, as one would expect.
Analogy – put a hat on. Yes, I know, and this I why I prefer reproducible experiments to theories or broadcasts from the Fortress of Arrogance.
Imagine this: Your calculations of heat input, total heat losses, and water quantity etc indicate the water in your pot will stabilise at a temperature of 107C, at standard temperature and pressure. You have measured all known external factors, the temperature of your room and so on.
You then do something unusual. You look at your pot. Not even boiling.
I don’t know about you, but I would recheck my calculations. Actually, coming up with water achieving a temperature of 107C at standard conditions would make me scratch my head a little bit in the first place.
But I digress. Your observation is fact. Do you first see if you have made an error in your calculations, or go off on a long hunt for a previously undiscovered facet of physics?
Another analogy. Did it change anything? No. Have I wasted my time? No.
I do it because I want to. My choice.
nobody seems to be able to demonstrate the increase in surface temperature of a body by interposing anything at all between a body with no internal source of heat, and an actively radiating source of heat
Uh, Mike – three guesses as to why it’s called the greenhouse effect.
I mean no offence, but as you are probably aware, a real (as opposed to an analogical thought experiment hand waving greenhouse) greenhouse has nothing to do with the magic properties of CO2 or anything else.
I can’t think of the other two guesses you might think are appropriate.
Please provide your demonstration. No analogies, inferences or hand-waving allowed.
If I’m wrong, I will change my mind. Wouldn’t you?
“nobody seems to be able to demonstrate the increase in surface temperature of a body by interposing anything at all between a body with no internal source of heat, and an actively radiating source of heat…If I’m wrong, I will change my mind”
Ozzie, I think Fred’s point is that a mere greenhouse successfully satisfies your condition of “interposing anything at all” to cause an increase in heat. The mechanism of heat retention is completely unrelated to CO2.
Well, ya see, a Greenhouse has the SUN for an energy supply to RAISE THE TEMPERATURE of the dead body!!!! A Greenhouse is not interposed as it does not stop the suns radiation. At night the Greenhouse is cooling and allows its contents to cool. That was a really sorry attempt there.
This discussion has been tedious and has sidetracked the discussion too much.
It is trivially true that without the sun, the presence of a greenhouse effect would be irrelevant (granted, it would become so cold that all the gases would condense from the atmosphere, but even if they could magically persist as gas molecules, the Earth would eventually relax to a temperature determined only by the cosmic background radiation from space, or any other form of heat flux such as internal heating by radioactive decay in the interior.)
Of course, the real Earth system has a permanent supply of external (solar) energy. This means it is allowed to settle to some temperature T1. Now suppose we introduce an absorbing infrared layer at a colder temperature than the surface that can intercept IR before it exits to space. If the temperature remains at T1, then this means the system is now absorbing more solar energy than infrared is leaving, and since the sun is always present, this would be the permanent case. This state of affair cannot persist, so the only option is for the system to warm to a new temperature T2 (where T2 >T1) so that it can reach a new radiative equilibrium. Thus the IR layer allows the planet to relax at a temperature somewhere between T1 and the photospheric temperature, without violating thermodynamics. The principle is much like how adding insulation to your house will keep it warmer than it would otherwise be, even if you keep the furnace at a constant. It’s really not hard to understand.
Put an object in the sun on a still day. Say a solar water heater collector. Build a greenhouse around it or lower one over it.
Wait while. Measure the temperature. If it has raised due to the interposition between the collector and the Sun, let me know. We will go into business and make a motza (or a SLOM.)
It took me a while to understand this (you helped some, and so did the post A Saturated Gassy Argument at realclimete.org). I didn’t post my understanding of how the GHE works in practice since ozzie said he didn’t want to hear anything about “spectroscopy”, so it wasn’t really worth trying to straighten him out.
For anyone interested in a good explanation of the GHE, check out the above referenced post by Spencer Weart.
Here is another explanation
More technical, but better yet…
Thank you for expressing your opinion of the tedious nature of more or less free and open discussion. I merely took the opportunity to restate a question I asked on your blog, and to which I did not receive a reply. No problem, your blog, your rules.
Now I realise you are lowering yourself to my level by promoting the fiction that all gases would condense from the atmosphere. You must be aware that the Moon does have an atmosphere, albeit very thin and of little mass.
But yes, it you want to use a little poetic license, I will agree the Moon has no atmosphere. to speak of. So no “magic” required.
You may care to comment on what I suppose would be called Tmax and Tmin on the Moon. Once again, you will be aware the Moon does rotate on its axis, and not expose one side to the Sun continuously.
As far as I know the maximum temperature on the Moon, in the absence of “greenhouse effect” exceeds 105C. I am not aware of any place on Earth where a temperature of >105C can be achieved by exposing a surface to the direct rays of the Sun.
Now your comment about the real Earth has an interesting IF. This is where you say “. . .If the temperature remains at T1, then this means the system is now absorbing more solar energy than infrared is leaving, and since the sun is always present, this would be the permanent case.. . .”
You say “. . .IF (my emphasis) the temperature remains at T1. . .”. Can I ask you how radiation can leave the surface without a drop in surface temperature?
I ask you again, given that you have IR from the surface escaping to space, when the IR leaves the surface will the surface temperature drop, rise or stay the same?
Now you may attempt to confuse the issue by pointing out that the outgoing radiation is more or less immediately replace by the incoming Solar radiation, but this doesn’t work either.
On to your last comment. The atmosphere is not “much like” an insulator (as though it has additional “magic” properties), it is exactly like an insulator. It behaves like one, so it is one in this context.
It’s really not that hard to understand.
Can I turn Weart’s words around a little? He says “. . .What happens to infrared radiation emitted by the Earth’s surface?. . .”
Can I ask you what happens to the temperature of the Earth’s surface when it emits infrared radiation? Rise, fall, stay the same?
Thank you. The first goes on at length about the atmosphere being an insulator, No problem with that.
The second is a highly obfuscatory effort to hide the fact that the OLR that comes from the surface lowers the temperature by as much as it originally increased it. Unless you have a “magic” surface which maintains its temperature, while simultaneously cooling. Tedious, I know. Sorry.
Ozzie Ozzie Ozzie Ozzie Ozzie
No one who chooses to take up your task is doing anything meaningful.
Your blanket is not an analogy for the atmosphere because you intend to use it differently than those who apply a different blanket analogy of atmosphere.
Your corpse is not an analogy for the Earth.
Your furnace is not an analogy for the Sun.
Your house is not a model of Earth-Sun-atmosphere Physics.
You’re using the shape of a question to not ask a question.
Try again, with something more apt.
Bart Bart Bart Bart Bart Bart Bart – do I win?
Interesting to note that the challenge you accepted at 10.27, uninvited I might add, seemed to indicate that you accepted the analogy chosen by Chris Colose.
By 1.27, you had decided that the analogy was no longer acceptable.
It would be churlish of me to suggest that in the interim you had discovered you had brought a knife to a gunfight. I didn’t invite your response, it was your idea. The fact that Chris Colose used the blanket analogy and the word nonsensical in the near vicinity expresses my views of the analogy exactly.
So we are in agreement, Bart. I am surprised that you did not immediately challenge the analogy when Chris first suggested it. Could you do me a favour, and refrain from using analogies of any sort when discussing the supposed “greenhouse gas effect”.
I like facts. Not inferences, not assumptions, unless clearly and unambiguously stated. That is why I usually state the assumptions I adopt if asking someone else to undertake an exercise. Unfortunately, I often assume that people are aware of what I consider basic knowledge that even a high school dropout like myself possesses.
Your condescending tone is counterproductive to building the bridge of understanding that you claim to be looking for. Please remember that we’re all(well most of us) here to better understand the climate problem, and to iron out some of the communication failures that have arisen.
If you don’t believe that an enclosed cavity will spontaneously heat up when placed in the sun, then would you have any hesitation about leaving a dog in a parked car with the windows rolled up?
Take a look here:
Or if you prefer a peer reviewed source:
I should apologize for lecturing you about your condescension. I see that you were reacting to Chris’s usual patronizing tone, which grates on all of us.
To answer your question we’ll use a simplified model with no diurnal cycle and we’ll ignore the heat capacity of the surface.
In this model the earth is receiving a constant ~160 W/m^2. It is radiating a constant ~160 W/m^2 so the temperature remains the same.
Using a more thorough model, with a diurnal cycle and some heat capacity for the surface, during the day the surface absorbs more than it emits (warms) and during the night it emits more than it absorbs and so cools. Simple really.
Please forgive me. I certainly intended no offence.
I’m not sure where you got the idea that I don’t believe an enclosed cavity would heat up in the sun. I would disagree that it “spontaneously” heats up, as it is absorbing radiant energy from the Sun.
Anyway, anyone that would leave anything in any enclosed, unventilated space exposed to a heat source such as the Sun, needs to be aware that convection cannot be involved in heat removal from that space internally to any great degree.
If you measure the maximum temperature of a surface of an object of known absorptivity and inside say, a sealed car, and measure the maximum temperature of that same object exposed to the direct rays of the Sun (with care taken to assure the same level of convective heat loss, you may well find that the object reaches a lower temperature in the car, than outside on the ground.
Please don’t feel that I am being condescending, but your statement including the word “spontaneously”, and your subsequent question assuming a belief based on your false assumption is not easy to answer without contradicting your assertion.
I am not sure what “question” you are answering. I don’t recollect asking you, but I may be wrong.
However your statement that the Earth surface warms during the daytime, and cools during the night is well known.
I assume you accidentally posted a truncated response. If you provide the rest, I will endeavour to respond.
It was in reference to your question here.
The answer is stay the same on average.
Well Ozzie this is exactly what you said:
“Put an object in the sun on a still day. Say a solar water heater collector. Build a greenhouse around it or lower one over it.Wait while. Measure the temperature. If it has raised due to the interposition between the collector and the Sun, let me know. We will go into business and make a motza (or a SLOM.)”
Now I think I know what you mean, which is that anything which can block light cannot help but decrease the temperature received by the object in its shade. However you are saying something quite different than that, which is leading to some of the miscommunication in this thread.
With regards to the point about shade reducing rather than increasing temperature, if the shade provided a broad based blockade of light across the entire spectrum of energy, you’d be right in all cases (I think). But CO2 blocks very specific wavelengths, and since a reflecting body, such as the earth can change the wavelengths of reflected energy, the simple analogy of an object in shadow no longer applies. You have something that behaves somewhat akin to a magic blanket, except it’s not really magic of course.
Chiefly, I’d like to thank you for your contribution to this thread.
You’ve held us all to high standards of precision in language – well, not all of us, those you favour you hold to no apparent standard at all except agreement with your views, but then, that’s not really a big deal.
You’ve presented us with (when one thinks about it, remarkably mild and simpleminded) opportunities to refine our cases and communications.
You’ve worked very hard to keep the blog’s many denizens entertained by your obscurely bendy presentations, which.. well, you’ve fallen short of being entertaining or persuasive, but sometimes it’s the thought that counts.
And what you lack in correctly interpreting back what has been said to you, you more than make up for with diction, near-creativity and the appearance of courtesy.
You’ve allowed Joshua to prove he’s worth his salt, which is I’d always believed he could.
Your efforts are sincerely appreciated.
Thank you for your thoughts. I appreciate them.
Now to your comment.
I meant what I said – although on reflection, I failed to realise that the word “motza” or the acronym SLOM may be unfamiliar to you.
A “motza” I use to indicate an undefined large amount. A SLOM is a S…Load Of Money. Sorry.
I repeat – I meant what I said. If you can prove otherwise by recourse to experiment with sufficiently accurate measurements, i believe I will change my mind. What would you do?
Your last paragraph is devoid of meaning. The minute you use terminology such as ” . . .You have something that behaves somewhat akin to a magic blanket, except it’s not really magic of course. . . .”
You don’t have any such thing. You want to deny that the Sun emits heat, that the law of the conservation of energy is not something that you can suspend at will, and that the Earths surface temperature does not drop when it emits heat energy.
Deny away, I can’t stop you. When you have performed the simple experiment I suggested in such form that you can afford, please let me know your results.
Ozzie Ostrich and Lt. Cmdr. Mike Flynn are two of my favorite antepodean television characters, so it’s nearly impossible for me not to proffer my two cents.. though I’ll resist asking for a pink feathered beakie autograph.
Models, like all analogies have rules of validation and verification against what that objective correlative they seek to simulate over the range of the problem space.
And Ozzie Mike Ostrich Flynn, I fear you’re breaking the rules of analogy with the models you offer. It can hardly be your fault; I doubt you’re nearly so familiar with corpses nor with hats as I, so please allow me to try where others have failed.
When Chris Colose, for reasons best known to himself, chose figures like 10x, 6x, 4x and 2x, he apparently intended to give a very greatly simplified analogy for what he was discussing. Chris left out what he felt was irrelevant, and picked only what was illustrative of his point. This is not unusual nor offside in the rules of analogy, but is helpful if done right.
You’ve done something similar when you took care to help us exorcise the ‘internal heat sources’ of microbes and the problems of escaping gases, and so forth, in the analogy of a corpse in a house that makes the story more fun but less apt.
My house furnace is set to 30C.
I have died.
My skin temperature is now 35C.
Your task: –
Your task, should you accept it, is to raise my skin temperature to 36C.
You have two choices –
1. Pile blankets on my cooling corpse.
2. Turn up the thermostat.
Now here we have several significant problems. A) Your house thermostat is set to 30C, which means the furnace turns on, generates heat (likely significantly) above 30C, and then turns off when the temperature gauge controling the thermostat reaches 30C. B) You only contemplate two constrained options which likewise bear no resemblance to the actual case being modeled within its problem space.
In language a feathery puppet or career naval officer might understand, you’re not playing fair.
An imaginative person could move the body closer to the heat register, or turn it so it blocks the outflow of the furnace, throw the blanket over the temperature gauge on the thermostat, pummel or shake the body so the mechanical force heats it, shake the house so the body shakes, endless variations on improper elements of analogy.. and then could do some things that would bring the analogy closer to the real situation, in ways that can be independently validated.
The Earth takes in the full spectrum of radiation from the Sun, and after shunting some aside by albedo effects and so forth, turns all the rest into a much narrower portion of the spectrum.
A better analogy than a blanket is a dirty, faulty lens between the corpse and the brilliantly lit furnace that provides not just heat but many times as much light as heat (analogous to an imaginary lens way out in space that focuses light onto Earth). Some of the light focused is scattered by the dirt and flaws in the lens, but the rest is concentrated by the lens onto the corpse, which gets hotter than it would have without the lens.
While the process of a lens concentrating light from a wider area onto a smaller focal plane is not the same as the process of the Earth concentrating a wider spectrum of light into the narrow bands CO2 absorbs and helps the atmosphere retain, the outcome is similar enough for analogy.
Chris Colose left out things he felt weren’t important. You left out things you felt weren’t important. It turns out Chris’s omissions were just fine, from the point of view of what Chris was trying to say, in that what Chris was trying to say does match something in the real world pertaining to the subject at hand. And, sadly, it turns out Ozzie’s omissions were not right, from the point of view of matching the real Sun-Earth-CO2 mechanism, even if Ozzie’s sort of right about how corpses in general might act in houses.
I hope that helps, my feathered pink beakie.
“While the process of a lens concentrating light from a wider area onto a smaller focal plane is not the same as the process of the Earth concentrating a wider spectrum of light into the narrow bands CO2 absorbs and helps the atmosphere retain, the outcome is similar enough for analogy.”
Nice, too bad we are cooling.
You may have overlooked the assumptions for the task.
Because the assumptions don’t allow you to reach the conclusion you would like, to take it upon yourself to solve a totally different problem, by substituting your own assumptions. And therein lies a problem.
You make assumptions that my furnace is not a “magic” one that maintains a fixed temperature, without hysteresis.
The Sun emits radiant energy. We have no way of moving the Earth closer, shaking the Earth or the Solar system, or wrapping the Earth in magical heat raising blanket.
You have two options if you accept the task
1. Turn up the Sun
2. Wrap the (supposedly no internal heat source) Earth in whatever you like.
More like the real situation?
Once again, your call – although originally addressed to Chris.
Another analogy? A lens? You really think that grabbing heat from outside that area that the Earth obstructs resembles reality?
I thank you for acknowledging that I am”sort of right”.
Better than “sort of wrong”.
I am skeptical about AGW, but not skeptical of the greenhouse effect per se. I’m glad that you’ve run some experiments yourself, which is more than I’ve done. Can you describe them in more detail?
Note that a direct analogy to the earth’s greenhouse effect would be fairly involved, because it would require a mechanism whereby incoming light is absorbed and re-radiated at a different wavelength. I suspect this is why the canned experiments in Gore’s recent movie had to be faked. In other words this is a hard experiment to get right, but that doesn’t make the effect impossible.
And even if the basic greenhouse theory is true, it leads to decelerated warming as the system heats up. For full scale Manhattan-underwater warming, one needs feedback effects beyond the CO2 blanket.
” For full scale Manhattan-underwater warming, one needs feedback effects beyond the CO2 blanket.”
Unfortunately not so. Manhatten was under water in the last interglacial period: the Eemian Period, with sea levels several metres high than now. Then, temperatures were just a degree or two higher than they’ve been in the Holocene. In fact, just about the same as they are now.
“In fact, just about the same as they are now.”
Then that point seems to be in dispute:
“The Eemian, or the last interglacial period, is the last time climate was as warm as it is today. in fact, it was warmer than it is today. “
Yes you possibly right is saying that the Eemian was slightly warmer than today. But for how much longer? Ten years, Fifty years?
You’d certainly be right in adding that sea levels are lower today than during the Eemain . But again, for how much longer?
Eemian peak > Holocene peak > Minoan > Roman > MWP > Now
It’s been warming for 100,000 years, likely. It’s been cooling for a quarter million years (or so), some evidence suggests. It’s been warming for half a million years and three quarters of a million years, maybe.
Our projections of the temperature are rough estimates with wide error bars.
So when you say, “Eemian peak > Holocene peak > Minoan > Roman > MWP > …” I must ask, how do you know? How confident are you? You sound awfully sure, but really, the error bars are so large and data analyses so speculative that you can’t be more than one percent likely to be fully correct, and we’re unlikely to ever know.
So when you carry your less than 1% likely to be right ‘certainties’ and parade them around while pretending to be justified by such slim pretext to argue against propositions more than 90% likely, the word that comes to mind is ‘bogus’.
To give kuhnkat his due (CAPital fellow that he is), his reasoning is somewhat less intelligence-insulting (though still wrong).
When Natural Variability carries temperature trends to the levels of a century ago, then he might have a basis for his argument. Otherwise, the data simply doesn’t support him.
However much kuhnkat misattributes assumptions, he cannot argue against the fact that the trends of trends, their frequencies of upward and downward decades, poor though they are, strongly support a generally warming climate due CO2, moderated by significant (but overall smaller) decadal ocean currents and the like.
“However much kuhnkat misattributes assumptions, he cannot argue against the fact that the trends of trends, their frequencies of upward and downward decades, poor though they are, strongly support a generally warming climate due CO2, moderated by significant (but overall smaller) decadal ocean currents and the like.”
If I make up adjustments and use the same original poor data that is based on anthropogenic contamination, I can have negative trends. They would prove the same thing your trends prove, nothing.
What of it?
Up to one in three decades in all the net rising 30+ year spans on record are cooling; there are longer spans up to 16 years in some net warming spans of 30+ years.
You say it like it means something.. or like it is some incantation you hope will vanquish reason by magickal thinking.
Doesn’t sound very kuhnian.
It’s cooling for 10,000 years.
Well Bart R,
it would seem that your mechanism for warming doesn’t work when the sun is not driving it otherwise we wouldn’t have these little periods of no warming which you ASSume are only occasional due to our poor temperature records.
Chris Colose writes “Current climate sensitivity estimates generally yield a coherent picture of ~2-4.5 C per doubling of CO2, with very little chance of sensitivity at the low end of this”
After I read this, I realized that there is no point in bothering about this thread at all. It is merely CAGW propaganda.
But Jim, you’ve told us “When I first heard about CAGW, maybe 12 years ago, I knew it was wrong. In the intervening years, I have learned a great deal, and everything I have learned, confirms my initial reaction.”
So you’ve been telling us porkies, have you? The truth is, when you are confronted with something that doesn’t “confirm your initial reaction”, you just don’t want to know! Much less learn from it.
And you say you “Graduated in Physics from Cavendish Labs, Cambridge at the end of WWII”. Such a waste.
Frankly until your guts agree to full disclosure and stop hiding their data, nothing you push is worth the bytes it takes up.
Until you who believe there is a climate crisis being caused by CO2 demand that all of the players on your side are held to reasonable standards of behavior irt data, communications, compliance with FOIA laws, and call out those who do not, there is no reason to believe or trust anything you say.
As long as your community relies on accusations of conspiracies by skeptics, call skeptics ‘deniers’ and pretend that no one reasonably questions AGW claims, you will never deserve the credibility you claim, nor will you receive it. And as much as you tell yourselves and each other how clever and right you are, as long as you and yours keep to this road, everyone knows you are at heart just pushing lies.
It is interesting, however, that you seem to claim feedbacks are linear in a system that is non-linear.
I don’t know if this is particularly useful here. Attacking Chris in this way in this context is ad hom I think. There are problems with the science (IMO) and he is making an effort to engage on that. One interesting point to note and discuss is on the ‘no-tipping point’ conclusions/idea/hypotheses.
I am quite sure Chris knows the accusations levelled at the orthodoxy, there is no point repeating them. If we don’t want a blog to be a self-congratulatory talking shop where no debate occurs then chasing off those we disagree with doesn’t serve anything. Since this site is known to be supportive of skeptical views, then his engaging here is a good sign and should be encouraged.
Agnostic, thanks for that statement
I am very supportive of the open debate.
Until Chris can address the issues I raised, the rest of his talk is really not meaningful.
He may know the issues, but that does mean he is addressing them.
Hunter, the issues of conduct that you raise have nothing to do with the concepts of feedback and sensitivity. You seem to be saying that you will not listen until all the climate scientists in the world obey your standards of conduct. It sounds stupid.
Your misinterpretation of what I am saying is, inmo, what sounds stupid.
The institutional corruption of cliamte science makes any claims they make questionable at best.
Those who ignore it enable it and are by implication corrupt as well.
In the thread on the ‘open letter’ to the dragon slayers, one thread of the argument that is very popular with believers is the lack of character of some of the dragonslayers.
But here that is supposed to be out of bounds?
I don’t think so.
We tolerate Lacis ratinalizing his rude and uninformed claims about skeptics by his claim that he is a New Yorker and so is justified in his rude self-chosen ignorance of skepticism. Chris, as a young grad student, parrots a great deal of that.
And we now know that AGW promoters working on the public dime are seeking ways to avoid FOIA- accountability to those who pay their bills.
Until more workers in cliamte science do as our hostess have done and point out the unacceptability of the things going on now and exposed in climategate, anything offered by a person pushing the idea of CO2 causing a climaze crisis should not be surprised if their credibilty is not very great.
hunter, I agree with agnostic. This kind of attack is off topic and worse than useless.
We can just agree to disagree.
I am tired of believers getting to say anything they want, ignore everything they wish, call out any names they want to call, and then skeptics get told to in effect stfu and take it.
I agree with Hunter. Chris may at times be helpful but in the end will only produce regurgitated IPCC dogma. He will only question those that dissent from the consensus. When he takes his blinders off he may have something of interest.
As a general rule we are tolerating policy demands and claims of expertise from people who demonstrate. or are silent about people who demonstrate, serious ethical lapses on the unfounded reason that we can seperate the good ideas from the bad character.
I would suggest that this is a grave fallacy.
Many in the AGW community has done this for years, even as they insist skeptics have no credibility because of their false claims of ‘big oil’, ‘Koch Brothers’, “death trains”, “denialist”, etc.
When I read the post on how the climatocracy is seeking to further evade normal disclosure of their work, it just struck me that this would be unacceptable in normal areas of life and that it long past time for the AGW movement and its promoters to be helpd to normal standards of behavior.
Thank God that our root cellars still work, in a PNS world.
Well, I suppose I ought to thank CC for trying to produced a climate/sensitivity “primer”, but he pretty quickly lost me, so I can’t say whether he’s right or wrong.
Matter of fact, that’s what nearly always happens in these technical threads, but I’d have hoped a primer would be more understandable.
I have a postgrad teaching cert. and a masters in education. There is one guiding principle I have found inestimably useful, namely, that to teach anything, you have to be aware of the conceptual framework within which students are working, and that includes likely misconceptions.
For all I know, what CC is saying may be resolvable into perfectly understandable English for the layman, without losing any of the necessary detail. But sans that, it might as well be Swahili, and all I can rely on is my understanding of feedback in the context of biological systems, which tend to be homeostatic, involving negative feedback. I find it difficult to lend credence to the idea that an earth that has existed for four billion years will be thrown out of kilter by a modest increase in CO2. This has already been said quite eloquently.
If the reason why that is faulty thinking is not actually explicable in plain English (I’m excluding hand-waving and mere assertion), then that’s one reason climate scientists have a problem. Some people may be prepared to accept what they say on faith, but others are always going to have doubts because they don’t have a conceptual model that hangs together in a logical fashion. Nor do they have the means to intelligently challenge something they might disagree with (if only they understood it). It’s no use my asking a question in plain English if the answer is too technical. Indeed, I may not even know how to frame the question, or even if there is a question worth asking at all.
In the posts above, I found that Brandon Schollenberger and Nullius in verba were the best and clearest communicators, but I’m already convinced that basic GH theory is correct and believe I have a good enough conceptual model of that.
Now if only someone like them were able to put across a real primer for sensitivity and feedback…
The interesting thing about water vapor and runaway global warming NOT is that the atmosphere COULD hold a lot more water vapor than it does… but, it doesn’t… which is why the thermostat theory is at least as robust as AGW theory that must violate the laws of thermodynamics to predict runaway global warming from relatively small increases in CO2.
I posted this earlier in the wrong thread, maybe it’s okay if I repear it here (edited a bit):
“There is a relatively simple method to analyse a signal (data series) to see if it is subject to positive or negative feedback because both have quite different characteristics. Negative feedback ‘subdues’ disturbances and changes (noise) while positive feedback ‘amplifies’ changes.
Therefore if some noise deviates the signal from the average equilibrium value, negative feedback tends to steer the signal right back, while positive feedback tends to increase the deviation from the average, so other factors like the forcing functions and random noise will have to restore the balance.
This means that a signal under negative feedback statistically shows more than average reversals back to the average (antipersistent), whereas a signal under positive feedback shows less than average reversals back to the equilibrium (persistent).
Olavi Karner et al have investigated many climate signals this way and found basically antipersistent behavior just about everywhere. They conclude that negative feedback prevails”
Andre – I haven’t read all of Karner’s papers at the site you linked to, but a glance at a few suggests that he misunderstands the concept of feedback as applied to the climate system. Chris Colose, in his post above, addresses this in detail, but a few points are worth repeating. The climate responds to an imposed perturbation of the radiative balance (a “forcing”) by tending to restore the balance, albeit at an altered temperature. In control system theory, this would be considered a negative feedback, and it is universally understood within climate science that this is in fact what happens. The phenomenon most important for ensuring this result is the Planck Response, which is the tendency of warmer bodies to shed more heat in accordance with the Stefan-Boltzmann law. That response is not always included in lists of “climate feedbacks”, but its effect is always included in the calculations.
When the term “net positive feedback” is applied to climate responses, that term refers to feedback effects outside of the Planck Response. In that sense, a positive feedback is one that amplifies the temperature response to a forcing to a magnitude greater than expected from the Planck Response alone. Water vapor, ice-snow albedo effects, and probably clouds contribute to this amplification, which is generally estimated to raise an equilibrium sensitivity response to CO2 doubling that would ordinarily be about 1.2 deg C to a level of somewhere between 2 and 4.5 deg C. There are some claims for values outside of that range, but that is the range typically estimated with 90 to 95% confidence limits.
This is a “positive feedback” only in the sense that it magnifies the effect expected from CO2 alone, but the climate still responds with a tendency to restore a balance. If Karner’s use of the term “negative feedback” simply refers to that fact, it agrees with the universal understanding within climate science.
No Fred, there is no mix up. The principles of feedback is not dependent in which physical environment it is, be it mechanic, electric, nuclear, gasseous, radiation. All engineers encounter the same basic principles to deal with the many feedback effects. So if you have noisy variation in parameters like for weather, albedo, clouds currents, causing noise in the system, all systems, mechanic, electric, gasseous, whatever do show persistent behavour in the case of positive feedback. Basic textbook work.
Andre – I don’t think you understood my point. Net feedback in the climate system is universally understood to be negative in the control theory sense that a stabilizing feedback is a negative feedback. This is due principally to the Planck Response. The net positive feedbacks refer to amplification of temperature responses to CO2 or other forcing mechanisms compared with a Planck Response alone. When the Planck Response is included, there is no dispute that the climate tends to be self-stabilizing. My impression from glancing at a few of Karner’s papers is that he didn’t understand this either.
I think I understood you perfectly well Fred and so does Karner. Now we always have read that -and you restate it- that CO2 is a forcing function, not a feedback. There is a planck responce or whatever you may call it and that is one of the things that the climate system does -converting energy to heat- but that is system response- no feedback either.
Next the main output of that system is a temperature, and now and only now the feedbacks start to work on the system, activated by that temperature, Some of these are water vapor, latent heat, convection, advection, ocean interaction, cloud, albedo, etc etc. Those are always in action, regardless of how much the CO2 greenhouse effect input is -or- is not doing. They change the impact of the forcing functions, by reenforcing or reducing the input. That’s how feedback works.
Karner demonstrates that the total of all those mechanism act antipersistent in all the series he measured, hence as a negative feedback on the system, which output was as we said, temperature, so all the feedbacks combined cause the temperature to be steered closer to the equilibrium temperature. Now if you change any of the forcing functions like sun or CO2 greenhouse effect, then these same mechanisms will still do the same.
Andre – I can’t force you to understand climate feedbacks if you are determined not to. However, I think that most readers of the post by Chris Colose as well as my comments will understand what I am saying, and will realize that Karner appears not to understand this, at least based on what I read in some of his papers. Not to belabor the point, but the climate is self-stabilizing. The positive feedbacks don’t change this fact but merely indicate that the temperature will change more before stabilizing than it would without the feedbacks.
If you have new specific evidence on this point, it would be welcome -particularly if you can refer to quantitative data on the altered temperature response as a function of feedbacks. Otherwise, I’m not sure we will get anywhere through repetition of what has already been said.
“I don’t think you understood my point. Net feedback in the climate system is universally understood to be negative in the control theory sense that a stabilizing feedback is a negative feedback”
So if you when to a doctor Fred, and he took your blood pressure, measured the Systolic & Diastolic Pressure added them together, then divided by two, would you be quite relaxed.
Then, explaining you average blood pressure of 115, he stated that your yellow and black bile were out of balance, would you be happy?
Thing is Fred, may people wonder why, ‘Climate Scientists’TM, use well defined terms to mean completely different things?
Why is it that the word ‘feedback’ means something different in the analysis of climate than it does in any other discipline?
Why does ‘equilibrium’ mean something other than it does in classical Thermodynamics?
Why is there the usage of the term ‘forceing’, a term not used to describe any other thermodynamic system?
What I don’t get is why Chris trash talks Judith on Tamino’s blog as little as 2 or 3 months ago and now guest on her blog.
Check out this blog that has upset them recently:
I disagree with Dr. Curry on a number of things, still maintain that much of what she says is sloppy and unjustified, but at the same time she still has the integrity to squash nonsensical “dragonslayer” type claims. But I e-mailed her with this post with her large and diversified readership in mind, and she took it. That is all.
You use The Day After Tomorrow in your articles for examples, and she is the one that is sloppy?
You might try to get some integrity yourself
Yes, the cognoscenti of the climate blogosphere and keepers of the climate “truth” continue to push the meme that what I say is “sloppy and unjustified”, see this recent gem from Michael Tobis at Collide-a-Scape.
“But then the closer she gets to science, the more absurd it gets. It’s not that she has unusual theories or interpretations. This isn’t Lindzen or Spencer territory. It’s just that she is plain wrong at an elementary level, with amazing regularity and stunning insouciance. Unfortunately if she really is as she claims, it’s a problem for the defenders of science. If one can have a successful ladder-climbing career in meteorology with the level of scientific sophistication she demonstrates, that doesn’t speak well for the quality control in meteorology. Look, I’m really rusty myself. I’ve spent half my career doing things other than science, and I’ve been stuck in a corner for five years meeting nobody in any capacity except as a blogger, and so though I am familiar with quite a few areas I’m not really ahead of a predoctoral grad student in any of them. But I can hardly read a paragraph from Curry about an actual scientific question without finding gobsmackingly sophomoric mistakes.”
Agnostic responds: “This jars somewhat. Please name 3 mistakes. If there is one in every paragraph it should be quite easy.”
Of course no response from Tobis. Here is an example of one of his brilliant takedowns:
The stuff that Tobis was so quick to criticize is now published:
So Chris, mt, and anyone else sharing this opinion, please provide me with an example of my sophomoric mistakes; to keep it topical to this thread, lets focus on the topic of feedbacks and the greenhouse effect. Saying an issue is complex, that there are uncertainties, and allowing a diversity of perspectives to be discussed should not be confused with making a “mistake.” It may be a strategic mistake in trying to win the AGW war, but these are not technical mistakes. If I have made a technical mistake, I would like to acknowledge it and fix it.
There are several people on this blog who routinely dismiss the work of others, and cite specific mistakes. When invited to do so they seem rarely able to detail what these mistakes actually are.
It seems to me that no matter how far up or down the climate food chain you are, if someone says you are wrong they should then detail the shortcomings in an intelligent and courteous fashion.That goes for Chris, Tobis or any of the others who frequent this or other blogs.
I think that Hunters comments above were excessive, and similarly other commenters here and elsewhere are routinely rude and arrogant for reasons that elude me.
I have had exchanges of private email with Chris and find him perfectly affable, but he seems to have a bit of a split personality when it comes to writing publicly on a subject he is obviously passionate about.
Probably because I’ve learned to tell who is serious about learning the subject and who just wants to point-score with repeated talking points.
I also don’t have the time to repeat my position about something to every person who asks, or to recollect every instance of my previous exchanges with Dr. Curry and where I agree or disagree. The wonderful thing about the internet is that stuff is kept on it as a permanent record (usually) for people who really care about the “who said what” game.
MT has actually provided an example of what he calls “sloppy thinking” on the page you linked (twice?). Let me start by saying that in my experience he argues dishonestly, taking any opportunity to misunderstand something an enemy says and twist it to “prove” some ideological point. He is the epitome of avoiding the principle of charity:
As I understand your Italian flag analogy it does seem to be mapping a two-dimensional function onto a single dimension. Like any simplification it leaves out important details, which offers him an opening to misunderstand it. Of course, he admits he doesn’t:
But that doesn’t stop from denigrating it as “sloppy thinking” rather than “sloppy understanding” on his part.
If he hadn’t done similar to me several times, I might be more open-minded about his criticisms, and even so I wonder if your analogy doesn’t actually have two referents. I have to admit with the number of unquantifiable issues I see with the modeling, I’ve pretty much skipped over the whole IF idea. My approach tends to be neurological: It’s all models all the way down into my brainstem (from my POV).
Looks like I messed up my link: Principle of Charity.
Chris Colose said to me
‘Probably because I’ve learned to tell who is serious about learning the subject and who just wants to point-score with repeated talking points.’
I sympathise- it happens on both sides of the debate. We have a couple of people here who continually parse answers to the thickness of Parma Ham-
When do you think the globe started generally warming Chris? Around 1900 as shown by Giss? Earlier?
I think stating that much of someone’s work is sloppy and unjustified, said work being plentiful and publicly available, without citing a single example, is sloppy and unjustified.
A Physical Realization of an Oxymoron.
Chris, my advice to you is to try to come up with something new and original in your work rather than always defending “the science is settled” meme.
Yes I disagree with Dr Curry too. She’s certainly right on the “dragonslayer” issue but is that enough to excuse her on what I would charge to be a disingenuous stance on the issues of uncertainty and risk? Her writings, in a previous personality, show that she understands the correct way to tackle these at least as well as anyone else. There is nothing she could have read in any leaked emails which, in any way, can have caused her to suspect she may have made an error in her previous analysis.
Judith is not like Prof Lindzen. She’s not saying climate sensitivity is acceptably low. If she were to change to sharing his opinion, she may well be wrong, but at least, if she genuinely felt it to be correct, her argument would be an honest one.
There is a lot of waffle, spin and propaganda here.
Regular readers of CE will know that Chris’s claim that
“Current climate sensitivity estimates generally yield a coherent picture of ~2-4.5 C per doubling of CO2, with very little chance of sensitivity at the low end of this.”
is false, since Nic Lewis’s post described how Forster and Gregory used observational evidence to get a median figure of 1.6C until the IPCC massaged their results with a prior assumption to get it up to 2.3.
Regarding nonlinearity and bifurcations it is not clear that Chris knows what he is talking about. He says nonlinearity is ‘of small significance’ but this is not true if we are talking about doubling CO2 (linearised equations are valid if the change is small). Furthermore, if there is a bifurcation in the system then nonlinear terms are crucial in determining what happens.
Finally, he still seems to think that radiation is the only mechanism of heat transfer.
You don’t seem to understand my views too well
Whose fault would that be?
Whose fault indeed?
Now, if we can just trust what we see…
you mean what others see
Paul – I believe your citation of Forster and Gregory 2006 is quite deceptive. If you read through the thread you linked to, you’ll find that Forster himself pointed out that his and Gregory’s updated analysis (I2008) yielded climate sensitivity estimates very much within the generally cited range. This has nothing to do with IPCC activity, since the 2008 paper came after the IPCC report.
Forster in fact refers to several papers with those same conclusions. Certainly, we can’t yet be absolutely certain of the limits of the range, but when all the data are looked at rather than selected examples, they support the range cited by Chris.
I apologise for reporting what Nic and the paper said, which was indeed quite deceptive of me. Next time I will remember to distort it to something the paper didn’t say.
Paul – My intended meaning was that it’s deceptive of you to selectively cite a paper discussed in a thread, when the author himself, in the same thread, reports that updated information yields a different conclusion from the one you report. It’s not FG-06 itself, but the cherry-picking, that I was referring to. It was actually an interesting thread, as were all the various papers cited, and readers interested in what Forster, Gregory, and others have done to estimate both equilibrium and transient climate responses might find it informative.
There’s an interesting ENSO development for this NH winter/spring…
Double La Nina is coming and some predictions are lower than -2.0 or even -2.5 in spring 2012.
So, temperature anomaly will fall.
to lower than -0.1 in 2012? Likely.
Natural variations? ENSO has longer cycles, still “unforced”? Sun is the player, climate is the harp. Solar system is the orchestra.
So we can be guaranteed of the continued global cooling trend of –0.1 deg C per decade: http://bit.ly/nz6PFx
I expect the cooling trend to get stronger in the near future (this decade).
@Chris Colose… (brought down from a thread above)
Thank you for an interesting article. I have some thoughts regarding:
A full list of his publications can be found here. The latest work, submitted (no info where), is quite interesting: Should the climate tail wag the policy dog?
Reviewing his home page, I find his specialty to be centered in “Meteorology and Climate Dynamics, Surface Processes, Glaciology, Paleoclimate, Mountain-belt dynamics.“. The paper you cited above (Roe and Baker 2011), is actually part of a discussion (debate?) between them and Zaliapin and Ghil (2010, 2011) regarding Roe and Baker (2007), and a disagreement over the relationship between large sensitivities and nearness to “bifurcation” points. Looking up Zaliapin’s publications, I find mathematical interest in chaos-related items, including climate. I would intrinsically expect a mathematician who studies chaos to have a better “feel” for this issue than somebody who studies weather/climate and earth sciences. Quoting from the abstract of
Zaliapin and Ghil (2010):
This resonates very strongly with me, despite possible reservations because the chaos the system demonstrates (to the extent it does) is intrinsically temporo-spatical.
There was discussion earlier about Science vs. politicization of science, this discussion seems to involve two different scientific opinions argued without reference to the political, social, or ideological perspectives of the scientists involved. Or am I wrong?
Roe, G. H. and Baker, M. B. (2007) Why is climate sensitivity so unpredictable?, Science, 318(5850), 629–632, doi:10.1126/science.1144735, 2007.
Roe, G. H. and Baker, M. B. (2011) Comment on “Another Look at Climate Sensitivity” by I. Zaliapin and M. Ghil, Nonlin. Proc. Geophys., 18, 125–127, doi:10.5194/npg-18-125-2011, 2011.
Zaliapin, I. and Ghil, M. (2010) Another look at climate sensitivity, Nonlin. Proc. Geophys 17, 113–122, doi:10.5194/npg-17-113-2010, 2010.
Zaliapin, I. and Ghil, M. (2011) Reply to Roe and Baker’s comment on “Another look at climate sensitivity” by Zaliapin and Ghil (2010), Nonlin. Proc. Geophys, 18, 129–131, 2011 doi:10.5194/npg-18-129-2011
AK – Thanks for returning to the ZG/RB argument, which is quite interesting and potentially important because of policy implications of extremely high climate sensitivities at the upper tail of the RB pdf.
I’m not qualified to issue decisive judgments on the debate, but I find myself somewhat sympathetic to the conclusions of Zaliapin and Ghil. Certainly, it would be comforting not to worry about a huge temperature jump (e.g. 15-20 deg C) from a CO2 doubling, even if the probability is asserted to be very small. The “fat tail” in the RB analysis retains that type of worry and so it’s appropriate to ask whether that high end of the pdf has the shape and amplitude Roe and Baker propose. In evaluating this, I’m assuming that these probabilities relate to statistical uncertainties in feedback behavior that is otherwise understood in a general sense – I say that because no-one can conclusively exclude the existence of unknown mechanisms in physics that would cause the climate to behave in a dramatically different fashion for reasons unrelated to known feedback effects.
For the statistical aspects, I see a strong case in the following argument in ZG-11:
To emphasize, however, a more fundamental issue with R&B’s arguments, let us assume that the linear approximation Δ R = Δ (1−f )/λ0 is actually true… RB07 state that “as is commonplace, we assume the errors in the feedback factors are normally distributed” (RB07, p. 631). Usually, the central limit theorem for the sum of random variables is invoked to assume a given variable is Gaussian. Why f would be the limit of such a sum, rather than the result of nonlinear feedback mechanisms, remains to be explained. Nevertheless, it is readily seen from Eq. (1) that using any broad and symmetric distribution of f will result in a distribution of the response ΔT to a ﬁxed change in ΔR that is strongly skewed towards large, positive ΔT
That seems to be the crux of the issue, or at least one of them, because a Gaussian assumption for errors in f is arbitrary, and making it creates a potential for extremely high sensitivity values for which I know of no physical basis, particularly in terms of moving f close to 1 (unless we are very close to a major bifurcation, which ZG deems unlikely). At the same time, the more likely values for sensitivity will not differ very much between RB and ZG, and the consequences of these probably deserve more attention than the extreme but highly improbable values.
Thanks for your thoughts, Fred. I wonder if you read the latest from Gerard Roe: Should the climate tail wag the policy dog? (I reproduced the abstract above.) Seems to me that he may not consider the “fat tail” a good reason for panic.
If I understand him correctly, he’s assuming a long settling time for this high sensitivity. IIRC there’ve been several discussions here regarding transient vs. long-term sensitivity, and perhaps that’s were we’re running into a problem with over-simplistic models.
Great post Chris – and a few more thought to contemplate.
In thinking about climate feedback sensitivity, it is important to keep in mind that climate feedbacks are not an observable quantity. Rather, ‘feedback sensitivity’ is a simplified interpretation describing what a climate model (or the real climate system) has done (as in completed action) between a well-specified reference state, and a second well-specified end state. And furthermore, climate feedbacks are not in any way direct or implied instructions that somehow act to instruct the climate model on what to do in response to some applied radiative forcing.
As noted, climate feedbacks and feedback sensitivity parameters are the analysis products of the simplified interpretation trying to make sense of the climate model ‘physics’ response to the applied forcing. Let me illustrate this by recounting the analysis of the doubled CO2 climate model experiments that were described by Hansen et al. (1984) http://pubs.giss.nasa.gov/abs/ha07600n.html
The ‘well-specified reference state’ is the control run reference equilibrium model. It is described by a global average annual mean surface temperature TS1, and the corresponding global distributions of water vapor, clouds, surface albedo, etc. (Since TS1 exhibits interannual (unforced) variability of order 0.1°C, TS1 is really an average over something like 5 to 10 years.) Model equilibrium means that however long the control run, for practical purposes, TS1 remains constant.
An instantaneous radiative forcing is applied by doubling the CO2 amount, which induces an instantaneous radiative forcing of about 4 W/m2. And the experiment model run is ready to go. From 1-D model results, or if the GCM is run to equilibrium by forcing its water vapor, cloud, and temperature gradient to remain unchanged, a global mean temperature change of 1.2°C us obtained. This is the same doubled CO2 radiative forcing of 4 W/m2 expressed in terms of a temperature change ΔTo = 1.2°C.
Model ‘physics’ is the set of ‘instructions’ that tell the model what to do at each grid box and each time step. The water vapor module responds to the ground surface conditions, and atmospheric temperature, humidity, and wind profiles that it sees at that grid box and that time step, and makes all the appropriate changes to the water vapor profile. It is not aware that the atmospheric CO2 amount has been changed, and does not care. Similarly, the cloud module responds to atmospheric temperature, humidity, and wind profiles that it sees at that grid box and that time step, and makes the appropriate changes as to whether current conditions require cloud formation. It also is not aware that the atmospheric CO2 amount has been changed, and does not care. The radiation module also responds to the ground surface conditions, and atmospheric temperature, humidity, and cloud profiles that it encounters at that grid box and at that time step. But the radiation module does see that the atmospheric CO2 amount has changed (actually it is only looking at the CO2 absolute amount, not the change), and it takes the CO2 amount that it sees and calculates the radiative heating and cooling rate profiles accordingly, at that grid box and that time step. The atmospheric temperature module takes the radiative heating and cooling rate profiles that it has been given, checks the temperature profile for convective instability, and readjusts the temperature profile accordingly, at that grid box and that time step. The atmospheric dynamics module does its thing in defining the atmospheric transport of water vapor, latent and sensible heat, geopotential energy, given the pressure, wind, temperature, and humidity that it sees at that grid box at that time step. It also does not know anything about the CO2 increase, although its real world counterpart would have noticed a very miniscule increase in the atmospheric gas amount.
The above cycle is then repeated over and over again, with small incremental changes being made at the ground surface and in the atmospheric temperature, water vapor, and cloud structure with each succeeding model time step – until it is decided that a new state of equilibrium has been reached, i.e., the end state. This is again recognized as the point in time where no further changes appears to be taking place in the global annual mean surface temperature TS2.
We now re-assess what all has transpired. In round numbers, the doubling of the atmospheric CO2 amount has caused the global average annual-mean surface temperature to increase by the amount ΔTS = 4 K. The global average annual-mean column amount of atmospheric water vapor has increased by about 30%. (There was also a change in the vertical water vapor profile.) There was also a global average annual-mean cloud top pressure decreased by 13 mb, and the global mean cloud cover decreased from 0.518 to 0.504. The global average annual-mean surface albedo decreased from 0.12 to 0.11. Also, the global average annual-mean temperature lapse rate changed from 5.9 K/km to 5.7 K/km.
What is to be made of all these changes? They all have radiative consequences. And, these radiative consequences can, by means of a 1-D radiative/convective model be converted to equivalent temperature changes. Furthermore, the 4 K temperature change that occurred in response to doubled CO2 must be fully explainable in terms of these structural changes that took place in the climate system in response to doubled CO2.
The results of this 1-D radiative modeling analysis showed that the global average annual-mean values in round numbers are:
(1) doubled CO2 accounts for ΔTo = 1.2°C
(2) water vapor change accounts for ΔTw = 1.6°C
(3) cloud change accounts for ΔTc = 0.8°C
(4) surface albedo change accounts for ΔTs = 0.4°C
(5) the surface temperature change is ΔTS = 4.0°C
The lapse rate change, which amounts to about a 1°C negative feedback, has been subsumed as part of the water vapor feedback since is the direct result of latent heat conversion.
At the time, it was thought desirable to identify and express the magnification (by feedback effects) of the global mean surface temperature change in the form: ΔTS = f ΔTo where f is termed to be the ‘feedback factor’. (Electrical engineers might well have preferred that f be call the ‘system gain factor’, but the digital electronics guys whom we questioned about the terminology, saw no problem.)
This analysis shows the overall model feedback sensitivity for doubled CO2 to be f = 4.0°C / 1.2°C = 3.33. The corresponding ‘feedback efficiency gain factors’ for the different feedback processes are:
(1) water vapor: gw = 1.6°C / 4.0°C = 0.4
(2) clouds: gc = 0.8°C / 4.0°C = 0.2
(3) snow/ice: gs = 0.4°C / 4.0°C = 0.1
The feedback efficiency gain factors add linearly (as if these feedback processes were linearly independent of each other). Thus, g = gw + gc + gs = 0.7. It follows directly from the analysis that f and g are related by
f = 1 / ( 1 – g ).
The meaning of the feedback efficiency gain factors is such that: e.g., for water vapor, gw represents the global annual mean water vapor response (of 1.6°C equivalent) to the global annual mean surface temperature change of 4.0°C (due to any and all causes). Similarly so for the other feedback processes.
It needs to be remembered that the above feedback coefficients were derived for global annual mean conditions, and are thus applicable only to those conditions. The same factors need not apply in the tropics and in the polar regions, or during summer as opposed to winter. In fact, the lapse rate component of the water vapor feedback efficiency factor is strongly negative in the tropics while being positive in the polar regions. Cloud feedback also is positive in the tropics and mid-latitudes, but is negative in the polar regions. (Cloud feedback is also strongly negative for thick low clouds, and strongly positive for cirrus clouds.) Globally, the water vapor, cloud, and snow/ice feedbacks are seen to be positive, i.e., they amplify the surface temperature change due to the CO2 radiative forcing.
These are the climate feedback results from 1984. If you find that the feedback sensitivity is much too low, or much too high, or that it is otherwise inappropriate, who is there to blame? You can of course blame the analysts. But they will likely respond that you are more than welcome to take the data and perform your own analysis as to how to make sense of the data. You could blame the radiation module. It is, after all, the one module that is informing all of the other GCM modules as to what effects the doubling of CO2 is causing. Or perhaps you can find blame with some obscure boundary layer module that treats turbulent energy transport at the ground surface, and might not be reacting properly to the radiative flux changes due to the doubling of CO2. It is really a sort of a Crime Scene Investigation in trying to decipher what actually happened, why it happened, and who it is that might be responsible for what happened.
We have checked for possible shortcomings of the radiation module. Numerous improvements have been made to the radiation module since 1984 (mostly minor in nature). It can now be shown to reproduced high-precision line-by-line calculations to within about 1%. The radiation module is not to blamed for model feedback sensitivity shortcomings. It is fair to say that all of the GCM physics modules have been significantly improved since 1984. In particular, the GCM cloud model has been significantly improved to treat clouds in a physically more realistic way.
With the latest GISS ModelE physics improvements, the global annual mean surface temperature response to doubled CO2 is somewhere in the range of 2.6°C to 3.0°C. From the foregoing, it should be apparent that getting any sort of a measure of feedback sensitivity verification from observations alone is going to be exceedingly problematic and difficult, especially since the time dependence of the climate system response is intertwined with the feedback sensitivity. Jim Hansen prefers to base his climate feedback sensitivity on the geological evidence of the observed CO2 changes, coupled with the temperatures and ice volume inferred from oxygen-18 variations in the polar ice and ocean sediment core records, as descried in his 2008 paper that infers a
3.0°C global annual mean surface temperature change for doubled CO2. http://pubs.giss.nasa.gov/abs/ha00410c.html
The results obtained in the recent cloud feedback studies by Spencer & Braswell and by Dessler are only as good as the assumptions that they make about the reference state of the atmosphere relative to which cloud changes are measured, and the ‘radiative forcing’ that is supposedly driving the cloud changes.
In an ‘equilibrium’ atmosphere that is undergoing natural (unforced) variability, there are observed substantial cloud and water vapor changes between the ‘hot’ and ‘cold’ years, with no readily identifiable changes in radiative forcing. If a cloud (or water vapor) feedback sensitivity is supposed to be the magnifying effect to an applied radiative forcing, how are we supposed to interpret cloud and water vapor changes when we have no readily identifiable forcing change?
So, it seems to me that climate feedback sensitivity can only be defined as occurring between a well-specified reference state, and a second well-specified end state in the limited sense as to how the feedback analysis is performed. As for observational verification, the closest we can come is to compare the climate model performance in how well the model simulations of water vapor, temperature, and cloud distributions agree with observations. If the model’s summer humidity is too high, and the winter humidity is too low, chances are that the water vapor feedback is going to be too high. Similarly for the seasonal and geographic variation of all the different cloud types. If any of them are too high, or too low, compared to observations, chances are that this will skew the cloud feedback.
I am currently in agreement with the general GISS thinking that paleoclimate is the best tool we have to diagnose climate sensitivity, in particular the LGM, but also responses witnessed during previous warm periods (PETM, Pliocene, etc) which suggest not only relativity high sensitivity but a prospect for important bifurcations which may be lurking in the system and are not well understood.
I also agree that observational tools (volcanic eruptions, radiation patterns over the last 10 years, etc) supplemented by simple statistical tools are extremely limited given the degree of internal variability in the climate system, non-equilibrium reference states generally considered, and modifications to water vapor, clouds, OLR, etc which are not “feedback” related. One of the chief criticisms of the original Lindzen and Choi paper for example were that his analysis was not robust to only slight modifications to the time intervals of consideration (which could be months). He’s made some changes, but the whole philosophy, as you note, is only as good as certain assumptions. To me at least, this can never be a predominant metric when thinking about the long-term response to 2xCO2. Of course. there are many tools in the toolkit for estimating climate sensitivity.
Isn’t the problem with using paleoclimate is that it builds in an assumption that the specific pattern of highlands (Tibetan, Andean, etc.), and for that matter ocean currents, can’t have an effect good for 10-20 degrees? I mean I’ve noticed the correlation between the general cooling since the early-mid Miocene and the conversion of a ocean floor convective zone (like the Andes) into the Himalayas and the Tibetan Plateau. I’ve always assumed this could well be the explanation for the cooling. (Not to say it is or course.)
A lot of the better paleoclimate estimates used (such as the LGM) are at times when continental positions/mountains were roughly the same as today, but there are of course deep-time people working on the problem as well (Dana Royer has some good work on this). Note also that even in deep climates, the critical issue is the temperature anomaly in response to a forcing, and thus the vital thing is not so much the different mean state, but the change from that mean state to the new perturbed state. The PETM, for example, happened in response to a large CO2 fluctuation which happened on a timescale far shorter than which plate tectonics is important.
For much longer timescales, when considering the trends in temperature (such as the Cenozoic cooling), changes in circulations and mountain uplift certainly have large climatic consequences (even if not globally, certainly on how how regional climates are distributed), and there’s a large literature on this of which I have relatively little background. In the 1990’s or earlier, there was debate concerning the importance of continental drift toward the Poles (which has been relatively minimal over the last 100 Myr). There has been some work discussing the role of greater poleward heat transport toward Antarctica before the formation of the circum-Antarctic current, work on the role of the opening of Isthmus of Panama, although these hypotheses are no longer favored for various reasons (for example, the Isthmus of Panama is offset by a few million years from the onset of glaciation). You’d have to take a course in this or do a literature review if you are interested in the evolution of ideas or all the technical details. The most favored way now to generate a Cenozoic cooling via mountain uplift is through carbon cycle feedbacks, notably a higher rate of CO2 uptake and consequent drawdown. There’s some debate into the technical details of how that works, but it’s the favored idea. Over longer periods of time, you also have to consider changes in the sun’s output (~ +7% per billion years)
“The PETM, for example, happened in response to a large CO2 fluctuation which happened on a timescale far shorter than which plate tectonics is important.”
PETM resulted from massive volcanic activity- which also created a lot of CO2.
“In the new study, detailed in the April 27 issue of the journal Science, the researchers linked the PETM to volcanic eruptions occurring from 55 to 61 million years ago. Back then, Greenland was still fused to Europe as part of one vast supercontinent, and the Northern Atlantic Ocean did not exist yet.
But the volcanism was only a trigger. All the greenhouse gas emitted by the eruptions and the ensuing cooking of organic matter would still not have been enough to cause the changes in climate and ocean chemistry seen during the PETM.
Other scientists have proposed the North Atlantic volcanism might have warmed the oceans enough to liberate methane trapped in icy sediments—called “methane hydrate”—on the ocean floor. ”
“Volcanic activity similar to that implicated in the PETM still occurs in regions like Yellowstone National Park and the Galápagos and the Hawaiian Islands. ”
Yellowstone is site of a supervolcano- not sure of Galápagos and the Hawaiian Islands. But there many sites of supervolcanos. And iceland seems more obvious example than Galápagos or Hawaiian islands, but anyhow.
“The PETM took roughly 100,000 years to peak, and it was another 100,000 years or so before the climate recovered. What triggered the PETM has been a topic of intense speculation by scientists. Theories have ranged from the extensive burning of peat and coal deposits to an impact by a carbon-rich comet.”
But basically most would agree that some major natural event occurred which also include greenhouse gases. Oceanic heating by major event gives us the CO2 and methane. But heating the ocean indicate massive amount of energy- a more energetic event than any that have occur in last few million years. And if super volcano of Yellowstone were erupt it could be quite minor in comparison to the event of PETM.
OOps, I un-nested my reply, here.
I ask you in all seriousness, could you provide a plot in the change of Tmin and of Tmax, in a grid in the center of the continental USA and in some where like Guam, in the middle of the Pacific?
I would like to know if you have bothered to examine the modeled change in two measured parameters, or if you just model (Tmax+Tmin)/2.
I agree with what you’ve said, especially the last paragraph
” If the model’s summer humidity is too high, and the winter humidity is too low, chances are that the water vapor feedback is going to be too high. Similarly for the seasonal and geographic variation of all the different cloud types. If any of them are too high, or too low, compared to observations, chances are that this will skew the cloud feedback.”
Andy – Your description is a very lucid exposition of the machinery involved in model performance – comprehensive but without the technical details that discourage readers lacking a strong background. Those details can generally be found at the website homes of various models.
It was particularly useful in dispelling the misconception that feedbacks and climate sensitivities are inputs in the model operation you describe. They are emergent properties. In this regard, can you comment about a different use of GCMs for “inverse modeling”, particularly regarding climate sensitivity estimates from paleoclimatologic data. Which values – forcings, parametrizations, etc. – are typically tweaked when they would not be for the climate projections of the type you describe above? Some of this is described in AR4 Chapter 9, but I would be interested in your “insider’s” perspective on this.
I believe that the climate GCMs are finally becoming useful as research tools with which to reconstruct and analyze past climate variations both within the historical time frame as well as in the geological time frame. The current effort is basically to fine-tune the climate model calibration in order to fully establish the modeling capability to reproduce current climate with adequate precision and with a reasonably complete documentation for all of the principal forcings and feedbacks.
At present, the greenhouse gas observational data and radiative modeling are fully accurate, water vapor and cloud feedbacks are probably accurate enough, but aerosols remain as the problem. There is an ongoing 3-way iterative interaction between analysis of satellite observational data, chemistry-transport model calculations of aerosol distributions, and GCM modeling of aerosol radiative properties (including accounting for relative humidity effects on aerosol radiative properties, and the atmospheric context for more self-consistent comparisons to satellite data).
There has been a bit of reverse engineering involved in checking the aerosol effect on the atmospheric temperature structure for compatibility with the observed atmospheric temperature profile and the amount of black carbon in the atmosphere. Also, there are substantial adjustments being made on the cloud-aerosol indirect effect to ensure optimum compatibility with a variety of observational, theoretical, and atmospheric temperature considerations.
The problem is that existing aerosol observational data are ‘definitive’ observations since the aerosol product entails the need for significant retrieval assumptions and ‘calibration’. The intrinsic ambiguity in ‘intensity only’ measurements requires assuming an aerosol type (composition). If the wrong aerosol type is assumed, the retrieved aerosol amount will be biased. This is where the chemistry-transport results in the GCM context can provide a consistency check for the assumed aerosol type in the satellite data retrieval algorithm. In this fashion, the aerosol data product and the model treatment of aerosols is improved.
This problem would have been resolved by now with definitive polarimetric measurements from the NASA Glory mission (which unfortunately crashed). It will probably take another five years for a replacement mission to get the necessary aerosol data.
The current best modeling estimate for climate sensitivity seems to be about 3 °C (or slightly less) for doubled CO2. Jim Hansen finds strong empirical support for this value in the 420,000-year geological record of ice-core GHG data that defines the radiative forcing and oxygen-18 data that defines the global temperature change, as described in Hansen et al. (2008) http://pubs.giss.nasa.gov/abs/ha00410c.html
With the GCM climate sensitivity reasonably well defined, we can start to look backward in the historical record to analyze the causes of past climate change. We can then look for what appear to be globally uniform forcings, like perhaps the Maunder minimum, to quantify the long-term solar variability. And we can look for regionally asymmetric climate changes that might be indicative of long-period ocean variability. At present, we don’t know enough about ocean modeling to anticipate the long-term variability modes of ocean circulation.
Modeling and measurement are strongly and synergistically intertwined. Observations without a model to interpret them have no real meaning, and modeling results without relevant observations have no basis in reality.
One outcome of the CERN CLOUD experiment was the very important role that chemistry and specifically the amount of ammonia had on the nucleation. This is one example of the importance of the composition of the aerosols that you mention.
Are the GCMs good enough today to make a an accurate prediction of future conditions that are important to policy makers? (Temperature and precipitation) at specific locations?
If I were to select say 25 locations around the globe and asked you to use the model of your choice to predict the temperature and precipitation with reasonable accuracy at these locations would you be willing to wager on the predictions of the model vs observations say 36 months from now?
“Cloud feedbacks are probably accurate enough”. That is a major point of contention, is it not? I buy much of your analysis, but clouds and solar effects (direct and indirect) are far from being well understood, “accurate enough”.
“With the latest GISS ModelE physics improvements, the global annual mean surface temperature response to doubled CO2 is somewhere in the range of 2.6°C to 3.0°C. ”
You realize this makes ModelE into a Lukewarmer!
What I saw in Schmidt et al’s paper is 2.6K and this is a decrease of 1.4K from the 1988 Hansen testimony. So lets see that’s a 40% change. I think that claims that its known to +-10% are clearly wrong. Look at Judith’s plot for the NCAR model. It overestimates the Delta T from 1900 to 2010 by 50%. In any other public policy debate, this would be a reason to urgently try to reduce the uncertainty.
Look at the validation of ModelE. It’s all about comparing to data that itself is pretty noisy. So, the numerical errors are large, the subgrid models are known to be wrong (think of convection), the data is noisy, but we should just say that “the results look reasonable and agree with the data.” Judith points out that they disagree with the data by 50%.
It looks like a case where we should urgently try to improve the science.
Chris, you make me nervous with statements like this:
Last I heard, methane was still in the running. I’m not saying it wasn’t CO2, rather that the notion that it was is a theory, not a “fact”. Maybe the most popular theory, but aren’t there alternatives that some experts still push? If the methane release had pushed things over a “tipping point” created by the configuration of the continents, CO2 could have been simply riding the tails of the warming.
It seems to me that you’ve built a paradigm, and started excluding anything that doesn’t fit it. What I wonder is if you’re confusing the language you’d use for persuading other scientists who understand the issues with language you’d use with skeptics who don’t understand the details but do understand how little is really certain in Science.
For instance, many (non-scientific) proponents of immediate action on “AGW” seem to believe that humans are descended from something that looked pretty much like a chimpanzee. That theory was finally falsified a couple years ago, and those of us skeptics who knew how little real evidential support there was for that theory have had a good laugh. I know I did.
But up until then, many scientists, even in the field were insisting that the human/pan common ancestor was pretty much chimpanzee-like.
MostMany of them didn’t express any doubt in their writing, peer-reviewed or blog. The parallels are certainly obvious to me, especially WRT paleo-, so I wonder…
I’m reminded of the saying that “If all you’ve got is a hammer, everything looks like a nail.” I know I’m not an expert in the field, but I’ve studied science as a (sociological) phenomenon enough to know that it duplicates the common human tendency to go overboard with new toys.
I’m highly skeptical of the value of trying to explain everything using CO2, and even more so of taking the results of that assumed explanation back into the modern models.
Sorry – improperly nested.
Very eloquent and patient.
“CO2 obsession” is how I describe the problem.
Nature has a ridiculous article about how ‘climate change’ is causing species to shrink. And the response of one well educate journalist I know was to state in effect, “if you do not like the idea, then come up with a better explanation”. not “check this out and see if it holds up under scrutiny”. Not, let’s see if this goes the way of so many other AGW related predictions.
No, just total acceptance and shut-down of critical thinking.
In fact,it would be interesting if you, as a biologist, would check into the article and let us know what you think of it, if I may be so bold.
Methane was probably involved too, but it tends to convert rather rapidly into CO2 in the atmosphere. But the reason CO2 is a building block of paleoclimatology (not everything, but the bulky tree trunk at least) is because it works, and it works after a lot of people have investigated it, criticized it, tried to interpret areas where it looked like a mis-match, improved data, etc. Richard Alley’s AGU lecture last year is still an articulate resource I point people too on this. It’s an emergent property of research, not an assumption… nor does anything about PETM/LGM/any other period sensitivity have any input into “assumptions” build into a model. Read Andy Lacis’ post above.
This might not work well with the crowd who believes that we can never know anything, and we minus well just arm wave about every topic. It might not work with the crowd who simply stick to 10 year old one-liners like “CO2 lags temperature! It can’t cause it!” that they picked up from a youtube video, without actually having read a single relevant study, or looking at any of the ice core data. These people claim they are interested in progress, under the guise of non-controversial talking points like “science is about testing things!,” yet they remain blissfully ignorant into the progress made in science since their worldview (that everything is unknown) allows them to justify it. And when paradigm shifts are occasionally made, they then sit there “laughing” and saying they knew it along, when in fact they had no clue, and were probably completely uninvolved in the developments leading to that paradigm shift. It’s a silly game serious people don’t have time for.
CO2 may have worked for some scientists’ reconstructions, but, it apparently hasn’t worked since about 1960!!!!
Since you didn’t give a link to that lecture, I will:
I made a point of listening to it all the way through, and what I noticed is that he that I never came across so positively as you did in your statement quoted above. For most of the lecture he sprinkled copious qualifications, and even in the end, when his summary clearly tilted towards advocacy, he quite specifically said that we’re not yet ready for “pound on the table” statements.
I’m perfectly willing to regard CO2 as the default hypothesis, and well supported for all the detailed scenarios that have been. I did notice that he specifically stated there were still some unknowns about the PETM, which had been my recollection, so I found that an interesting example for you to be so positive about.
Well, of course there are uncertainties; I’m not really sure you got the take-home point of the talk, which is that CO2 is a first-order agent in most of the geologic climate record, with a lot of uncertain details hanging off of that (but which a lot of progress is being made). Just because there are uncertainties doesn’t mean we can’t say a lot of things with high confidence, or rule out things that are completely unreasonable. I don’t understand why this is so hard to understand, or why people think they can just make up stuff since things are “uncertain.”
Oh, I do get it, and pretty much agree, to the extent I’ve actually dug into it. And I’m willing to treat alternatives as low-probability (except for something I’ve looked into enough to feel some confidence I understand what’s going on).
But IMO it’s a bad idea for scientists pushing reasonable alternatives to be marginalized, or excluded from publishing. Much less attacked by people who don’t understand science as
hereticsdeniers, just because they don’t agree. I haven’t seen Jeffry Schwartz being denigrated and called a “denier” for arguing that humans are more closely related to orangutangs than chimpanzees or gorillas. His theory seems to require throwing out much of what we’ve learned about DNA evolution, and I suspect he’s considered a “bozo” in some scholarly venues, but the vitriol isn’t there (AFAIK).
As for “making up stuff since things are ‘uncertain’” I certainly wouldn’t support that. However, are you trying to say that an amateur couldn’t come up with a good idea the experts hadn’t thought of?
One of the differences between science in practice and the storyline narrative of science in high school is that radical paradigm shifts by “amateurs” (which of course the community laughed at endlessly, only for the hard-working, tireless, and noble crusader to be vindicated, thus overturning all the textbooks) are extremely rare, and arguably non-existent in the more modern era of science. Science is also such that new ideas are tested rather quickly, and in the case of climate change, is a discipline with many different perspectives engaging from many different angles (theoretical physics, modeling, observations, paleoclimate studies ranging all timescales, etc). Thousands of people at universities, laboratories, etc are spending their life on the problem. People screaming “Galileo” and citing a couple of exceptions to my above statement from decades or centuries ago as some sort of evidence that everything is going to be overturned tomorrow night in climate is not convincing, and more often than not only gains points on Baez’s science crackpot index
Instead, science takes a similar form to Alley’s talk, with a storyline, small details following from the development of the “big picture,” a constant refining of those details and how they project onto the big picture, and with independent pieces of evidence converging to a best answer. This involves substantial disagreements and debates within the literature by people who understand the basic details, and are working to refine the fine details. This is often done by many independent groups attacking the issue from many different perspectives, and indeed this happened with the “CO2-theory” of climate change a century ago, following the history of outcasts like Arrhenius and Callendar, until finally after the spectroscopy work of Plass and the modeling of Manabe/Wetherald, the carbon cycle work of Revelle and Suess, or the observations of CO2 by Keeling, and worldwide temperature measurements, and substantial developments in understanding water vapor feedback, etc made it undeniably clear that those who think CO2 does not have a large impact on climate are simply wrong. There are thousands of journal papers investigating all of things, and I would bet a lot that youtube videos or blogs will not alter the big picture. At best, they might provoke a few studies of little consequence.
No one is trying to cut off dissenting views, in fact they are encouraged, and this is what Lindzen or Spencer has been doing. In the case of Lindzen, he had a hypothesis in the early 90’s that water vapor feedback was negative. It was tested, and further improvements in observations, theory, modeling, etc came about and was shown to be invalid. Lindzen backed off from this idea, and then went on to suggest that high clouds provided a negative feedback to rising SST’s in the tropics. That was tested too by the observational specialists over the next few years, as well as by other theorists, etc, and became widely rejected by most in the community on a number of reasons. All of this “debate” was beneficial for the science, and is encouraged, and for the most part took place cleanly within the academic literature. He continues to push with his negative feedback ideas on faith it will work, most of which is backed by poor methodology and extremely odd views outside the refereed literature, which is why a lot of people don’t take him serious anymore. Of course, MIT can’t get rid of him, so we’ll probably be stuck with it until he retires.
Yeah that MIT, pfft!
What do they know?
You write about accepting things based on faith and that seems a reasonable description.
It seems that we are expected to agree on faith that we know what the worldwide impact of additional CO2 will be to the climate. We certainly do not have any GCM that can accurately predict temperature and precipitation at a regional level as a function of atmospheric CO2 do we?
Based on not having ANY verifiable information of the models outputs vs. actual observed conditions of the environment it seems like little more than faith to accept some of the conclusions written about potential harms to humanity.
I divide my time between here and John Baez’s Azimuth site, which is rareified air for the mathematically inclined. Doing the citizen science thing, I walk the crackpot line myself and you really can’t avoid it unless you simply volunteer ideas nonchalantly. The Galileo persecution complex indeed.
Interesting post, AK – and the link above to “Should the climate tail wag the policy dog?” in interesting also.
That said – I’m struck by this part of your comment:
I hope you don’t think this is too off-topic – but I think you did open the door by referring to “proponents of immediate action on AGW” who believe(d) a theory for which there was little evidential support, and skeptics “who understand how little is really certain in Science” (why the capital “S?”) and who laugh at theories that have little evidential support.
What do you think about the “evidence” for Intentional Design, and what do you think about “skeptics” who believe that Intentional Design is a “major scientific theory” for which there is “scientific evidence?”
ID, whether “Intentional Design” or “Intelligent Design” has nothing to do with Science. It’s just Creationism with the serial numbers filed off. All the “evidence” for the notion is based on arguments from ignorance: “We/you can’t explain in detail how natural evolutionary processes could produce this, therefore it ‘must’ be something outside nature”.
Assuming ID, for the sake of (essentially pointless) argument, the most parsimonious explanation is that the occasional tourist from elsewhere in the Galaxy dropped in an played around with some sort of DNA manipulator, of the sort we’ll probably be able to make within the century, if not within the next couple decades. If somebody would only make a movie about it (e.g. palaeontologists dig up remnants of what’s clearly a badly damaged spaceship of some sort from, say, the middle Triassic, with a resulting controversy about ID) I’ll bet most of the impetus for ID would go away. Most ID proponents are looking for “scientific” confirmation of their religious impulses. A clear case of motivated reasoning.
My question wasn’t WRT your opinions about ID, but about your opinions about “skeptics” in general based on the fact that there are some “skeptics” who believe that ID is an “important scientific theory” based on “scientific evidence.
It seemed to me that you were willing to make generalizations about “proponents of immediate action on AGW” based on the existence of some people who fit that description believing theories that aren’t well-founded on an evidentiary basis. Obviously, I’m speculating that there is an unevenness in your willingness to generalize about an entire group on the basis of one attribute of some % of the members of that group – and I’m checking to see if that is the case.
“Skeptics” who are open to “ID” either don’t understand Science or are skeptical of it. I’m certainly willing, myself, to step outside the bounds of Science and, for the sake of discussion, postulate e.g. “spiritual” powers that intervened in evolution, human history, or the like. I don’t bring such discussions into a basically scientific venue like this. Similarly, if people want to oppose some specific action(s) out of some belief in “spirits”, that’s their option, but it shouldn’t be allowed to interfere in a scientific discussion.
Creationists (including proponents of ID) who come into a scientific discussion usually just pollute it. I suppose that doesn’t mean they can’t be skeptics, about Science in general.
I think you’re still not responding to my point.
As I see it, you characterized “proponents of immediate action on AGW” by virtue of a certain subset of them believing in a theory that isn’t based on scientific evidence.
Am I wrong about that? If not, then do you make a similar categorization of climate “skeptics” based on a subset that believe in a theory that you think is not based on scientific evidence?
See my comment here. It’s not an unscientific theory, it’s an obsolete theory. If people who “believe” in it aren’t willing to change their views when confronted with the evidence (do I really need to dig up a link to the discussion?) then their attitudes aren’t scientific. Part of the reason (IMO) is the too positive attitude of scientists who know better.
I asked you about your willingness to generalize about “skeptics” based on a subset of them who think that ID is supported by “scientific evidence” – even though you think that it is not.
Ok, it looks like I’m not going to get you to address the question I’m asking.
I can’t tell if I answered your question in the other thread or not.
I try not to generalize about anybody without caveats. I’m not going to hold skeptics who have one religious belief responsible for what skeptics who have another say. In fact, I try not to hold anybody responsible for what anybody else says. Of course, if people show voluntary “solidarity” with others who behave badly, or express/act on an opinions I find repugnant, I may hold all the “solidaritizers” responsible for what any of them does whom they do not repudiate. This applies to
bothsides of the political climate question.
This applies to
bothsides of the political climate question.
This applies to
bothall sides of the political climate question.
Making too many mistakes. Time to sign off.
“Most ID proponents are looking for “scientific” confirmation of their religious impulses. A clear case of motivated reasoning.”
Interesting. What drives the agnostics and atheists to look to ID for answers?
You do realize that the alien scenario is apparently the one that Dawkins favors at this point (as long as the aliens EVOLVED) due to the extreme lack of plausible evolutionary evidence on earth??
No, I didn’t know, I don’t follow Dawkins. I know I find the idea of lonely little RNA molecules discovering replication in a black smoker very unlikely. Not completely implausible, but I can think of at least one scenario (actually a large bundle of related scenarios, of course) that IMO is much more plausible.
Any plausible theory that includes a likely explanation why no evidence is left, or the evidence that is left is easily mistaken for something else (non-biotic or modern-style biotic), belongs in the running. As we come to understand complexity theory better, or perhaps the implications of complexity theory in pre-biotic organic chemistry (or perhaps vice versa), I expect more plausible theories will start to show up.
IMO a retreat to deus ex machina represents a lack of confidence in human ingenuity.
You will have to watch the movie “Expelled” as it was a videotaped response by him to questions about evolution and the beginnings of life that evolutionary theory does not address. I think he may be trying to modify this bald statement since the movie was released.
Notice Dawkins claims that he was conned into being interviewed for a different purpose. With all the bluster and accusation of the post he never seems to get around to explaining his bald statements that were videotaped complete, in context.
As I have read, and you can find on the net, there is a rather wide interpretation of the actual situation where Ben was questioning Richard until the statement was made. Some try and claim it was speculative and not what Richard believes. I find those comments silly. Hypotheses are speculative. The fact Evolution has been accorded theory status does not mean it isn’t still speculative in part.
You will have to watch and evaluate it for yourself. Evolution offers no answer for the beginnings of life, and facts on earth offer no confirmation for the increase in complexity Evolution is alledged to have caused. With those issues on the table Richard punted with the “Evolved Aliens designing us” speculation to salvage Evolution!!
That is my story and I am sticking to it!!! 8>)
Some other time. It’s off-topic here.
something like this?
Joshua, One book says…it’s in the air too.
This equals “favors?”
“even if the alien life form was itself seeded four billion years earlier, the regress must ultimately be terminated (and we have only some 13 billion years to play with because of the finite age of the universe). ”
I would point out that he himself believes that there simply isn’t enough time for the hypothesized Evolution to have happened on earth else this statement is simply pointless.
“even in the highly unlikely event that some such ‘Directed Panspermia’ was responsible for designing life on this planet, the alien beings would THEMSELVES have to have evolved, ”
“My point here was that design can never be an ULTIMATE explanation for organized complexity.”
He is still not offering his FAVORED method for our existence much less the start of life so your response is inadequate, unless my statement is valid that he favors our creation by EVOLVED aliens (aliens being a broad term but apparently excluding religious Gods).
“Organized complexity cannot just spontaneously happen.”
What?? So SOMETHING CREATED ORGANIZED COMPLEXITY?!?!?!?!
“even in the highly unlikely event that some such ‘Directed Panspermia’ was responsible for designing life on this planet, the alien beings would THEMSELVES have to have evolved, ”
But you suggesting that no intelligent life can ever control time?
I would say it’s a law, but laws could possibly be broken. I mainly believe this because I believe we know very little about this universe- rather than think we know almost everything.
I don’t believe space aliens have visited Earth in last million years,
but if anyone think such thing is possible and don’t believe time can controlled, that seems to be contradiction.
I believe that there are probably about 1000 intelligent civilization in this galaxy. Which means there could trillions of civilizations in this universe.
If there is 1000 civilizations in this galaxy, then it’s seems unlikely that Earth [sol system] has visited in last million years.
If there is not say 10 or more civilization in the galaxy, it seems that evolution can’t explain why we are here. If there is only one intelligent civilization in this universe. God seems the only possible answer why we are here.
Finding another intelligent civilization in this universe doesn’t disprove a God- but having no other seems about as good a proof one could expect.
Very interesting. So what happened to the missing heat? Still missing?
I think the argument of the Earth being a stable system so therefore positive feedbacks are less of a factor is pretty weak. Consider that in addition to stable and unstable systems, there is the idea of a metastable system. By metastable, the meaning is that you don’t necessarily know which way it will go when you enter a state but once it starts in a certain direction it will keep its inertia for some time. The other thing that commenters don’t seem to understand is the fact that metastable systems can also cycle between asymptotic rails and don’t necessarily go completely open-loop and runaway.
With that in mind there is probably a lot to be learned from the Vostok ice core and other historical data. IMO the data suggests that it is easily could pass for a metastable system that likely follows the positive feedbacks of CO2 outgassing in the ocean for both temperature directions. The upper limit rail being the need for greater amounts of CO2 than the activation energy from ocean water can provide.
Take a look at the argument and the charts in this link I put together over the weekend:
Not enough people are doing real model-based exploratory data analysis. It might be possible to find hysteresis effects and other clues to what is going on just by plotting the parallelogram-shaped diagrams as Chris Colose has done. Check the CO2 versus temperature that I mapped here:
It would be neat to actually plot the back-and-forth swings and perhaps narrow down on the activation energy or perhaps extract the climate sensitivity.
Its strikes me that the clash between scientists and rejectionists on the AGW isn’t just a matter of normal debate and that ‘clash’ is really the correct term.
Scientists generally adopt an inquisitorial approach. Rather like the legal systems of France, and other European countries, where the court is set up to investigate the facts of the case rather than take particular sides on an issue. But, of course in the end they do tend towards a common view, just like climate scientists on the AGW issue.
Rejectionists are certainly not of this mindset. They have clients in the dock, CO2 and other GH gases, and like a defence counsel they’ll use any and every possible argument to get them off. They don’t necessarily have to believe them themselves, and indeed many of them will be contradictory, but no matter , if they’ll possibly sway any of the jurors then they are fair enough.
Does that sound about right? Is there ever going to be any resolution of the issues through rational argument? Is it even possible, under any circumstances, that defence counsel would ever say they’ve been convinced by the evidence, and they are now changing their plea to ‘guilty’?
“Rather like the legal systems of France, and other European countries, where the court is set up to investigate the facts of the case rather than take particular sides on an issue.”
This gets it exactly backwards. In the European countries where the court conducts inquiries, the court most directly is taking a particular side in the case, that of the government. The judges or magistrates manage the prosecution, causing charges to be brought.
It is in the American system where the court is designed as an objective arbiter between the conflicting parties. The court does not originate or participate in a prosecution, thus is in a better position to be objective.
It is no surprise that a CAGW true believer sees the government as not “taking sides” in a prosecution, just as the CAGW consensus advocates are only pursuing pure science, the results of which just happen to coincide with the political aims of their governmental funding patrons.
I like the way you brazenly attempt to stake out the moral and intellectual high-ground, by characterizing the ‘clash’ as being between the scientists on one side and the rejectionistas on the other. You are funny. It’s not really working for you. Are you hopeful that Kyoto will be re-affirmed, renewed?
Your analysis misses a key point.
You describe “scientists” as if this were a united bloc, who fully endorse the IPCC premise that AGW is a serious threat.
It is NOT a battle between “scientists” on the one hand and “rejectionists” on the other, as you naively paint it.
It is a dispute “among scientists” – some of whom support the IPCC premise and others who do not.
(The “science” is NOT “settled”.)
You’d like the dispute to be amongst scientists but it isn’t. For every one who may agree with Lindzen there are a hundred who would agree with Chris Colose. You don’t have a single uni department or a single climate organisation in the world who would agree with your line that AGW is something insignificantly small. Much less would they agree with your claim that its all a hoax.
Even Judith daren’t quite say AGW can safely be ignored although she may secretly like to.
You bring up a fully unsubstantiated “1 to 100” claim.
Eli Rabett and Senator Inhofe have (unwillingly) collaborated to produce a list of some 220 qualified scientists, who have openly stated their disagreement with the IPCC conclusions.
I do not believe that you can produce a list of 22,000 qualified scientists who have openly stated that they do support these conclusions.
And, more importantly, it is not the number of dissentlng scientists that is important, it is the fact that there are scientists, who do not accept the IPCC conclusions on AGW, so your initial premise is false.
Speculating on Judith’s thoughts is silly. She is quite capable of expressing them herself.
It strikes me as a bit pitiful that you are suffering for some sort of dyslexia or other cognitive dysfunction that makes you unable to recognize that many skeptics are also scientists.
It reminds me of that book about the guy suffering from a brain trauma who mistook his wife for a hat.
I hope you can come up with a way to compensate for your disability and join in with some rational comments.
I am glad to see that this has come down to paleoclimate estimates again, because it seems to me as an outsider that this is even more implausible than the models. Let me just posit some things and have you correct me.
1. The difference between the LGM and our current relatively warm climate is a change in the meridianal distribution of solar forcing and not a change in total forcing. This would seem to imply an almost infinite climate sensitivity if it is naively defined as a ratio of temperature change to total forcing change.
2. It strikes me as implausible that one could accurately estimate such things as aerosols for the LGM when conditions were so outside our current experience when we can’t even estimate it for the current climate to within 2 W/m2.
3. Things like ice sheet albedo must be even more uncertain. Albedo varies locally for all sorts of reasons which it seems to me are impossible to determine 10000 years later.
4. The Roe and apparently Colose doctrine that we are in the linear feedback range can hardly be inferred with any confidence for the LGM. Even supposing that climate sensitivity could be infered for that time, what possible rationale could be used to argue that it applied to today’s climate?
5. I am fascinated by the implications of the admission that climate sensitivty estimates must rely on paleoclimate. Andy gave us an excellent description of the complex modeling process. If we don’t trust models whose parameters can at least in principle be correlated with current data and at least in principle (but not in reality unfortunately) be made numerically accurate, how in the blazes can we trust extrapolations and inferences about small effects operating 10000 years ago.
My credulity is sometimes suggested by my wife to be too high, but even I see this as a ridiculous idea. Of course, I’m open to explanations of why I am wrong.
We may not nearly undestand the Last Glacial Maximum as you think we might, especially when we don’t cherry pick data and information.
Check Hubberten et al 2004,
check page 1339 (7 of 25) fig 6 leading to the comment on the next page:
“That definitely indicates lower summer temperatures than in the Middle Weichselian, but still warmer temperatures than today are indicated
by the occurrence of some thermophilic plant species (Kienast, 2002).”
So what would that say if our understanding is that the LGM was oh maybe 10-15 degrees C colder than today?
That paper is interesting! Thanks. We don’t understand anything as we think we might. So much room for science!
Sorry, I forgot to mention vegetation and its effect on albedo.
You know, the whole Mann vs. McIntyre controversy had to do with reconstructing temperatures 1000 years ago. The main outcome to me is just how unreliable and contradictory the proxies can be. Tell me again why we believe estimates of much smaller effects for 10000 years ago when where I am sitting was buried under 2000 feet of ice and the vegetation profile of the planet was totally different than it is today?
You have put your finger on it. With all the alleged knowledge, computer power, instrumentation, satellites, radiosonde, fancy buoys, $BILLION$, to gather and interpret modern era data, the climate scientists prefer to determine climate sensitivity, by reading paleoclimate tea leaves. What is the matter with the data from 1880 (or pick a year) to present? No climate sensitivity there?
Some of your concerns are valid (especially 2 and 3) and are widely discussed in the literature, others aren’t. The non-cryosphere albedo (including dust and vegetation) changes however are small relative to estimates of the total forcing, so I do not envision this as an extremely significant consequence to the method (see e.g Kohler et al 2010 for discussion of all this). There are also warm paleoclimates to sample from, and all this work (plus modeling, and observations) all seem to converge on similar answers. Putting faith in an extremely low sensitivity only for the anthropegenic era seems a bit too religious to me, but that’s me
Why don’t you tell us what climate sensitivity is in the anthropogenic era?
You ask Chris Colose:
The reason why Chris does not want to answer your question is real simple:
The record since 1850 shows a 2xCO2 temperature response of 1.5 degC if we accept IPCC estimates that 93% of the forcing was attributed to anthropogenic factors and that these = forcing from CO2 alone.
If we accept the conclusions of several independent solar studies, which attribute 50% of the warming to the unusually high level of 20th century solar activity (highest in several thousand years), the 2xCO2 response is 0.8 degC.
These figures are too low for Chris, so he prefers to ignore them.
Yes, they can tell us the average temperature of the earth (adjusted) down to about 9 decimal places, but they can’t find their missing heat. And they have to reach back into murky antiquity to divine a number for climate sensitivity to CO2, that justifies their doomsday prophesy of a World fried by fossil-fueled capitalist demons .
See my later post on this. (Sorry, its a few posts down). I forgot to press the reply button.
My own thinking follows here basically the same lines as yours. That may be due to my very lacking knowledge on the details of paleoclimatic research, but I this is an area, where I believe that generic caveats are essential and high level of skepticism justified.
Interpreting paleontological data is certainly a field of study where the existing paradigm and preferred narratives affect the research very much, but have a high likelihood of being erroneous in some important ways. This is an inherent and fundamental problem that cannot be resolved. Here we enter the world of unknown unknowns, where estimating the accuracy and reliability of results becomes extremely difficult, if not impossible. There’s enough freedom in building the storyline to allow for reaching wide agreement with data with a seriously faulty interpretation.
It’s always discouraging, when people conclude that best evidence is coming from the most deficiently understood sources – or from sources that they themselves know least and for which they are most dependent on authorities. It gets even worse, when the most influential authorities are exceptionally eloquent.
Thanks for some very insightful thoughts on the shortfalls of interpretations of reconstructed paleoclimate data.
I realize a number of people here will laugh at me, but, here is another rather important issue.
Immanuel Velikovsky researching early civilizations found that they all had 360 day years. These are civilizations alledgedly without communication and using instruments similar to crude astrolabes to track the stars and navigate. They also had reasonably accurate devices to keep time outside of the astronomical observations. With the accuracy of their measurements there is simply no way that they would be shifting their calendars by 5 days every year to keep them in synch with planting etc. Their records show they had 360 day years for a long period before changing them. In less than one hundred years, using the same methods, they all computed years of 365 days 5 hours. Claiming that all these civilizations somehow lived with the same mistakes in observation and computation and then changed to an accurate method so closely together in time, which appears to be the same method as the original, simply boggles the mind. I would point out that he showed they recorded changes in the moon and Venus orbit also. This has been ignored as simple mistranslations or errors by historians and archaeologists as they could not accept the possibility of a catastrophe(s) actually changing orbits.
This would seem to show that the earth DID have a change in orbit where it became 5 days longer. How much change in insolation would this cause?? How much would it change the early dim sun assumption compared to current? We can also wonder if the tilt was also changed by any amount at the same time!! It would seem that the current north star was not always recorded as the same star. Again, how much would that change the assumptions used to evaluate the paleo data compared to current conditions?
I’m not putting faith in anything. My point is that we don’t know and we had better get busy and find out since the team wants to totally redefine how we live our lives. You know, biofuels are raising food costs. This has consequences. As fuel prices go up, a lot of people suffer. If I went to an executive or to my brother with this kind of implausible stuff I’d be summarily told to get my facts and data straight and then come back.
Part of the problem, and I find the denial of this unethical, is that the climate science community is not very concerned with admitting the problems and fixing them. They can’t even convincingly refute a retired statistician who does this in his spare time.
Sorry, but you bums who are trying to paint skeptics as bozo religious fanatics are just stupid, disingenous punks. I am talking in particular about you Joshua, and Chris Colose.
I’m not trying to paint “skeptics as bozo religious fanatics.”
I assume that you’re referring to my question to AK?
In his post, it seemed that AK was drawing some line of distinction between “skeptics,” as a group, and “(non-scientific) proponents of immediate action on AGW,” as a group, on the basis of belief that humans descended from something that pretty much looks like a chimpanzee. So my question to him was to see whether, assuming my reading was correct, he draws some line of distinction between “skeptics” and “proponents of immediate action on AGW” on the basis of belief that a supernatural force controls evolution.
My belief is that “skeptics,” and those who are convinced that at least 50% of recent global warming is 90% likely due to anthropogenic CO2, are equally likely to be influenced by motivated reasoning, confirmation bias, etc., in how they interpret scientific evidence (or the lack thereof) regarding various theories they are predisposed to believe.
No, Joshua, I wasn’t
comparingcontrasting proponents of AGW action to skeptics, I was pointing out a fallacious attitude towards Science among them: the failure to distinguish between a scientific theory and something pretty much indistinguishable from from religious “truth”.
AFAIK there were very few people who were specifically skeptical about the nature of the common ancestor, however there were some scientists as well as an unknown number of amateurs (including me) who really understand evolution who had actually considered the evidence pro and con. The reason for laughing wasn’t that a theory had been proven (probably) wrong, but the positive attitudes of scientists and bloggers about the now falsified theory.
I seriously doubt that any significant number of people who bring their religious prejudices into Science understand evolution well enough to understand the issues.
<…No, Joshua, I wasn’t comparing contrasting proponents of AGW action to skeptics, I was pointing out a fallacious attitude towards Science among them:
With “them” being proponents of AGW action – or “them” being both groups?
Assuming it was the former, why were you singling them out in that respect, as distinguished from “skeptics?”
Also, just for my information – why are you capitalizing “science?”
“Them” being some proponents of AGW action (I know, “among” could mean some or all, but if the shoe doesn’t fit, don’t wear it). I’m singling them out because they invoke (sic!) “Science” for their opinions of AGW, then show they don’t understand “Science” at all.
As for why I’m capitalizing Science, I’m using it as a proper noun (sensu strictu), to distinguish from science (sensu latu) which derives from the (essentially) identical Latin word best translated as “knowledge”. People use the word in a variety of ways, and I’m trying to keep focus on knowledge (theory, not “fact”) derived from some version of the Scientific Method.
“It might not work with the crowd who simply stick to 10 year old one-liners like “CO2 lags temperature! It can’t cause it!” that they picked up from a youtube video, without actually having read a single relevant study, or looking at any of the ice core data.”
You are back in your “Young Scientist” mode with the arrogance, sarcasm and BS at full blast.
We physicists looked at the GISP, GRIP, DYE and Vostok ice core data and saw what you and Richard Alley apparently missed. Temperature does lead CO2 concentration.
We also continue to believe that cause precedes effect in spite of a few super luminal neutrinos on the road to Gran Sasso.
We physicists looked at the GISP, GRIP, DYE and Vostok ice core data and saw what you and Richard Alley apparently missed. Temperature does lead CO2 concentration.
You mean temperature can lead CO2 concentration. While I don’t have any mandate to speak for Chris and Richard Alley I would guess they share this view, and I’m pretty certain they have also looked at the GISP, GRIP, DYE and Vostok ice core data.
Since it is clear that CO2 is not a thermostat driving climate throughout Earth’s history, as has been claimed many times, can we drop that line now?
So then explain everything else about the Vostok data then, such as the asymmetry of rise vs fall, the upper and lower limits, etc. That would be nice stuff to know as well.
Read what I said downwthread. Since you are a physicist, you should be intellectually curious about this stuff, and you should be able to give a hand with analysis.
Right now, I want to get temperature and CO2 data that has a similar resolution. The temperature has a much finer interval than the CO2 concentration.
In the meantime, I will devise some other interesting exploratory data analysis approaches on this data.
Many beleivers seem to cycle through a series of arguments taht nearly always center around dismissing skeptics without actually speaking to the issues they raise and demanding that skeptics be silent or be silenced, depending on how emotional they have gotten at that particular moment.
Read your response to Chris’s piece earlier in this thread and then re-read what you just wrote.
Cause and effect are an artifact of the human brain.
What Chris Close, and Richard Alley, are saying is that there are both mechanisms in which rising temperatures produce a (lagging) increase in atmospheric CO2, and at least one mechanism (Greenhouse Effect) by which increasing atmospheric CO2 causes increasing temperatures. This produces a feedback so that an increase in CO2 from other sources (e.g. vulcanism, fossil carbon) causes a rise in temperature that’s magnified by feedback caused by CO2 released due to higher temperatures.
In the Vostok cores, what they’re saying we see is a thermal process as the first step in the feedback loop: changes to Solar irradiation cause reduced ice caps, causing increased temperature, which is magnified by CO2 released due to increased temperature.
What I see looking at a rough graph of temp vs. CO2 is a very large amount of noise, probably at many frequencies, that I would intuitively attribute to many different sink/sources with different response curves and lag times.
Why do that when you can look at the processed data? See elsewhere in this thread so I don’t have to repeat myself:
Unless I’ve misunderstood your charts, you’re just looking for lags vs. leads, and finding mostly lags. That’s appropriate for a feedback with thermal forcing.
I’m more interested in teasing out the separate sink/source objects, each with its own response curve and lag times. The first thing I’d want to do is correct somehow for the Milankovitch forcing. There are both differences and similarities in those four peaks, and if possible I’d like to figure out which differences are likely due to differences in Milankovitch forcing, and which might be due to other causes (e.g. landscape changes). If those could removed from the signal, and the peaks merged, we might be able to tease out a few (say 2-12) major sink/source objects with different response curves, which we could then look for in the geology/oceanology.
But in all this, I don’t see any reason to question CO2 as a (perhaps the) major driver of temperature.
Give it a shot.
I think the real eye-opener in all of this is understanding how the rate law outgassing feedback merges into the climate sensitivity feedback as in this figure.
The rate laws follow this kind of Arrhenius activation energy curve:
C ~ exp(-E/kT)
while the climate sensitivity goes as T ~ alpha * log(C)
When those two curves match is when the temperature stops climbing (I don’t care as much as cooling for the moment). Now introduce another CO2 forcing function, a huge one from fossil fuel emissions in fact that occurs over a relatively short time period.
The steady-state point now shifts and it moves up the sensitivity curve. Look at this figure:
This really explains the paleo data and what we have in store for us right now. I think this is a very simple analysis, similar to supply and demand curves or for establishing quiescent points, and don’t know whether it has been overlooked or not.
If one Googles “CO2 temperature lag” one gets hundreds of hits, which are either originals or copies of RealClimate, Grist, SkepticalScience or other “pro-AGW consensus” blogsites, all defending the notion that “CO2 is the driver of temperature, even if temperature came first because…”
There are also a very small number of hits to articles that dare to question the orthodoxy and dig a bit deeper into the story.
Here is one:
The “which came first: CO2 or temperature?” debate has been going on for some time.
Chris Colose tries to simply shrug it off (see above post).
I would submit that there is no more enthusiastic or convinced supporter of the “CO2 control knob” premise than Dr. Richard Alley.
This question came up at his now-famous “CO2 control knob” lecture at the AGU meeting on 15 December 2009.
Interestingly, Alley did not respond with any specific scientific explanations for the time lag dilemma, but rather started talking about his credit card debt and interests, instead.
This, in itself, told me that there is more to the story than meets the eye.
What’s so essential in that?
There has certainly been some positive feedback between temperature and CO2, but fortunately that’s not so strong that it would make the present climate unstable.
Learning more about the cross-influences and past feedbacks adds definitely to the understanding of the Earth system, but the whole issue is of very little direct relevance to the present climate issue.
I wonder… I wonder if the 2-3ppm (IIRC: I’m not going to re-listen to be sure) signal found by Murry Salby might not be just that (or part of it). Thus the multi-year (ENSO?) might be temperature driving CO2, while the underlying multi-decadal signal (in CO2) might be driven by human emissions, along with a small amplification due to temperature feedback.
If so, we might hypothesize that the short-term signal represents net flux into and out of a pool (sink?) somewhere, and what’s the possibility we can modify the parameters of the process to increase the flux into the pool for any temperature? Assuming, of course, that we don’t overflow the pool’s banks. And how big is the pool?
It seems to me that until we know exactly why the short-term signal exists, we can’t be sure there’s an opportunity to deal with the problem quickly and easily.
One good place to look might be arctic and sub-arctic peat bogs.
The main stream view as described in the IPCC reports agrees with Salby on the point that weather drives the short term (year to year) variability in CO2 concentration. The disagreement concerns the possibility that this variability could accumulate to form a major part of the trend we have seen over last 50 years.
Understanding the Earth system is badly incomplete as long as there are important open issues in understanding regional and shorter term effects like ENSO. The significance of these issues on the long term climate change is an essential point. More optimistic main stream climate scientists believe that the main trends can be estimated in spite of such incompleteness of knowledge. They justify that belief by noting that the present climate models can describe very many things correctly, and that the models predict internal variability that of the same order of magnitude as that observed in real climate. Some other scientists feel that those arguments are not strong enough.
I don’t really know, but I think that a large fraction of good climate scientists is undecided on the issue. They are not happy with the level of evidence and they have doubts on the reliability of the model results. They feel that the accuracy of the results is unknown. On the other hand they still believe that the results are not without merit, and that they present the most likely outcome based on the present understanding. Many of these scientists are not willing to be explicit on their doubts in public, because they feel that they would be misinterpreted. They may feel also some pressure from colleagues and people involved in climate policy.
This is a point that I have made also before: The politicization of the climate issue has stopped a fraction of of the normal scientific critical discussion and made much more of it less public. The scientists continue to be critical on the work of other scientists as they are in all fields of science, but they are not as open on that as they would be in absence of the politicization. This effect is detrimental to the progress of science. It doesn’t stop progress, but makes it slower.
Many scientists spend now more time in defending the main stream views against attacks from non-scientific skeptics than in being critical on the work of other scientists, where they disagree. In general, I’m not worried about the behavior of some individuals, what I’m worrying more are the systematic effects that are due to group behavior of all important groups involved: the scientists, politicians, pressure groups, major businesses, and environmental movement. Some of them try intentionally distort the outcome, but the most serious errors may be due to unintentional biases.
Thanks. You said a mouthful. That’s a position I could get on-board with.
So, to summarize, it’s possible that the variability found by Salby “could accumulate to form a major part of the trend we have seen over last 50 years“, but for many scientists in the field a large anthropogenic component is “the most likely outcome based on the present understanding.” Others are more skeptical. And the whole political debate is joggling their elbows and slowing and distorting the science.
Or perhaps I should say: “THE WHOLE POLITICAL DEBATE IS JOGGLING THEIR ELBOWS AND SLOWING AND DISTORTING THE SCIENCE!”
I could add a bit on, what I think on various main issues.
Basically I have full trust in issues that I feel that I understand thoroughly as a physicist and on which I also agree with main stream. That includes the basic description of the atmosphere, the radiative heat transfer and essentially everything that’s needed to determine the radiative forcing of CO2 and the “no-feedback climate sensitivity” (although I have some reservations on the suitability of the term).
Very close to the same level of trust comes also the role of humans in the increasing level of CO2, because the increase fits very well the expectations (which are, however, not very accurate) and because there are no credible alternatives for the continuing increase over such a long period.
This is enough to justify my belief in a significant AGW, but not enough to tell, how threatening it is, or what should be done to mitigate it. I’m most uncertain on the correct policy actions, because I don’t think that the present policies are working well. I feel that the politicians here in Europe have erred in their belief in the Kyoto process and in the particular approaches that EU has taken and planning to take to increase the share of renewable energy and to regulate energy use. At the same time I do think that U.S. should initiate something that’s more substantial, systematic and effective than the various policies taken by some states.
My view is that much more emphasis should be directed in the analysis of possible policies both on national and international level. Kyoto agreement is what it is due to political reasons, not based on good analysis. The present policies are based largely on two factors: wishful thinking (on either the benefits of some measures or on the smallness of risks from climate science) and the basic choice on, whether something substantive should be done even, when its consequences are unknown.
I agree with you WRT the basic Greenhouse effect. The arguments against it are clearly based on misunderstanding of the physics.
I’d agree that there don’t seem to be any non-anthropogenic alternatives, but I’m somewhat skeptical of the attribution to fossil carbon. AFAIK all the major players in the atmospheric carbon budget are biological, and it seems probable that they are at least somewhat elastic in their response to rising CO2 concentrations. But that doesn’t mean those players have necessarily stood still during the 20th century.
From what I know (as an amateur) about marine biology and ecology, I can see a possible very strong linkage between e.g. whaling and changes to the marine ecosystem. Of whale species that have pretty much been eliminated ecologically, the blue whale (Balaenoptera musculus), fin whale (Balaenoptera physalus), North Atlantic right whale (Eubalaena glacialis), North Pacific right whale (Eubalaena japonica), and sei whale (Balaenoptera borealis) are plankton filter feeders, feeding primarily (AFAIK) on krill and other zooplanton low on the food chain. By eliminating them from the ecology, we’ve made major changes to the ocean’s surface ecology, and thus probably the carbon budget.
From my position of ignorance, it seems quite possible that if whales hadn’t been reduced to such an extent, the ocean surface would have been able to handle the increased human emissions with much less increase in atmospheric CO2 (by increased pumping into the deep layers). It’s also quite possible that it wouldn’t have handled it as well, and the CO2 levels would have risen much faster.
Similar logic applies to overfishing of large climax fish, as well as terrestrial changes such as tropical deforestation. The latter has gotten much attention, but AFAIK both the possible marine “forcings” have barely been studied, if that. I can’t say for sure, but it wouldn’t surprise me if the general scientific community were just as ignorant in that regard as I am.
When I contact Richard Alley directly he is always courteous and helpful. He has helped me to correct some errors in my own analysis of the GISP2 data. He is a very likable person, a riveting speaker and nifty musician.
In spite of the high regard I have for Alley, his “Control Knob” theory is more about entertainment than science. I suspect he knows this very well but enjoys the attention such nonsense brings in the “Media”.
There are plenty of peer reviewed papers showing CO2 lagging temperature, For example Fischer et al., 1999:
I live in a high rise. My walls are glass. At night we open all the blinds so we can enjoy the city lights. When there is a change in the sun, say it rises, the temperature in my unit starts changing. I adjust the control knob and about 20 minutes later my room has reached a new temperature.
What’s the big deal with the lag?
So let’s study this set of charts I put together based on the Vostok data:
The top chart shows the direction of the CO2:Temperature movements. Lots of noise but a lagged chart will show hints of lissajous figures, which are somewhat noticeable as CCW rotations for a lag. On temperature increase, more of the CO2 is low than high, as you can see it occupying the bottom half of the top curve.
The middle chart shows where both CO2 and T are heading in the same direction. The lower half is more sparsely populated because temperature shoots up more sharply than it cools down.
The bottom chart shows where the CO2 and Temperature are out-of-phase. Again T leads CO2 based on the number you see on the high edge versus the low edge. The lissajous CCW rotations are more obvious as well.
More here http://theoilconundrum.blogspot.com/2011/10/vostok-ice-cores.html
Bottom line is that Temperature will likely lead CO2 because I can’t think of any Paleo events that will spontaneously create 10 to 100 PPM of CO2 quickly, yet Temperature forcings likely occur. Once set in motion, the huge adjustment time of CO2 and the positive feedback outgassing from the oceans will allow it to hit the climate sensitivity rail on the top.
So what is the big deal? We don’t have a historical forcing of CO2 to compare with, yet we have one today that is 100 PPM.
That people is a significant event, and whether it is important or mot we can rely on the models to help.
I went to one of those Skeptical Science hits, and from it I saw the explanation that when the climate changed due to other, known, causes, CO2 rise lagged temperature rise because the increased temperature of the climate (which occurred first) caused an increase in CO2 (which occurred second). The explanation also said that the increased CO2 fed back to further increase the global temperature.
It doesn’t seem to me that any of that is inconsistent with AGW theory.
Obviously, you think there is something insufficient about that explanation, and I have seen many “skeptics” speak of evidence of CO2 rise lagging behind temperature rise in past eras as a foundational reason for their “skepticism.”
Would you mind giving me a brief summary of your thinking?
That Skepticalscience (SKS) “explanation” is the worst kind of sophistry. When they continued to defend the indefensible position that CO2 drives temperature they were so deluged with rebuttals based on solid data that they introduced heavy handed moderation (censorship) earlier this year. Then SKS retroactively edited comments they didn’t like but they forgot about the “Wayback” machine.
Since then, the fortunes of SKS have been in decline as it is has become another echo chamber in the style of Joe Romm’s Realclimate.
Would you mind giving a brief summary (keeping in mind that my technical background and intellectual resources are limited) of the flaws in the explanation as I summarized it above?
Is it that in the previous eras where CO2 increase lagged temperature increase, the temperature increases were not attributable to other, known causes? Is it that temperature increases cannot cause increased CO2? Is it that CO2 cannot increase global temperatures?
I’m not sure why your opinions about the source of that explanation, whether it is in “decline,” etc., are relevant to the plausibility of the explanation itself.
Joshua, why don’t you ask him if he believes in evolution?
My assumption is that like the majority of “skeptics” who post at this site, he does believe in evolution.
As such, I’m curious about whether he generalizes about “skeptics” – based on beliefs (among some “skeptics) in theories that (presumably he believes) aren’t backed by evidence — in the same way that he seems to generalize about “(non-scientific) proponents of immediate action on AGW,” based on belief (among some “(non-scientific) proponents of immediate action on AGW” in theories that aren’t backed by evidence.
Joshua, gives the majority of skeptics here credit for believing in evolution. The other 49% are bozo religious fanatics.
I assume that the vast majority of “skeptics” here reject Intentional Design.
And even those who don’t, I don’t assume to be “bozo religious fanatics.” I think that ID is a reasonably logical belief – depending on your starting premise. My question is whether that premise is based on scientific evidence.
“The other 49% are bozo religious fanatics.”
As VeryTallGuy points out (down thread) there are many peer reviewed papers concluding that the concentration of CO2 in the atmosphere is a significant factor driving global temperatures. The people who write these papers are professional scientists, many of them specialists in “Climate Science”.
While I am a professional physicist, I am not a “Climate Scientist” so why should you believe me rather than them? I know what good science looks like and in my judgment the GRIP, GISP, DYE and Vostok ice cores provide credible evidence of CO2 concentrations and temperatures over the last 700,000 years. Historians and archaeologists provide information on warm and cold periods going back over 4,000 years and these are consistent with the ice core records.
If you find the ice core “Science” as convincing as I do, you have to reject the hypothesis that CO2 drives temperature because ice core proxies show a phase relationship between these variables that is the reverse of what it would be if the hypothesis was true. In simple terms, temperature change precedes changes in CO2 concentration.
Please note that simple physics says that adding CO2 to the atmosphere will tend to retain more heat (~3.5 W/sq. m/doubling of CO2) and thereby raise global temperatures. The ice cores tell us that this is not important compared to all the other things going on.
In a nutshell, I am not asking you to believe me; I am asking you to believe the story that the ice cores tell.
The Vostok ice core data is a great set of data for working a model of CO2-based climate change. We have a situation of a 12K swing in temperature and 100 PPM change in CO2 and a few possible variates to test hypotheses on. Increasing temperature is likely driving the CO2 out of the oceans but historically something stops it at the high rails. What could this be? Oh yeah, CO2 starts to show its logarithmic sensitivity, and that could be what is putting the brakes on. Now that we have pumped another 100 PPM, we kind of want to know how much more the temperature will go up.
” you have to reject the hypothesis that CO2 drives temperature because ice core proxies show a phase relationship between these variables that is the reverse of what it would be if the hypothesis was true”
Quite right if the hypothesis was that a change in CO2 drove interglacial changes.
But it’s not – the hypothesis is that orbital variation drove changes in temperature which had a knock on effect to CO2. That then amplified the original effect of orbital change.
The difference today is anthropogenic GHGs. The hypothesis for this is that they are emitted by human activity – for which there is unequivocal proof.
The Vostok ice cores are entirely consistent with this hypothesis. If temperature lagged CO2 in the Vostok cores, you’d have to imagine a hypothesis for what drove the CO2 change. If CO2 did not have an amplifying effect, you’ll struggle to understand the magnitude of changes driven by the Milankovitch cycles.
There are the Vostok ice cores and there are other paleo data sets from the tropical oceans which agree with the Antarctic data. http://journals.ametsoc.org/doi/full/10.1175/1520-0442%282004%29017%3C2170%3ATYCITS%3E2.0.CO%3B2
The very plausible explanation is that like 80% of this is GHG forcing abetted by the huge reservoir of CO2 available from the oceans, with a 5K change from doubling estimated.
The Milankovitch cycles initiate the moves but do not sustain it. Very fascinating reading about this data because the effects are so large, and there are really no counter or alternate theories available.
The whole idea of just because CO2 lags temperature doesn’t prove a thing, just as the fact that a chicken hatches from an egg doesn”t mean that a chicken wasn’t involved in the process, and it likely was :)
I do have some sympathy with your views as to the changing tone of SkS.
I’d also ask you to consider how it could be possible for that site, specifically set up to reflect the peer reviewed literature, to engage with someone who believes it is an “… indefensible position that CO2 drives temperature…”
Given that the overwhelming majority of the papers on the subject do in fact conclude that CO2 does drive temperature, it appears that you’ve rejected the scientific literature out of hand.
Which appears to preclude any constructive engagement.
While many papers in the literature in fact assume that CO2 drives temperature, virtually none concludes that. Journal articles report research results and that CO2 drives temperature is not a plausible result for a single research effort. There is no killer finding in the literature. Rather some results suggest or provide evidence that CO2 drives temperature. Moreover, some results, probably just as many, suggest the opposite.
SkS is a bit of a trick, possibly even a hoax. They start with a lay version of a skeptical argument, then rebut it with a knowledgeable version of a pro-AGW argument, or often several such arguments. They completely ignore the fact that there are equally knowledgeable skeptical counter arguments to the pro-AGW arguments they present. This is pure advocacy, about as unscientific as one can be.
Setting the question as Does CO2 drive temperature or vice versa? is not the right way for science as the answer is certainly: Both.
The two separate questions: What is the influence of atmospheric CO2 on temperature) and What is the influence of temperature on atmospheric CO2? are both reasonable, when it has been specified in more detail, how the temperature is considered (global average, average SST, more local, ..).
“They completely ignore the fact that there are equally knowledgeable skeptical counter arguments to the pro-AGW arguments they present. This is pure advocacy, about as unscientific as one can be.”
What would be great, if that’s how you feel, is to put together a coherent set of “skeptic” arguments which build the case across multiple lines of evidence, for the lack of a CO2 effect.
There is no such resource presently, and it is instructive to consider why not.
I’ve seen theoretical arguments that CO2 could not increase global temperatures (apparently largely rejected by “skeptics” who post at this site) – but I haven’t seen the argument made that temperature increases due to other factors cannot increase CO2 – or that past interglacial changes were not attributable to the factors discussed in the Skeptical Science explanation.
Do you have a link to knowledgeable skeptical counter-arguments to the explanation that Skeptical Science gives for why records showing a lag between temperature rises and rises in CO2 don’t contradict AGW theory?
I would agree with Pekka
I’d go a step further, however.
The pertinent question is NOT “does CO2 drive temperature?” BUT <em"how much does CO2 drive temperature?"
If I dump a liter of boiling water into Lake Baikal it will raise the average temperature of the lake.
But the increase will be imperceptible for practical purposes.
And this is where the ongoing scientific debate on the validity of the IPCC premise of alarming AGW is centered.
And it is also.where the theory and the actual physical observations on CO2 climate sensitvity diverge.
The amplification of warming by CO2 is just wishful thinking by the alarmists.
It has never been measured or even proven to exist. [it may well be .01 ° C or less] It is an obvious fig leaf to cover the alarmist nakedness on this point.
Skeptical Science is a crooked game and the main rule is “let the wookie [appear to] win”!
My best posts were deleted. The alarmists are allowed to make off topic objections but skeptics are not allowed to respond.
I just read an article by Patrick Michaels, where he wrote that CO2 does warm the climate (and that the degree of forcing precisely known).
Do you disagree with him, or is your point that warming due to C02 doesn’t “amplify” warming caused by other factors (e.g. CO2 levels are not increased as the result of warming)?
Joshua, ask him if he reads the Bible?
Why would that be relevant?
Can you provide a link to the article by Patrick Michaels?
I found the link to the Patrick Michaels paper
Here is what he states:
BTW Michaels wrote this back in 2000, before it became apparent that global warming has stopped temporarily.
His 0.65-0.75C expected rise from 2000 to 2050 will have to speed up a bit, since the first decade has shown no rise at all.
I don’t understand the problem.
1) Historically, external forcing, primarily from orbital variation, leads to changes in temperature which then drive changes in Co2. There are known physical processes which we might expect to produce this effect. It appears that the time constant for this process is of the order of 800 years.
2) We now have the position, which we did not have historically, where CO2 is being artifically injected into the atmosphere. This we expect to raise surface temperatures, with a time constant on the order of decades.
3) We might expect (1) to kick in as a positive feedback, making the problems caused by (2) larger. My understanding is that the feedbacks which lead to a roughly 3 degree temperature tise for a CO2 doubling do NOT include this carbon cycle feedback (see A Lacis comment above).
In other words the lag seen in the historical data mean things are worse than the basic feedback of 3 degrees per doubling.
At the low end of CO2 spectrum which is where the Vostok data is, it is arguable that it is 10 to 15 degrees per doubling, probably due to positive feedback ocean outgassing. I posted this upthread a moment ago:
At the higher end the atmospheric sensitivity starts kicking in so no one thinks that the 15 degree with doubling will occur
A way off topic analogy if you will allow.
There’s a party going on next door. A big party. More people keep arriving and it keeps getting noisier.
Now, I go and turn up the PA system. It’s really loud now, and that attracts more partygoers out of their flats.
Does noise drive the number of partygoers or does the number of partgoers drive the noise?
Does CO2 drive temperature or does temperature drive CO2?
Can both be true?
My guess is that the partygoers would also have a greater noise to p.g. ratio because they have to shout louder to be heard above the PA system – thus another factor increasing the sensitivity as more partygoers at the party gives you reason to crank up the volume on the PA system.
And the theory of CPAPGN (catastrophic PA partygoer noise) is born.
ha ha you forgot to consider the feedback that makes the PA system crash.
My guess is that he’s deliberately not mentioning that because he has a socialistic, eco-Nazi, agenda to eliminate noise pollution by inventing the hoax of CPAPGN.
And admit it – you’re being paid by the PA manufacturing companies to deny CPAPGN.
To get this back on topic, I would suggest that readers re-read Chris Colose’s paper and then read the earlier post by Judith cited above.
It will become clear that Chris is presenting a very simple postulation of how feedbacks in climate work. This is a “black and white” linear explanation. “Feedbacks for dummies”.
Judith raises the point:
“The problem flat out isn’t linear, and attempting to do a nonlinear control theory analysis is pretty hopeless”
Nonlinearity results in uncertainty.
Sure, “uncertainty” can go both ways – the ” skewed tail toward higher values” as described by Chris..
But Occam’s Razor, the 160+ year CO2/temperature record and our long-term climate history tell us a different story IMO.
Max, Whiie I, and many other denizens on this blog, like Girma, agree with you, to some extent what we say falls on deaf ears. Dr. Curry is a firm believer in CAGW. However, unlike just about all other proponests of CAGW, she attempts to sponsor a proper scientific dialogue; our posts are never censored. However, that does not mean that any of the warmists take any notice of them. We can quote all the science we like, and until global temperatures actually start to fall significantly, people like Chris Colose will continue to post the sort of thing that is the basis of this thread; whether it has any scientific merit or not.
Does this mean it is useless to write the sort of scientific facts that you have just written? I cannot answer that question. But what we must recognize is that this is Judith’s blog, and she starts the threads she likes. And just like in the current state of a negative PDO, we are likely to see more La Ninas than El Ninos, on this blog, we are going to see more pro-CAGW threads, than anti-CAGW ones. That is what life is all about.
You may be right on the % breakdown between pro-CAGW and anti-CAGW lead posts on this blog site.
But this may be less an indication of where our host stands on the issues than the fact that there is an overwhelming preponderance of pro-CAGW stuff being published out there.
All one has to do, for example, is Google “ocean cooling” and for every post that mentions the cooling observed by the ARGO system since its start in 2003 one sees four articles pooh-poohing these observations and proclaiming that the ocean is still warming.
And then there is this fact: the more preposterous pro-AGW articles our host posts the easier it is for these to get refuted by the bloggers here.
She has been quoted in Wiki:
The best way for ”aggressively challenging the IPCC consensus” may well be to expose its bases for all to see, as is being done here.
Just another slant on it, Jim.
The ocean is not a 700 meter layer. So an observation that the 700 meter layer is cooling cannot be rolled up into a claim the oceans are cooling.
Most of the ocean below 700 meters is at a few degrees above freezing and doesn’t count. In fact, the thermocline is usually above 300 meters even in the tropics.
You raise the interesting question about how much energy the lower ocean is absorbing out of the upper ocean. It must be a lot.
And since the size of the heat sink (lower ocean) is vast, this has significant implications.
There have been a few papers recently that have found warming in the deep ocean, and over the last few months I have linked to them on this blog. Even so, some persist in characterizing the oceans as cooling.
In recent decades there have been flat periods in upper layer ocean warming. They consistently have been followed by a resumption of warming. It is easy to point them out and screech cooling, but there has been given not a single reasonable reason not to expect a resumption of warming.
Yes, the deep ocean is vast, but a click up of a fraction of a degree C cannot be ignored, and it appears that it has happened.
Accounting for multiple sources of uncertainty, a composite of several OHCA curves using different XBT bias corrections still yields a statistically significant linear warming trend for 1993–2008 of 0.64 W m-2 (calculated for the Earth’s entire surface area), with a 90-per-cent confidence interval of 0.53–0.75 W m
Yes, below 700m, the oceans are heated by the heat from the earth’s core. Sun light is not necessary. Don’t we see that during swimming in the oceans during winter.
Girma – where was the earth’s core when the deep oceans were not warming?
I think it’s more likely GHGs are adding heat to the surface, and that heat has found its way into the depths, my personal pet theory, since we’re talking pet theories, is Mermaids have seduced the warmth downward.
The study you cite covers the upper ocean over the period 1993-2008.
The Knox + Douglass study below covers only the period since mid 2003, when the more reliable and comprehensive ARGO system replaced the expendable XBT devices (which were shown to introduce a warming bias).
The K+D study shows that four out of five data series confirm that the upper ocean has cooled since 2003.
K+D refers to the earlier study you cited:
[This unexplained cooling was part of Trenberth’s “travesty”.]
I have written on this before. The paper presents really poor and even explicitly erroneous statistical analysis. You have seen this comment and its justification, but you continue to refer to the wrong results.
Only one of their trend estimates makes sense. Smoothing first the data series and determining the trend out of that introduces a severe error that produces most of the trend of that approach.
Additional data has turned over even the very weak trend that the only reasonable version of their analysis gives.
I could easily have missed the discussions of the mechanism that will warm the lower ocean while the upper layer is cooling and Argo shows no flux going down??
Does convection work in reverse below 700m??
What about the energy that would be required to drive warming against convection?
I can accept that the amount of warming being discussed distributed throughout the deep oceans wouldn’t amount to much per cubic meter making its confirmation extremely difficult. This is why a mechanism is so important. Without a mechanism it is simply speculation.
There you go again.
I have seen no rebuttal of K+D 2010.
Your statement that its conclusions are false is interesting, but not conclusive.
Let’s wait and see if there is a real rebuttal, which effectively refutes the K+D conclusions.
After all, ARGO is still in its infancy and all the data prior to ARGO are highly suspect, for the many reasons cited.
Kevin Trenberth apparently attempted to refute K+D 2010, but was unsuccessful.
You brought up the question of ocean cooling/heating that started this whole exchange.
Josh Willis is the ARGO team leader and expert. He has apparently confirmed to Roger Pielke Sr. that the data used by K+D 2010 are correct and that there has been a recent “lack of warming”. In another statement, Willis referred to this as a “speed bump”.
Willis was a co-author of the famous 2005 “hidden in the pipeline” paper by James E. Hansen et al.
Some quotations from that paper:
IOW the computer models have told Hansen et al. that the forcing from CO2 from 1880 to 2003 should have resulted in around twice the amount of atmospheric warming as was actually observed.
Instead iof questioning the validity of the computer models, Hansen et al. look for another explanation. The “missing” warming could be “hidden in the pipeline”, from where it will emerge some day in the future to cause more warming.
Where would this “pipeline” be?
That’s where Josh Willis came in: it is the upper ocean. At that time (before ARGO) there were no ” precise measurements of increasing ocean heat content over the past 10 years”, but some rather doubtful measurements made by expendable XBT devices, which were later admitted (by Josh Willis) to introduce “a warming bias”.
So now we see why the ARGO results are embarrassing for Willis as well as Hansen and Trenberth. They show that the upper ocean has cooled instead of warmed, since they were installed in 2003.
If a continuation of the cooling trend is confirmed by future ARGO readings, this would raise serious questions, not only about the “hidden in the pipeline” postulation but also about the model-based climate forcing of CO2 cited by IPCC (including the overall magnitude and sign of feedbacks, the topic of this thread) and, hence, the whole premise of alarming AGW.
RealClimate, SkepticalScience, etc. have already cried out against the K+D 2010 conclusions of the ARGO data, as has Kevin Trenberth (see above post).
But so far there has not been any rebuttal that has stood up.
PS There have also been speculations that some of the “missing heat” may have disappeared forever into the deep ocean (your point). This would be extremely difficult to substantiate with empirical data, but is probably a moot point in any case, since this heat sink is so vast that the “missing heat” would be hardly noticed and gone forever.
I believe Willis and Lyman have also said the cooling found in K-D has no significance.
I have really presented the evidence here twice. First in a comment directed to one of the authors, when he was commenting on this site. He didn’t respond. The other time was directly to you.
One more time:
The temperature has seasonal variations. The data used in the paper starts with the cooler season and ends with the warmer. The simple way of getting the right trend is to use annual averages, because they reflect the different seasons equally and remove the influence of the seasonal variations from the trend. That’s one of their approaches and leads to very weak and statistically totally insignificant cooling. That’s the only reasonable result that can be obtained from such limited set of data.
Two other trends are formally correct as they are based on specific months. These results are, however, statistically so insignificant that they tell nothing worthwhile, because fluctuation in single month values are too large.
The one method that the paper presents most visibly is the one that has a really stupid and really serious error in it. They smoothen the data using 12 month mowing averages and use those values in the analysis. That means in practice that the points at least 12 months from each end are used in calculating 12 points, while the extreme months are used only once. That way they give less weight to the early values from the cold season and to the last values from the warm season. That causes a bias to the result from the seasonal variation and doing that the way they do produce the spurious cooling trend.
It should have been clear from the outset that the method based on the annual averages is correct and any method based on exactly the same data that gives a significantly different result has some error in that.
It doesn’t speak much good about the journal either that the peer review didn’t catch the internal contradiction in the paper.
The paper is also a good example of breaking the rule discussed often on this site, that preprocessing data before final statistical analysis leads very often to errors.
“But this may be less an indication of where our host stands on the issues than the fact that there is an overwhelming preponderance of pro-CAGW stuff being published out there.”
We are saturated with all kinds of propaganda.
I would say propaganda works. One needs only to examine the
amount of money spent on ads. But I don’t think propaganda wins.
If propaganda actually wins, our world would different than it is.
More speech is always better than less speech.
I welcome more pro-CAGW speech, they can’t win.
Their only hope to delay losing is less speech.
To your second point that the “pro-CAGW” bloggers here have deaf ears for any data, which contradicts their belief, that’s the nature of most people (especially “true believers”).
Some are willing to at least look at other arguments (while desperately searching for counterarguments).
Others simply reject other arguments outright.
And a few react with open hostility.
Will another decade of no warming of the atmosphere and the ocean convince the “true believers” that their CAGW vision is flawed?
Time will tell, but I wouldn’t bet on it (they’re not too impressed by the most recent decade of no warming)..