Atmospheric CO2: the greenhouse thermostat

by Andrew Lacis

The one year anniversary is soon approaching for the Science paper that we wrote a year ago to illustrate the nature of the terrestrial greenhouse effect. I describe here how this paper came to be.

The title of the paper:  “Atmospheric CO2: Principal Control Knob Governing Earth’s Temperature“ is also the principal conclusion of the paper. The full text, including the Supporting Online Material, is downloadable from the GISS webpage. The abstract describes the physical basis and rationale for the key point that is being expressed in the title.

Ample physical evidence shows that carbon dioxide is the single most important climate-relevant greenhouse gas in the Earth’s atmosphere. This is because CO2, like ozone, N2O, CH4 and CFCs, does not condense and precipitate from the atmosphere at current climate temperatures, whereas water vapor can, and does. Noncondensing greenhouse gases, which account for 25% of the total terrestrial greenhouse effect, thus serve to provide the stable temperature structure that sustains the current levels of atmospheric water vapor and clouds via feedback processes that account for the remaining 75% of the greenhouse effect. Without the radiative forcing supplied by CO2 and the other non-condensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate to an icebound Earth state.

The text of the paper provides the supporting science and illustrates the key role that atmospheric CO2 plays in the operation of the terrestrial greenhouse effect, perhaps more directly than has been done before. The paper also makes a bit of a digression in pointing out the erroneous and irresponsible assertion by Dick Lindzen that  “about 98% of the natural greenhouse effect is due to water vapour and stratiform clouds withCO2 contributing less than 2%”.  (Lindzen really should have made some effort to correct this misinformation, instead of letting people quote his erroneous result ad infinitum.)

The Supporting Online Material for the Science paper provides additional background information, including a table that lists the fractionalattributionof theterrestrialgreenhousecontributorsshown in Figure 1 of the Science paper.  There is also the accompanying GRL paper by Gavin Schmidt et al. (2010) that describes the GCM modeling runs for the greenhouse attribution analysis.

This paper drew initial attention in the form of a NASA press release on  ‘How Carbon Dioxide Controls Earth’s Temperature’.

Two related science briefs were also displayed on the GISS webpage:  ‘CO2: The Thermostat that Controls Earth’s Temperature’, and ‘Taking a Measure of the Greenhouse Effect’.

Our Science paper also caught the attention of the climate skeptics crowd. Roy Spencer commented that  “there was a very clever paper published in Science this past week . . . in an attempt to prove that carbon dioxide is the main driver of the climate system”.

But then Roy Spencer went astray by claiming that “After assuming that clouds and water vapor are no more than feedbacks upon temperature, the Lacis et al. paper then uses a climate experiment to ‘prove’ their paradigm that CO2 drives climate – by forcing the model with a CO2 change, resulting in a large temperature response!” followed by an erroneous  (but nevertheless a useful point) comment that “Well, DUH! If they had forced the model with a water vapor change, it would have done the same thing.”   (It would not.)

Roy’s claim about our “assuming water vapor and clouds to be feedbacks might have been a valid point if we had used an old 1970s vintage 1-D model to perform our analysis. In current climate GCMs no such assumptions are being made. Atmospheric water vapor and cloud distributions are the direct results of the model physics interactions (via evaporation, transport, condensation, precipitation).

We later went on to demonstrate this very point by forcing the model with a water vapor change by instantaneously doubling (and zeroing out) water vapor in a couple of GCM runs. These GCM experiments further re-emphasized the key point of our Science paper that water vapor is indeed a fast feedback process in the climate system. Within about two-weeks time, the atmospheric water vapor distribution had essentially returned back to control run levels. During this two-week transition period, any water vapor excess (or deficit) relative to the equilibrium distribution did of course produce a radiative greenhouse heating (or cooling) effect, but this ‘virtual forcing’ was very transient in nature, without any lasting impact on the global temperature.

Roy Spencer concluded his analysis by stating that “the paper really tells us nothing new about (1) how much warming we can expect from adding more CO2 to the atmosphere, or (2) how much of recent warming was caused by CO2”. (So, nothing new, but nothing wrong!)

Roger Pielke, Sr. also commented on our Science paper, stating that “The paper is an interesting model experiment, but it really does not present any new insight beyond what we already know.” And further that “My conclusion is that their paper does not present new scientific insight but is actually an op-ed presented in the guise of a research paper by Science magazine.” (Nothing new, only an op-ed.)

I since have had some useful dialogue with Roger, and went on to post some commentary items on his climate blog. The first posting was basically the GISS webpage science brief. I then later posted a longer commentary on the Atmospheric CO2 Thermostat that included (1) a description of our recent water vapor feedback/forcing experiments, (2) an illustration describing high accuracy GCM LW radiation calculations, (3) a short discourse on the latitudinal nature of climate feedbacks, and (4) an overview of those things that we know well (about climate), and those things that we know less well.

In regard to questioning the lack of any ‘new scientific insight’, I scarcely think that Jim Hansen’s opinion (or mine) would really differ greatly from what Roy Spencer and Roger Pielke, Sr.  have expressed. However, Jim Hansen did go on to say in addition, that “It’s about time that somebody wrote a paper like that”. Even though we have known and understood for decades the basic science of the terrestrial greenhouse effect, and water vapor feedback effects, in the current climate (politically speaking) of the frequently expressed irrational thinking, there is unfortunately a clear and pressing need to keep on repeating and explaining the most basic of global climate concepts.

So, if there really was ‘nothing new’ in our Science paper . . .

then how did this paper come to be?

First, let me state here what the paper is not. The paper is not a snowball Earth paper (although it is relevant.) Geological evidence suggests that tropical latitudes were glaciated some 600M years ago. Even with near zero CO2, and the Sun 3-4% dimmer than now, the tropics require albedo help from clouds and encroaching sea ice for global freeze-0ver – hence, an interesting science problem that needs careful cold-climate cloud and ocean dynamics modeling. Also, as Roy Spencer noted, this paper is not an explanation for past decadal temperature change (although it is relevant). Modeling of the recent decadal climate record would require careful accounting for all of the radiative forcings, and would also require accurate modeling of ocean dynamics to accurately simulate the climate system’s response time.

Instead, the aim of our Science paper was to illustrate as clearly and as simply as possible the basic operating principles of the terrestrial greenhouse effect in terms of the sustaining radiative forcing that is provided by the non-condensing greenhouse gases, which is further augmented by the feedback response of water vapor and clouds.

If you were to go and read the acknowledgment that is at the end of the Science paper, you would see the very standard “thank you” for helpful comments from numerous GISS colleagues, and a “thank you” for funding support from NASA program managers.

But, you would not see there any mention of Bishop Hill.  Why so?  And, would the Science editors have really let that happen?

It started with the following (February 9, 2010) posting on the Bishop Hill blog that stated:  “While perusing some of the review comments to the IPCC’s Fourth Assessment Report, I came across the contributions of Andrew Lacis, a colleague of James Hansen’s at GISS.  . . . Remember, this guy is mainstream, not a skeptic, and you may need to remind yourself of that fact several times as [you] read through his comment on the executive summary of the chapter:” This topic was also later picked up and commented on at WUWT.

I was being hailed as a fellow critic of the IPCC AR4 Report, and by some, as a newly-found hero of the climate change denier cause.

Back in 2005, having uploaded countless review suggestions for the IPCC AR4 Report, toward the end, I did make some intemperate remarks that were directed at the Executive Summary of Chapter 9.

I was irked by the persistent use of wishy-washy terminology such as  ‘likely’ and ‘very likely’ that was totally uncalled for. One example: “It is likely that there has been a substantial anthropogenic contribution to surface temperature increases in every continent except Antarctica since the middle of the 20th century.

Such ‘social sciences’ terminology might be allowable if there was no other available evidence for global warming except for the statistical analysis of a relatively short global temperature time-series (on which there is superimposed a substantial natural variability component). But the physical evidence for global warming is quite overwhelming, and it is downright irresponsible (and stupid) not to make use of it.

More specifically: (1) precise measurements show atmospheric CO2 has increased from its 280 ppm pre-industrial value to the current ~390 ppm; (2) there is available an accurate HITRAN tabulation of line absorption coefficients for all of the atmospheric absorbing gases; (3) we have available accurate radiation modeling techniques as well as capable global climate models; and (4) that 9 Gigatons of carbon (coal, gas, oil) are being burned each year (by us humans).

Based on this basic input data, the relevant physics is inescapably clear that the increase in atmospheric CO2 is indeed enhancing the strength of the terrestrial greenhouse effect, and thus causing global warming to happen – all directly attributable to human industrial activity. To characterize this fully documented global warming only as being ‘likely’ a ’substantial’ anthropogenic contribution is clearly resorting to unscientific understatement that does nothing to clarify or accurately portray our understanding of global climate change. Rather, using such under-whelming weasel words only adds to the deliberate public confusion regarding climate change. Unfortunately, such subtle misinformation is being actively promoted by the fossil fuel lobbyists and their growing multitude of dupes and minions.

The above was the essence of my response to Bishop Hill, as it came to be posted on Andy Revkin’s New York Times dotearth blog.

I went on to comment further on the IPCC review process, and posted a more complete description of the Role of CO2 in Global Warming, followed by a brief tutorial on the greenhouse effect.

Blog commentaries, however, are too transient to have any lasting impact. It became increasingly clear that the current climate situation really called for a simple and convincing demonstration of just how the terrestrial greenhouse effect operates in maintaining the surface temperature of the Earth. Hence, our writing of the Science paper.

Basic conclusions that can be drawn from this exercise:

(1) The terrestrial greenhouse effect is comprised of two distinct components: (a) the non-condensing greenhouse gases that provide the ‘radiative forcing’ that sustains the terrestrial greenhouse effect; (b) the ‘feedback component’ by water vapor and clouds that acts to amplify the radiative effect of the non-condensing greenhouse gases.

(2) The radiative forcing by the non-condensing greenhouse gases is accurately known, and fully understood. Of the GHGs, atmospheric CO2 is the principal contributor, hence the principal control knob that governs the strength of the greenhouse effect and global temperature. The greenhouse physics, and the increase of atmospheric greenhouse gases as the fundamental basis for global warming, are well founded.

(3) Water vapor and clouds account for about 75% the strength of the terrestrial greenhouse effect, but are feedback effects that require sustained radiative forcing to maintain their atmospheric distribution. Their radiative effects are accurately known. The magnitude of their feedback sensitivity is also reliably known, to within order of 10%.

(4) The temporal record of global climate change can be separated into two distinct components: (a) global warming – this is the steady and predictable increase in the strength of the terrestrial greenhouse effect that is caused by the increase in atmospheric greenhouse gases resulting from human industrial activity; (b) natural variability – this is the unforced and mostly unpredictable inter-annual, regional, and decadal variability of the climate system that is superimposed upon the steadily increasing global warming component.

(5) Global warming, the climate change component that is driven by greenhouse gas increases, is the reason for concern because of its increasing impact on ecosystems and polar ice caps/sea level rise. Whether humans like it or not, and whether humans realize it or not, global warming has been so, and continues to be, fully under human control via fossil fuel burning. Smaller contributors such as changes in aerosols, solar irradiance, and sporadic large volcanoes exist. But aerosol forcing is also anthropogenic and/or short lived. Solar forcing is cyclical and small, while the GHG residence time is very long.

(6) Natural (unforced) climate variability is the principal reason for the uncertainty manifested in the largely unpredictable temperature and precipitation fluctuations that occur on regional spatial scales, and on inter-annual and decadal time scales. Arising from changes in advective energy transports and poorly understood interactions with ocean dynamics, this is where uncertainty reigns supreme. However, these advective transports must globally add to zero, and the unforced fluctuations are necessarily fluctuations about the global equilibrium reference point. Nature conserves energy very carefully. Hence, large deviations from the global equilibrium cannot be sustained. So, this unforced climate variability cannot significantly impact the long-term global temperature trend, but its effects on local and regional climate will remain the main source of uncertainty for the foreseeable future.

(7) Global climate change is far too complex to be understandable in one swoop. Fortunately, the global warming component, it being tied directly to the growing strength of the terrestrial greenhouse effect, is a uniquely radiative effect that can be addressed independently of the other climate complexities. The basic physics of the greenhouse effect is rooted to the conservation of global energy. Precise measurements of the rising concentration of atmospheric CO2 are irrefutable, leaving nodoubtthatglobalwarmingis happening. Geological evidence shows that 450 ppm of atmospheric CO2 is the critical level that is needed to sustain polar ice caps, although the time scale for the melting of polar ice caps is many centuries. That is the scientific perspective on global warming. Deciding what, if anything, to do about global warming is a political problem, but the politicians should keep the science in mind.

Moderation note:  this is a technical thread.  Comments will be moderated for relevance.

794 responses to “Atmospheric CO2: the greenhouse thermostat

  1. Just because you don’t explicitly assume something doesn’t mean that you haven’t implictly assumed it in the parameterisation of your models. It’s very hard to avoid implict assumptions in any complex model.

  2. “7. … The basic physics of the greenhouse effect is rooted to the conservation of global energy.”

    Actually, the basic physics of the greenhouse effect is rooted to the dissipation of absorbed solar energy. This introduces the thermodynamic notion of “free energy” which is quite distinct from the function currently employed in climate models and a concept yet to find its way into climate theory.

    • And the energy absorbed is conserved, but transformed into heat.

      • Can the Rabett tell us what happens when heat is created?

      • Ooooo a first law fail. The heat is not created but the solar energy is transformed into heat. This tends to warm things up as anyone living on the dark side of Mercury could tell you.

      • The Rabett needs to read for comprehension.
        If you wish to quibble over semantics, Lacis has a whole long post you could chew on.
        Answer the question: What happens heat shows up in a system?

      • Another first law fail. Where does it come from? inside or outside the system???

    • You are right in noting that the free energy is not usually (to my knowledge, but I may err) discussed explicitly or used in common mathematical formulation of the thermodynamics of atmosphere. It’s, however, taken into account in practical calculations. After the solar radiation gets absorbed the remaining free energy appears as such temperature differentials that can maintain atmospheric circulation.

      The hot equatorial surface has free energy in the Earth system. Free energy is used also in evaporation.

      Free energy is energy that can be converted to work. Maintaining circulation of air and water as well as creating hurricanes and other weather phenomena are the principal processes, where the free energy has it’s influence.

  3. or…
    7. The basic physics of the greenhouse affect is rooted to the conservation of global energy, with centralized control from the well head up.

    Just a few more words, and hear we are.

  4. So, in essence, you wrote some words that were critical of the IPCC, then you worried that people might think that you were giving succour to the enemy, so you then wrote a paper to demonstrate your orthodoxy.

    You mention the following:
    “…the climate change denier cause…”
    “…the climate skeptics crowd…”
    “Unfortunately, such subtle misinformation is being actively promoted by the fossil fuel lobbyists and their growing multitude of dupes and minions.”

    Might I suggest you take time out from busily demonstrating your orthodox credentials, and take a course in “how to make friends and influence people.”

    • …dupes and minions…

      Dr. Lacis: You have commented here before using this sort of rhetoric. FYI, when you do, you come across as a close-minded fool.

      I’m not a climate scientist, so I am limited in my ability to understand and critique your technical work. But when you talk about something I do understand — who the skeptics are and how climate skepticism works — and you come across as clueless, It makes me wonder whether the thinking behind your climate science is similarly skewed.

      That’s not a scientific argument, of course, but it’s not without merit either. I keep searching for signs of intelligence in the climate orthodoxy beyond their climate expertise and I’m not finding much.

    • A “climate denier” is one who does what exactly? Why invent nonsensical phrases and try to use them to win a debate?

      • Sorry. Thought I saw the “climate denier” phrase but it’s not here. The “dupes”, “minions” and “deniers” still are.

    • James, you appear to think that the only criticism of the IPCC comes from your camp of rejectionists. Andy Lacis’ criticism is that the IPCC’s evaluation of the results of increasing greenhouse gas concentrations was not strong enough in emphasizing the strong warming effects to be expected.

      • “James, you appear to think that the only criticism of the IPCC comes from your camp of rejectionists.”

        Where are you getting that from?

        “Andy Lacis’ criticism is that the IPCC’s evaluation of the results of increasing greenhouse gas concentrations was not strong enough in emphasizing the strong warming effects to be expected.”

        Yes, he explains all that above. I found that out by using my eyes to read it. I find that it helps to read the post before commenting on it.

      • Excellent advice

  5. Not even wrong. CO2 principal control knob? CO2 is strongly driven by Earth’s temperature, so it’s very unlikely that it has any significant (warming) effect.

    This was in Science? They should change their name to PseudoScience.

    • CO2 is strongly driven by Earth’s temperature, so it’s very unlikely that it has any significant (warming) effect.

      I believe this is another positive feedback. We have a strong forcing function from fossil fuel emissions contributing to the atmospheric CO2 concentration rise. We also have an increase in temperature in the last one hundred years which should also contribute to the CO2 rise. In fact this does show up in differential d[CO2] measurements with a strong cross-correlation against temperature. If most of this is from the ocean outgassing (according to Henry’s Law) as it tries to equilibriate with the new temperatures, atmospheric CO2 concentration will continue to rise along with the fossil fuel component part of it.

      My problem with the Lacis article is that they have the CO2 residence time of thousands of years, whereas it is actually the adjustment time which is the slow one. The CO2 residence time is on the order of 10 years.

      • WHT,

        The adjustment time is much shorter than you think. In 1998 (very warm year, El Nino), ~80% of the human CO2 emission “remained” in Earth’s atmosphere. In 1999 (cold year, La Nina), only ~20% remained, the rest was removed from the atmosphere.

      • Edim 1.24

        That’s very interesting. I’d like to follow up on that. Do you have a link please?

        tonyb

      • tonyb

        I did a post on that on an earlier thread.

        I found a correlation between the amount of annually emitted CO2 “staying” in the atmosphere and the change in global average temperature from the previous year.

        Years that showed warming compared to the previous year, showed a higher percentage than years that showed cooling, with the annual range varying from around 16% to over 80% (and the long-term average around 50%).

        CO2 remaining in atmosphere versus temperature change – Calculation
        http://farm7.static.flickr.com/6088/6125488794_8ef0233067_b.jpg

        CO2 remaining in atmosphere versus temperature change – Graph
        http://farm7.static.flickr.com/6080/6125478512_1eb60e073e_b.jpg

        Don’t know exactly what this tells us except that there may be a natural temperature correlation with atmospheric CO2 change, as Prof. Salby has suggested.

        Max

      • Don’t know exactly what this tells us except that there may be a natural temperature correlation with atmospheric CO2 change, as Prof. Salby has suggested.

        No one disputes this. Unfortunately, it is a positive feedback kind of behavior. CO2 from fossil fuel emissions leads to a temperature rise due to the GHG effect. Then this temperature rise coaxes more CO2 out of the oceans. This brand of CO2 is also just as potent a GHG, so it is a reinforcing or positive feedback behavior.

        Salby is probably right in that the excess CO2 doesn’t have fossil fuel markers but then again he doesn’t understand the difference between adjustment time and residence time of CO2. Adjusted CO2 will lack the fossil fuel markers, but fresh CO2 that hasn’t past through a cycle won’t.

      • WHT,

        The adjustment time is much shorter than you think. In 1998 (very warm year, El Nino), ~80% of the human CO2 emission “remained” in Earth’s atmosphere. In 1999 (cold year, La Nina), only ~20% remained, the rest was removed from the atmosphere.

        Do you have a problem with reading comprehension? I said that there is a difference between residence time and adjustment time. Residence time is like 10 years but adjustment time has statistical moments that diverge.

        The CO2 was not permanently removed from the atmosphere. Instead it was trapped in a dynamic carbon cycle, squeezing out other CO2 that had been there for awhile.

        The owner of this site is obviously interested in quantifying uncertainty and I suggest this is a good place to start. Everything about potential future trajectories revolves around this bit of scientific evidence. For example, if the adjustment time was equal to the residence time, and this value was 5 years, then we would be seeing only 1/4 the amount of excess CO2 than what we are measuring, and we wouldn’t even be having this conversation.

      • “Atmospheric CO2: the greenhouse thermostat:
        I believe this is another positive feedback. We have a strong forcing function from fossil fuel emissions contributing to the atmospheric CO2 concentration rise. ”
        A thermostat built upon a positive feedback! This is a completely novel concept in physics. Climate scientists will always stun me.

      • “Atmospheric CO2: the greenhouse thermostat:
        I believe this is another positive feedback. We have a strong forcing function from fossil fuel emissions contributing to the atmospheric CO2 concentration rise. ”
        A thermostat built upon a positive feedback! This is a completely novel concept in physics. Climate scientists will always stun me.

        Novel or not, do you disagree with the statement? The climate change skeptics are the ones that think some invisible hand will execute the control algorithms, reminding me vaguely of the invisible hand of the free market.

      • WHT,

        The invisible hand is physical (or scientific) law.

      • WHT,

        The invisible hand is physical (or scientific) law.

        Fair enough, and the feedback can go either way, depending on the sign of a coefficient.

  6. “Based on this basic input data, the relevant physics is inescapably clear that the increase in atmospheric CO2 is indeed enhancing the strength of the terrestrial greenhouse effect, and thus causing global warming to happen – all directly attributable to human industrial activity. To characterize this fully documented global warming only as being ‘likely’ a ’substantial’ anthropogenic contribution is clearly resorting to unscientific understatement that does nothing to clarify or accurately portray our understanding of global climate change.”

    I’m unclear as to what you are saying here. Are you saying that the 4 pieces of physical evidence that you mention demonstrate that *all* of the warming in the thermometer record is due to anthropogenic CO2?

    • Brandon Shollenberger

      No he isn’t. What he’s saying there is the evidence he lists demonstrates that humans are causing global warming. That doesn’t say how much warming has been caused, just that some amount of anthropogenic warming is undeniable.

      • Then what would be wrong with the statement that there is “‘likely’ a ’substantial’ anthropogenic contribution”? That seems a stronger statement than “some amount of anthropogenic warming is undeniable”, as it’s the size of the “some” that is the issue.

      • Brandon Shollenberger

        I think it’s questionable which of those two statements is stronger, but that isn’t important. What’s important is when I said “some,” I didn’t mean to suggest Andrew Lacis has some unclear value in mind. I used “some” because I don’t know what value he has in mind. I’m sure he considers it substantial, but beyond that, I’m not willing to guess.

        If he were writing that sentence instead, he might replace “some” with a more specific description. Perhaps he’d say “at least 70%,” or maybe he’d just say “most.” The vagueness here comes from me not wanting to put words in his mouth, not from him having a vague position. I’m sorry my wording caused confusion.

        It would obviously help if he actually said how much warming is directly attributable to anthropogenic influence, but you don’t need him to do so to understand his position.

      • “It would obviously help if he actually said how much warming is directly attributable to anthropogenic influence, but you don’t need him to do so to understand his position.”

        I rather think that I do.

      • Brandon Shollenberger

        I don’t see why you would. You could put in a value like 70% as a placeholder, and that should be enough to make clear what he was saying. I don’t understand why that wouldn’t work for you, but if it doesn’t, I’m sorry I can’t be of more help.

      • Brandon,

        “I don’t see why you would. You could put in a value like 70% as a placeholder, and that should be enough to make clear what he was saying. I don’t understand why that wouldn’t work for you, but if it doesn’t, I’m sorry I can’t be of more help.”

        I understand that you are trying to help. I appreciate that. But without Mr Lacis actually saying what he thinks the IPCC should have said, it’s difficult to know what his position actually is. If it was, say, “75% of warming is undeniably due to anthropogenic CO2”, then he’d have a lot more evidence to produce than his 4 points.

      • “No he isn’t. What he’s saying there is the evidence he lists demonstrates that humans are causing global warming. That doesn’t say how much warming has been caused, just that some amount of anthropogenic warming is undeniable.”

        Yes he is. If he did not intend that paragraph to mean that all global warming is attributable to anthropogenic causes, then it is just poor writing, and he should say so. But as written, the second sentence makes clear that he is rejecting both “likely” and “some” as being understatements.

        He is claiming that the IPCC is exaggerating uncertainty, and understating the amount of attribution. Since “some” can refer to any amount less than 100%, it makes it clear that Lacis’ use of the word “all” was intended exactly as James Evans reads it.

      • Brandon Shollenberger

        GaryM, claiming text means something doesn’t make it so. The most relevant part of his comment said humans are “causing global warming to happen.” Neither this, nor anything else, says all the warming seen in the modern temperature record which is directly attributable to anthropogenic.

        If you think otherwise, you ought to explain what part of his comment says humans are responsible for 100% of the warming seen in the modern temperature record.

      • Brandon Shollenberger.

        James Evans pointed out “what part of his comment says humans are responsible for 100% of the warming.” I did in a comment below as well.

        It’s that pesky word “all.”

        Lacis expressly rejects the IPCC’s use of the word a “substantial” factor, and argues: “Based on this basic input data, the relevant physics is inescapably clear that the increase in atmospheric CO2 is indeed enhancing the strength of the terrestrial greenhouse effect, and thus causing global warming to happen – all directly attributable to human industrial activity.”

        There is simply no other way to read that sentence as written,

        What precisely do you think he meant in writing “all directly attributable to human industrial activity?”

        The increase in atmospheric CO2 – enhances the terrestrial greenhouse effect – which causes global warming – which is all attributable to human industrial activity.

        If he meant only that the “increase in CO2” was “all” a result of human industrial activity, then the paragraph is poorly written. But that still does not change the meaning of the paragraph. “Thus causing global warming to happen.” Not “some” global warming, not “most” global warming, global warming period.

        I don’t know what the author thinks, but I can read what he writes. And what he wrote is only consistent with attributing all of global warming to human industrial activity. Once again, if that is not what he meant, it is easy to say so. And since the entire point of this guest post is to clarify the misconstruction of his position by skeptics, this would not seem to be asking too much. In the abscence of a clarification/correction….

      • Yes, this is his point. He doesn’t like the IPCC statement that very likely (95% sure) most (> 50%) of the warming is anthropogenic, He says all of the warming is anthropogenic. The expected magnitude comes from physics, and fully accounts for the observed change.

      • Brandon Shollenberger

        Jim D, first, “very likely” meant >90%, not >95%.. Second, you should see my comment directly above yours for why I say you’re wrong.

      • OK 90%, even worse from his point of view.
        This is what he said.
        “Based on this basic input data, the relevant physics is inescapably clear that the increase in atmospheric CO2 is indeed enhancing the strength of the terrestrial greenhouse effect, and thus causing global warming to happen – all directly attributable to human industrial activity. To characterize this fully documented global warming only as being ‘likely’ a ’substantial’ anthropogenic contribution is clearly resorting to unscientific understatement that does nothing to clarify or accurately portray our understanding of global climate change.”
        Note the use of the word “all”. I think he means 100% and not just the CO2, but the global warming too.

      • Brandon Shollenberger

        Jim D, it is true he used the word “all” in that paragraph, but it was not referring to the amount of global warming. Read that paragraph again, but this time read “all” as referring to everything he wrote just before (all of what was listed in that sentence).

        If you do so, you’ll see “all” has a clear antecedent in what came before it. This makes far more sense than it referring to the percentage of the warming seen in the modern temperature record, something which hadn’t even been brought up.

      • Brandon, “all” of what “is directly attributable to human industrial activity”? I don’t see how to interpret it, if it doesn’t mean global warming.

      • Brandon Shollenberger

        Jim D, as I said just above, it would be referring to everything he mentioned previously in that sentence. Specifically, it would be referring to the increase in CO2 enhancing the greenhouse effect and that causing global warming. It would be akin to if you replace “all” with “both of which are.”

      • I’m with Jim D on this one.
        Especially when you consider:

        Whether humans like it or not, and whether humans realize it or not, global warming has been so, and continues to be, fully under human control via fossil fuel burning

      • Brandon Shollenberger

        Peter317, your comment makes no sense. Andrew Lacis said global warming is the trend you’d get if you remove natural variability, and that this trend was caused by anthropogenic influences. If he defines global warming this way, obviously the quote you offered would be true. Moreover, since his definition of global warming specifically excludes natural variability, he couldn’t possibly say all warming seen in the modern temperature record is due to humans. That warming and global warming are not necessarily the exact same, so it wouldn’t make sense for him to claim what you guys are saying he claims.

        Ultimately, you guys are picking an interpretation which requires Andrew Lacis have said something which was obviously wrong and contradicts himself. You are doing this while ignoring a perfectly sensible interpretation which offers no negative impressions. If you think the interpretation I offered is wrong, I’m happy to hear an explanation, but otherwise, your behavior seems questionable.

        I’m quite fine with people being confused about what a person means, but if you can’t point to something wrong with the interpretation I offered, there is no basis for these criticisms of Andrew Lacis. You could say he was less clear than he should have been, but that’s it.

      • Brandon,

        Those are his words, not mine.

        “… fully under human control via fossil fuel burning” leaves no room for any other cause, does it?

      • Brandon Shollenberger

        Peter317, if you actually responded to what I say, this exchange would probably be more productive. It would prevent us from talking past each other, as you just did. The second sentence of my latest comment answers your current response completely. Namely, if Andrew Lacis defines global warming as the trend you get when you remove natural variability, obviously there is no room within the trend for any natural variability. This is neither surprising nor problematic.

        What it means is he accepts the modern temperature record may currently show some warming due to natural variability, but that warming is not part of what he calls global warming.

      • Brandon,

        I’ve read it over and over again, and I fail to see where I’ve taken anything out of context.
        I think we’ll just have to agree to disagree on this, otherwise we’re in danger of hogging the thread.

      • Brandon, Lacis has also said that natural variability cancels out in the long term average, which is probably why it is not an issue for what he would define as climate change.

      • “…warming and global warming are not necessarily the exact same….”

        This is becoming a Joshuaseque argument of semantics. But while Andrew Lacis is certainly under no obligation to clarify his post, I think most will take this point as it is clearly written (Brandon’s tortured parsing notwithstanding) if he fails to do so.

        I for one will demur. Lacis will either comment further that he does not believe that “all” of global warming is attributable to human causes, or he won’t.

      • Brandon Shollenberger

        Peter317, while you were rereading it, did you happen to go back and look at my responses to you? To this point, you have still not addressed anything I’ve said. Given that, it’s hardly surprising we may have to agree to disagree.

        Jim D, that’s quite correct.

        GaryM, you’ve accused me of tortured parsing, but you’re the one who has been completely unwilling to address an alternative interpretation. I explained, simply and clearly, why the interpretation used to criticize Andrew Lacis is wrong. Neither you, nor anyone else, has said a word about how my interpretation is flawed. Without addressing my contrary position, you now say you’ll demur and leave the discussion. Ultimately, this means you have done nothing more than raise false criticisms, ignore your critics then level baseless attacks against them in what appears to be an attempt to diminish their credibility, and retreat rather than have an actual discussion.

        Quite frankly, we’ve reached the point where the dialogue breaks down. I’ve repeated the same position time and time again, and none of those who disagree with it have made any effort to explain how it is wrong. This leaves us with one inescapable conclusion. Unless and until someone can actually show my interpretation does not make sense, there is no basis for these criticisms leveled against Andrew Lacis.

      • I responded to you in detail at 3:02 above. You did not reply. Do not bother yourself by doing so now. I am not really interested in reading again what you think the post means. There really is nothing more to be gained at this point by redefining words and quibbling over context.

        But I would be interested in a response from the author himself. If he comments, great. If he doesn’t, no big deal.

      • Brandon, Of course I read your replies, and I do know what you’re saying.
        But If you’re naive enough to believe that Lacis doesn’t know exactly what he’s saying then so be it. I’m not prepared to argue the toss.

      • Brandon Shollenberger

        Gary M, I did not reply to that particular post because I dealt with the exact same point here, here and here. After making the first of those comments, I saw no reason to reply to your lengthy comment as well. It would just be me repeating myself, and it would cause more clutter. I assumed you’d be able to find this fork and see my responses, and clearly, you have. For whatever reason, you apparently haven’t understood my responses, but you have clearly found where I addressed the position you advanced in the comment you say I didn’t reply to.

        If my interpretation isn’t clear enough for somebody, I’d be happy to restate it. However, neither you, nor anybody else, has actually discussed any supposed flaws in it

      • Brandon,

        I’ve been reading this whole string regarding what Andrew Lacis was stating in his comments. I don’t believe a person needs a degree in the sciences to reach the conclusion that he is saying any statement by the IPCC that that doesn’t attribute all (or at least all that matters) AGW to CO2 is performing a disservice to policy makers and the public. Trying to argue he meant something else based on (a faulty interpretation of) grammer looks like a fools errand.

  7. cementafriend

    I do not know what Andrew Lacis’s qualifications are but it is clear that he has little knowledge of heat and mass transfer. It is very likely he has never opened up a book such as Perry’s Chemical Engineering Handbook and followed up some of the vast collection of research information such as that carried out by Prof Hoyt Hottel, Prof Thomas Chilton & Dr Allan Colburn. Chemical Engineering of course goes much further than heat & mass transfer -mathematics, thermodynamics, fluid dynamics, particle dynamics, reaction kinetics, measurement and control, adsorption, energy conversion etc which are all useful and necessary to get some understanding of climate complexity. Radiation absorption and emission of CO2 in the atmosphere is insignificant in the overall complexity.. Anyone who thinks CO2 is of major importance clearly has no understanding of technology.

    • Andy Lacis has a B.A. in Physics, a M.S. in Astronomy and a Ph.D. in Physics. He has several hundred refereed journal publications.

      • Unfortunately he has his mind made up on a lot of open questions. Are we supposed to argue all these issues from scratch, to prove yet agian the existence of the scientific debate?

      • What’s your opinion on the paper he talks about, David?

      • The fact that Andy Lacis reads the blog and provided a guest post demonstrates to me that he has an open mind

      • But his claims are ridiculously strong. There is not an “I think”, “this suggests” or “it appears that” in the pile. He has presented the basic, lengthy case for AGW as a series of bald assertions, raising at least 100 separate scientific arguments. The hundreds of counter arguments are well known. Are we supposed to present all of these? To what end?

        If so then I will start by noting that the climate appears to be a far-from-equilibrium system, hence Andy’s basic premise is false. That should do it, as far as argument by assertion is concerned.

      • steven mosher

        david, if he said ” I think” your response would be that its an open question and not proved. The most interesting thing is they tested Roys conjecture and found that Roy was wrong. The second most interesting thing is understanding the difference between condensible andnon condensible GHGs. do you get the point of that at least

      • Unfortunately, his rude uniformed attitude really shows that he is just very confident that he can talk down to the unwashed and show off to his AGW promoter pals how big he is.
        He may impress his peers, but he is losing completely in the public square.

      • Mosh, my point is that these are open points, so his language is ridiculous.

      • If so then I will start by noting that the climate appears to be a far-from-equilibrium system, hence Andy’s basic premise is false. That should do it, as far as argument by assertion is concerned.

        You can have a system that is “far-from-equilibrium” yet it still exhibits steady-state properties. A photo-voltaic cell under constant illumination is a good example of this. The PV cell will show constant current-voltage characteristics under a load, even though it is far from equilibrium, as the incident photons are in no way in equilibrium with the output current.

        Solution: don’t use the word equilibrium, and instead substitute the word steady-state or even quasi-equilibrium if we want to be able to solve practical problems.

      • Dr. Curry,
        Perhaps Dr. Lacis would find a much more hospitable reception if he posted something not aimed to insult the readers, and then actually had a conversation on the thread.
        Posting a bomb and then leaving is not really accomplishing very much.

      • Dr. Lacis sticks to old theories that are unvalidated by today’s science and disagree with observations. We are in the 21st century, and an average junior level knows more about the earth than Fourier, Tyndall, and Arrhenius combined. Dr. Lacis is not an open minded for he still lives in the past.

      • steven mosher

        which points do you think are open to debate? As student of philosophy I think the existence of your mind is open to debate ( the problem of other minds) but not a very interesting debate.. only a few of us would enjoy it. scientifically, I don’t think that RTE are open to debate. However, I debate them all the time. its not very interesting to me because the other side is just ill informed, but I still debate them. so which statements of his do you think are open to an interesting debate.. not mere gainsaying by the ill informed, but real debate

      • In science, all points should be open for debate. In pseudo-science not so much.

      • And I’m sure he has never been censored on “judithcurry.com” …. which appears to be the gold standard whenever one is in danger of being right about something and not afraid to say it directly.

      • cementafriend

        There is a lot more to heat transfer than radiation (where the S-B law applies only to black bodies in a vacuum and needs adjustment factors). For a example, phase change which in the atmosphere mainly concerns evaporation of water at the surface (or boundary between surface and the fluid atmosphere) and condensation in the various layers of the atmosphere leading to cloud formation and precipitation. Is cloud formation part of physics? Certainly, not the physics I studied. There is at this time no one that fully understands clouds so there is no one that understand climate change. Convective heat transfer (natural and forced) also has its complexities.

      • Dr. Curry:
        Perry’s Chemical Engineering is a great book. As you will find, it contains so much about heat transfer and thermodynamics that are transferable to climate studies. I used it extensively in my climate calculations.

    • I do not know what Andrew Lacis’s qualifications are…

      Do you see how his name at the top of the post is in blue letters?

      That means that it’s hypertext. You can click on his name, and like magic, it will take you to other webpages. If you use that process and explore a bit, you can find out information about his qualifications.

      Hope that helps.

  8. An amazing sequence of wildly strong, and unsubstantiated, claims, completely lacking in scientific caution. Truly a tour de force of false certainty. But such a list of wild claims is valuable in its own way, as they are plainly spelled out. The trunk of the climate change issue tree, as it were.

    • steven mosher

      yes wild claims like: water condenses out of the atmosphere, C02 does not.. and the importance of that in viewing GHGs as a “control knob”.. unforntunate metaphor

      • Claiming to know that CO2 is a control knob is certainly one of the wild claims. So is claiming to know that the climate system is in equilibrium, for that matter. There is evidence that it is a far from equilibrium system. Claiming to know that natural variability evens out on any specific time scale is a wild claim. Claiming to know that solar input is minor is a wild claim. Shall I continue? There are too many to list. Reading this post one would never know that the scientific debate exists. How silly is that?

      • steven mosher

        you should continue cause you missed on the first two. the control knob is an unforntunate metaphor, but once you understand what he is talking about its pretty clear. The issue, the open issue, is what is the GAIN on that knob. If you drop all the H20 from the atmosphere, guess what? it comes back after a couple weeks.. its a feedback. If you drop C02 to zero.. frozen world. The point of C02 and the other non condensible GHGs should be clear.. they “control” or force the system. If you drop C02 to zero its doesn magically come back as water vapor does. I think the terminology of “control knob” is very unfortunate because of all the collateral concepts it imports, but in terms of describing the role it plays its not a horrible metaphor. On the equillibrium claims, read the SI to understand how gavin ( I suspect it was gavin) handled that issue.

        So a debate does exist. What is the gain on that knob?

      • quote
        If you drop all the H20 from the atmosphere, guess what? it comes back after a couple weeks.. its a feedback. If you drop C02 to zero.. frozen world.
        unquote

        If you drop atmospheric water vapour to zero, it will reconstitute. If Henry’s law holds then I reckon CO2 would reconstitute although I have no idea of the time frame. So, to make the two cases equivalent you should, in the water vapour case, also remove the liquid water reservoir which is the cause of the water vapour restoration. Then, in the CO2 case, you should… oh, look, same thing.

        The control knob of the climate is not CO2 or water vapour. It is the oceanic/atmospheric boundary layer. This layer, microns thick and covering 70% of the entire platetary surface, determines: the rate of CO2 and water vapour fluxes; the albedo of smooth and ruffled open water; the nutrient status of the lit surface layers; the production of mechanically and biologically mediated aerosols; the albedo of 23% of the global surface from essentially zero to 60 by modification of boundary layer cloud . (That’s the other boundary layer, the atmospheric one.)

        Dr Lacis expresses very clearly the determined view that all other effects are dwarfed by CO2. He is to be congratulated on his certainty in the face of uncertainty.

        JF

      • the control knob is an unforntunate metaphor,
        Metaphor? That is his thesis.

      • So is claiming to know that the climate system is in equilibrium, for that matter. There is evidence that it is a far from equilibrium system.

        Of course it is a far from equilibrium system. The earth is not in equilibrium with the sun. The earth keeps on getting hit with the sun’s photon’s and it is just responding to the continuous forcing function.
        As I said in a previous comment above, this doesn’t mean that we can’t try to solve these kinds of systems. Of course we can, it is called a steady-state response function.

      • steven,
        “thermostat” is certainly a poor choice, but is Lacis’ deliberate choice.
        And since he ignores the historic record regarding CO2 and climate, he comes across on this far different than what I am sure he wished.
        And then getting to his cartoon view of skeptics. It has already been pointed out that if he in the same article speaks about something like skeptics in such an incredibly ignorant fashion, why should his science be any less so?

      • there is no logical connection between the things he says about skeptics and the science. Look Jones violated FOIA, but that didnt make his science wrong. His science stands or falls on the maths. Now its easy for you to find a personal flaw and discount the science you dont understand.
        So, Andrew ais wrong about the skeptics and right about the science. go figure, mann was wrong about the skeptics and wrong about the science.

        for the history of C02 and how its connected to this work, I suppose I would recommend Alley

      • for the history of C02 and how its connected to this work, I suppose I would recommend Alley

        I had a nice discussion with Waughan Pratt about Alley’s hilarous statements on the history of CO2… and mostly about the history of its effects (none).

        In short, he talks a lot about CO2-temperatures correlation in the past, though never questionning which comes first and showing no evidence (of course) for a CO2 –> temperature relationship. Then, quickly adressing that crucial question, he says: “… and how do we know that…? and answers: “Because it’s physics! It’s physics, stupid!

        Yes, it’s somehow “connected to this work“, if you mean Lacis’ series of wild claims we have here…

      • steven,
        When someone is wildly illogical and deceptive in one area, then the chances of them containing that failing to only one area is very small.
        Since Lacis has built a career enabling or pushing the idea of a climate catastrophe, and relies on conspiratorial fantasies to defend it, rather than actual facts, I think it is not illogical at all to wonder what else he has wrong.
        Something to ponder is this:
        Why has the climatocracy refused to come clean about climategate, and why have they apparently avoided foia even more since, and why are they apparently taking steps (illegal?) to make sure there are no records of their work or communications?
        That is not the behavior of a group that is dealing in truth.
        Lacis’ post here is part of that same spectrum of bad anti-science unethical behavior.
        Why should anyone believe anything he says at this point?

      • steven mosher | October 9, 2011 at 11:57 am | Reply

        “GHGs as a “control knob”.. unforntunate metaphor”

        Not another “unfortunate metaphor”. Blimey let’s see, how many is that now.

        . “Greenhouse Effect”
        . “Greenhouse Gases”
        . “Heat Trapping Gas”
        . “Back Radiation”
        . “Atmospheric Blanket”
        . “control knob”

        I think that pretty much covers the entire silly hypothesis. AGW is derived primarily from the use of six main “unfortunate metaphors” and propped up by every logical fallacy ever documented and many more yet to be so.

        http://en.wikipedia.org/wiki/List_of_fallacies

        What is the difference between Mosher’s pathetic “unfortunate metaphor” excuses for such logical fallacies, and the response you get from a child when they are caught lying?

        NOTHING!

    • To some skeptics they are wild ideas, to others like Spencer and Pielke, they are too obvious to even talk about.

  9. “Unfortunately, such subtle misinformation is being actively promoted by the fossil fuel lobbyists and their growing multitude of dupes and minions”

    Pass out the tin foil hats. This is beyond preposterous. Dupes and minions? You left out lackeys.

    • My apologies for the somewhat strident tone in language.

      I was merely following that old and trusted sage advise of when in Rome, try conversing in the local vernacular.

  10. Based on this basic input data, the relevant physics is inescapably clear that the increase in atmospheric CO2 is indeed enhancing the strength of the terrestrial greenhouse effect, and thus causing global warming to happen – all directly attributable to human industrial activity. To characterize this fully documented global warming only as being ‘likely’ a ’substantial’ anthropogenic contribution is clearly resorting to unscientific understatement that does nothing to clarify or accurately portray our understanding of global climate change.

    In other words, the science is settled.
    Can we quote you on that?

  11. This paper is a “one year anniversary” non-event, in an apparent attempt to get everyone’s attention off of IPCC, Climategate, unexplained lack of warming of both the atmosphere and the upper ocean, unusually harsh winters across the northern hemisphere, loss of public confidence and trust and a host of other worries for the “alarming AGW faithful”.

    Although the approach used is radically different, the conclusions reached are similar to those of the lecture given by Dr. Richard B. Alley entitled:
    “Biggest Control Knob – Carbon Dioxide in Earth’s Climate History” at an AGU meeting on 15 December 2009
    http://www.agu.org/meetings/fm09/lectures/lecture_videos/A23A.shtml

    While Alley “interprets” reconstructed data series from selected periods of our geological past to try to prove his “control knob” hypothesis (and a 2xCO2 climate sensitivity of 3°C) the Lacis et al. paper relies on model simulations (hey, Gavin Schmidt is one of the co-authors).

    Alley’s presentation has been debunked elsewhere, but what is missing from both studies is empirical evidence based on real-time physical observations or reproducible experimentation.

    Result: No news here IMO.

    Max

  12. Thank you, Dr. Curry, for this extensive coverage of what you believe the physics to be on the subject of CAGW. As an avid reader of your blog since it started, and many other sources of information, I do not believe that what various people have written support all the conclusions you espouse. It would be far too long to give the reasons why I diagree with you, but some of the specific items that you mention which I believe are just plain wrong are as follows:-

    “The greenhouse physics, (and the increase of atmospheric greenhouse gases) as the fundamental basis for global warming, are well founded. (My brackets)

    Solar forcing is cyclical and small, while the GHG residence time is very long.

    Fortunately, the global warming component, it being tied directly to the growing strength of the terrestrial greenhouse effect, is a uniquely radiative effect that can be addressed independently of the other climate complexities

    Geological evidence shows that 450 ppm of atmospheric CO2 is the critical level that is needed to sustain polar ice caps, although the time scale for the melting of polar ice caps is many centuries.”

  13. “Geological evidence shows that 450ppm of atmospheric CO2 is the critical level that is needed to maintain polar ice caps….”

    Really? The sort of evidence that you would characterise as “scientific”?

    If this is the science that politicians should “keep in mind” then we are in for some truly cranky policy decisions.

    • I actually think it is a fascinating paper that really makes you think.

      The premise that Lacis presents is: “what happens if we turned off the GHG property of atmospherics CO2?”

      The results, summarized in Fig. 2, show unequivocally that the radiative forcing by noncondensing GHGs is essential to sustain the atmospheric temperatures that are needed for significant levels of water vapor and cloud feedback. Without this noncondensable GHG forcing, the physics of this model send the climate of Earth plunging rapidly and irrevocably to an icebound state, though perhaps not to total ocean freezeover.

      How does one systematically argue this and then argue the other etxreme of a situation like Venus, for which the role of CO2 obviously keeps the planet in an absurdly hot state.

      So the control knob of CO2 is there, and that is what they are encouraging people to keep in mind.

      • WHT,
        And if we turned off the chemical/physical properties of oxygen, we could all be brain dead Malthusians.
        And if a blackhole drifted into solar space, we would be smashed to a pulp before passing the event horizon.
        Lacis’ experiment is useless.

      • Lacis’ experiment is useless.

        Limiting evaluations and Gedanken experiments are useful in the absence of a controlled experiment. They also provide sanity checks for the models.

      • No, they are no more useful than reading back issues of Analog Science Fiction magazine for PhD thesis ideas.
        Turning off the GHE means Earth starts heating and cooling like Luna, excepting for a different diurnal cycle.
        I jsut wish these great experiemtners would actually address why CO2, according to the history they claim to believe, does not act as a thermostat, but is very much a delayed response.
        But ignoring skeptics is a specialty of the climatocrats, so I am not expecting an answer any time soon.

      • Turning off the GHE means Earth starts heating and cooling like Luna, excepting for a different diurnal cycle.

        What happened to the 33 degree warming shift? How convenient of you not to mention it.

      • Hunter,

        The experimenters have actually addressed why CO2 lags and acts as a thermostat.

        It’s quite simple really… during an ice age, something happens external to natural factors that causes the temperature to rise a little bit (maybe a shift in orbit, or something else). That temp rise then causes something to outgas CO2 (possibly oceans, but maybe not) that then raises the temp even more (along with other GHG that feedback and enhance the warming), which causes more outgasing. This continues until some unknown factor either greatly slows the output rate of whatever is outgasing or something else (like plants) start taking in all the extra CO2 or something happens to the other GHG’s, or something external causes a bump downward in temp (or a combination of the 4 as the CO2 doesn’t just level off but drops along with the temp). Since CO2 cannot be removed as fast as it was initially outgased, the CO2 then acts as a sort of parachute to slow the temperature decrease back to the iceage.

        We know all that above is true because scientists cannot figure out any other way for the current temperature to rise that much today other than man-caused CO2 plus feedbacks from other GHG’s.

        You see, simple. You are a fossil fuel dupe or minion if you question that rock solid explanation.

  14. Judith –

    Did you explain to Andrew how rude some of the “denizens” get when they’re feeding on red meat?

    It would be interesting to read “skeptical” viewpoints on the paper Andrew writes about. I wonder if any “skeptics”:will step up to the plate. Of course, I suppose it’s much easier to “reverse appeal to authority” by questioning Andrew’s qualifications, or to blithely talk of “wild claims?”

    • Joshua, I will be weeding out the content free attacks (I’ve already deleted a bunch of comments). Hopefully we can get a good discussion going.

      • My lack of content in the post you deleted was an objection to this article along the lines of David Wojicks comment above. But if you insist …
        1) Why does temperature precede CO2 changes by 500-1000 years ?
        2) Why has temperature not risen in the last 15 years or so ?
        3) Why was the temperature in the Holocene so much higher than today even though CO2 levels were so much lower ?
        4) Is there any conclusive evidence that the T rises over the last 150 years are definitively not natural ?

        And why is it OK to use language like “fossil fuel lobby minions” and “climate change deniers” ? From an academic for gods sake.

      • On technical threads with a guest post, I do insist. Thank you for your modified comment.

      • Judith the poster has rather set the abusive tone here, with his “fossil-fuel minions” mouth-breather drivel. If you are going to censure comments for that sort of abuse, why not start with the original post? Could you not have asked Lacis to remove the teenage taunts before publishing (you would, after all, have been doing him a favour)? You would then be on firmer ground when censuring the comments.

      • Joshua, I will be weeding out the content free attacks (I’ve already deleted a bunch of comments). Hopefully we can get a good discussion going.

        Thanks Judith.

        Actually, I’d appreciate it if you delete that 10:11 post. of mine also. It was stupid – and served no real purpose w.r.t. advancing a good discussion. Apologies.

        Still, I would be interested in reading discussion about the paper Andrew discusses – the related posts at Pielke Sr.’s blog are interesting.

      • Willis Eschenbach

        curryja | October 9, 2011 at 10:17 am

        Now if only you would weed out the content free posts like this attempt by Lacis to prop up his paper … this is another modeling exercise, models all the way down.

        Lacis keeps talking about how he has demonstrated a host of things, but he has only demonstrated them in model-world. This lack of distinction between what model results show to be unalterable truth in model-world, and what observations actually show about the real world, is a consistent problem with modelers, one that Lacis has so badly that he doesn’t see it at all.

        You appear to be caught up in this as well, Judith. For example, you say:

        The text of the paper provides the supporting science and illustrates the key role that atmospheric CO2 plays in the operation of the terrestrial greenhouse effect, perhaps more directly than has been done before.

        No, the paper provides the supporting MODEL RESULTS, not supporting science. And if you weren’t caught up in the modeler’s dream, you would have written:

        The text of the paper provides the supporting science and illustrates the key role that atmospheric CO2 plays in the operation of the MODELED terrestrial greenhouse effect.

        This is far from a trivial or unimportant difference. The model can only show us the beliefs and ideas of the programmer, and we have no evidence that those beliefs and ideas are tested or correct.

        If I were king, I’d require that people put the word “MODELED” in every one of these kind of specious attempts to slide model results past our guard as if they were actually evidence about the real world.

        This post strikes me as very desperate, just another modeler clutching at straws … but unfortunately, they are not real straws, just modeled straws, so he’s likely to go down with the modeled ship …

        w.

      • Richard Hill

        “All models are wrong, but some are useful.” So proclaimed statistician George Box 30 years ago, and he was right.
        As an engineer/programmer who has worked with simulations for many years (in a very different area), I fully agree with Willis. Also the use of the word “experiment” to refer to a model run grates.

      • “All models are wrong, but some are useful.” So proclaimed statistician George Box 30 years ago, and he was right.

        Everyone uses this quote to mock any kind of mathematical analysis (which is all a model is BTW). But if you look at the context of Box’s original quote, the preceding line is “The fact that the polynomial is an approximation does not necessarily detract from its usefulness because all models are approximations.” No big deal, as Box basically is saying that models don’t always do these things accurately enough, but it has nothing to do if the model is necessarily wrong conceptually. The lazies quoting this don’t realize that all Box was criticizing was numerical accuracy, and everyone else is applying it to some strawman of the futility of modeling.

        Go look up the original Box quote. It is pretty funny how it has been twisted to meet people’s preconceived notions as to what Box meant. It’s all about approximations and errors, both epistemic and aleatory interfering with how well a job we can do with the model.

      • Your defense begs the question:

        “No big deal, as Box basically is saying that models don’t always do these things accurately enough, but it has nothing to do if the model is necessarily wrong conceptually.”

        The models have been shown conceptually correct how? We are really arguing the “useful” in the Box statement.

      • Your defense begs the question:

        “No big deal, as Box basically is saying that models don’t always do these things accurately enough, but it has nothing to do if the model is necessarily wrong conceptually.”

        The models have been shown conceptually correct how? We are really arguing the “useful” in the Box statement.

        Box had a throwaway line that has been totally twisted by anti-modelers. His previous sentence in that quote said that if models were numerically accurate enough they could prove useful.

      • Willis

        This is far from a trivial or unimportant difference. The model can only show us the beliefs and ideas of the programmer, and we have no evidence that those beliefs and ideas are tested or correct.

        Willis, your statement is supported by a concession made by an expert:


        …we are no where close to knowing where energy is going or whether clouds are changing to make the planet brighter. We are not close to balancing the energy budget. The fact that we can not account for what is happening in the climate system makes any consideration of geoengineering quite hopeless as we will never be able to tell if it is successful or not! It is a travesty!

  15. “(1) a description of our recent water vapor feedback/forcing experiments”. Can anyone say what these experiments actually consisted of and what the results were? Were they carried out in a lab somewhere?

  16. Hank Zentgraf

    Andrew Lacis, your use of pejorative language reveals your lack of confidence in your own work.

  17. Morley Sutter

    There is difficulty with the analogy of CO2 being the “control knob” of global temperature. Control knobs as are present on audio systems and thermostats always alter sound or temperature when they are rotated unless the system is not working properly. For the last decade, atmospheric CO2 has increased without a significant increase in the average surface temperature of the earth. Has the control knob come loose?

    • steven mosher

      No, there is a lag in the system. Think rudder on an oil tanker. The control knob on your stereo act instantaneously. increases in GHGs do not. The point of the control knob metaphor is tied to the fact that GHGs do not rain out of the sky, H2O does

      • Steven Mosher wrote:

        “The point of the control knob metaphor is tied to the fact that GHGs do not rain out of the sky, H2O does”

        CO2 dissolves in water, CO2 rains from the sky at the same time H2O does.

      • what part of non condensible do you not get

      • steven mosher | October 10, 2011 at 3:29 am | Reply

        “what part of non condensible do you not get”

        What part of pH 5.6 – 6.0 for rain water don’t you get Mosher?

        What part of H2CO3 don’t you get Mosher?

        What part of relentless fool/ deliberate deceiver don’t you get Mosher?

      • Steven Mosher,

        When is the last time that all, or most of, or a great deal of, or half, or 12% of the water rained out of the sky, and was not immediately replaced?

      • Exactly. I keep hearing the statement that H2O precipitates out of the sky as if it disappears altogether.
        Where it precipitates in one place, it is replaced via evaporation in another.
        Radiation doesn’t distinguish between WV from last week or WV that just evaporated from the ocean or ground.

        In fact, one can argue that because H2O precipitates and evaporates, it has a much larger influence on climate than CO2 ever can.

        This point, which Lacis and like minded others who keep repeating it, needs to be clarified.

      • Don that is the point! You run a GCM and drop the C02. see what happens. you drop the water and as andy notes.. it gets replaced. THAT is what makes the not condensible GHGs the CONTROL…

      • steven,
        the historical record suggests that CO2 is a very unique rudder: it turns after the ship has turned.

      • steven mosher | October 9, 2011 at 12:02 pm | Reply

        “GHGs do not rain out of the sky”

        Is it even possible to be more confused or deliberately deceptive than this?

        Pure water has a pH of 7.0.

        Rain water has a pH of 5.6 because it contains H2CO3, carbonic acid.

        Can you credibly deny all knowledge of such basic facts?

        I have said it before and I will say it again. There are three kinds of AGW proponents, liars, fools and lying fools.

      • Pure water has a pH of 7.0.

        Rain water has a pH of 5.6 because it contains H2CO3, carbonic acid.

        Can you credibly deny all knowledge of such basic facts?

        Indeed CO2 has fascinating properties and is inscrutable to many.
        For instance, how can something so important to life, also be considered a pollutant?

  18. “(3)…The magnitude of their [water vapor and clouds] feedback sensitivity is also reliably known, to within order of 10%.” This does not seem to correspond with other assessments of the effects of clouds. For example, AR4 WG1 assesses the level of scientific understanding of cloud albedo effects as “low.” Can you please clarify?

    • Exactly the point I was going to make. Table 1 in Soden & Held “An assessment of climate feedbacks in coupled ocean-atmosphere models” (Jnl. Climate, 2006) shows cloud feedbacks varying from 0.14 to 1.18. Hardly within 10%. And observationally-based estimates of actual cloud feedback from different studies show even larger variations.

  19. Thanks for this good summary. Will you kindly consider addressing a few additional related issues.

    It is my understanding that few, if any, of the important physical phenomena and processes related to clouds are treated from first principles. These include the vertical motions of clouds, all the radiative-energy-transport characterizations of the non-vaporous ( gaseous ) phases of water in the clouds, the vertical locations of the cloud tops, the distributions of the non-vaporous phases of water within the clouds, and all aspects of precipitation of liquid- and solid-phase water from the clouds. There are very likely many others. Discussions of the accuracy of radiative-energy transport in the presence of the vaporous phase of water is all well and good, but is that the dominate physical phenomena of interest when clouds are the focus?

    How can we be assured that these parameterizations have not introduced phenomena and processes that are not in accord with the real-world systems of interest. For example, have sensitivity investigations of the effects of uncertainties in the parameterizations been conducted so as to show that these are not important to the conclusions of the papers cited in your post.

    Conservation of energy. Some GCM numerical solution methods do not conserve energy ( or mass ) but instead include use of energy ( and mass ) fixers to attempt to conserve energy ( and mass ). Is there information available to show that the magnitude of these ad hoc conservation fixers are sufficiently small so as to not affect the results of the papers cited in your post. What is the magnitude of the corrections compared to that of the signal of interest?

    The physical system of interest is not now and has never been in equilibrium. What is the estimated time scale necessary to ensure that the periods when there is an excess of net energy loss from the system is balanced by those for which there is an excess of net energy input into the system. Are the GCM calculations of the radiative-energy budget at the TOA in accord with measured data?

    Thanks

    • Dan,

      I would not say that GCM clouds are computed from first principles. Cloud physics is quite complex, so we need to make use of a number of empirical relationships that are established from field or laboratory measurements. The end product of the cloud parameterization are model generated cloud properties, distributions, and variability that resembles the real world. Given the model generated clouds, we can calculate their radiative effects on atmospheric fluxes accurately for both solar and thermal radiation. It is the same sort of radiation modeling techniques that are used in calculating GCM radiative fluxes as in retrieving cloud information from remote sensing measurements.

      In the so-called model numerics, a great deal of care is used in formulating the differential equation solution approach so as to explicitly conserve a number of quantities (mass, energy, water substance, angular momentum, linear momentum, vorticity) that are all important for the accurate representation of atmospheric dynamics.

      Equilibrium is a relative concept in climate modeling. In the real sense, nothing is ever in equilibrium. Solar radiative forcing varies enormously through the course of the day. Then there is the seasonal variability. It might be said that the climate system is always striving to approach equilibrium. But if we select a time period of one year, then it is more appropriate to speak of the Earth being in ‘equilibrium’ with the periodic forcing, if the periodicity of that forcing remains trendless.

      The GCM calculations of the radiation budget are indeed consistent with measured data. The problem is that satellite flux measurements are not precise enough to validate GCM fluxes to the extent that is desired. Because of the large ocean heat capacity, the global surface temperature does not respond immediately to the applied radiative forcing due to the greenhouse gas increase, causing about a 0.5 W/m2 imbalance between the absorbed solar flux and the outgoing thermal flux. Existing satellite measurements lack the precision to see this flux difference.

  20. Hi Andrew,

    Thanks for posting this. Kudos that you are willing to take the personal invective such a post is sure to attract from some quarters. I admire your efforts at trying to communicate your scientific views.

    I think that the seven points you raise could be used to point the way toward establishing the requirements necessary for formal IV&V of the global climate models. Many people think that the models cannot be formally verified and validated. But I do not agree. As you noted, everyone seems to agree that your paper was not about anything really new or previously unknown. So what’s the problem? At exactly which of your seven points would the models fail IV&V? I don’t see any problem. It will take some work, sure, to clear things up. Dan Hughes, in a comment above, lists some of the more important ones. But, IMHO, nothing remotely impossible.

    Everyone is beginning to agree that the IPCC’s approach won’t work. But it’s not the models fault. It’s not your fault. The IPCC lacks the necessary independence and knowledge/use of consensus IV&V methods. Time for a new entity.

  21. As engineer working for French and European Space Agencies, I have the greatest respect for NASA achievements, especially in the field of man flight. Unfortunately US Space Agency has lost part of its credibility by cancelling ARES program and ending Shuttle flights, without proposing any credible alternate to provide access to ISS and pursue space exploration. And I’m not so sure that supporting dubious scientific claims about Global Warming, driven by (manmade) CO2 concentration is the best way for NASA to regain its lost credibility.

    Former NASA administrator, M. Griffith, has always claimed its skepticism regarding AGW theory and recalled that the Agency’s mission was to collect data for scientific community, not to promote policies for alleviating potential effects of climate change. Dr John Theon, previous Director / Supervisor of Hansen & Schmidt at NASA also issued very sharp criticisms of AGW theory and of the models that were supposed to support it. So I just wonder how the agency could have come to such a tricky situation !

    In order to verify Lacis’ claim that CO2 is driving Earth climate, I propose a small exercise regarding variations of CO2 concentration vs. variations of T° and PDO index, just using a convenient tool and data set available on the Net.

    Proceeding
    Step 1: go to woodfortrees site (http://www.woodfortrees.org)

    Step 2: for each of the 3 parameters (HADCRUT3 variance-adjusted global mean / ESRL CO2 / JISAO PDO Index) apply following treatment:
    a) From time… to time…. : select a ~ 20 or even 10 years period to get sufficient accuracy
    b) Mean(Sample) => 12 (months) : to get rid of seasonal variations, especially for CO2
    c) Derivative : provides the variations of the parameter w.r.t time
    d) Mean(Sample) => 12 (months) : for “smoothing” the output signal
    e) Normalize : to get comparable outputs’ scales.

    Step 3: repeat the exercise using a 3 years (36 months) and a 11 or 13 years (132 or 156 months) averaging (here you can use the full [1958 – 2011] available data).

    Results

    [1970-1980]

    [1974-1994]

    [1990-2010]

    3 years’ averaging

    13 years’ averaging

    Discussion
    Main outcomes are the following:
    1) All variations follow a similar pattern showing a roughly 3 years’ quasi-periodic cycle, likely to correspond to El Nino oscillation (ENSO)

    2) [CO2] variations are following T° variations with about 6 to 12 months lag…

    3) T° variations are generally following PDO index variations with a shorter lag (about 0 to 6 months)

    4) By increasing the averaging time scale one remove “high frequency” cycles (i.e. ENSO) but put in evidence some larger scale cycles such as :
    a) Solar cycle (11 years) using a 3 to 4 years averaging
    b) PDO cycle (60 years) using a 13 years averaging.

    5) Indeed, at any time scale you’re looking at this issue, the conclusion remains unchanged :
    PDO variations are preceding T° ones, which are themselves preceding variations of [CO2]

    Conclusions
    1) Earth’ climate is not driven by CO2 concentration but by complex Oceans’ (thermal) Oscillations, Oceans’ being of course main heat reserve & inertia wheel of Earth climate system.

    2) Variations of CO2 concentration are actually following these Oceans’ Oscillations and the subsequent ones of global temperature and of Ocean’s degasing rate.

    3) IPCC claims that human use of fossil fuels causes global warming are not funded and formally falsified by comparison with observational data. AGW theory is fully based on flawed and formally invalidated models.

    4) IPCC has promoted alarmist propaganda and dangerous policies, only based one this junk science.

    5) NASA is losing money and credibility by supporting such dubious scientific claims.

    • Eric Ollivet

      PDO variations are preceding T° ones, which are themselves preceding variations of [CO2]

      Thanks for a very interesting analysis.

      Max

      • Thanks for a very interesting analysis.

        Not really. It doesn’t have any meat to it and Eric is just playing around with some curves and then making some assertions.

        I recommend the obvious which is to dig into the data seriously
        http://theoilconundrum.blogspot.com/2011/10/temperature-induced-co2-release-adds-to.html

        .

      • Eric Ollivet

        WHT,
        Could you please tell us where my “playing around with some curves” is wrong ?
        The way you recommend for digging the data seriously is flawed :
        Good fit for [1970 – 2000] period, i.e. only 30 years, but very poor representativeness for the rest of the 20th century, as well as since the beginning of the new millennium !

        – How do you explain that warming rate along [1910 – 1840] period is exactly the same (+0,45°C over 30 years) as the one observed over [1970 – 2000] period, whereas [CO2] was about 30% lower and human emissions 5 time lower ?

        – How do you explain [1940 – 1970] cooling period whereas [CO2] had steadily increased ?

        – Why has there been no warming since 1997 (14 years), which all models failed to foresee, whereas [CO2] has also steadily increased (which indeed explains why they failed)?

        Just open your mind and look at the data, seriously !

      • Could you please tell us where my “playing around with some curves” is wrong ?

        Because you didn’t do what I did. I don’t know how else to put this besides saying that you actually have to lift a finger beyond naive “trendology” to understand what is happening. I didn’t say that multi-decadal temperature fluctuations can’t occur. They do occur and the rate of change in CO2 carefully reflects this as a positive feedback.

      • WHT, you still make lot of buzz but without providing any formal rebuttal.

      • Yes Bob, look seriously at the data !
        Plots since October 1997

      • WHT,
        Talking about substance from a guy who tried to make money off of peak oil fear is pretty laughable.
        Instead of arrogantly dismissing someone who is surely your better, why not try and understand what he says?

      • WHT,
        Talking about substance from a guy who tried to make money off of peak oil fear is pretty laughable.
        Instead of arrogantly dismissing someone who is surely your better, why not try and understand what he says?

        I think it may be you that is playing off of fear of knowledge.
        Climate science is really part of systems science and the understanding I have gained from modeling oil depletion is valuable, IMO.

        One of the problems with most of the people commenting on this web site is that they have little proficiency with important elements of mathematical analysis. For example, one of the important techniques that interested parties should learn about is the technique of convolution. This is a huge part of modeling oil production. That it is also at the heart of determining responses to forcing functions is well known, yet it only rarely gets discussed on ClimateEtc. I recently googled the term for occurrences here, and I got hits but they mostly consisting me mentioning it in the last few months.

        BTW, if you have some inside knowledge on how I made money off of my studies on oil, let me know, because I must have missed the check in the mail.
        Or maybe I should add some Google ads to my blog-site or create a tip-jar?

      • WHT,
        I thought you had turned your misunderstanding of oil into a book. Sorry about the confusion.
        Climate science has little to do with AGW.

      • WHT,
        I thought you had turned your misunderstanding of oil into a book. Sorry about the confusion.
        Climate science has little to do with AGW.

        Of course it’s a book. You can click on the link on my handle if you want to read it online via Google Docs or download it as a PDF, absolutely FREE OF CHARGE.

        In your excitement over my book, I assume that when you say “Climate science has little to do with AGW.” that you really mean “Fossil fuel depletion has everything to do with AGW”, so I will say that you are welcome in advance.

    • Try plotting CO2 from Mauna Loa and Antarctic Law Ice dome vs the Temperature anomaly from any of the major indices.

      I have a copy of someone else’s work that I can’t trace, so I wont post it.

      But anyone can do that provided they have some experience with excell and a few hours of free time.

    • Eric Ollivet

      http://www.woodfortrees.org/plot/hadcrut3vgl/from:1957/mean:204/derivative/mean:36/normalise/plot/esrl-co2/mean:204/derivative/mean:36/normalise/plot/jisao-pdo/from:1957/mean:204/derivative/mean:36/normalise

      As just some guy, I believe that I can remove the noise from a signal up to one third of the length of the trend by smoothing to the mean, and only improve the clarity of the signal.

      Oh, look. At 17 years, it becomes plain that the PDO-Global relationship ceases to correlate well by the early 1970’s, and continues to degrade so much by the mid-80’s as to become almost completely non-explanatory. Indeed, by that point, global temperature precedes PDO.

      While the CO2 relationship with global temperature continues and becomes stronger throughout the span of your graph. Further, the more you smooth to remove noise, the clearer the signal gets.

      And as a bonus, we see that as a distant second, the PDO does account for variations in global temperature.. after the much stronger CO2 effect is taken into account.

      So, which is the driver, Temperature of CO2?

      Without a doubt, Temperature drives some of the CO2 level, but we can see by the variations due PDO in the global temperature curtailment in CO2 due temperature drops is not very large compared the overall CO2 curve, however large the short-term drop in temperature.

      CO2 is the dominant driver, clearly. In a century, the same noise due PDO flux will likely remain. It will just remain at a higher level of global temperature and CO2, if this graph is representative of what is happening.

      Still, WHT’s graph is far better, so playing with the little toy graphing tool from woodfortrees seems silly at this point.

    • Eric Ollivet

      Dr Roy Spencer’s analysis about Increasing Atmospheric CO2: Manmade…or Natural?

      Some extracts

      “The yearly increase of CO2 measured at Mauna Loa shows huge natural fluctuations which are caused by temperature changes”.
      ….
      “In fact, it turns out that these large year-to-year fluctuations in the rate of atmospheric accumulation are tied to temperature changes, which are in turn due mostly to El Nino, La Nina, and volcanic eruptions. And as shown in the next figure, the CO2 changes tend to follow the temperature changes, by an average of 9 months”.

      “Year to year CO2 fluctuations at Mauna Loa show that the temperature changes tend to precede the CO2 changes”.

      “This means that most (1.71/1.98 = 86%) of the upward trend in carbon dioxide since CO2 monitoring began at Mauna Loa 50 years ago could indeed be explained as a result of the warming, rather than the other way around”.

      “So, there is at least empirical evidence that increasing temperatures are causing some portion of the recent rise in atmospheric CO2, in which case CO2 is not the only cause of the warming.”

      Tends to support my analysis and conclusions

      • “Year to year CO2 fluctuations at Mauna Loa show that the temperature changes tend to precede the CO2 changes”.

        Certainly this shows up in the cross-correlation, as the temperature anomaly shows zero lag with differential CO2 changes, about 1 PPM per degree temperature change.That is a clear derivative term, but the proportional term is still there as well.

        The question is how much of the CO2 increase is due to fossil fuel and how much is due to positive feedback in temperature. My data-driven estimate is that at worst 75% is fossil-fuel emission based and 25% is reinforced latent CO2 outgassing. This assumes that the 1 PPM/degree change has a latent inertia that will accumulate for awhile (the oceans have a huge latent heat capacity that will continue to release CO2 until it catches up to the atmospheric steady-state).
        http://theoilconundrum.blogspot.com/2011/10/temperature-induced-co2-release-adds-to.html
        How much of the 25% is caused ultimately by the original fossil fuel emissions is then up for debate. Obviously multi-decadal temperature variations can account for some of this, but after 100 years, the long-term change starts to assert its authority.

      • Eric,
        Dealing with Web is something in which you should not expect a reasonable discussion as an outcome. He is a Malthusian and is very tenacious.

      • Eric,
        Dealing with Web is something in which you should not expect a reasonable discussion as an outcome. He is a Malthusian and is very tenacious.

        Malthusian (???)
        I would go for tenacious because I was taught the scientific method properly.

      • Properly?
        lol.

      • Properly?
        lol.

        I actually lift a finger as that is half the battle.

      • Eric Ollivet

        Looking at http://woodfortrees.org/plot/esrl-co2/from:2010 we see what Dr. Spencer calls huge and large. From just over 386.5 to just under 394.5.

        That’s less than 8/387.5. According to your source, 2% is huge and large. Perhaps he has been consulted on dress sizes for Hollywood actresses.

        And while by eye I could conjecture 86% of the one year CO2 rise were temperature-correlated in any yearly cycle, clearly there is much greater temperature variability in the region of Mauna Loa in a year (~5-10C) than there has been globally since observations started (~0.7C), so one would only consider Dr. Spencer’s claims plausible if the rise in CO2 since 1960 were smaller than the change in a single year by a factor of ten, rather than larger by an order of magnitude.

        It is impossible to attribute such estimation error to anything but foregone conclusion on Dr. Spencer’s part.

        All we can say of your citation is that your confirmation bias tends to be confirmed when compared to Dr. Spencer’s confirmation bias.

  22. This might have been useful if it were an attempt at what McIntyre calls an “engineering quality” report on the basics rather than an attempt to make a debate point about water vapor that really is at best a side show.

  23. ” a warmer world is preferable to a colder one.”

    This is the premise that began my journey toward skepticism. I didn’t know enough to question the establishment science, but I kept wondering why I was never encountering reasonable discussions of what has to be the pros of a warmer world. Surely, at least for people living in harsh northern climes, warmer has to be better. And yet concerning the benefits, there was only silence.

    • Slightly warmer, slightly wetter, definitely more CO2 – wonderful for life to thrive.

  24. While the current principal interest in climatology is the climate change induced in the 21st century by increasing the CO2 concentration from 280 to 560 ppm, multiple efforts by many climatologists cannot seem to overcome the uncertainties inherent in their models that still lack credibility and consistency. It has therefore occurred to a number of climatologists that perhaps by studying the past (tens of thousands of years ago to hundreds of millions of years ago) and seeking relationships between CO2 and climate during those periods, we might be able to obtain real world data on how climate and CO2 are connected. This real world data will presumably have built into it all the secondary processes that take place. For example, we have very good data on CO2 concentration during the Last Glacial Maximum, some 20,000 years ago, so that is one important historical point for further study. In addition, there are also a variety of estimates of CO2 concentration that go back as far as 500 million years, but unfortunately such data are very scattered and do not appear to be very reliable. But climatologists are a sturdy lot, and they are willing to derive a dollar’s worth of conclusions from a penny’s worth of data.

    What we seek is a relationship between CO2 concentration and the Earth’s climate over long geological periods during which the CO2 concentration varied over a very wide range. There is evidence that the CO2 concentration may have been very high in the distant past, and it has been as low as ~180 ppm only 20,000 years ago. It would be very nice if there were a single curve relating the global average temperature to CO2 concentration. In that case, if we could find several points on the curve, we could attempt to map out a good portion of the curve. However, over long time periods, the variation of the global average temperature with CO2 concentration depends on various factors such as the placement of the continents on Earth, the functionality of ocean currents, the past history of the climate, the orientation of the Earth’s orbit relative to the Sun, the luminosity of the Sun, the presence of aerosols in the atmosphere, volcanic action, land clearing, biological evolution, etc. Hence, there is probably no single curve relating the global average temperature to CO2 concentration, but rather, a set of curves that depend on the above factors.

    The argument for CO2 as the “greenhouse thermostat” for long-term climate change goes (more or less): If it wasn’t CO2, what else could it have been? Foster et al. (2009) described this as the “accepted paradigm”. This argument has some merit. We can estimate from first principles the heating effect that rising CO2 will produce in the atmosphere. If that was the only thing that occurred – that is, only the CO2 concentration changed and no secondary effects took place– we would be able to predict the effect of changing CO2 with some precision. The problem is that other effects take place as a consequence of the climate changes induced by changing CO2, such as changes in humidity, cloudiness, winds, ocean currents, land cover, ice sheets and glaciers, etc., and these secondary changes may be of greater magnitude than the original stimulus of CO2 change, and they are very difficult to predict.

    I present summaries of all the paleoclimatic analyses of CO2 vs. climate that I could find, dating back as far as 500 million years that is accessible at:

    http://www.spaceclimate.net/Ancient.climates.and.CO2.pdf

    The results, such as they are, suggest that the rise in temperature due to doubling of CO2 from 280 ppm may be in the range 1°C to 3°C with considerable uncertainty remaining.

    • Nice article, thanks for the link

    • Fred, Your post is an accurate description of the correct way to use models. However, in lots of fields, this doesn’t happen. First, if you need tools to distinguish different sources of error. I mean this in a technical sense. You need some way (and I think this may be the biggest issue in climate models) of distinguishing numerical errors and model errors. The way to do this is to admit that there are problems, so that you can get the money to improve. If you just try to cover up the issues or insist to policy makers that things are fine, you are dooming the science to stagnation. It is a profoundlly counterproductive thing that brilliant scientists should avoid.

    • Sorry, the previous post is a reply to Fred.

      I did find your article very interesting and it looks to me like an excellent critical examination of the science.

      Thanks,

    • This is a summary of a piece I wrote over 2 years ago, one of the predictions is a temperature rise of 2 deg C over the next 12,000 years using CO2 as the thermostat
      1. The earth is heated by the energy of sunlight in a variable cycle
      2. The Atmospheric Thermal Amplifier controls the temperature and consists of the earth and some or all of its processes
      3. The control method is the carbon cycle
      4. The carbon cycle is the transfer of carbon between
      the Biosphere, Atmosphere, Ocean and Lithosphere
      5. Humans now control the carbon cycle
      6, The Climate is now more stable than it has been in at least 3.5 million years
      7. We are now the principle driving force of the climate
      8. The amplifier comes with a calibration curve, that means we can decide how hot we want the bath water

      regards
      Mike Davies

    • Donald,

      You might also want to take a look at the Hansen et al. (2008) analysis found at: http://pubs.giss.nasa.gov/abs/ha00410c.html

      This paper analyzes the 420,00o year Antarctic Vostok ice core data comparing the CO2, CH4, sea level, and surface albedo changes do derive his empirical 3 °C per 4 W/m2 climate sensitivity from the ice core data.

      • Donald Rapp and Andy Lacis

        Well, now my weekend’s shot thanks to you two.

        Two competing and coherent cases to compare, contrast and examine.

        Bah.

      • I have a feeling the Vostok Ice Core data never broke the 300 PPM barrier because there was not a real CO2 forcing apart from the positive feedback from seawater CO2 ougassing. This then hit the climate sensitivity asymptote near 300 PPM.

        I put together the argument here:

        http://theoilconundrum.blogspot.com/2011/10/vostok-ice-cores.html

        The math is surprisingly simple, but this doesn’t include the long adjustment time of CO2 and other temporal latencies.

  25. “(1) The terrestrial greenhouse effect is comprised of two distinct components: (a) the non-condensing greenhouse gases that provide the ‘radiative forcing’ that sustains the terrestrial greenhouse effect; (b) the ‘feedback component’ by water vapor and clouds that acts to amplify the radiative effect of the non-condensing greenhouse gases.”

    Highly speculative. CO2 seems to be quasi-condensing. It seems to be driven by climatic factors. If the cooling continues and gets stronger, CO2 annual change will decrease and eventually get zero and negative.

    (2)…

    Radiative forcing settled? NOT convinced.

    (3)…

    Settled? I don’t think so.

    (4)…

    Global warming is any global warming at any time scale. There is natural variability at all time scales. The most important scale for us humans is the last ~5,000 – 10,000 years. The linear trend is COOLING and according to observations (ice cores…), the trend can only continue and get more negative. Sooner or later the interglacial will change to glacial.

    (5)…

    Nonsense.

    And so on…

    • Highly speculative. CO2 seems to be quasi-condensing.

      What? Are you seeing blocks of dry ice spontaneously forming around your neighborhood?

      If the cooling continues and gets stronger, CO2 annual change will decrease and eventually get zero and negative.

      Some might but we still have this huge excess CO2 from fossil fuel emissions. Where is this supposed to go? And what exactly will cause massive cooling — a new ice age brought about from those blocks of dry ice that you think are condensing out of the atmosphere?

      I get the sense that you haven’t thought this through well.

      • WHT, that’s the reason I said QUASI-condensing. It’s not really condensing, but its behavior is very similar to the condensing gases like water vapor, only the removal time is a bit longer, but still very short. Atmospheric CO2 seems to be driven by temperature, so any disturbances in fluxes (anthro or not) are compensated by ocean/atmosphere fluxes in order to restore the temperature dependent atmospheric CO2 concentration.

      • WHT, that’s the reason I said QUASI-condensing. It’s not really condensing, but its behavior is very similar to the condensing gases like water vapor, only the removal time is a bit longer, but still very short.

        The removal is based on diffusional processes. The nature of a diffusional random walk shows a predictable long-tail temporal behavior.

        Atmospheric CO2 seems to be driven by temperature, so any disturbances in fluxes (anthro or not) are compensated by ocean/atmosphere fluxes in order to restore the temperature dependent atmospheric CO2 concentration.

        You do not seem to realize that this is a positive feedback situation (if you believe that CO2 is a GHG ) or is neutral feedback (if you believe in partial pressures). It is definitely not a compensated restoration process. Why would you believe that?

  26. Brandon Shollenberger

    Andrew Lacis, thank you for this post, and your paper. I haven’t had a chance to read the paper, but I’ll do so sometime today, and I’ll comment more afterwards. In the meantime, I want to touch on some wording issues with I know will be (and already have been) brought up. First, you say you were hailed “by some, as a newly-found hero of the climate change denier cause.” I advise avoiding the word “denier” as it is offensive to some, though I don’t think your usage here is particularly problematic. Second, you say:

    Unfortunately, such subtle misinformation is being actively promoted by the fossil fuel lobbyists and their growing multitude of dupes and minions.

    This is one of those accusations which gets thrown around a lot, but it really just sounds like conspiritorial gibberish. Not only do you claim there is an active disinformation campaign, you claim the “dupes and minions” involved in it are a “growing multitude.” You’re going to lose a lot of people right there, and I think with good reason. Fortunately, the majority of your post is unaffected by this, so now I’ll move onto my reaction to your seven bullets.

    • Brandon Shollenberger

      Er, sorry for the last sentence there. I was originally intending on also posting my reaction to the seven bullet points, but I decided I wanted to wait a little while before doing so. Unfortunately, I forgot to fix that sentence when I deleted some other text.

    • Nice post, Brandon.

      Although I think that discussion about “deniers” and disinformation campaigns have their place, I think it should be largely distinct from discussions about the physics of AGW – and the discussions should be appropriately qualified.

      That said, I think that it is appropriate in this context for Andrew to discuss how his work was misappropriated to advance perspectives other than his own.

      Anyway, I look forward to you asking for more precise language when “skeptics” talk about “fraud climate scientists” advancing their “socialist agenda” via an “AGW cabal” – certainly rhetoric that sounds like “conspiratorial gibberish,” don’t you think?

      • Brandon Shollenberger

        If Judith Curry hosts a guest post in which the author uses such language, you can be certain I’ll comment on it!

      • steven mosher

        Joshua wont get that

      • Actually, steven –

        I’m trying to not clutter up this thread with the usual back and forth that tends to get nowhere – but….

        I do see a valid differentiation in what Brandon wrote. Saying that he only wants to respond to “conspiratorial gibberish” when it is a lead post makes sense to me.

        But how he chooses to differentiate what he wants to respond to is different than saying that there is a vast asymmetry in the influence of tribalism or political orientation in the climate debate writ large, or in the sausage making of related policies. No doubt, certain individuals have more “isolated power” (to use a Sabermetric term) in the debate than others. So to certain groups. That, in itself, tells us nothing about the scale of varying influences within the different sides of the debate in aggregate. That’s a worth discussion, IMO – but it isn’t served well by facile assumptions.

      • That’s fair.

        I do remember a guest lead post a while back that strongly insinuated deliberate and deceptive manipulation of data by scientists writing IPCC reports – but that isn’t as broad in scope as Andrew’s statements in this post.

        There seems to me to be a fair amount of evidence of deliberate promotion of disinformation (for example, the reactions to the CERN Cloud study or the reaction to Mojib Latif’s statements about “global cooling), but the assertion of a “campaign” requires an elaboration of evidence, and the use of “dupes and minions” is unnecessary and gratuitous.

    • Van Jones learned the hard way that if you don’t want people to think you’re a truther nutcase, you don’t go around mumbling about WTC 7. These climate guys apparently haven’t learned that lesson.

  27. Brandon Shollenberger

    Could you explain just how any of those words affects any of Andrew Lacis’s points enough to merit concern, much less justify dismissing it in its entirety? I agree his post would have been better without including those, but they are just throwaway lines.

    • It is a marker, nay a measure of his bias. It explains why he can’t even imagine millenial scale solar variability.
      =================

    • Whether or not it diminishes the point of the paper, in a larger sense, it diminishes all of science when scientific papers are polluted with such emotional rubbish. How do you expect people outside of the “community” to take something like that as serious scientific advice?

      • Actually P.E., this publication will prove invaluable as a teaching tool. I will be able to show Figure 1., to the Ph.D. students and the residents and state with authority “this is what you should never do’.

      • make sure you don’t show them the paper though. Wouldn’t want them to learn anything.

      • lolwot,
        The point is to show the paper so they will learn what a bad paper looks like.

      • Everyone has a purpose in life, even if it is to be a bad example.

      • Everyone has a purpose in life, even if it is to be a bad example.

        Hockey stick, anyone?

      • steven mosher

        the point of the ploy was to engender a fight and nasty rhetoric. That’s not too hard to do. Its a lovely strategy. It goes like this.

        “You stupid twit, 2+2 =4”. Almost everyone will rise to the bait and not discuss 2+2. In the end, you stand back and complain that nobody would discuss your science when you showed up.

      • Steve, Andy is to be commended for answering questions. But his final post is just stupid and shows a lack of integrity and clear thinking.

      • Do you think that overall warming can be proved by a mean-value argument, or do you think that all the dynamics are necessary? Some suggest that all the dynamics analysis does is provide the fluctuations on the overall profile, and the greater truth lies in the average. If that is indeed the case, all these numerical accuracies in the time integration steps are not important. I am serious about this because many, many physics problems are more easily solved by overall conservation of energy and other first-order arguments.

      • My interpretation of the rationale behind climate modeling is that both are important.

        The statement that climate modeling is solving a boundary value problem is an expression of the view that the overall constraints determine the main lines of changes in climate. The essentially time accurate model is needed to get coefficients right within those main lines and to figure out more than the global average changes. The role of the time accurate models is to describe, what happens to atmospheric and ocean circulation and how clouds change. As Andy explained the task of time accurate modeling is to reach right statistical properties of climate, not right weather forecasts or history paths.

        Everybody admits that the models cannot describe clouds properly, but are forced to use parameterizations for them, which brings always the question of validity of the parameterization, when the situation is new. All submodels have their own problems, and we have the problems of discretization, but even with all these problems the use of GCM type models brings improvements to what can be learned from overall constraints alone.

        Those results are likely to be most reliable that are least sensitive to the details of the models and thus most completely determined by the overall constraints. Unfortunately very few properties of the real Earth system fall to those, where details of the models make little difference.

        We have artificial concepts that are defined to allow for reliable calculation, such as radiative forcing directly caused by a specific change and the related non-feedback sensitivity, but these concepts are not properties of the real Earth system in the sense that they could be directly observed even in principle, because they are defined to be only a part of a real observable variable.

        To me the Science paper discussed in this thread is a comment of certain artificial concepts. Many of them would be directly observable in principle, but only in principle, because we cannot experiment with the total removal of CO2 from the atmosphere. I do believe that much of what the paper describes is not particularly model dependent, when looked semiquantitatively. I’m fully confident that removal of all noncondensible GHG’s would lead to a drop in temperature that’s not much less than presented in the paper, but it’s quite possible that even the equator would get colder than the final point of the model calculation. It’s quite possible that the amount of moisture in the atmosphere would be reduced more and the clouds might get thinner.

        I don’t think that the model is reliable at that level, but the overall change in the global temperature is one of those things that can, indeed, be estimated based on overall constraints, and they confirm that the model cannot be far from truth on that. What H2O remains in the atmosphere will be too little to maintain a significantly stronger GHE than what the model contains. The largest uncertainty concerns the albedo of the surface. It might get so high that the temperatures would drop even more. Uncertainties in the clouds are less essential, because clouds contribute both to the albedo and to the GHE. As the paper explains, the changes in cloudiness may speed up the change, but the clouds are not likely to affect strongly the ultimate average surface temperature.

        While the paper tells intellectually interesting results on the effects of removal of GHG’s, it doesn’t add anything to our understanding on the influence of additional CO2 in the atmosphere. (By our I refer to people, who believe in the main stream basic understanding of the atmosphere, but not necessarily to the main stream estimates of climate sensitivity).

      • As Andy explained the task of time accurate modeling is to reach right statistical properties of climate, not right weather forecasts or history paths.

        I think this is the salient point. The dynamic models really provide the extra insight necessary to fully characterize the system. If the dynamics said that all the excess CO2 would spontaneously cluster around the poles where it would really change the theory, then that would be one thing. But if the simulations suggest that CO2 would mix uniformly, then you use this information to simplify the solution.

        Same goes for clouds. The results of the simulations should be that they give us ideas for statistical distributions such that we can use these for BVA and MVA solutions.

        I am only suggesting this point-of-view because David Young’s views of numerical stability are likely very valid, but perhaps misdirected when we consider how far we can go with an alternative statistical mechanical solution. I am thinking that someday it will become possible to work completely more with the concepts of superstatistics to average out all the dynamics.

      • WHT

        Be careful with the term superstatistics, lest someone accuse you of using numbers that only exist in computers to draw conclusions about Mathematics.

        Imagine the uproar, should it be discovered your Mathematics were not grounded on observations taken from beaker and plumbline, test tube and thermometer.

        Why, no one would be able to rely on Mathematics ever again!

        There’d be accusations of trigonometric fraud, actuaries put on trial for treason, whole blogs dedicated to ferreting out the errors of differential equations, and copious new proofs of the squaring of the cube, with books published by groups of valiant Pi slayers.

      • Bart, No problem, I get the intent of your jibes.
        I am of the school of playing along with the uncertainty and if we are uncertain about the numbers, then perhaps nature is as well. The physicist Jaynes used this approach when he devised the maximum entropy strategy, which is very closely aligned with Christian Beck’s idea of superstatistics. It will take awhile to determine what the fundamental distinctions are between the approaches.

      • WHT

        What you say makes good sense.

        I’m interested in hearing more, and think it likely to be productive.

      • Web, let me just argue with you a little here.

        1. Look at Paul Williams example of the Lorentz attractor. Numerical errors can yield totally wrong long term statistics.

        2. There are bifurcation points in the system. If you are on the wrong trajectory, you will totally miss a point where the complete character of the statistics changes.

        3. The strength and complexity of attractors for the Navier-Stokes equations are unknown. There is some theory in Temam’s book but its of no pracitical value. Also, the attractor can be very weak so that errors build up and get you into a totally wrong area.

        Just to claim that “the long term behaviour looks reasonable” is of no scientific value. You need validation that is quantatative and independent of numerical errors.

      • David,
        I think that the Lorentz attractor has been overemphasized far too much. When the system is complex and has also a lot of stochasticity, the attractors tend to smoothen out, but something similar may remain. By something similar I mean all kind of quasistationary modes like circulation patterns that are formed, live for a considerable time and disappear or change form. Thus I don’t dismiss the significance of such phenomena, while the similarity with the original attractor is limited. Furthermore a model may be fully deterministic and simple enough to have purer cases of attractor than the real physical system.

        The above covers largely also the bifurcation points.

        One difficulty in responding to your critique seems to be that full answers are very complex or actually lacking. The issues are known, some thought has certainly been given to all of them and very much thought and research to some of them, but the answers are not straightforward. Building models means always making compromises of many types. Some of the are for reasons of performance, but many are deeper in the structure of the methods.

        Different methods of discretization and time stepping have all their strengths and weaknesses. Making compromises means an attempt to avoid faults that influence the outcome most severely, while it may mean that some other weaknesses must be accepted. Every method of discretization creates some deviations from the continuous equations. Some of the essential conservation laws are violated by the removal of higher order terms, but are so essential that they must be reinstated by some global corrections. Some methods are inherently (more) stable, but they may introduce larger errors in some problems.

        I share with you the wish of gaining better understanding on, how the climate modelers have solved the problems. I wish to know, why they have made the specific choices, and how they have estimated the severity of the remaining issues. As I mentioned, I bought and read one book on the models. As is to be expected, an introductory book didn’t answer at all all the questions I had in mind, but I didn’t conclude that the modelers were ignorant on issues not discussed in the book.

        I don’t think it’s possible to get simple answers to all questions of methodology, because the issues are too complex for that and because compromises have been made to make any simple answer wrong. You may get some good answers by your approach of contesting the modelers, but what’s really needed is a new type of systematic presentation of the whole field of climate modeling. There have been some proposals of that nature in these threads like this one from John Carperter.. I hope that a group of modelers would join forces to create and maintain such a description at a level suitable for a reasonably wide audience of people with fair knowledge on modeling physical systems, but not expert climate modelers.

    • I’m not entirely sure from the timestamp whether that was intended to be a reply to my comment shown as 6.13 but actually made at 11.13pm UK time.

      Assuming that it was, I think it’s quite odd to say that his explanation of the whole reason why he wrote the paper can be dismissed as “throwaway lines”.

      If a scientist’s reason for writing a paper is based on an obviously false premise – why would anything in it be worth reading?

    • Why would a scientist put throwaway lines in a paper?

      Andrew

      • Brandon Shollenberger

        Because, scientists, like most people, tend not to be the best of writers. It’s easy to let irrelevant things slip into what you write, especially when there is an emotional involvement.

      • “It’s easy to let irrelevant things slip into what you write, especially when there is an emotional involvement”

        Interesting that readers have the burden of figuring put what in climate science papers is relevant and what is irrelevant filler. Normally it would be up to the writer to do that kind of exercise(to include only what is relevant). Evidently, climate scientists should go back to high school and learn how to write papers.

        Andrew

      • BA,
        You make a great point.
        We skeptics, after being insulted by a performance of infantile conspiratorial insults, are not only supposed to overlook the complete lack of technical content, ignore the insults, but also wade through the post and pull out the nuggest of deep thought hidden in the text.
        Climate science, as currently obsessed with AGW, is a very special science, as Lysenkoism and Eugenics were special.

      • Thank you. I don’t understand the tolerance and excuse for something that would never be tolerated or excused in any other professional-level job. If an engineer or accountant went off on a pontification tangent like that in a report, the elders would be very displeased. Are there any elders in the climate science tribe? It almost reminds me of that Star Trek episode where there was a planet with nobody but kids.

      • Striling English

        Lacis is an Elder of Climatology.

        Does this increase or decrease your confidence in their work?

        For me, it makes the matra ‘Trust Us, We’re Climate Scientists’ even more of a laugh.

        But I guess Lacis’s pathetic gibes show that instead of trying to persuade the uncommitted that he is right, he is reduced to attemtping to keep his supportrs onside. When you have a very poor case, distartcing attention from it by attacjking you renemies is an old – and utimately doomed – tactic. Since Climategate it is noticeable that the rhetoric has changed from the Muhammad Ali style –

        ‘we will win, we are Masters of the Universe and we have Right on our side’

        to the loser’s

        ‘see – they barely scratched me that time. Honest it didn’t hurt much . And you wouldn’t let an ugly lot like them over there beat me would you chaps? Only another fourteen long long rounds to go…..’

      • On a fellowship at Lockheed-Martin a few years ago we had a chance to ask LM engineering managers what they needed in employees. “Please God,” one said, “send us engineers who can write.”

      • Brandon,

        Based on my graduate school experience, my professors had an excellent grasp of the English language and a well honed ability to communicate in writing. Unlike most of my undergrad classes, these professors regularly marked up papers and exams with regard to grammer and spelling.

      • Brandon Shollenberger

        timg56, first, I just have to say there is a degree of humor in you having typed “grammer.” Thanks for making me chuckle.

        Second, I won’t disagree with you about professors (does Andrew Lacis actually teach?) being good with regard to grammar and spelling. However, understanding the English language doesn’t make one a great writer. There are all sorts of things involved in being a great writer which many professors don’t have (and probably have never had a reason to develop). For just one example, think about how many professors are long-winded.

      • Brandon,

        As you can surmise, I saw my fair share of red ink. In defense, I finally lost the personal penchant for carefully proof reading my comments on blogs a couple of years ago.

        I think the distinction you are trying to make – between scientists who teach and those who don’t – having any meaningful impact on the ability to write is a false construct. Both subsets have the necessity to publish and to apply for grants. Unless I have a completely skewed understanding of what skill set is needed for performing these tasks, I would argue that the burden of proof any distinction exists would be on you. Referring to long-winded professors falls short of that.

        I volunteer as a mentor with and on the board of an educational non-profit. One that focuses on science. It has been my experience that a majority of the students I have worked with (1st grade through 12th) would be able to grasp the difference between a science experiment and a model. Which is why I also don’t quite understand when you try to argue they are basically the same as a response to those folks (myself included) who have a degree of doubt concerning outcomes that are based solely on modeling and even more so when the outcomes are extrapolations of possible effects of models.

      • Brandon Shollenberger

        tim56, I’m not trying to make a distinction between between scientists who teach and those who don’t. I only asked that question because I know next to nothing about Andrew Lacis, so I was curious if you were referring to professors because you knew he taught.

        Anyway, if you honestly think Andrew Lacis is incapable of including comments like the one he did about “dupes” and “minions” due to a combination of bad writing and emotional interference, simply because he’s a scientist, I don’t think there’s any way we’ll come to an agreement. Since that’s the extent of our disagreement, I’m not sure what more there is to say.

        As for the issue about whether or not computer models can be used for experiments, you and I haven’t said anything to each other about that issue before, so I’m not sure why you brought it up here. However, if you want my view on that issue, I think it’s best summarized here.

      • Brandon,

        Whether or not Dr Lacis teaches in immaterial. I referred to my experience with my professors because in addition to teaching, they engage in the same sort of scientific research as Dr. Lacis. The purpose of that statement was to refute your claim that scientists are poor writers. I presented evidence (granted, anecdotal evidence) to the contrary.

        I don’t think it is my place to assume or assert anything about Dr. Lacis. I do not know the man. However I do know that when a professional scientist is posting on a topic that he is supposedly an expert on and in a public forum, the display of “emotional interference” or poor writing skills are not something I would expect. Is it possible this is in fact what has occured? Yes. Is it a good sign? I don’t think so.

        I personally can’t get too worked up about the name calling, as some people do. If someone like Dr Lacis wants to label me as a denier or denialist, trust me, I’m not going to lose any sleep. The reason I won’t is because I was taught at a very early age to ignore name calling (but watch out for those sticks and stones). The other lesson I was taught was that people who engage in name calling are at best juvenile and likely are afraid of being on the losing side of an argument. (BTW – thanks Mom and Dad). So tell me, just how much credence should the lay person give to someone who exhibits at least one of the following traits:
        – has poor writing skills
        – is subject to emotional interference which clouds his judgement
        – resorts to name calling and labeling

      • “Whether or not Dr Lacis teaches in immaterial. ”

        He just did.

      • “Whether or not Dr Lacis teaches in immaterial. ”

        He just did.

        …and it was immaterial.

        Max

      • Did you mean grammar and speling?

      • Mark,

        Did you think I was referring to my mother’s mother?

    • It is not a matter of dismissing his claims as conjectures, it is a matter of dismissing his claims as certainties. It is incredible that someone would post such certainty claims here.

      • I am not arguing the physics of Andy’s claim, just the epistemology. It is the certainty that makes his claims wildly exaggerated. I have no quarrel with conjecture.

      • David Wojick

        I’m not sure I follow.

        Do you mean to say Dr. Lacis is perfectly correct, but too sure of himself?

        Or that you know you must argue with anyone too sure of himself on principle, but do not care to consider the subject matter of what they say before certainty they express is judged by you on no foundation whatsoever?

        Or that your studies have established a foundation for determining on pure epistemology the degree of exaggeration?

        It seems if someone were making Dr. Lacis’ claims with less evidence than he has offered of data collection and rational analyses, your epistemological claims might have merit.

        Which poor me, I have to argue the physics of with many sources before I could conclude of Dr. Lacis, being neither omniscient nor possessed of your secret epistemology formula.

        I have yet to argue epistemology of wild exaggeration, however as you have provided this ample example, I’d be pleased to hear out your certain-to-be entertaining conjectures on the topic.

      • Bart R, it is quite simple. My field is the logic of complex issues and I have studied the climate debate for 19 years. Dr. Lacis is asserting as known what is in fact highly controversial. Thus the certainty implied is false. His statements are actually conjectures. As such they may or may be true, but the implied certainty is certainly false.

      • Scientific language provides a lot of terminology that one is supposed to use to express limited degrees of confidence. Terms like “suggests”, “seems”, “appears”, “prepared to believe”, etc. Dr. Lacis chooses not to use these epistemic modifiers, so he winds up expressing a false degree of confidence. False confidence is one of the great fallacies of the AGW movement. This has little to do with the ultimate truth of his claims. It is akin to the “likely” etc., language issues with the IPCC, which is a major focus of the blog.

      • David Wojick

        Oddly, I’ve worked in applied logic in complex issues for quite some time — indeed, I’ve applied your techniques at times — and have watched the climate debate for as long as you have studied it.

        I’m familiar with what the words “asserting”, “known”, “controversial”, “certainty”, “implied”, “false”, “statements”, “conjectures”, and “true” mean both as generally accepted and technically.

        However, at least some of the ways you use these words must substantially differ from the definitions I’ve encountered before now.

        While Dr. Lacis makes some assertions, he is for the most part assiduous about providing evidentiary and theoretical support either directly or by reference.

        These supporting arguments and evidence take Andy Lacis’ expressions — for the most part — from mere assertion or claim into the realm of supported and generally accepted knowledge, about which anyone might express the utmost degree of confidence, conventionally.

        Where there is controversy about what Dr. Lacis proves, the description ‘highly’ is ambiguous. Among some who eschew logic, scientific method, reason, careful analyses and honesty, it is easy to observe a high degree of agitation associated with what Andy Lacis says; among those who apply logic, the scientific method, reason, care in analysis of the subject (and not of how it is said), and are honest, the degree of controversy is observably low to moderate. You can certainly see this correlation as a dominant trend using the very methodologies you have developed.

        Implied certainty, while perhaps a social phenomenon, is not a mathematical one.

        I look at the datasets, and the metadata tells me what confidence interval is appropriate to them, thereby limiting the certainty.

        I think for myself about the complexity of the systems under examination, and the properties of the systems further limit the certainty.

        How any scientist says what he says may be a function of taste for brevity and economy of expression, which will always sound more certain to those who do not take the care to examine the underlying supports for the claims.

        Take, for example, what you say. You imply by the admirable economy of expression you use (such as “certainly false”) an absolute degree of certainty.

        Yet when I open up the logic of what you say, and look specifically at the source data (ie this thread), the complexity of the process of reading scientific writings, and the superficial process you claim to have used, I find your implied certainty entirely unwarranted, and by far greater margin than might be concluded of Dr. Lacis.

      • Bart R, interesting argument. My point is that most of what Andy claims as certain is in fact highly debatable. My evidence is empirical, namely observing the debate, including this blog. Your claim is basically that my evidence is no good because the people I observe (including here) are either unscientific, illogical, irrational or dishonest. Good luck with that claim. I don’t suppose you have any evidence to support it.

        Also I trust you realize that you are insulting most of the people here. Have you classified us according to your taxonomy of failures? Where do I fall on your list?

      • David Wojick

        I’d have expected I passed the point of mere insult to ‘most’ (?) people here long ago by expressing doubt about their logic, rationale, scientific rigor or honesty, and both they and I are inured to the queasy social footing this affords us. Indeed, when I make such statements, I generally support the claims with substantive reasoning, too glad to point out the logical fallacy, factual error, lack of support, weaknesses of citations, contradictions, or blatant duplicity in detail and with explicit commentary.

        What’s more, I do it as readily to my own postings, (a dozen or more discarded for every heavily-revised remark I do make), and about others for whom I have the utmost regard and general agreement, where their postings appear to warrant.

        The distinction, where I get adequate reply, I learn something of the science. Where I get just more of the same, I learn something of the quality of my correspondent.

        You’ve taken the rather indefensible position that you can pass scientific-sounding pronouncements on scientific writings merely by the tone the writer has taken. I’ve counted backwards and forwards postings with similar marks of certainty to what you have described, and see no objection by you in those threads, so must conclude bias not to do with tone but with content.. which you refuse to speak to.

        I’d have to classify that as dishonest.

      • Bart R,
        That is not dishonest at all.
        Lacis is deceptive in his approach and his writing style demonstrates just that. If he had a solid argument he would not use deception.
        People develop a good nose for bs.
        Lacis’ post and his prior work smell like bs.

      • Bart R @ October 10, 2011 at 9:37 pm

        You lost me months ago: here to here.

      • huxley

        For ten months (an eternity in the blogosphere) you have grudge-nursingly so cherished my every syllable?

        Well, if ever there were evidence of holding the low ethical ground, you’re establishing it.

        Yes, I stand by what I have said, with obviously amendments from having made efforts to grow and learn in the time since I posted those statements.

        Good to see you haven’t changed.

      • That’s your wild claim. support it. lets go to the actual text you are complaining about and quit waving your arms

      • ‘solar forcing is cyclical and small’.
        =================

      • That’s in response to moshe’s call for text.
        ================

      • Thanks Kim. Yes, “solar forcing is cyclical and small” is an obvious example of false confidence, a claim to know that is simply ridiculous. The nature of solar forcing is one of the greatest known unknowns, but only one.

        There are at least dozens of lines like this in Andy’s post, perhaps over 100. Just ask how many of these supposedly certain statements have been debated here in the past year? I do not intend to take the time to list them, unless someone wants to organize a contest, to see who can find the most. That would be fun.

        By coincidence (or not), these ridiculous confidence claims are similar to what I long ago termed the “RC fallacy,” because it is endemic at RealClimate, namely taking speculation to be established fact. It is the ‘settled science’ hoax writ out line by line.

      • Knowing the exact density of the atmosphere would be another.

  28. Thanks for the contribution Andy. There really are about 6 different topics here.

  29. John Carpenter

    Andrew,

    Thanks for contributing here, your knowledge of climate models and their inner workings would be of great interest to me and many others here. Many of us here do embrace the accepted physics of radiative transfer theory and the role of CO2 as a green house gas. What many of us have trouble accepting are the results of model ‘experiments’ as true and accurate predictions of the future. Specifically for me, this comes from, primarily, the lack of understanding of how the models are constructed. What I would find much more informative than a re-hash on your paper of one year ago would be a tutorial on how the mechanics of the GISS ModelE works. I have visited the NASA site that describes the model and many details of the subroutines etc… but there is a ‘big’ picture image missing. A master diagram showing how the pieces of the model go together, interact and where the input data comes from and is used within the model and how the output is generated and shared within the model. Such an explanation would be enlightening and would generate, IMO, a far more interesting discussion of the science. If such a description is already available, point me in the right direction as I have not found one yet.

    • John,

      A very good question, but also one that does not have a simple and short answer. How do the mechanics of the GISS ModelE work?

      A trite but not very useful answer would be to say that it is all spelled out the ModelE FORTRAN code which is available from the GISS web page. It is not encrypted in any way, but it is totally opaque. Even someone specifically trained in writing GCM code would be hard pressed to figure out what precisely is being done.

      An outline of what the model is doing is described in the published model papers: e.g., Schmidt et al. (2006) for GISS ModelE http://pubs.giss.nasa.gov/abs/sc05200y.html
      Also, the early Hansen et al. (1983) Model I & Model II http://pubs.giss.nasa.gov/abs/ha05900x.html
      All available from the GISS web page. A quick look at the papers gives an idea as to what quantities are being calculated, and how the basic approach for doing so is formulated.

      Basically, the GCM is attempting to model ‘all relevant’ climate processes in terms of basic physics relationships. The global surface is set up as a grid with several dozen vertical layers to resolve the atmospheric temperature structure. At each grid box all significant climate variables (temperature, water vapor, winds, clouds, aerosols, greenhouse gases, etc.) are defined. The model is imparted with its sidereal rotation rate and time marched forward with, say, 30-minute time steps during which all of the climate variables get updated according to the local meteorological conditions.

      The model consists of specialized modules. For example, the surface module updates the ground surface properties (temperature, soil wetness, snow accumulation, water runoff, evaporation, surface albedo, etc.). The cloud module checks the temperature, humidity, stability, and wind profiles to see if the meteorological conditions are consistent for generating clouds, and if so, at what height, how thick, what particle size, are they going to be liquid water or ice. There is a hydrodynamics module for computing winds and for transporting water vapor horizontally and vertically. There is also a planetary boundary layer module that evaluates the turbulent transport of heat and water vapor from the ground surface into the atmosphere. The ocean model is in a sense a module parallel to that of the atmosphere in treating the transports of heat, salinity, and water/ice. All of these modules are developed, tested, and validated off-line against available observational data. The total ModelE FORTRAN code is something close to 500,000 lines of code, although most of that is for diagnostic purposes to keep track and manage the model generated output of all of the climate variables.

      My responsibility in ModelE is the radiation module. It is more than 15,000 lines of code. The job of the radiation module is to calculate the solar heating rate profiles and the thermal cooling rate profiles, including the energy deposition at the ground surface, as well as the energy balance at the top of the atmosphere for the specified climate variable distribution at each grid box. The atmospheric heating and cooling rates are then passed back to the atmosphere structure module that calculates how much the surface and atmospheric temperatures would change during the 30-minute times step given the radiative heating and cooling rates. And so an updated atmospheric structure is sent back again to all of the different modules to repeat the cycle all over again.

      • Andy, This looks like a good summary but it raises more questions for me than it answers.

        1. The first question is how are all the modules linked. Apparently some terms are done implicitly and other explicitly. Is there ever a point where the residuals for all the models is small? How is this measured and validated?

        2. Is the time stepping algorithm dissipative like the Robert Asselim filter? If so, your dissipation could easily swamp the signal you are trying to compute. Worse yet, the model might appear to be “stable” but that stability might be covering up important dynamics that are simply lost.

        3. Is there any error control in determining time step and grid spacing?

        4. Sounds like a ton of subgrid models. How are these calibrated? Are they dissipative. If so, is the dissipation affecting the overall dynamics. This might be easy to test. Generally subgrid models of turbulence are too dissipative and the result is answers that are a lot worse than one would expect based on the literature.

        5. How do you deal with sound waves which are present in the Navier-Stokes equations but have time scales much shorter than your 30 minute time step.

        6. Generally, how do you validate these things? Are there any rigorous simple cases where the answers are known or is it just “the results look reasonable?”

        7. You are aware that finite differences are the best technology from the 1950’s and that far better methods are available such as finite elements and backward differentiation schemes.

        8. How sensitive are the results to parameters? Just looking at the AR4 and early AR5 simulations, it looks as if the different climate models give a wide range of answers. Any attempt to track this down and understand the origin of the differences?

        9. Since the scientific understanding of clouds and aerosols is low, how do you validate your subgrid models for these things?

        10. How can you possibly get away with such a small number of points in the vertical direction? Convection is quite important in the tropics and is quite complex. Do you just sweep this all up into a subgrid model too?

        11. Have you done systematic tests using different time steps such as has been done by Paul Williams? Have you ever considered any scheme that is better than 2nd order accurate? You know there can be huge advantages to this as well as using modern (1970’s vintage) methods for choosing time step sizes and varying the order of the scheme.

        12. What is done to control the error in time from accumulating? Do you use error per step or error per unit step, or none of these?

        13. What is your response to the work of Paul Williams who has shown the critical importance of better numerical methods in climate models, not just for local error (which everyone acknowledges is large) but for the time averaged properties and “patterns” that are claimed to be meaningful and repeatable.

        14. I’m assuming that there is a coupled ocean model. The ocean is incompressible, whereas the atmosphere is compressible. This would seem to me to require different numerical methods for the two. How do you handle the different time scales for pressure waves? it surely must make the system very stiff.

        If you don’t have a strong handle on numerical error, parameter estimation for the many subgrid models you have is really little better than guessing. At least for turbulence models canonical simple cases where there are analytic solutions are used to calibrate the models so there is some expectation of predictive capability in new situations. Even then the results are not very good. If we can’t even model simple boundary layer turbulence, how can we expect to model clouds and other complex processes?

        Basically, looking at the AR4 and AR5 results which I’m assuming are the result of years of tuning and running models and looking at results, it looks obvious that there are large errors and discrepancies. What is the plan to scientifically resolve these issues? Just running models and taking votes is not scientific in my book.

        In short, what I have seen so far about how models are validated and parameters determined is not very convincing. I used to think that CFD was bad for its reliance on “colorful fluid dynamics.” I’d be curious to know what quantative information you use to track what seems to me to be scores of sources of model and numerical errors in such a complex computer code as you are describing here.

        David Young

      • David,
        I mention in my message below a book that answers some of your questions, but an introductory book of 350 pages is not nearly detailed enough to answer all or to answer any of them in full detail.

        One thing that becomes very clear is that the modeling community is very well aware of the issues that you have brought up. They have not been able to resolve all issues, but that’s not due to not being aware of them. You have proposed some specific approaches, which are not always used, but there are other reasons for that than not knowing or not caring. Without knowing much about the field, I’m sure that some of the reasons are not very good, while the choices made are in most cases well justified.

        I just pick some sentences from the book of Washington and Parkinson (end of chapter on numerical methods, p. 191):

        The solving of the dynamics and physical processes locally on a node has special advantages compared to the conventional global spectral method. In the field of oceanography, the finite element method allows for improved resolution in parts of the ocean where strong gradients or other smaller scale features exist. There are, however, some limitations that have not been fully resolved. For instance, using the semi-implicit time stepping method requires global sums which may still limit this method even on parallel computers.

      • Yes, yes. They are just saying that for ocean modeling its incompressible and so to conserve mass you need to solve a Poisson equation at each time step. The POINT is that the Newton Krylov Schwarz is parallel and much faster than older point or line relaxation methods. We are talking about orders of magnitude here. These differences are CRITICAL when computer resources limit resolution and keep numerical errors high.

        However, the language they use is rather odd and not the standard terminology. Another red flag!!

      • Another thing. I want to hear a real climate scientist explain to me why they use the overly dissipative leapfrog scheme with this Robert-Asselin filter. My problem here is that even Andy just says that he can’t answer my questions. OK, that’s fine, he does radiation models. Please, tell me who to contact. It’s clearly not Schmidt either. Has anyone heard of Newton Krylov Schwarz?

        This is not just a question of numerical errors, it is a question of methods that open up whole new possibilities, like solving inverse problems using numerical optimization to estimate parameters. This could be a breakthrough, not just a small improvement. You cannot do this with explicit methods, its just not possible. You resort to trial and error and then that’s why you are short of computer power, which is why you use coarser grids, and with dissipative methods, you get wrong answers. It happens in computational physics all the time.

      • David,
        I’m on your side in the wish of getting more specifics from the modelers themselves, but I find your aggressive and insulting way of writing to them very counterproductive in getting that wish fulfilled. On that point I agree with dhogaza.

      • OK, point taken. Sometimes its tempting to generate a little heat. It also gets frustrating when dealing with the peanut gallery. I’m not going to do that anymore. I invested a lot of time in explaining some very detailed science, and the response was non technical. I won’t go through the things that were annoying at RC. D’Hog is particularaly guilty of taking statements out of context and of having no feeling for tongue in cheek comments. He is also totally ignorant of the technical issues and is very defensive.

        However, forgetting about issues of “tone,” RC is often insulting to other scientists and even the scientists there often engage in name calling. The substance is that there seems to me to be nothing that addresses the issues of numerical errors that anyone could cite for me. The only thing is Paul Williams. If I could get a name of someone who has written a paper on the subject, that would be ideal. My goal here really is to get them to pay attention and I’m working on that in some other more productive ways. RC is a not in my opinion a forum for serious discussion of science, its a forum for the team to educate journalists and members of the peanut gallery about the party line. Now that I know that, I will ignore them.

      • David,

        You make some good points. There is a whole science out there on how best to do climate model numerics. At the core of the problem, even though current computer speed and memory are nothing short of impressive, is the fact that computer speed and memory are still very much finite and optimizations have to be made depending on the computer resources available for the computation problem that is to be addressed.

        This is illustrated by the clear distinction that exists between weather and climate models. Weather is an initial value problem where the meteorology representing the current wind, temperature, and humidity distributions needs to be accurately projected for the next several days. It matters a great deal if the storm hits New Jersey on Tuesday morning, or misses it altogether. A climate model, on the other hand, is a boundary value problem and could care less when or where the storm hit, as long as the number of storms per unit area was approximately of the right order. Thus a weather model would not want to unnecessarily waste computing time on model ‘physics’ such as radiation, when it should be concentrating on atmospheric dynamics, while a climate model would be doing just the opposite.

        I work on modeling radiation, there are other guys working on model dynamics and numerics. They worry about things like forward and backward leapfrog schemes, second and fourth order differencing schemes, Kelvin, Rossby, and gravity waves – stuff that I try to stay clear of. Basically, I am aware that the model differencing schemes are specifically designed to conserve, mass, energy, linear and angular momentum, and vorticity. Some model numerics are computer hardware specific, depending on whether the computer arithmetic truncates, or rounds off their numbers.

        There is a desire to have as high a horizontal resolution as possible, but this is constrained by the time step required to avoid instability. Problems also arise in the polar regions for models that use a lat-lon spatial grid, requiring noise filters to eliminate spurious oscillations. To address this problem, a number of modeling groups are testing and using approaches such as the cube-sphere representation. Basically, the optimum model resolution and time step selection is made empirically to get the best speed performance while keeping at bay undesirable diffusivity, instability, and other non-physical behavior.

        The GISS ModelE supports a tracer capability where the global dispersion of local pollution or chemical isotopes can be studied in detail. This capability is also important for atmospheric chemistry and aerosol studies where the emission sources are localized and non-uniformly distributed.

        One reason to separate the global climate change problem into the two components of (1) global warming, and (2) natural variability is to recognize that the model analysis of these two components has different modeling requirements. For global warming, the GHG forcing is globally uniform, and the modeling goal emphasis is on global energy balance and global temperature change. For this purpose, coarser model resolution is adequate since the advective transports of energy (latent and sensible heat, geopotential energy), which are an order of magnitude larger than the radiative terms, must by definition globally add to zero. Since the global energy balance and the greenhouse effect are all radiative quantities, the emphasis then is on assuring the accuracy of the radiation modeling.

        The natural variability component, which includes the unforced local, regional, and interannual climate changes is a more difficult problem to address, and requires higher model spatial resolution and greater care in dealing with horizontal enrgy transports and conversions.

      • Andy, I really appreciate your responses and coming here to reply. It does make me respect you. Perhaps I just need to educate myself. However, the feel I get from the literature is the same feel I get from NASA CFD codes, viz., using numerics that is very unreliable but encrusted with a ton of “filters”, “variable dampings”, etc.

        I am pleased to hear that mass, momentum, and energy are conserved discretely. I however know that the leapfrog scheme is not very good technology. What raises a further red flag is that when provided with really good references written by top people in numerical methods, the responses are all on issues that I would call “physics” issues, and not on the numerics. Worse yet, it gets personal very fast at RC (I know not your fault). If you could point me to the most mathematical person on your team, I could form a better opinion just by emailing him. I promise not to take much of his time.

        Or another thing would be to try to convince me that Paul Williams is overlooking something. His video is quite convincing that there is a problem and it looks pretty serious to me anyway.

        Have you done systematic time step studies? Have you done grid refinement studies? If you use the computer models to tune parameters for the subgrid models, it becomes critical to control numerical error or else the tuned parameters will only work in the code you used with its time step and grids.

        David Young

      • Sorry to drone on, but just a very succinct question that I’ve asked at least 20 times in the last 2 weeks. If the scientific understanding of clouds and aerosols is low and there are large error bars on the forcings involved, how is it possible that there is not a large error bar on the sensitivity you are calculating? If the system is so sensitive to CO2 forcings, it must be also sensitive to these forcings, nes pas? Particularly after the CERN experiments, one must also place a big error bar on the solar forcing it would seem to me until we do a lot of further research.

      • David,

        I checked the Schmidt et al (2006) paper to see what we say about dynamics. Apparently, “Tracers, including heat and humidity, are advected using the highly nondiffusive Quadratic Upstream Scheme (QUS; Prather 1986), which keep track of nine subgrid-scale moments as well as eh mean within each gridbox.”

        People do keep working on various different methods, and we do from time to time test somebody’s new and highly touted scheme. Changing model dynamics is a fairly time consuming task, and few papers get published on model numerical methodologies, unless they happen to show some dramatic improvement.

        Basically, it is the ‘proof-in-the-pudding’ approach. If the climatic variable fields and distributions look good, the dynamics scheme is taken to be adequate. If not, changes and corrections need to be made.

      • I appreciate the proof is in the pudding approach. Just saying there are modern methods for error control that are more expensive but very effective, such as adjoint methods.

      • Andy, Something you said that was revealing was about the inadequacies of the computing speed and memory and that a lot of decisions were based on these issues. I would caution you that this can become a POSITIVE feedback on numerical error. You use a poor scheme like leapfrog with RA filter because its (just guessing) 20% faster and that leads to errors that propagate in time, so you introduce yet more filters, ad hoc corrections, or even worse changes to your subgrid model parameters to get “reasonable” results. I’m not saying you are doing this, but I’ve seen it so many times. It’s not science. You are better off FIRST URGENTLY getting rigorous control on numerical error. Then, you can work on the parameterizations, etc. Also in a problem where the subgrid processes are VASTLY complex, it becomes even more critical because I suspect the parameterizations are critical to any kind of reasonable accuracy. Anyway, I humbly submit it for your consideration!!

      • David,
        Here’s what I understand in response to your points. There is a f90tohtml presentation of the code here, which makes navigation a lot easier.

        1. “The first question is how are all the modules linked. “
        There is an extensive diagnostics section, which seems to compute many residuals. It is called from the main routine. Look for the comment
        C**** WRITE SUB-DAILY DIAGNOSTICS EVERY NSUBDD hours
        I don’t know what NSUBDD is, but they say it is sub daily – ie at least once every 50 steps.

        2. “Is the time stepping algorithm dissipative”
        Leap-frogging is well studied and its dissipativeness analysed. As Andy says they use nine moment schemes with QUS for heat and humidity that they want to advect without dissipation.

        3.Is there any error control in determining time step and grid spacing?
        There is a subroutine QDYNAM which tracks the Courant limits.

        5. How do you deal with sound waves which are present in the Navier-Stokes equations but have time scales much shorter than your 30 minute time step.

        It isn’t much shorter, and I think they resolve them. The smallest horizontal grid I saw mentioned was 2° or about 220 km – about 10 min at 330 m/s. They use eighth order Shapiro filtering, which might damp out the wavelengths otherwise likely to be magnified. They use Arakawa-B staggered P-V grids, which might also help to bridge the gap.

        “6. Generally, how do you validate these things?”
        There is a big section (5. Evaluation, pp 168-184) in the 2006 Schmidt et al paper. Check it out.

        “7. You are aware that finite differences are the best technology from the 1950’s and that far better methods are available such as finite elements and backward differentiation schemes.”

        No-one would use finite elements on a problem with an essentially uniform hexahedral grid. Finite difference is still the fastest.

        “10. How can you possibly get away with such a small number of points in the vertical direction? Convection is quite important in the tropics and is quite complex. Do you just sweep this all up into a subgrid model too?”

        GCM’s don’t attempt to resolve convection. There is no vertical momentum equation. From the GISS documentation:
        “The moist convection routine is a plume based model (Yao and Del Genio, 1995) that incorporates entraining and non-entraining plumes, downdrafts (which can also entrain environmental air), subsidence (using the quadratic upstream scheme).”

        “14. I’m assuming that there is a coupled ocean model. The ocean is incompressible, whereas the atmosphere is compressible.”
        Mach numbers in the atmosphere are low. Again, there is no vertical momentum equation, so one doesn’t have to worry about how it is transferred across a boundary.

      • Ok, Nick. I appreciate your research on these questions.

        2. Leapfrog scheme is not OK. You need the RA filter which is quite dissipative and gets more so for bigger time steps. Analyzed shanalyzed, its only relevant if you use the analysis to control step size (see 3)

        3. The Courant Friedrichs Levy condition tells you the maximum time step for numerical stability, it tells you nothing about accuracy. That has to be looked at separately. Generally, for implicit methods you don’t have to worry about the CFL condition, one of the reasons people use them.

        5. Yea, I don’t know these filters. With good modern methods you don’t need to filter out spurious modes or anything else, the scheme is accurate and stable. This is a red flag for me.

        6. I read this section. Unless I missed something, its just comparing to data and has nothing to do with numerical validation. Given how noisy the data surely is, it might be more meaningful to validate against analytic solutions in simpler situations, such as the Taylor and Wavy vortices in the Taylor column problem. At least here you know quite precisely what the right answer is.

        7. I know, computer speed often keeps people from using better methods. The thing about the FEM is that you can easily do solution adaptive grid refinement. For the global circulation, this could dramatically improve accuracy. Just look at the latest National Weather Service surface pressure charts, pressure gradients are hugely different in different regions. Adaptivity might enable better resolution of terrain, even starting to deal with convection by using finer grid only where convection was becoming significant. You know, I stand by my statement that finite differences are the best methods from the 1950’s. Another thing is upwinding. Even in incompressible flow, you can need that and FEM is hugely better at it than finite differences.

        10. I really question the possibility of modeling convection with a subgrid model which seems to be what they say they are doing. Convection easily leads to chaos and it is extremely difficult to model turbulence using subgrid models. There is a ton of literature on this and even a NASA website about turbulence model validation.

        14. I seem to recall that in the 1970’s they were using shallow water equations that are incompressible for the atmosphere. I’m a little surprised they still do that, because compressibility effects in boundary layers for example can be significant even at pretty low Mach numbers.
        Once again it raises a red flag. Have they validated that compressibility effects are indeed small? Nothing in the 2006 paper about this.

        Bottom line, you need to abandon first the idea that computer speed matters and find something that is stable and accurate and can be validated against something that is really known (not noisy satellite data). They you speed up your method

      • Andy,

        Some time ago I wanted to learn a bit on climate models and ended up in buying (and also reading almost fully, what isn’t true for all books that I buy, as I often read very selectively to complement my preexisting knowledge skipping many details) the book of Washington and Parkinson An Introduction to Three-Dimensional Climate Modeling, 2nd ed (2005). Do you know the book and can you comment, how well it’s up-to-date.

      • Pekka,

        I have not read the Washington and Parkinson book myself. I recall seeing a reasonable review. Warren Washington is a well respected generalist in climate modeling. Claire Parkinson’s expertise is in satellite observations and sea ice. I don’t believe either one has done much in the area of radiation modeling. My guess is that it is a reasonable book, and I don’t expect that it is in any way ‘out-of-date’.

      • John Carpenter

        Andrew,

        Thanks for taking the time to answer my question and providing the links for further explanation. I appreciate the complexity of the model and various modules and is why I am having a difficult time getting a mental image of how it works, however I believe my question would be better answered via a diagram or ‘map’. I understand this is not possible here. The type of 30,000 ft view of the GCM I am looking for could be quite revealing to even yourself.

        The exercise of constructing a ‘visual’ image of how the GCM works requires one to break down the individual components, i.e. the various modules, in a way that it becomes clear how they interact during a single ‘step’. This process requires the creator of the diagram to think about how the model is working in new ways, perhaps revealing connections that need to be made and other connections that appear to be weak. After the 30,000 ft view, you will have to explore the 10,000 ft view of the modules and finally the 1000 ft view of the actual physics involved. It will require you to look at relationships you may even see as mysterious within the model. The exercise of going from the macro to micro image makes one re-learn what is going on within the model, like performing a surveillance audit on the process.

        Once you have mapped out how you visually see the model working, the interesting part comes when you give it to a colleague to review, comment and correct. He/she will see it differently…. so the image will perhaps blur or focus based on their input.

        By iteration, i.e. modifying the image by garnering input, comments and corrections from additional colleagues, the image should eventually sharpen and become clearer. The final end product could be a very useful tool itself in understanding how to add in new modules or modify the model in the future.

        I find it fascinating how doing this type of exercise broadens ones overall understanding of complex ideas to new levels. I am not a computer programmer, I can’t read or write FORTRAN, but with this type of image, it’s not necessary in order to understand what the model is doing.

        Perhaps I am asking for a visual that is not possible…. but once you start putting pencil to paper you may find it hard to not finish.

        Thanks again for your reply.

  30. “Could you explain just how any of those words affects any of Andrew Lacis’s points enough to merit concern, much less justify dismissing it in its entirety? I agree his post would have been better without including those, but they are just throwaway lines.”

    To put it politely, they’re indicative of a world-view that’s flawed enough to raise serious questions about the man’s objectivity.

    • Brandon Shollenberger

      Wondering about a person’s objectivity is fine. Dismissing someone’s comments out-of-hand based upon that musing is not fine. Unless one can show a connection between Andrew Lacis’s questionable word choice(s) and a flaw in the positions he advances (such as if he used ad hominems), it doesn’t really matter what biases he may hold.

      He’s advanced an argument. That argument is either right or wrong, and it is distinct from whether or not he is objective enough.

      • Yes and no. In principle, yes, you’re right. In reality, none of this climate science is so rigorous that there isn’t some room for debate, and so none of the arguments proffered are airtight. So reasonable people have to fall back on other information. One obvious place to look is to see if the person making the argument has the demeanor of a disinterested party, or is clearly on one side, and trying to buttress his position. Lawyers get paid to do that, scientists don’t, at least in theory.

      • steven mosher – are you reading this?

    • Attn: steven mosher

      • Joshua, go learn the science so you, like me, can dismiss the silly things andy says about skeptics and focus on the science. You focus on personality. its all you look it because its all you think your feeble brain can handle. and it doesnt handle that very well.

      • Steven, I may be completely wrong. You may be quite a nice guy in real life, but comments like this leave me with the feeling you are suffering from some sort of superiority complex!

      • steven –

        Thanks for the advice. Words of wisdom from someone as smart as you mean a lot to me. All I can do is hope that you can understand that not everyone can be as smart as you. I do my best, steven, with the limited intellectual resources I have available, but I’ll never be able to attain the deep logic and understanding that you display in this post and the many similar posts that your write so often. All I can do is ask you to be patient – but I do fully understand that your disgust is justified by your exalted and noble pursuit of the truth; it must be terribly hard on you to tolerate inferior intellect, so I’m grateful that your condescension and expression of superiority aren’t even more severe.

        I guess my limited intelligence is the reason that I can’t understand why you seem obsessed with me, yet fail to point out to the numerous other commenters who discuss bias related to partisan influences that they, too, are “IDJTs” and “feeble-brained.” Perhaps you could break down the reasoning behind that discrepancy in a way that is simple enough that even someone so feeble-minded could understand? I know it would be very hard to reduce the complexity of your thinking so exponentially without distorting your meaning – but if anyone could do it, I think you’re up to the task.

      • Steven,
        Just final thought. If you were as smart as you think you are, you wouldn’t indulge in name calling. Anyone can accuse anyone else of having a ‘feeble brain’, and you might just like to consider that this is a tactic used primarily by those who don’t have the intellectual capability to sustain a reasoned argument.

      • Latimer Alder.

        @tempterrain

        Umm….are you the same guy who accused me of a ‘creationist trick ‘ yesterday?

        As a fully paid up atheist from the age of 15 I found your label deeply offensive – and remarked so at the time

        Pots and kettles?

      • LA,

        “Creationist trick” was actually Lolwot’s phrase, incorrectly attributed by myself, to Joshua. But, that seems fair enough to me. It’s not name calling, neither does it mean that all climate science rejectionists are necessarily creationists. However, it does imply there are many parallels in the two lines of argument: Lists of dissenters. Attacks on the consensus. Fake experts. Claims that scientists don’t properly consider the opinions of non-scientists. Its an attack on American values. Its a hoax – they were found out with Piltdown man. Unrealistic demands for experimental proof etc etc.

      • Latimer Alder

        @tempterrain

        Perish the thought that I shoud ever be guilty of an ‘attack on the consensus’ about anything at all. Not little old me. No sirree Bob – I’m with you. I go along with everything the Big Boys tell me becaue they are bigger and smarter than me. Look – they got a Nobel Prize so they mst be dead clever!

        And as a proud Englishman, I doubt if I have ever ‘attacked American values’.. though I do like the food in New Orleans.

        In essence you have produced a long list of ‘creationist tricks’ – which boils down to ‘but Mummy, why don;t they just shut up and believe what I tell them’

        Pathetic.

        PS – unreallistic demands fro experimental proof….like showing that the models have some resemblance to the real world. Yep – Im going to keep on making that point loud and long. If you want to base your ‘science’ and your policies on some game of Climate Fanatasia – that;s fine with me, But if you ever return to the same world as 6.5 billion other people inhabit, then you have to prove it. Aristotle and knowledge by asserttion died five hundred years ago. You seem to regret his passing

      • Latimer,

        If you don’t believe me on the parallels between various forms of scientific rejectionism , maybe you might from John Cook.

        http://www.skepticalscience.com/5-characteristics-of-scientific-denialism.html

        PS I’ve taken to using the term ‘rejectionist’ rather than ‘denier’. Denier seems to have unfortunate associations. Is that any better?

      • Latimer,

        I came across a remark by Stephen Fry the other day which I wish I had thought of in connection with your “deeply offensive” comment.

        “It’s now very common to hear people say, ‘I’m rather offended by that’ , as if that gives them certain rights. It’s no more than a whine. It has no meaning, it has no purpose, it has no reason to be respected as a phrase. ‘I’m offended by that.’ Well, so f*****g what?”

      • I would agree with Fry 100%.

        Why the hell should I concern myself whether somebody gets offended? There is no right to go through life without ever having to feel offended. We have the right to life, liberty and the pursuit of happiness. People who are easily offended are those who don’t know how to purse happiness.

        BTW – I’m offended by stupidity. Should I look into a class action suit against all of the folks claiming catastrophy due to global warming? In addition to being offended, I may have a case of mental anguish.

      • timg56,

        I’m afraid you are guilty of some slight contradiction when you say you agree with Stephen Fry 100% and yet at the same time show hostility to those are concerned about AGW.

        Mr Fry may well be capable of causing you some offence but it would be due to any stupidity on his part. If you were to meet, you may well find yourself in a similar position to his American dinner companion who cared to use the term “a piece of shit” about Al Gore.

        You might care to start reading at the heading “Getting Overheated”

        PS I’ll put the link in a separate comment. Judith’s spam filter has decided to get stroppy!

      • timg56,

        I’m afraid you are guilty of some slight contradiction when you say you agree with Stephen Fry 100% and yet at the same time show hostility to those are concerned about AGW.

        Mr Fry may well be capable of causing you some offence but it would be due to any stupidity on his part. If you were to meet, you may well find yourself in a similar position to his American dinner companion who cared to use the term “a piece of s**t” about Al Gore.

        You might care to start reading at the heading “Getting Overheated”

        PS I’ll put the link in a separate comment. Judith’s spam filter has decided to get stroppy!

      • timg56,

        It’s pretty obvious but I missed out a “not” in front of “any stupidity …” in my last post.

        I must say that my experiences do very much match up with Stephen Fry’s in terms of American sensibilities as regards robust debate at the dinner table. Americans can be a nice as pie if you don’t say anything of consequence to them, but just a hint that you might feel the US are being slightly too one sided in the Middle East, or even feel the British NHS isn’t the Devil’s spawn can certainly get the feathers flying in a way that just wouldn’t happen anywhere else.

      • Its very simple. Joshua said he could not understand the science so he would focus on “motivated reasoning” I point out that he is trying to answer questions about science by using a methodology that is not testable. he impugned his own intelligence. I remind him of that

      • Sorry Steven, but it raises a red flag for me too. If he was joking or engaging in hyperbole that would be OK, but it looks deadly serious. This conspiracy theory about the “denialists’ is just tine foil hat nonsense. I agree that he can say whatever he wants. But after a while, people start to dismiss people who believe in such obviously conspiratorial thinking. There is no conspiracy. It’s all out in the open. In the US anyway, its called freedom of speech.

        By the way, I was just reading Avery’s response to his critics over on the other thread and it actually angered me. The team was openly discussing using a phony libel action to silence critics. What we need in climate science is a Teddy Roosevelt to take on the corrupt establishment. Who is that going to be? Maybe Judith has some of the right stuff?

  31. David McKeever

    I usually rely on comments to help me improve my understanding of what a paper is really saying and I don’t really see that in these comments. I was hoping someone would point out what difference the residence time makes..if water vapor is say 2% day after day year after year what difference does it make if it is the same water molecules year after year…the concentration is what matters..or I am missing something?

    • Brandon Shollenberger

      David McKeever, remember, this post hasn’t been up very long. It’s quite likely many people haven’t even read the paper yet. I just finished the paper (I was surprised at how short it is), but I haven’t had a chance to look at any of the references yet. If you give it more time, I suspect you’ll see more detailed comments.

      That said, I think I can answer your concern. In a general sense, it doesn’t really matter if the water molecules in the air are the same from one day to the next. As you say, it’s the concentration which matters. However, residence time is part of what determines concentration. Residence time tells you how quickly the molecules will go away. The shorter it is, the lower concentration will be. If you emit two substances at the same rate, but one decays/vanishes/whatever more quickly than the other, obviously you will wind up having a lower concentration of that one than the other.

      Also, if emissions change, concentration won’t stay the same. At that point, you have to know residence times in order to be able to figure out what concentrations will change too.

    • David,

      Are you referring to the phrase in the paper ” Furthermore, the atmospheric residence time of CO2 is exceedingly long, being measured in thousands of years …….”

      The point about “same …molecules’ is often exploited by the rejectionists. The concentration of Co2 has been raised in the atmosphere since pre-industrial times by 40% as a result of fossil fuel burning. However, due to the dynamic nature of the CO2 cycle all the excess CO2 cannot be attributed, molecule by molecule, as a product of fossil fuel burning. So if you want to play down the the 40% increase in CO2 levels you naturally emphasise that fact.

      Similarly on residence times. The residence time of an individual CO2 molecule produced by fossil fuel combustion would be only a few years, not the thousands of years mentioned in the paper. But, as you say, it’s the concentration that matters. So, which figure you quote depends on whether you wish to work with information or disinformation.

  32. Judith – you HAVE to explain …why is a technical thread opened with accusations of conspiracy and worse? Are you afraid of Andy Lacis? Or desperate of getting his likes involved to the point of allowing him what you deny your commenters?

    What’s the meaning of censorship for the comments and eyes wide shut for the post author?

    • This is a technical thread about a scientific paper and the response to it. If the author used intemperate words, this does not necessarily detract from the content of his argument. I am deleting comments that have no relevant technical content. Commenters are free to comment on one of the other threads.

      • As a reader, not a contributor, can I say that for me both decisions have to be right: the invitation to Andrew Lacis to say it how he sees it and the removal of comments annoyed by his tone but failing to add anything substantive. Much easier to read this way. That’s the key virtue here, not the kind of even-handedness that leads to every thread sounding the same.

      • Judith,

        The guest author’s post contained gratuitous intemperate words that the author knew would insult many of the readers here. Why did you not suggest that he drop the inflammatory BS? If you are going to censor intemperate response to his provocations, you might also strike the offending words from his post.

      • And what iron law is there that we must all instantly become highly flammable because of such ‘inflammatory’ language? It all depends on context. I detest certain terms – like denier – being used from a position of authority, like Kevin Trenberth at the AMS last January. But anyone with an ounce of sensitivity can see that Dr Lacis is not in a similar position writing on Climate Etc. For me, like Judith, the fact he “reads the blog and [has] provided a guest post demonstrates … that he has an open mind”. So we grow up a little and give him a little slack.

      • thank you Richard

      • But does it contribute anything?

      • Richard Drake,

        Actually, I did not say there was an iron law. Judith described his words as “intemperate”, yet she says they do not detract from his arguments. I have not seen the posts that she has apparently deleted, so perhaps they contain words that are more intemperate, that do detract from the censored posters arguments. So be it. I would rather make that judgment for myself, but it is Judith’s blog, and I offer her my apology for questioning her judgment. And thank you for answering for her. And on that last thing you said, you can kiss my ass.

      • More of my posts were deleted than anyone else’s. My words were not intemperate, but they were a rebuttal of some of Lacis’s underlying assumptions about sustainability, and therefore, off the main topic.

        I don’t really mind being deleted. I’m not the only one with such thoughts.
        ====================

      • Any desire to kiss your ass would also depend on context. You failed to mention context, which was at the heart of what I wrote, now and back in January. So there are two hallmarks for me now of immaturity: inability to sense the importance of context and inability to discern the heart of what someone different to you is saying. In this new context the expectation of Richard Drake kissing your ass suggests that I may have erred in one thing: that some of us need to grow up just a little. But by all means prove me wrong by your civility and other basic evidences of maturity in the days and weeks to come.

      • Why don’t you give us some examples of context , where it would be OK to throw around the word “nigger”?

        Even though I don’t possess an ounce of sensitivity, I do know it is not a good idea to use that word, because I have seen the reactions that it causes. Just a tip for you; don’t ever use that word in front of a lot of black people, and then try to explain to them that they didn’t understand your context. Just run!

        Do you think that Andy Lacis uses the word “denier”, as a term of endearment, while his teammate Trenberth, wields it as a perjorative? What is the context here? You don’t really have a clue.

      • PS: And the fact that we are having this discussion proves that Lacis should have left out the grauitous BS.

      • kim

        Ah’ve been cheated
        Been mistreated
        And deleted….

      • PS: And the fact that we are having this discussion proves that Lacis should have left out the grauitous BS.

        Yes. Andrew is responsible for what you choose to post about and not post about. My life would be so much simpler if I could just find ways to hold other people responsible for my decisions.

  33. Andy – I see little to disagree with in your overall assessment. Certainly, CO2 and other anthropogenic GHG emissions are a potent driver of warming, with water serving in a feedback role due to its short atmospheric lifetime. I do, however, want to ask you to elaborate on a point you made in your item 6, which in my view is consistent with the evidence but not necessarily self evident or indisputable. I quote the entire paragraph, with the salient passages bolded:

    ” Natural (unforced) climate variability is the principal reason for the uncertainty manifested in the largely unpredictable temperature and precipitation fluctuations that occur on regional spatial scales, and on inter-annual and decadal time scales. Arising from changes in advective energy transports and poorly understood interactions with ocean dynamics, this is where uncertainty reigns supreme. However, these advective transports must globally add to zero, and the unforced fluctuations are necessarily fluctuations about the global equilibrium reference point. Nature conserves energy very carefully. Hence, large deviations from the global equilibrium cannot be sustained. So, this unforced climate variability cannot significantly impact the long-term global temperature trend, but its effects on local and regional climate will remain the main source of uncertainty for the foreseeable future.”

    My question is this. Isn’t “long-term” a relative term, which in this case simply compares the oscillation length of natural fluctuations with the century-long climate record that includes an anthropogenic warming signal? The argument has been mounted that even records of this length may contain fluctuations “about the global equilibrium reference point” that are part of long duration oscillations, or as sometimes stated, “one person’s trend is another’s cycle”. None of this, of course, refutes the conclusion that the GHGs are potent climate drivers, which is solidly based in the physics, but relates more to the long term apportionment of warming between anthropogenic (and other) forcings and natural fluctuations. (I should mention that a few threads relevant to the topic of “cyclomania” appeared in this blog a number of months ago).

    Having said this, my own interpretation of the data record for the twentieth century suggests a relatively modest role overall for long term oscillations, and a minimal one for the warming from about 1950 to the past few years, and so empirically, a hypothetically substantial role is not supported by the available data (the same might not be true for other eras or shorter or longer intervals). The major natural fluctuations of more than decadal length have been the AMO and the PDO, which have tended to exhibit irregular interval lengths in the neighborhood of 60 years. Combined, their net contribution from 1950-2007 (the AR 4 year) appears to be very small despite larger amplitudes within that interval itself.

    A small additional point relates to the assumption that the AMO and PDO are in fact natural internal climate modes acting independently of anthropogenic or natural forcings. It has been suggested in fact that the AMO may be predominantly a statistical phantom and there has been recent evidence that the PDO may include a significant anthropogenically forced component. This would further confound attempts to assess their contribution to temperature change during intervals when their net deviation from their baseline levels was large, although it would have less significance for the post-1950 decades when their net contribution would be small even as independent sources of warming.

    It is always possible that we have been missing other multidecadal oscillations that affected the climate record of the past century. That precludes statements of absolute certainty about the proportional role of GHGs, although a major role seems well established.

    • Fred Moolten

      You beat me to this point, though we come at the difficulties in this passage from different directions.

      Taking inspiration from the Three Body Gravitational Problem (http://www.upscale.utoronto.ca/PVB/Harrison/Flash/Chaos/ThreeBody/ThreeBody.html), with anthropogenic influences as Sun 1 and natural variability as Sun 2, the climate (planet) does not promise forever to orbit in familiar paths.

      That is why adding significant anthropogenic influences so substantially affects the risks of extremes in climate.

      For those who haven’t followed Chaos Theory, go ahead, open the animation, play with the various sizes of Sun 1 (anthropogenic influences) and the initial position of the planet (climate), and watch and wait.

      Keeping in mind, the model is greatly simplified at only 3 bodies from our own actual system of interacting ocean oscillations and ocean life and ocean chemistry, terrestrial conditions and terrestrial life, solar variability, orbital variability, land use, anthropogenic aerosols, and GHGs, any of which might suffer the eventual fate of a body in the 3 Body problem: ejection or collision more rapidly with larger perturbation, and all of which are more certain to follow irregular and extreme paths.

      Remove the anthropogenic components, and the extremes, ejection and collision might still happen, despite Andy’s contention they cannot significantly impact, however I will allow that their impacts are less likely to take the whole system off the rails than large anthropogenic influences.

    • ‘Nature conserves energy very carefully’

      What a nice supernatural entity she is.

      I always believed that it got dark and cold at night because the planet was radiating heat and not getting any from the sun. What a fool I have been.

    • “It has been suggested in fact that the AMO may be predominantly a statistical phantom and there has been recent evidence that the PDO may include a significant anthropogenically forced component”

      It has been suggested that the moon is made of cheese and that Judy is a witch. However, one thing we do know for sure is that the Earth is not and has never been at any sort of thermal equilibrium. This sort of blows away everything you have written about. Having a 1 kg block of ice and a liter of boiling water does not give you an ‘equilibrium’ temperature of 50 degrees.
      An equilibrium is not an average of a large number of objects with different temperatures.

    • Fred – I fully agree that “long-term” is a relative term. I am thinking in terms of a simplified globally averaged annual mean energy balance for the climate system that is fully insulated by the lithosphere from the very hot thermal reservoir of the mantle region, and also fully insulated by a stable warm mixed layer from the cold temperature reservoir of the deep ocean. Some of the surface temperature oscillations may be more regional in nature, and thus not have a significant global residual. By “long-term” I means long enough to average out the inter-annual fluctuations like El Nino and La Nina.

      Obviously, the climate relevant region of the Earth is not strictly a closed system. The heat leaking in from the hot mantle reservoir is (fortunately) negligibly small. But the ocean mixed layer is not all that efficient in insulting the biosphere from the cold ocean reservoir, as evidenced by the fluctuations in the deep ocean heat storage, indicating that blobs of cold deep water get periodically exchanged with the warmer water, and need then to be warmed up. But these will necessarily be cold fluctuations as there are no ‘hot’ blobs of deep water.

      We basically need to monitor the energy balance of the Earth at TOA and also in the ocean to keep track of what is going on in the climate zone.

  34. I find it very difficult to understand how someone with a PhD in physics can call a run of a computer model, an experiment. When I was doing research, an experiment involved empirical data. It is difficult to take him seriously after reading his post-modern scientific definition of an experiment.

    • Brandon Shollenberger

      You confusion stems from the fact your position is irrational. A computer model can be used to do experiments. For example, I can experiment with what results I get if I change a variable from 3 to 4. That this experiment doesn’t involve the “real world” doesn’t change the fact it is an experiment.

      It’s understandable to question the significance of an experiment solely involving computer models, but it’s silly to say it isn’t an experiment simply because it is done on a computer.

      • When Richard Feynman said: “The test of all knowledge is experiment. Experiment is the sole judge of scientific ‘truth’,” he was not talking about running computer programs. So was Feynman also confused?

      • Brandon Shollenberger

        I’m sure he was not “talking about running computer programs” in the sense that was not all he was referring to. However, I see nothing but your unsupported claim to indicate he was actually excluding experiments ran with computer programs.

      • How about the first paragraph of the Wikipedia entry for the Scientific Method? Scientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge.[1] To be termed scientific, a method of inquiry must be based on gathering empirical and measurable evidence subject to specific principles of reasoning.[2] The Oxford English Dictionary says that scientific method is: “a method of procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.”[3]

        A climate model is a hypothesis in the above terminology, not an experiment, measurement, or systematic observation.

      • Brandon Shollenberger

        George Crews, your comment here makes no sense. There is nothing in that quote which would indicate computer models are hypothesis, not experiments. You’ve simply claimed it is without any offering any explanation or justification. It is pure, tautological hand-waving. This is no different from what you did in your previous comment, something I pointed out, and you ignored.

        If your intent is to simply throw quote after quote at me until I concede your point, I’m afraid you’ll be sorely mistaken. The best you can hope for is to make me stop responding to you.

      • Brandon, you realize we are talking about arriving at a common definition for experiment don’t you? If you refuse to accept/assume/debate using the Wikipedia definition, that’s fine.

        But the risk is that someone will use the word “experiment” in your sense, but someone else will interpret it in the Wikipedia sense. For example, mathematicians use the term “there exists” (say, a circle) which is not to be taken in the same way that a physicist would say “there exists” (say, the sun). Otherwise, confusion reigns.

      • Brandon Shollenberger

        George Crews, I understand what you claim the Wikipedia definition is isn’t actually what the Wikipedia definition is. Given this, I would hardly be surprised if confusion existed. Vigorous hand-waving tends to invoke that in people.

      • I have no confusion. Solving a set of equations, whether on a piece of paper or by computer is not an experiment.

      • Brandon Shollenberger

        Seeing as the experiment I described was not simply solving a set of equations, I’m not sure what the relevance of your comment here is.

      • Changing a variable from 3 to 4 is not an experiment. What you describe as an experiment is just not an experiment.

      • Brandon Shollenberger

        Steeptown, your response would be meaningful if all I said was change a variable. I didn’t. I said see what results you get when you change the variable. The distinction here is extremely simple and clear, so I’m not sure how you came up with your misrepresentation above.

      • ex·per·i·ment (k-spr-mnt)
        n.
        1.
        a. A test under controlled conditions that is made to demonstrate a known truth, examine the validity of a hypothesis, or determine the efficacy of something previously untried.
        b. The process of conducting such a test; experimentation

        Let’s don’t fall into the trap of calling a “numbers crunching exercise” (whether by hand or on a computer) an “experiment” in the scientific sense.

        It ain’t.

        Max

      • It’s not a trap at all. Testing computer models with different setups is running experiments.

      • You make the mistake of confusing a model with reality

      • no i am not.

        A model is not reality.

        It’s still an experiment.

      • K Scott Denison

        It just amazes me there are so many who think running a computer model with varying parameters as input is an experiment. Wondering when our host will weigh in with her thoughts on this.

        Reminds me of the Star Trek episode where instead of fighting wars, the two worlds ran simulations to determine the extent of damage and deaths and the required their citizens to show up to be killed to match the results of this “experiment”. How can so many otherwise intelligent people not see how silly this position is?

        To me, this is one, of many, items that need to be addressed before climate “science” can truly become a science.

      • Pragmatically, we can’t do the experiment on a controlled configuration the size of the earth. Therefore we do the best we can with models.

        Reminds me of the Star Trek episode where instead of fighting wars, the two worlds ran simulations to determine the extent of damage and deaths and the required their citizens to show up to be killed to match the results of this “experiment”.

        Wasn’t Star Track some sort of fictional television show?

      • K Scott Denison

        Well, just because we are doing the best we can doesn’t mean the results of the models have any meaning. When they are verified and validated with observations let me know.

      • Well, just because we are doing the best we can doesn’t mean the results of the models have any meaning. When they are verified and validated with observations let me know.

        Sure, we can wait another 100 years. Elapsed time is an experimental value that we can’t control either.

      • I tend to agree that a distinction should be made between experiment in its traditional sense and what happens in computer.

        I would suggest ‘simulation’ is a better term for the latter.

        Having said that, its still unrealistic for climate science rejectionists to call for ‘experimental proof’. We don’t have any spare atmospheres available for testing to destruction!

      • WisconsinitesForGlobalWarming

        “Having said that, its still unrealistic for climate science rejectionists to call for ‘experimental proof’. ”

        Yes, and it is also unrealistic for climate “scientists” to state any certainty for projections generated from models which have not been formally V&V’d.

        So, guess it’s a stalemate… or one could set off trying to do science versus post-modern science.

      • Brandon, for a model to have any scientific relevance, the DATA upon which the model is based must be replicable. In engineering, organizations such as the ASTM define data collection and testing standards, which can be carried out by independent laboratories. The data must be reproducible — and the independent replication of outcomes is the basis of the scientific method.

        In climate science the data (the historical temperature/CO2 record) is historical and non-linear. We can ascertain trends, but trends are not scientific — they are statistical. Science is not based on trends or statistics. If it were, then economics, history, sociology, fashion, etc. would be “hard sciences.” There are things that we can never model, no matter how powerful the computers or complex the programs.

      • Brandon Shollenberger

        Jim S, I’m afraid I don’t understand the point of this response. Even if GCMs were not scientifically relevant (a claim I’d certainly dispute), they could still be experiments. Since whether or not Andrew Lacis was idiotically wrong for using the word experiment is the issue at hand, not the relevance of GCMs to scientific understanding, I don’t see the relevance of your comment here.

      • Brandon, we can create a model that “explains” the impact of tooth-loss by children and the impact on the economy by the monetary contribution of the tooth-fairy. But if the model is not testable (and falsifiable), then it is of no value whatsoever.

        You’re use of the term “experiment” differs from others.

      • That’s not a very sensible example.

        How about a model of a pan of water on a fire? So you have such a model and decide to experiment with what happens when you turn the heat on, what happens when you turn it off and what happens when you turn it on and off every minute. Does the temperature settle at the average in that latter case? That’s an experiment, I even accidentally used the word experiment in the passage without realizing it.

      • lolwot, what you are doing with a real pan of water on a real stove is an experiment. It becomes a model when you try and describe the observation mathematically, so as to be able to extrapolate what happens when a variable changes (ie the amount of water, thickness of the pot, the duration of the heat source, etc.). This mathematical description IS the model — and it only has relevance if it can be corroborated with further real-world tests. Just running the model without testing it against further real-world experiments tells you nothing.

      • So you run it a few times and it matches reality.

        Then you want to try something like a pot the size of the Earth and a heat source like the Sun. You can’t do that experiment for real, so you use the model to do the experiment.

      • On reading this I went in search of the phrase “the best model of the world is itself”, which turns out to be (among others, no doubt) MIT roboticist Rodney Brooks. Taken a little out of that context it can do wonders for your thinking. Here’s helpful input to a discussion last year of whether global tyranny is going to be necessary to avoid eco-disaster:

        The real, living world has reached it’s present state partly through the operation of two simple facts: the enormous depth of time in which life has existed on this planet, and the constancy, inevitability and universality of death. Evolution has through these two facts produced a material reality that is so fantastically complex, random and unpredictable that it can never be modeled except in the crudest way — the only accurate model of the world is itself. But we don’t see that! We fasten on what we know and fail to see the vastness of our ignorance. A great illustration of that is how long it’s taken technology to produce machines that can move around a complex terrain unaided. The value of computers has partly been to reveal the extent of our ignorance by allowing us to attempt such things as AI.

        I don’t personally take it as proven that evolution could achieve all that through known natural processes, given information theory. But the bit about what we learn from serious attempts to do AI is spot on. Such processes have clear, pretty much instantaneous feedback of failure. That’s what we lack with climate. Way to go.

      • Eric Ollivet

        Brandon,

        You can test the ability of a computer model to faithfully represent “real world” physics. Indeed this test shall be part of the validation process that any model (whatever the topic is) is supposed to undergo before being stated as validated and OK for use (i.e. able to represent “real world” physics and to provide reliable predictions of the modeled system’s behavior)

        But calling this test an experiment is just pure confusion that is very common in Climate Modelers’ community, where scientists tend to believe their nice climate models represent “real world’s” climate. Calling a computer model run an “experiment” would be an acceptable wording provided this model had been formally validated.

        But actually none of the Climate Models has ever been subjected to a real Verification & Validation process (for the very good reason that they would all have failed!). Indeed none of them is able to hind-cast past observations and none of them has been able to foresee / explain current 14 years pause in climate warming since 1997 (even slight cooling since 2002).

        This is definitely why all climate models are formally invalidated, and why a climate computer model run cannot be called an experiment.

      • Brandon Shollenberger

        Eric Ollivet, your first paragraph talks about validation testing of a model, and then your second paragraph starts off by talking about why said test shouldn’t be considered an experiment. However, the “experiment” being discussed in this issue isn’t the test you’re talking about. This makes the first part of your comment mostly irrelevant.

        The second part of your comment claims climate models are non-validated, thus model runs can’t be considered experiments. Unfortunately, while you claim this, you don’t offer any explanation or justification for the claim. This makes it rather difficult to respond in any meaningful way. Your claim doesn’t make sense to me, as an experiment can be faulty while still being an experiment. However, I may be missing some nuance, so if you could explain why you say a model needs to be validated for it to be considered an experiment, that would help.

      • Brandon, I’m mystified as to why you can’t see the objection to using the term “experiment”, without lengthy qualification, to refer to a model run. Plenty of computer games consist of elaborate models of a physical world, albeit one that contains all manner of invented machinery (space-ships, etc) and organisms (fire-breathing monsters, super-heroes with special powers). These models present an INTERNALLY consistent model of reality, with objects behaving, in simulation, much as they would in real life, if only they in fact existed. Every time a kid plays the game, he performs an experiment, if we are to allow your definition. If he repeats exactly his moves on another occasion, he will get the same result. But even he won’t claim that his results tell us anything about the real world.
        Until, that is, he grows up to be a climate “scientist”.

        Let’s just recall the dissenting voice of the UEA’s Michael Kelly:

        “I take real exception to having simulation runs described as experiments (without at least the qualification of ‘computer’ experiments). It does a disservice to centuries of real experimentation and allows simulations output to be considered as real data. This last is a very serious matter, as it can lead to the idea that real ‘real data’ might be wrong simply because it disagrees with the models! That is turning centuries of science on its head.”

        He concludes with
        “My overall sympathy is with Ernest Rutherford: “If your experiment needs statistics, you ought to have done a better experiment.””

      • Brandon, the answer is already in my original comment :
        1) None of the climate models has been subjected to a formal V&V process (no validation report available)
        2) None of the models is able to formally hind-cast past observations and as a matter of fact there is a significant mismatch between models outputs and measurements over [1880 – 1970] and [2000 – 2010] periods, which means that all models would have failed to pass such a validation process.

      • Eric,

        “But calling this test an experiment is just pure confusion that is very common in Climate Modelers’ community, where scientists tend to believe their nice climate models represent “real world’s” climate. Calling a computer model run an “experiment” would be an acceptable wording provided this model had been formally validated.”

        They over-reach and call it an “experiment”, because they are sorely lacking in real experimental evidence to support their theory. When the results of some of their model runs are pleasing to them, they call it experimental evidence. But no amount of semantic quibbling will ever make model runs of unvalidated computer models into experiments. And unvalidated models do not produce experimental evidence. They produce SWAG.

      • Brandon, what does not make a computer model an experiment is that even the best computer model is an inaccurate representation of the real physical system. A model contains the implicit bias of the person who created the computer model and therefore cannot be regarded as an objective arbiter of the true behavior of the system.

        The only real experiment must involve the system itself.

      • Brandon Shollenberger

        It’s strange how many people are making different claims as to why experiments cannot be done with computer models without actually providing a justification for their claim. For example Brad, why should something have to be completely objective to be used for an experiment? Would you say something wasn’t an experiment if the researcher used a ruler which was known to be biased on the short side? No, yet you answer yes for a computer model, which in the end is just a tool. This means your position isn’t just unsupported, it’s apparently contradictory.

        By the way, your claim about implicit bias isn’t inherently true.

      • Brandon Shollenberger

        It is not that the concept of making model runs to test assumptions is not a valid pursuit, it just isn’t an “experiment” in the scientific sense, so should not be called that in a scientific paper.

        Max

      • It’s not a claim I am making, I am merely specifying that the definition of an experiment does not include simulations.

        “By the way, your claim about implicit bias isn’t inherently true.”

        Correct, but it is impossible to prove that models aren’t biased unless they can be compared against the behavior of the real physical system. Only the real world is a truly objective test.

      • Brad, This position leads to subjectivism in which NO knowledge is possible.

        Engineers (and their models) break big problems down into little, manageable, testable (falsifiable) problems. They then include redundancy into their designs, so that the failure of any one component , due to an unaccounted for variable, will not collapse the whole system.

        The inability to construct “omniscient” models is not because they are “biased” by the creator. Models can be objective.

      • The critical component in the advancement of knowledge is to implement/test your simulated creation in the real world. Engineers do make models of buildings, but those models have been honed to high degrees of objective accuracy by decades of building actual real buildings.

        Climate science doesn’t have a chance to build climates in the real world. Thus their models lack this kind of objective test.

      • A computer model run is a test of a hypothesis. It is not evidence and calling it evidence only leads to muddle-headed thinking.

      • Actually a computer model is not even a test of a hypothesis. It is a simulated test of a hypothesis.

        On the one hand, I hate to sound like a broken record, but the importance of validation by real world tests is the most important part of a model construction.

        This is why the LHC was constructed. I am sure that physicists would have preferred to get by with just simulations, but they knew that real world tests were the only way to evaluate the models they had. These tests are very inconvenient, and very expensive, but not optional.

    • steven mosher

      Its an experiment. What is being tested is the model. when we cannot do controlled physical experiments ( go double C02 ) then we only have one tool. The physics as we know them embodied in computer code. Computer code is the embodiment of the theory.

      • Reread your Feynman. He didn’t leave any room for doubt about what an experiment was. A computer model isn’t an experiment in the sense that he was talking about. The neutrino thing? That’s an experiment. It may turn out to be wrong, but it’s a real physical measurement. A model is nothing more than a complicated calculation.

      • Oops. Never mind. Lost in the nesting.

      • Steven, at some point, it is necessary to realize that there are somethings in this indeterministic universe that we cannot know or “predict” scientifically. Every problem does not have a “solution”.

      • “Its an experiment. What is being tested is the model. when we cannot do controlled physical experiments ( go double C02 ) then we only have one tool. The physics as we know them embodied in computer code.”

        But surely, the model isn’t being tested. Unless we’re going to redefine “tested” while we’re redefining “experiment”. The “experiment” doesn’t test whether the model is any good or not (which would be the meaning of “testing a model” to me), it is running a scenario using the model and taking the output as some sort of evidence with respect to the real world.

        “Computer code is the embodiment of the theory.” But experiments tend to be used to test a theory, don’t they? You can’t test the theory by running these “experiments”, surely? You can’t even test the model.

      • Maybe I’m missing the point here, but how can you call something “an experiment” if it will never discover anything new? A model will return the information that was coded into the model, it can’t do anything more than that. So varying the inputs and confirming that the model behaves as expected, isn’t an experiment. At best, it’s software testing.

        If the model is a good model, then the results might be usefully illustrative, but that’s probably the point most in contention.

      • “Maybe I’m missing the point here, but how can you call something “an experiment” if it will never discover anything new? A model will return the information that was coded into the model”

        The behavior of GCMs emerges from the complexity of the model. It isn’t coded in. Great effort often goes into trying to understand why climate models exhibit certain behaviors.

        So in this case noone knew beforehand what would happen in the model world if the non-condensing greenhouse gases were removed. Until the experiment was performed the result was not known.

      • Steve, imagine we had a model embodying the theory: “each doubling of CO2 will result in a doubling of temperature”. We run the model and see that, as the CO2 variable doubles, the temperature output doubles as well.

        Is this an “experiment”? If so, what is it testing? In a trivial sense it is testing the program to make sure that it can do the simple arithmetic embodied in the model. But that is about all it is testing. It would reveal nothing at all about climate.

        For any sort of useful “experiment” to take place you would have to test your model’s output against actual observed values. If you did that with my doubling model you would discover, rather quickly, that your model was wrong because the observed temp would very quickly part company from the model’s predicted temp.

        Presumably, a scientist would take a look at this deviation and see if there was some function which would fit the model output more closely to the observed. Then test again.

        All of which you know Steve. And it is the essential meta problem with climate models in general. The validation and verification which would measure their ability to make accurate hindcasts (and thus potentially accurate forecasts) has been neglected.

        Dr. Lacie’s points may very well be true within the world of his model; the experimental question is whether that world has much to do with the real world.

        How that is working out has been interesting recently: the modeling community has realized that there is “missing heat”, heat which the models say should be somewhere isn’t. This has lead to the Treberth “it’s in the deep ocean”, the resurrection of the aerosol fudge factor and desperate attempts to prove that clouds raise temp.

        All of which illustrates that there is lots of work to be done before results of model runs should be taken seriously for policy purposes. A point which you don’t have to be a dupe, minion or fossil fuel cheque taker to recognize.

      • I think JC is right on the money here.

        The climate scientists suffer from exactly the same epistemic difficulties as economists do. They study a complex system that essentially has one history. You cannot get more than one run of the real thing. You can do informative laboratory experiments (as in economics) but they abstract from so much of the complexity of the real thing that you always have some questions about their external validity. Computer models are simply complex extensions of analytical theory, to a realm of deductive reasoning that outruns what one can accomplish with pencil and paper and analytical solutions. But they are still theory of the reality, not the reality itself.

        But you can forget about “experiments” in the classical sense of the word. You can’t do controlled experiments on the actual world climate, because you can]t re-run climate history several times in two or more conditions all else held constant.

        All you can do is look at the one history you have. So the epistemic basis of a science of the world climate (or world economy, or world ecology) is always a mosaic of laboratory results and observations of the one real run of the real system you have in front of you.

        Pretending that this kind of science is anything like chemistry or engineering is just silly…and asking it to actually BE like chemistry or engineering is silly too, IMO.

        The computer model is still a model. Changing its settings and seeing what happens is no different in principle from looking at the comparative statics predictions of a theory as you change a parameter, by analytical mathematical methods. It certainly ain’t an experiment in my mind.

        Yet people who do computational theory frequently refer to these comparative statics exercises as experiments. I suggest we don’t get bent out of shape by this semantic quirk. They know they aren’t testing the model against real observations when they do this.

      • We should get bent out of shape. Confusing simulations for experiments is precisely part of the reason for the overconfidence in these models

      • John DeFayette

        I am glad to see this thread finally branch out to touch this piece of the CAGW problem: the astounding misconception that computer simulations are the equivalent of physical reality. It is refreshing to see the fallacy lain bare by Prof. Lacis’ anniversary musings.

        NW, your economics parallel is perfect, and it also highlights why we need to get bent out of shape over the semantics. After all, there are not many people who would rely on discrete economics models to predict a return on investment 100 years out. Nobody would be so foolish as to assume that such a computer model could ever be built to represent the real economy with anything nearing accuracy–at least not with our current tools and knowledge.

        But look at Prof. Lacis’ wording in the lead. His whole reasoning revolves on how computer simulations (experiments) trump any criticism of climatologists’ predictions. Note this list of “physical evidence” given by Prof. Lacis himself in the text:

        “…(1) precise measurements show atmospheric CO2 has increased from its 280 ppm pre-industrial value to the current ~390 ppm; (2) there is available an accurate HITRAN tabulation of line absorption coefficients for all of the atmospheric absorbing gases; (3) we have available accurate radiation modeling techniques as well as capable global climate models; and (4) that 9 Gigatons of carbon (coal, gas, oil) are being burned each year (by us humans).”

        Am I dreaming or did I just see a world class physicist equate three reasonably straight-forward measured values to GCM outputs? Sure, he also equated (perhaps unknowingly) GCM’s with radiation modelling techniques so that the audience might further confuse the former with the straight-forward latter. After all, radiation models can be validated ad nauseam. We have it from the experts: GCM’s are physical evidence, just like measurements of photon absorption in materials and of CO2 concentrations in the air.

        So while Prof. Lacis is bent out of shape because the IPCC insists on using “social science” terms in their tomes, he wants to hammer home the concept that computer simulations that could very well be no more valid than economics models (a social science perhaps?) must be considered as hard evidence for the hard sciences. We need to bend back reality to its proper shape: number 3)b) does not belong in the good professor’s list. The rest of his paper and current writing rests entirely on that erroneous inclusion; there must be a drawing board somewhere begging for attention.

        I have a modest proposal for the climate modelling community. If you want to demonstrate that your codes can really do a good job of modelling our world just show us the “experiments” that actually model (without too much fudge, mind you) the MWP and the LIA to some accuracy, along with the 20th century. No hockey sticks, now, go ahead and model reality, not Reality 2.0.

      • Very well put NW. This is THE central problem with Climate Science and the very reason that it’s “predictions” can be rejected categorically. The climate is not a clock. Many people have a vague understanding of Popper’s concept of falsifiability, but most do not understand what drove him to develop it — it was his rejection of what he termed “historicism”. Non-linear, non-replicable systems cannot be modeled. For a model to be valid, the DATA must be replicable by anyone at any time. You cannot do this with the historical temperature record.

      • Steven,

        Can you please point out the particular GCM’s that have the physics right?

      • Ummm…. no.

        A computer model is a simulation. What is being simulated is the climate. When we cannot do controlled physical experiments, we simulate them. The physics as we know them embodied in computer code. Computer code is the embodiment of the theory.

        The difference is in the “physics as we know them”. A simulator may or may not be the actual physics of the real world (at no fault of the modeler, JC’s uncertainty monster). An experiment is done to utilize the actual physical processes as a test.

        Physical = experiment
        virtual = simulation

        As much as some video gamers and climate scientists like to believe, being good at a simulation is not the same thing as doing it in reality. As a programmer, you should never, ever believe that the simulator is a valid substitute for the real thing (even if you cant test using the real thing, don’t confuse simulator success as validation of reality). To believe otherwise will only come back to bite you later on. Climate scientists have not been taught this lesson.

      • Brandon Shollenberger

        I’m curious what you have to say about this comment of mine Stilgar. Would you mind telling me what you think of it?

      • It was a term used to get an idea across that you needed to verify that the variables are doing what you think they should be doing.

        He could have also told you to try “playing” with the values of the variables. It would have meant the same thing.

        Playing with computer code is not the same thing as performing a scientific experiment.

  35. “The greennhouse physics, and the increase of atmospheric greenhouse gases as the fundamental basis for global warming, are well founded.”

    Andy, thanks for posting. I would add, and hope to see a response, that CO2 levels can be impacted by long-term warming/cooling events. Do we truly have accurate historical data upon which to base models that can discern which causes which? More CO2 = warming; or More warming = more C02?

  36. Looking at the Vostok Ice core data I would think it is much more likely that the Earths temperature is more of a control valve for atmospheric Co2 content.

    source – http://www.brighton73.freeserve.co.uk/gw/paleo/400000yrfig.htm

    • Exactly! At the highest “CO2 forcings” warming shifts to cooling and vice versa.

      • Exactly! At the highest “CO2 forcings” warming shifts to cooling and vice versa.

        But those highest forcings are only 280-300 PPM. The initial forcing that initiated the warming interglacial periods may have been completely compensated by the time the atmospheric concentration reached 300 PPM. For example, the ocean temperature may have equilibrated by that time. We now have a forcing that will no doubt reach >100 PPM higher shortly.

        The only time constant left is the CO2 adjustment time which may be the driver to cooling. (Notice how the Vostok ice core data shows a much slower slide toward cooling than warming)

      • The Ice core data only goes back a mere 400,000 years. Try going back about 600 million years and charting the CO2 and temps and it will become quite obvious that atmospheric Co2 and temperature don’t correlate well at all. Too many otehr factors. The forcing embraced by the CAGW crowd to me is resembles forcing a square peg into a round hole, it just does not fit.

      • goes back over 400 million years, CO2+solar forcing and temp seem to be in reasonable agreement:
        http://www.skepticalscience.com/images/Phanerozoic_Forcing.gif
        http://www.skepticalscience.com/co2-higher-in-past-intermediate.htm

      • you may want to read the caption from the link you posted LOLwot, it is not relevant

        Figure 2: Combined radiative forcing from CO2 and sun through the Phanerozoic. Values are expressed relative to pre-industrial conditions (CO2 = 280 ppm; solar luminosity = 342 W/m2). The dark shaded bands correspond to periods with strong evidence for geographically widespread ice

  37. steven mosher

    Andy, Its not exactly clear where the SI is

    • steven mosher

      found it

    • Brandon Shollenberger

      I thought it was pretty clear. Right next to the download link, it says:

      (Document is 1.8 MB; Document on GISS site includes appended supplementary material.)

      That says it is attached to the end of the file, which it is. It’s a little weird to have to scroll past part of another paper to get to it, but…

  38. Oh the irony of it! There was this XIX Century Italian politician who famously compared women voting to cows being given suffrage. So let’s hear what kind of woman would have wasted time discussing whatever TECHNICAL detail of his policies?

  39. Lacis did not like the use of “very likely” by the AR4 report because to him it is obvious first that the CO2 increase is more than accounted for by fossil fuel emissions, and second that the global temperature rise is more than accounted for by the expected effects of increased CO2. I tend to agree.

  40. You know, indulging in conspiratorial clap-trap talk, instead of dealing with the issues- which your paper does not deal with- only fulfills the stereotypical behavior of someone making a great career selling fear.
    Attributing to CO2 magical control abilities in the atmosphere is a nice excursion for you. Pretending that the skeptics are part of a fossil fuel industry plot is just more magical thinking on your part. And,since BP, Shell, Exxon and other big oil companies are major backers of research you and your colleagues engage in, you are also much less than sincere in your diversionary tactics than an ethical person would otherwise be.

  41. steven mosher

    Andrew. Your last two sentences were interesting

    “Furthermore,the atmospheric residence time of CO2 is exceedingly long, being measured in thousands of years (23). This makes the reduction and control of atmospheric CO2 a serious and pressing issue,
    worthy of real-time attention.”

    I don’t see how that logically follows or follows in any other sort of scientific way from what you have proved in the paper. Consider my version to see what I mean.

    “Furthermore, the atmospheric residence time of CO2 is exceedingly long, being measured in thousands of years (23). This makes the adaptation to a warmer world a serious and pressing issue, worthy of real-time attention.”

    What you see by changing that last sentence to the one I used is the following. There is no logical or scientific force behind the sentence that you used. You imposed a solution as a consequence of the science when in fact that solution is not a consequence of the science. That solution may be better, however, the sentence you used is not supported by the science in the paper you wrote. It may be back by science other places, but I’d argue that its a useless ornament in your paper.

    • Brandon Shollenberger

      Steven Mosher, I noticed the exact same thing the first time I went through the paper. In fact, it wasn’t the only strange leap I encountered. I was considering making a comment listing some examples, but I guess you kidn of beat me to it.

    • In physical chemical circles, “residence time” has a definition. If you stop putting any of a substance into a well-mixed system, it’s the “e-folding time”; the time that it takes to drop to 1/e times the original concentration. Am I reading that right? With half of the current output disappearing, he’s claiming that if we stop producing CO2 completely, that it’ll take thousands of years to drop to 1/e = 1/2.7818*(390-280) + 280 = 320? Or was that more of a rhetorical flourish?

      • The semantics entail different terms – “residence time”, or “adjustment time” (see WHT’s comments), but in any case, you are referring to the time required for a concentration decline of CO2 to an equilibrium value if no more is added. That can’t be characterized by an e-folding time because it is not the result of a single exponential decay function, but rather by a series of curves with different time constants varying from a few decades to hundreds of thousands of years – the latter for restoration of oceanic carbonate stores from the weathering of terrestrial silicate and carbonate rocks. At best, one can compute a rough average, which runs to about 100 to 200 years, but this shouldn’t be thought of as a “half-life”, because the first half decays faster than succeeding halves of what is left.

        None of this is the same as the residence time for individual CO2 molecules, which is probably a decade or less, but involves replacement of molecules that disappear into sinks by others that emerge from sinks into the atmosphere.

      • What Fred said, exactly.

      • Really? You think that before we started burning coal and oil that [CO2] was in equilibrium?
        What about oxygen?

        Do you think that the concentration of oxygen in the oceans is in equilibrium with the atmosphere?
        What about DMSO ? Is that in equilibrium?
        What about methane? Is methane in the oceans in equilibrium with the atmosphere?
        Methyl Bromide? Is that in equilibrium or dis-equilibrium?
        Perhaps Fred and Web could define what an ‘equilibrium’ is, with respect to the concentration gradients of gasses in the atmosphere and in the oceans and state which gasses are in ‘equilibrium’.

      • Really? You think that before we started burning coal and oil that [CO2] was in equilibrium?

        Many solutions to analysis problems only need to assume a steady state and not necessarily an equilibrium.

      • K Scott Denison

        Oh, so not equilibrium, but steady state. And when was the climate in steady state?

      • Oh, so not equilibrium, but steady state. And when was the climate in steady state?

        What time range do you want to talk about?

      • I’m still suspicious of a claim of even 100-200 years given the way half of CO2 production disappears into some combination of sinks, but I’m glad you said that about the individual molecules. That’s why the isotopic studies don’t mean as much as a lot of people think they do.

      • Fred Moolten

        At best, one can compute a rough average, which runs to about 100 to 200 years, but this shouldn’t be thought of as a “half-life”, because the first half decays faster than succeeding halves of what is left.

        Interesting observation. We have started this conversation once before, but never quite got it resolved.

        Let’s say your statement is correct and that the half-life of CO2 in our climate system (including all your caveats) is 100 to 120 years, as shown in the presentation of Zeke Hausfather at the Yale Forum (this would be at the upper end of your estimate)..

        And, for now, let’s ignore your statement that the“first half decays faster than succeeding halves”.

        If it decayed at the same rate, this would be at a rate of 0.58% of the concentration annually or 2.3 ppmv/year at today’s 390 ppmv, following a standard half-life equation..

        Interestingly, this is roughly the amount of CO2 that is “missing” per year on average (if we assume that human CO2 emissions are the only net “addition” into the climate system, as IPCC does).

        So this would mean that essentially all of the “missing” CO2 is disappearing from the climate system.

        Of course, if you are correct in saying that “the first half decays faster than succeeding halves of what is left”, there would be an even greater amount that is leaving our climate system each year on average.

        Interesting.

        Max

      • Fred Moolten

        At best, one can compute a rough average, which runs to about 100 to 200 years, but this shouldn’t be thought of as a “half-life”, because the first half decays faster than succeeding halves of what is left.

        Interesting observation. We have started this conversation once before, but never quite got it resolved.

        Let’s say your statement is correct and that the half-life of CO2 in our climate system (including all your caveats) is 100 to 120 years, as shown in the presentation of Zeke Hausfather at the Yale Forum (this would be at the upper end of your estimate)..

        And, for now, let’s ignore your statement that the“first half decays faster than succeeding halves”.

        If it decayed at the same rate, this would be at a rate of 0.58% of the concentration annually or 2.3 ppmv/year at today’s 390 ppmv, following a standard half-life equation..

        Interestingly, this is roughly the amount of CO2 that is “missing” per year on average (if we assume that human CO2 emissions are the only net “addition” into the climate system, as IPCC does).

        So this would mean that essentially all of the “missing” CO2 is disappearing from the climate system. (Where it is going would be a second question.)

        Of course, if you are correct in saying that “the first half decays faster than succeeding halves of what is left”, there would be an even greater amount that is leaving our climate system each year on average.

        Interesting.

        Max

      • Looks like my message got posted twice. Sorry

    • Aside from your rhetorical point, which is good, there is another technical point that needs cleaning up.

      The “residence time” point is a definitional problem. Some very simple carbon cycle arguments show that the average residence time of a single CO2 molecule in the atmosphere is like 10 years and there is no way that this turns into thousands of years. The correct measure is actually one of considering adjustment time, which is defined as the excess CO2 which has not diffused into deep sequestering sites. This in fact has no mean value and is the serious and pressing issue that the climate and the world will have to adapt to.

      • “excess CO2 which has not diffused into deep sequestering sites”

        Sadly, the CO2 activity does not suggest that the top of the ocean is stuffed to the gills with CO2 and the bottom slowly soaking it up.
        The denuding of oxygen by organisms metabolizing organic debris falling as snow might give you an insight.
        No, don’t bother. Just assume that everything is a thermodynamic equilibrium. Ignore life all together and just assume its all about chemistry.

      • Just assume that everything is a thermodynamic equilibrium. Ignore life all together and just assume its all about chemistry.

        Far from it. I solve the Fokker-Planck master equation for diffusion processes and this is what I get, a long-tailed adjustment time. The Fokker-Planck is a dynamic equation that considers conservation of mass and the kernel solution to the equation is used to show any kind of spatio-temporal behavior that you might be interested in.

        If you think this is chemistry, you have that right. I prefer to think that all science falls under physical laws and I use the physics that matches the problem domain I am studying.

    • This is an excellent point, Steve.

  42. Dr C

    You say this is a technical thread

    I do not see any technical content in Lacis’ post. It is an ‘argument from incredulity’ and ‘argument from appeal to intuition’.

    Namely:

    More specifically: (1) precise measurements show atmospheric CO2 has increased from its 280 ppm pre-industrial value to the current ~390 ppm; (2) there is available an accurate HITRAN tabulation of line absorption coefficients for all of the atmospheric absorbing gases; (3) we have available accurate radiation modeling techniques as well as capable global climate models; and (4) that 9 Gigatons of carbon (coal, gas, oil) are being burned each year (by us humans).

    None of the above, need necessarily add up to “global” warming.

    For instance, there is a model that indicates that, upto 5C of Southern warming, will worsen Antarctic sea, and eventually continental ice. (worsen = increase).

    The results are counter-intuitive, arent they?

    If intuition alone would lead us from increasing CO2 to “global” warming, we wouldn’t have to resort to ‘capable global climate models’, would we?

    If we believe in the process-driven climate model paradigm, where we plug in ‘known’ climate system subcomponents and let them run, we should be ready to doubt them as well, when do not recapitulate -observed changes-.

    If CO2 is such a overpowering factor, as Lacis claims, and the models fail to recapitulate observed temperature trends, it must be accepted that there are equally powerful factors which are not represented in the models, but present in the earth system, which are capable of keeping the putative CO2 effect in check.

    Secondly, it appears to me that Lacis, considering my previous experience with his comments, has

    [1] not given up his inflammatory terminology
    [2] appeared here so as to balance his own account book, on the charge that he provided ‘succour to the deniers’.

    Esp., regarding [2] above, we have ample evidence that ‘wanting to be seen as not providing support to the ‘deniers” is a powerful motivating factor for the actions of many scientists who wish to support or sustain the present orthodoxy. The recent apology tendered by the editor of Remote Sensing is a case in point.

    The present article, with its fact-free sermonising, and the open attempt at hitting all the right buttons, is another one, in the same vein.

    Lastly, I examined the Bishop Hill thread Lacis point to. What is quoted as being from Lacis, hardly squares with his remarks here. Does he mean to say that Greenpeace activists are likely to require caveats to be introduced into a statement attributing global warming to humans? I find that incredible.

    A more simpler explanation is, that his “intemperate” remarks, unfortunately were picked up by Bishop Hill and WUWT and Lacis ever since has laboured in climate penance, to be able to return as the prodigal son.

  43. Andrew Lacis

    If CO2 was the principal control knob governing earth’s temperature, how come there was no change in the global warming rate of 0.06 deg C per decade in 160 years of temperature data shown below?

    http://bit.ly/nw52EP

    Human emission of CO2 that has increased exponentially in the last century has not changed the global warming rate. As a result, its effect on global temperature must be nil.

    Please let us not confuse the CO2 in the globe with the human emission of CO2.

  44. The folks at NASA were recently unable to predict where and when a large piece of space junk would land – too complicated for orbital mechanics. Yet the scientific community apparently believes it can predict the earth’s future climate and the impact on mankind. Pure hokum; it is way too complicated.

    While this whole AGW exercise is undoubtedly fascinating from an academic standpoint, the actual problem remains: reasonably priced energy for mankind. To the extent that valuable resources are excessively diverted for “classroom exercises” and subsequent ill-conceived solutions to the speculated “bogeymen” (i.e. CO2) problem, then the real risk to man becomes ever greater.

    I suspect this comment will be scrubbed, but the scientific community really needs to get out of the Ivory Towers, consider the broader picture, recognize where the real threats lie and help develop ways to solve those problems. IMO, CO2 is not a pressing threat and we really can not do much about it in any case.

    • Yes, Mike. Well said. Thank you.

    • “The folks at NASA were recently unable to predict where and when a large piece of space junk would land – too complicated for orbital mechanics. Yet the scientific community apparently believes it can predict the earth’s future climate and the impact on mankind.”

      They predicted it would fall though didn’t they

      • K Scott Denison

        “They predicted it would fall though didn’t they”

        Yes, and I can predict the sun will shine tomorrow. Doesn’t mean I know anything about the climate 10 years from now.

        Are you really that naive? Are your standards for evidence of success really that low?

        Good thing the folks who design the products you use have much higher standards.

  45. “Yes and no. In principle, yes, you’re right. In reality, none of this climate science is so rigorous that there isn’t some room for debate, and so none of the arguments proffered are airtight. So reasonable people have to fall back on other information. One obvious place to look is to see if the person making the argument has the demeanor of a disinterested party, or is clearly on one side, and trying to buttress his position. Lawyers get paid to do that, scientists don’t, at least in theory.”

    This is exactly right. Thank you. If a man’s willing to cook up scenarios that border on the paranoid, I’m certainly not going to trust him. I’m not a scientist. I have to rely on my own experience and good judgment in a complex world of fiercely competing theories.

    Put the shoe on the other foot for a second. Suppose I made the wild accusation that establishment climate scientists are essentially bought and paid for the government, as well as various green businesses, foundations, and agencies whose interests are clearly served by global warming alarmism…

    Oh wait…

  46. “…(3) we have available accurate radiation modeling techniques as well as capable global climate models….”

    The CAGW movement rises or falls on whether one accepts unvalidated, unverifiable climate models, generated by CAGW true believers, as authoritative.

    As everyone seems to agree, there is nothing new here. Just another re-framing of the CAGW dogma.

  47. Andrew Lacis

    This is because CO2, like ozone, N2O, CH4 and CFCs, does not condense and precipitate from the atmosphere at current climate temperatures, whereas water vapor can, and does.

    The water vapor in the atmosphere varies from 1% to 4%, while CO2 is about 0.038%. At the highest water vapor condensation, the 1% water vapor is still 26 times than that of CO2. The increase in water vapor from 1% to 4% does not result in global warming, so does the increase in CO2 by 0.01 % ( a change from 0.028% to 0.038%) in the atmosphere since the beginning of the industrial revolution.

    • The increase in water vapor from 1% to 4% does not result in global warming, so does the increase in CO2 by 0.01 % ( a change from 0.028% to 0.038%) in the atmosphere since the beginning of the industrial revolution.

      Girma, I hope you just made a naive mistake. Changing CO2 concentration from 0.028 to 0.038 is a 36% increase, not a 0.01% increase.

      • Girma, I hope you just made a naive mistake. Changing CO2 concentration from 0.028 to 0.038 is a 36% increase, not a 0.01% increase.

        The proportion of CO2 in the atmosphere increased from about 280 ppm to a about 380 ppm. 280 ppm means 280*100/1,000,000 = 0.028 %. 380 ppm means 280*100/1,000,000 = 0.038 %. The increase in percentage of CO2 in the atmosphere is therefore 0.01 % (=0.038% – 0.028%).

        WebHubTelescope, after 100 years of human emission of CO2, the atmosphere still consists about 78% Nitrogen, 21% oxygen, 0.9% Argon, 1% water vapor, 0.039% CO2, and other trace gasess. At the beginning of the industrial revolution, the proportion of CO2 in the atmosphere was 0.028%.

        http://bit.ly/ph4Ex3

        The proportion of CO2 in the atmosphere increased by only 0.01% since the beginning of industrial revolution.

      • Girma, Concerning your understanding on how percentages work, you really do have a naive take on things. A dopant in a semiconductor can be at the 1 PPM level, yet if you change something from 1 PPM to 2 PPM it could spell the difference between a transistor working well or not. However, in your superficial view, the percentage change would be 0.0001% and thus be inconsequential.
        If that is too hard for you to comprehend, ask your doctor to play around with your bloodstream’s elemental ion concentrations and see what happens.

      • I am only stating a fact:

        The proportion of CO2 in the atmosphere increased by only 0.01% since the beginning of industrial revolution.

        This could all be released by the sea due to the long-term global warming trend of only 0.06 deg C per decade.

        http://bit.ly/nw52EP

        WebHubTelescope, could you please explain to me why the global mean temperature touches but NEVER exceeds the upper global mean temperature for long in the last 160 years of data?

        WebHubTelescope, is it possible that the oscillation in global mean temperature between the upper and lower global mean temperature boundary lines are due to the thermohaline circulation cycles described in the following paper?

        http://bit.ly/nfQr92

      • @Girma…

        I’ve seen your first link (or very similar) used many times, and I always have the following question: why are you imposing a linear trend on the data, rather than, for instance, one with an exponential rise? For that matter, a bent line with its break point somewhere around 1920? Depending on the actual cause of the trend, either of these would be plausible, wouldn’t they?

      • AK

        why are you imposing a linear trend on the data

        Because all the peaks lie on a straight line, all the valley lie on a straight line, and these two lines are parallel!

        In addition, the slope of these boundary lines is identical to the global mean temperature trend for the data from 1880 to 2010.

        The oscillation between these two lines is due to thermohaline circulation cycles.

      • WisconsinitesForGlobalWarming

        AK, that’s the interesting thing… Girma isn’t “…imposing a linear trend on the data…”, rather he is OBSERVING that the trend of temperature peaks and valleys IS A LINE.

        Fascinating this idea of OBSERVATION versus IMPOSITION (MODELING). You might want to try it sometime.

      • @WisconsinitesForGlobalWarming…

        Girma isn’t “…imposing a linear trend on the data…”, rather he is OBSERVING that the trend of temperature peaks and valleys IS A LINE.

        And I’m OBSERVING that the data actually looks like it fits a curve or broken line better than the straight line Girma is imposing on the data. You can see the imposed line right there on the graph.

  48. On further review, the referees have determined that there may be something new, in this blog post, if not in the Science paper.

    “Based on this basic input data, the relevant physics is inescapably clear that the increase in atmospheric CO2 is indeed enhancing the strength of the terrestrial greenhouse effect, and thus causing global warming to happen – all directly attributable to human industrial activity. To characterize this fully documented global warming only as being ‘likely’ a ’substantial’ anthropogenic contribution is clearly resorting to unscientific understatement that does nothing to clarify or accurately portray our understanding of global climate change.”

    The AR4 exaggerates uncertainty?

    And what about this: “All directly attributable to human industrial activity?” ALL? I thought I might be misreading that part , but the very next sentence rejects the IPCC claim that the human contribution to global warming is just “substantial” (the cowards).

    And here I thought we were supposed to be approaching a kumbaya moment of agreement on the need to acknowledge uncertainty in climate science. Guess not.

    But I do want to congratulate the author for at least using the more accurate term “global warming,” rather than re-framed terminology “climate change” (though I suspect an angry memo from Hansen of Schmidt on that point may be in the offing).

    • Based on this basic input data, the relevant physics is inescapably clear that the increase in atmospheric CO2 is indeed enhancing the strength of the terrestrial greenhouse effect, and thus causing global warming to happen – all directly attributable to human industrial activity.

      Watch the pea under the thimble.

      Based on this basic input data, the relevant physics is inescapably clear that the increase in atmospheric CO2 is indeed enhancing the strength of the terrestrial greenhouse effect,

      Ok so far.

      and thus causing global warming to happen

      Oops. I’d have been ok with causing some warming, but they just slipped a joker in the deck.

      all directly attributable to human industrial activity.

      What was the point of that?

      And then on to the sermon:

      To characterize this fully documented global warming only as being ‘likely’ a ’substantial’ anthropogenic contribution is clearly resorting to unscientific understatement that does nothing to clarify or accurately portray our understanding of global climate change.”

      That’s not a scientific conclusion, that’s a speech.

  49. Andrew’s article is interesting. I don’t care about the use of derogatory terminology to describe the opposition, but he should at least be clear who he is talking about.

    The reliance on models is the main problem here. Apparently, it is not the models but paleoclimate that gives the sensitivity that Gavin Schmidt says is reliable. But there is a great deal of controversy about the paleoclimate estimates. We can’t even seem to get straight whether or not there was a Mideval warm period, much less understand the last glacial maximum.

    In any event, the case for the models is not nearly as strong as usually asserted in public forums. I won’t repeat what I said on an earlier forum, but a quick look at Paul Williams’ presentation on numerical errors in climate modeling shows a host of issues that would lead me to assign a rather high uncertainty to the model results, and then we have the uncertainties in the physical models themselves. Even the IPCC says that the understanding of aerosols and clouds is “low.”

    There are very technical issues here that I won’t attempt to go into. The history of computational physics has not been as successful as is often portrayed particularly if the effect is a small effect, like the ones we are talking about here. The path to improvement in the models relies heavily on better numerics and computers. This is difficult and not as lavishly rewarded as colorful fluid dynamics is, but is more important.

    What is needed here is better science and an attempt to quantify uncertainty.

    • Pinning the consensus down on the basis for their confidence is a game of whack-a -mole. If you criticize the models, it is paleo; if you criticize paleo, it is the basic physics; if you say the basic physics does not account for all the variables, they go back to the models, and on and on….

    • …but he should at least be clear who he is talking about.

      I think that this is a very important point – and I think that it extends much wider to everyone who participates in these debates.

    • There are simple energy balance models without the limitations you ascribe to GCMs, and which allow us to compute transient climate sensitivity values that match fairly well what the GCMs estimate for a climate en route to equilibrium. These results enhance confidence in the typically quoted ranges for climate sensitivity. Some of this was addressed in detail in the recent thread on probabilistic estimates of transient climate sensitivity.

      • ‘a climate en route to equilibrium’

        Would you describe the moon as being at equilibrium? It has no CO2 or H2O, and so it should be easy for you to calculate the moons equilibrium temperature. I can’t find it anywhere, could you tell me what is the moons equilibrium temperature?

      • Would you describe the moon as being at equilibrium? It has no CO2 or H2O, and so it should be easy for you to calculate the moons equilibrium temperature. I can’t find it anywhere, could you tell me what is the moons equilibrium temperature?

        Good exercise and I recommend that you go ahead and do the moon model. You will find a steady-state result which oscillates between extremes. There is a better name for this steady state result than equilibrium, and some people prefer to use the term quiescent value.

      • Equilibrium, like virginity, is absolute. A system at equilibrium is thermally isolated. The Earth is not thermally isolated, indeed, we know this by monitoring the light flux and temperature during the daily and yearly day/nigh, winter/summer cycle.
        Steady state is indeed the term. Moreover, when you realize that a system is a steady state, one can then know that the application of equilibrium thermodynamics is completely wrong and that one must use non-equilibrium thermodynamics.
        Still, the Climate scientists cleave to their box models, chemical equilibrium and averaging of cyclical processes.

        ‘some people prefer to use the term quiescent value’

        only those who have never studied any of the advances in control theory since the 70’s.

    • David, regarding:

      But there is a great deal of controversy about the paleoclimate estimates. We can’t even seem to get straight whether or not there was a Mideval warm period, much less understand the last glacial maximum.

      The reason for relatively large uncertainty regarding the Medieval Warm Period is not so much about reliability of the data as it is about the magnitude of the difference (if any) from today. The wealth of evidence currently available points to the latter decades of the 20th Century being warmer than the medieval peak but there is only a couple of tenths of a degree in it.

      There is greater than an order of magnitude difference when you shift focus to the LGM.

    • Excellent post, David. I would add that computer models have been great enhancements to industry, for engineers use them all the time now to complement product construction and to shorten the time frame from concept to production line.

      As everyone knows, however, GIGO, and therein lies the problem.

      As I see the situation currently, there are far too many unknown parameters and uncertainties in climate science to successfully construct a believable computer model; thus, it is highly inappropriate to rush to judgment, enact enabling legislation to “save ourselves from ourselves”, and cause economic ruin for many.

      Additionally, when a computer model indicates that the Medieval Warm Period did not exist, that raises a red flag for me, for the archeological record is quite definitive on this subject, i.e. its existence is bona fide.

  50. Andrew Lacis

    So, this unforced climate variability cannot significantly impact the long-term global temperature trend

    Is the long-term global temperature trend 0.16 deg C per decade as shown below?

    http://bit.ly/oEJHAk

    Or is it 0.06 deg C per decade as shown below?

    http://bit.ly/nEUMsQ

    This is extremely important. What is the estimate for the long-term global mean temperature trend that the models are based on?

    • Girma,

      I think Andrew was talking about long-term global temperature trends in a general sense on that occasion, not a particular trend instance.

      Regarding what should be considered the long term trend for the present, the expected trend is dependent on the magnitude and changes over time of Earth’s energy imbalance. Across 1880 to the early 20th Century the energy imbalance was small, with a slight increase up to the middle of the century. From around 1960 the energy imbalance trend accelerated to something similar to the present so that seems to me a reasonable starting point for the ‘present’ long-term global average temperature trend. HadCRUT, Gistemp and NCDC records all report ~0.14K/Decade for 1960-2010 Your own suggestion of 1970 as the starting point seems reasonable too. Starting from 1880 doesn’t make sense though since the energy imbalance conditions were so different.

      Given the temperature trend acceleration in more recent decades (albeit with substantial sub-decadal variability, seemingly associated with the 11-year solar cycle), I would estimate the ‘current’ long-term temperature trend to lie somewhere within 0.13-0.19K/Decade.

      Figures a) and b) near the bottom of this link are estimates of forcing changes (which are the cause of energy imbalances) over time, to give you an idea of what I’m talking about.

      • Paul S

        What does the data show?

        Paul, if you draw a line through all the global mean temperature (GMT) peaks, you get the upper GMT boundary line shown below:

        http://bit.ly/nw52EP

        The fact that this is a line, not a curve with increasing slope with increasing years shows that there has not been any change in the global warming rate.

        A straight line also passes through all the GMT valleys, and this line is parallel to the upper GMT boundary line. These two lines are separated by 0.5 deg C.

        This oscillation of 0.5 deg C between the two boundary lines is due to thermohaline circulation cycles as described in a paper that Mann is a coauthor:

        http://bit.ly/nfQr92

        Note also that once the GMT reaches its the upper boundary line (the 1880s & 1940s) it bounces back and moves to the lower GMT boundary line. The same should happen after the current peak (the 2000s).

        That is what the GMT pattern for the last 160 years show.

        There is no evidence for ANY man made global warming so far.

      • Girma

        Sorry, the link was incomplete. It should be http://data.giss.nasa.gov/modelforce/

        The effects of the AMO are small in the Southern Hemisphere so it can be considered something of a control to check against. What you see with Southern Hemispheric temperature trends is very much a curve, with acceleration past 1960. Indeed I used an AMO time series to “correct” the Global Gistemp and HadCRUT records for this factor and the results were quite similar to the SH graph. This suggests NH temperature trends have followed a similar pattern but are masked by larger internal variability.

        Nevertheless the paper was interesting and, based on it, I’ve revised down my estimate of the ‘current’ trend to 0.09-0.17K/Decade.

        There is no innate reason why man-made global warming should occur at a higher rate than warming caused by other factors, so it is irrelevant to your last point whether or not the trend has increased. If anthropogenic warming factors (mainly GHGs) are balanced out by anthropogenic cooling factors (mainly aerosols) then there should be only a very small.man-made trend.

  51. One more comment. The thing that really disturbs me about all this, including the pejorative language is a question of scientific integrity. Presenting this material without error bars or some statements about the uncertainty is a basic integrity question.

    You know this leads to tremendous harm, because it can lead to incorrect decisions. One need only cite the subprime financial meltdown to see the harmful effects of incorrect assessments of risk and uncertainty. This is an example of dramatically underestimating risk and uncertainty. But still, Judith is correct to point out that the public presentation of climate science is very bad at communicating uncertainty. I know, you will say that the “deniers” will seize on any admission of uncertainty. But, you know integrity is not always rewarded in the short term.

    • David –

      I generally agree, very much, with your comment. However,

      I know, you will say that the “deniers” will seize on any admission of uncertainty. But, you know integrity is not always rewarded in the short term.

      I think that the dynamic is more complicated than that. “Deniers,” as opposed to the “skeptical un-convinced” (I make no presumptions whether individual “skeptics” fall on into either of those two categories ), also refuse to acknowledge the degree to which the “pro-AGW consensus” does acknowledge uncertainty.

      For example, while charges are frequently made that the “AGW-cabal” argues that the “science is settled,” in fact, you will find very few, if any, climate scientists who have made that argument. But even if you extend that argument to say that many climates scientists state with certainty their opinions that AGW is a reality, you must also acknowledge that the IPCC statement is that more than 50% of GW is 90% likely to be A. In that very important summarization of the IPCC’s work – we can see a recognition of uncertainty. Yet, claims that the IPCC refuses to recognize uncertainty are ubiquitous. I’m sure you’ve seen many. Have you not?

      • OK, I take your point. I’m just concerned that the main sources of uncertainty are not yet understood and measured. If you don’t understand, its hard to include them.

      • Point taken back at you.

  52. Be kind to mortally wounded warriors, it is The Last Hurrah for the Great Lost Cause.

  53. “And here I thought we were supposed to be approaching a kumbaya moment of agreement on the need to acknowledge uncertainty in climate science. Guess not.”

    What I’m not getting is why Judith posted this, especially given all her good work re the uncertainty monster. Finding fault with the IPCC for being too cautious is pretty stunning. She obviously knew this would incite a near riot. In thinking about it, it shows I think quite a bit of confidence on her end. I don’t think there’s another scientist around who could argue against climate certainty more effectively than Dr. C., but she hasn’t felt it necessary to do so, knowing full well the denizens would do the job for her.

    Of course I might be all wet. But for the moment it’s the only thing that makes sense to me.

    • pokerguy

      Posting “consensus” garbage might be a subtle ploy.

      Let the denizens rip it apart and stand back far enough not to get splattered.

      Outsourcing?

  54. Eric Ollivet

    Q. Fu, S. Manabe & C.M. Johanson have recently published (August 2011) a paper titled
    “On the warming in the tropical upper troposphere: Models versus observations”
    (GRL, VOL. 38, L15704, doi:10.1029/2011GL048101, 2011).

    Summary and Conclusions

    [20] One of the striking features in GCM‐predicted climate change due to the increase of greenhouse gases is the much enhanced warming in the tropical upper troposphere. Here we examine this feature by using satellite MSU/AMSUderived deep‐layer temperatures in the tropical upper‐ (T24) and lower‐ (T2LT) middle troposphere for 1979–2010. It is shown that T24‐T2LT trends from both RSS and UAH are significantly smaller than those from AR4 GCMs. This indicates possible common errors among GCMs although we cannot exclude the possibility that the discrepancy between models and observations is partly caused by biases in satellite data.

    [21] IPCC AR4 GCMs overestimate the warming in the tropics for 1979–2010, which is partly responsible for the larger T24‐T2LT trends in GCMs. It is found that the discrepancy between model and observations is also caused by the trend ratio of T24 to T2LT, which is ∼1.2 from models but ∼1.1 from observations. While strong observational evidence indicates that tropical deep‐layer troposphere warms faster than surface, this study suggests that the AR4 GCMs may exaggerate the increase in static stability between tropical middle and upper troposphere in the last three decades. In view of the importance of the enhanced tropical upper tropospheric warming to the climate sensitivity and to the change of atmospheric circulations, it is critically important to understand the causes responsible for the discrepancy between the models and observations.”

    Fu, Manabe & Johanson paper comes to the same conclusions than Christy & al 2010 paper (Remote Sensing) that was already adressing “missing hot-spot” issue.

    Abstract: Updated tropical lower tropospheric temperature datasets covering the period 1979–2009 are presented and assessed for accuracy based upon recent publications and several analyses conducted here. We conclude that the lower tropospheric temperature (TLT) trend over these 31 years is +0.09 ± 0.03 °C decade−1. Given that the surface temperature (Tsfc) trends from three different groups agree extremely closely among themselves (~ +0.12 °C decade−1) this indicates that the “scaling ratio” (SR, or ratio of atmospheric trend to surface trend: TLT/Tsfc) of the observations is ~0.8 ± 0.3. This is significantly different from the average SR calculated from the IPCC AR4 model simulations which is ~1.4. This result indicates the majority of AR4 simulations tend to portray significantly greater warming in the troposphere relative to the surface than is found in observations. The SR, as an internal, normalized metric of model behavior, largely avoids the confounding influence of short-term fluctuations such as El Niños which make direct comparison of trend magnitudes less confident, even over multi-decadal periods.

    What is more interesting in Fu & al paper is that is that it is co-signed by Syukuro Manabe who is one of the popes of Climate modeling. So when he is pointing out “possible common errors” in the climate models… I guess he knows what he is talking about…

  55. Richard Drake – it’s not a matter of slack – unless one is truly desperate to attract Lacis or any team member to this blog. It’s a matter of COMMUNication and there is nothing in COMMON with a person who denigrates me as a human being. It’s more likely than not actually that all this effort had nothing to do with explaining a technical paper (David W rightly wondered why repeat the usual argument) and all with Lacis getting his name cleared from the evil association with Bishop Hill, conquering the world from rural Scotland. In that regard the decision to have this as a censored technical thread doesn’t appear very understanding, as if Judith had fallen for the usual manipulative tactics.

    • I’m happy to give Dr Lacis some slack, as I’ve indicated. I don’t see how you can infer that I am ‘truly desperate to attract Lacis or any team member to this blog’. What concerns me is the readability of this thread and any others like it. As for Judith, I suggest you are man enough (or woman enough) to say that she got it wrong, rather than make the mealy-mouthed insinuation at the end. I’m sure she can take it. She may also delete it. Either would be fine by me.

  56. Dear Andrew,

    You are using a model. In this model, you have formulated your conceptions about how CO2 would affect temperature, and how you would allow other forcings, such as clouds not to interfere. Modelling is the perfect circular reasoning: see the model shows that we are right. You only forget to mention that you made the model yourself. Take one of my models and try to tweak them to show the influence of CO2. I will guarantee that you will only find a negative influence on global temperature, since that is the way I have build my models. And still they fit the observed miniscule warming.

    It is utter nonsense to base the correctness of ones assumption, predisponitions on the results of models. I can model anything, and still get completely different relations or causations. And do not get back with the old meme that the model is based on physics. Never ever try that, since it is hubris. We still do not understand the complete system by far.

    • There is more to it that that. A model is a complex mathematical hypothesis. Should a model/hypothesis fail to describe some actual measured phenomena, then the hypothesis fails and the model should be trashed.
      If the models do not describe tropical temperatures, or ocean heating or the response to clouds; then they fail.
      As it is we are not dealing with ‘models’, as used in classical science. These are complex fits to known data-sets. These ‘models’ have the same amount of information as a polynomial fit, given they have been trained like performing seals. Any discrepancy between what the writers want in terms of W/m2 in or out is conveniently changed by unmeasured aerosol changes.

      • They are also trained to fit a one-time, non-linear historical temperature record that cannot be replicated. This is the equivalent of inducting that “all swans are white” after having only ever seen one swan. Hume would weep.

      • A GCM is not just a complex mathematical formulation. It is the numerical implementation or approximation of a large set of differential equations, which by definition are not optimally solved by binary arithmetic. As such, in its conception, it is already hubris to claim any accuracy for models. An analog model would be free from this error, but is very hard if not impossible to solve. That is why analog, symbolic solutions have been replaced by binary approximations, which are solved by iterations. Every iteration adds an error to the outcome of the in its origen abstract and well defined problem. And here comes the well known magic of parametrization of the model inputs. Tweak them until you get the outcome one would like to have from the model.

        QED.

        Impressive? Not really. Try to solve your differental equations analytically, they may end up with completely different solutions compared to the numerically obtained results. Have a look at Claes Johnsons site.

  57. I read Lacis’s paper to the 6th paragraph:

    “Because the solar-thermal energy balance of Earth [at the top of the atmosphere (TOA)] is maintained by radiative processes only, and because all the global net advective energy transports must equal zero, it follows that the global average surface temperature must be determined in full by the radiative fluxes arising from the patterns of temperature and absorption of radiation.”

    Dubious, I googled “must be determined by the radiative fluxes” and found a guest post by Willis Eschenbach at WUWT that questions that and other assertions, along with many reasonable comments. ‘Twould be nice to see Lacis reply to those criticisms as well as the critical comments here.

  58. Dear Andrew, the extremely long residence time of CO2 is based on the Bern carbon cycle model, which is extremely flawed. Their assumption about the capture of CO2 by biomass is off by a factor of four, which will invalidate their entire model. It furthermore ignores the fact that CO2 readily dissolves in water, especially at low temperatures and increased surfaces, such as in the top of clouds where the surface to volume ratio of tiny water droplets is more than 10000 times that at the surface. It will result in the down fall of CO2 much more efficiently than the Bern model assumes.

    Just to mention some of my concerns.

    Good luck with modelling, I just finished a model for my financial future.

    • Yes. Earth’s atmosphere is a CO2 scrubber. Ocean/bio is a giant reservoir. Cold global climates remove CO2 from the atmosphere – hydrosphere and biosphere store it, atmospheric CO2 sinks. Warm global climates cause atmospheric CO2 inrease.

      Atmosphere is tiny compared to hydro/bio-sphere, regarding content and human emissions are tiny compared to natural emissions, regarding flux rates.

  59. Dear Andrew,

    If the Bern model would be correct, that once released CO2 has a residence time of hundreds or thousands of years in thge atmosphere, why would we have to reduce or stop CO2 emissions? It will last hundreds or thousands of years before we can expect any effect of a complete shutdown of CO2 emissions. Warming would continue unabated, even under the most vigorous CO2 elimination schemes. Why waste so much money on a policy that you seem to agree with me that it would be utter nonsense to do so by any lack of results in the foreseeable future (ie in the life of me and my children)?

    • Warming would continue unabated, even under the most vigorous CO2 elimination schemes. Why waste so much money on a policy that you seem to agree with me that it would be utter nonsense to do so by any lack of results in the foreseeable future (ie in the life of me and my children)?

      That’s actually a sensible position. We usually just hope that the negative consequences won’t happen.
      I have had enough experience with devastating illnesses in my family. However harrowing the prognosis, I have never shied away from hitting the research and plodding through the experimental results, avoiding depression while looking for any glimmers of hope. Understandably, not everyone is willing to do this, just like many people don’t want to discuss mortality.

      • “Understandably, not everyone is willing to do this, just like many people don’t want to discuss mortality”

        I have a dog in this fight so to speak, but I will ask the question anyway.

        Given the projected aging of the Western population don’t you think that the 100’s of billions spent on the modelers and international piss-ups could have better spend on Dementia research or Parkinson’s Research?

      • don’t you think that the 100′s of billions spent on the modelers and international piss-ups could have better spend on ..

        I see you want to bring up Bjorn Lomborg’s favorite topic. Plenty of pro and con on that argument if you want to dig it up.

      • Dear WebHubTelescope,

        I just buried my son after I spent two years of experimental treatment on him, based on the latest insights in cancer research. And I swear by God,that I have tried everything what seemed reasonable. The billions that have been spent on proving a 0.6 degree Celcius warming per century could have been used much more efficiently, and to the benefit of millions of people. It is an utter shame.

      • Crackpot,
        Please accept my deepset symathy for your loss.
        Your comment puts this CO2 folly into a stark light.

  60. Bruce Cunningham

    The main premise of Lacis’ work is fatally flawed. As has been pointed out by some others, water vapor does not precipitate out. Rain merely lowers the relative humidity to a level that the current air conditions will support. At no time does all the water vapor present fall as rain. Even on the driest of days, there is far more water vapor in the atmosphere than CO2. Even after it has rained. Water vapor is variable, but never zero.

    • What Lacis means is that because of condensation and precipitation, water vapor is limited in the atmosphere by the temperature. CO2 has no such limitation.

      • Jim D,
        Do photons check the provenance of a particular molecule they come in contact with?

      • No, so the more CO2 you have in the atmosphere, the more photons interact with it. It is an effect that just grows with CO2.

      • JimD,
        Don’t avoid the point: photons do not care if water vapor can condense and precipitate out.
        By claiming there is some difference in the way photons interact with CO2 and H2O for their overlap, which is what Lacis implies, he is imply punting and hoping no one will notice the distraction and dissembling.
        Then he can toss in a few conspiracy theory grenades and head to the house.

        And Lacis still does not explain why CO2 goes up in the environment as a response to warming, not as a leading thermostat, and then does not lead to the runaway magical thinking the ‘team’ relies on.
        And then of course, we can discuss how a GCM model enables those who believe in it to attribute motive to those who disagree with the believer. And also how the GCM model empowers its believers to not only attribute motive but to prescribe the only acceptable cures for the problem they perceive.
        All in all a very powerful model, indeed.

      • hunter, read my reply to Bruce Cunningham below, where I explained the difference between H2O and CO2 and why CO2 is the control knob while H2O isn’t. You don’t need a GCM to understand this.

      • Jim D,
        The photons don’t care what is there, water or CO2.
        If they are at the appropriate wavelength, they will get absorbed by either.
        This entire conjecture by Lacis is silly and ignores the reality of Earth.

      • I keep saying I am not disagreeing about the photons. Both are GHGs, so of course they absorb and emit photons. Lacis is a radiative transfer expert. What didn’t you understand from his essay?

      • hunter,

        Can you please provide a cite from Lacis’s post or his paper where he either claims or implies that “there is some difference in the way photons interact with CO2 and H2O for their overlap”.

      • He makes a lot of noise about the behavior of CO2 being different from H2O.
        I am just wondering if he has an ID system in place so the photons know what they are to do?
        Since we know that vapor in the atmosphere is not directly controlled by temperature, he must have something new to offer. It would be interesting it photons know how they are supposed to behave with CO2 and H2O, particualrly in the overlap absorption areas.

      • He makes a lot of noise about the behavior of CO2 being different from H2O.
        I am just wondering if he has an ID system in place so the photons know what they are to do?

        His argument is nothing to do with photons, it is to do with the difference between condensing and non-condensing gasses.

        Since we know that vapor in the atmosphere is not directly controlled by temperature, he must have something new to offer.

        I don’t know if “directly controlled” is the right expression, there is certainly a relationship between the two.

      • CO2 has limitation by the temperature as well. The annual CO2 growth rate is much smaller in colder years. It tracks the temperature anomaly. So it’s temperature dependent.

      • Yes, if you found a way to cool the earth, some of the added CO2 would be absorbed back into the ocean and biosphere like in the Ice Ages. As it is, we are on the opposite track.

      • We are not on the opposite track. Earth’s surface has been cooling for ~10,000 years. The trend will not reverse.

      • You think that the Milankovitch orbital change effects are more important than CO2 in the last century. Interesting, but not a workable idea when you put the numbers in.

      • Orbital or solar or whatever, I don’t jump to conclusions. What’s robust is that the linear trend since the interglacial maximum is COOLING. At shorter, multidecadal/centennial timescales global temperature seems to variate (~1-2°C) without ceasing. We are entering a period of cooling. For how long, nobody knows.

      • Jim D,
        You are the one missing the point.
        Humidity can increase to saturation in very low temperatures, and can be very low in very high temps.
        To posit that CO2 controls water vapor is to ignore reality.
        Additionally, check out ozzieostrich’s excellent point down thread regarding a fallacy climatocrats seem to be making.
        .

      • hunter, ozzio seems to have forgotten that the ground is warmed by the sun, which in turn warms the atmosphere. The sun is his infinite source. Your own point doesn’t account for the ability of a warmer ocean to support more moisture in the atmosphere, because ultimately that is the balance that matters.

      • Jim D,
        I would suggest that you are not reading ozzie very carefully.

      • Why doesn’t ozzio see that the ground is net warmed by solar radiation and net cooled by thermal radiation and there is an equilibrium when you account for other fluxes too (as in the K&T budget)?

      • Bruce Cunningham

        Your point is even worse than Lacis’. The fact that infinite amounts of CO2 could be added to the atmosphere means nothing. You are saying that some possible scenario that could exist, but doesn’t and never will, is what matters versus what the actual state of the atmosphere is. Water vapor, CO2, methane, etc., are the source of the back radiation that slows the cooling rate at night. The total amount of GHGs at any given moment are all the photons react to, and at any given time there are more H2O molecules than CO2. Next question.

      • The point Lacis makes is that H2O can increase only when the temperature does, CO2 has increased because of fossil fuel burning recently, and so the warming from the CO2 increase can allow the H2O to increase and amplify its effect. This is why CO2 is a thermostat control knob, not H2O.

      • Jim, if you want me to take your point, please answer this question: Out here in the desert, away from agriculture, why is the precipitation/humidity not increasing since CO2 is increasing. The highs and lows are the same since the settlement of whites in the late 19th century. Thank you.

      • The H2O will increase over the oceans as they get warmer. Whether that gets to your desert is a different question. Maybe it won’t, because circulations don’t put there currently, and won’t in the future, but the global average will be higher.

      • Jim D,
        Now yo uare arm waving.
        Lacis made a specific claim that is not accurate: H2O is controlled by CO2.
        It is shown that is a false claim.
        Additionally, we can talk about the phantom hotspots and the ocean declining to cooperate with the team.
        CO2 is a non-thermostat, CO2 historically response long after temperatures increase, and CO2’s increase, historically, does not lead to ever more warming.
        This entire thread only shows Lacis as rude, and wrong.

      • Hunter, you don’t believe the globe cools if CO2 is removed, yet the last 100 million years seems to be demonstration of your being wrong. It wasn’t H2O being removed by weathering, it was CO2. How would you even remove H2O with the ocean being an infinite source?

      • Jim D,
        You are spending a lot of time defending Lacis and clarifying what he was saying.
        You are just guessing, since beyond bomb throwing he seems to see no need to communicate.
        If CO2 does not directly control water vapor, then he is less than clear in calling it a thermostat.
        The contrast between his paper and the guest post that was just made is not favorable to Dr. Lacis.

      • You probably understand that “thermostat” means CO2 is controlling the temperature. The water vapor is slave to the temperature. This is the main point of the paper.

  61. Your Figure 1 is a joke. Forcings, Feedbacks and plots that look Oh so scientific, almost like real statistical analysis.
    You, Schmidt, Rind and Ruedy are not scientists, you are imitative magicians. You think that if you mimic the style and presentation of actual scientists, you are actually performing science.
    Like the Cargo Cultists of Papua New Guinea, you build fakes and expect your magic to work.
    Not one single testable hypothesis is presented.
    Shame on you all.

    • I see a testable hypothesis:
      “Without the radiative forcing supplied by CO2 and the other noncondensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state”

      Go grab a climate model and try to prove him wrong

    • Did you notice Pielke and Spencer subscribe to the same view as Lacis, saying this paper just states the obvious. What would you say to them?

    • Doc,

      I, too, cannot help but continue being amused by Figure 1 of our Science paper. There is only one scale (no x-scale). There is something that looks like a teeter-totter balancing feedbacks and forcings. Also, why are the ‘CO2’ and ‘Other’ bars made fatter so as to make them look heavier?

      Often the Science editor will suggest to the authors to delete half of the figures in order to shorten the paper. But not a single reviewer of the paper, or the Science editor, so much as made a comment, or hinted that there might be something funny or non-relevant about our Figure 1.

      The Figure does contain all of the basic information that summarizes the basic conclusions of the paper, allowing the reader to use his imagination as to what exactly Figure 1 signifies. Perhaps that is the magic factor.

  62. Judith,

    Hmmmm…science is settled, yet still do not understand this planet mechanically.
    Nor is their a desire to understand this planet as it has been made perfectly clear that the science is settled.

    • Joe,

      The science isn’t totally settled on the HIV/AIDs issue either.
      Nevertheless, I would still advise that you don’t engage in unprotected casual sex !

  63. May I interject a comment. We need to be kind to the author of this guest post and not spoil the dialogue. Judith is correct to let him post it, his point of view is one shared by a lot of good scientists.

    Please, please, don’t start with the “we shouldn’t give hiim a forum.” It’s not the right approach.

  64. It seems to me that some earlier comments in this thread reflect confusion about climate models – for example, are model runs “experiments”? The notion that the runs are “experiments” invokes arguments that are at least partly semantic, because it involves how one defines “experiment”. It is probably more important to ask whether they contribute to advancing our knowledge – an expectation we apply to experiments. In one sense, a model run is experimental in that it applies an independent variable to a system – the model input – and looks at dependent variables – the output. This is not as simple as multiplying 7 x 3 and asking what the answer is, because models are sufficiently complex combinations of basic physical principles, observations, and parametrizations that the person who supplies an input will rarely be able to predict what the output will be. In that sense, it is an “experiment” in the true spirit of the word.

    In science, it is rare for an experiment to definitively answer an important general question. Most experiments raise questions as much as they answer them, and those questions are typically addressed through additional observations. Model runs illustrate this principle. In discussing this, there has been a tendency to focus on the use of models for predictions, which leads to interminable arguments about their value based on how much or how little their output deviates from observational data. Those arguments need not be repeated here, because they will remain a matter of judgment, and therefore unresolved.

    What probably needs to be emphasized is that models have other important uses. Typically, a model is constructed to reproduce what the modeler sees as a representation of the physical principles and starting data determining real world climate behavior. If those values are entered accurately, the model should simulate the real world reasonably well, with due allowances for certain irreducible sources of uncertainty. Running the model is then a form of hypothesis testing that asks, “have we accurately represented the factors that dictate how the climate behaves?” To the extent that the results depart from reality, the modeler (“experimenter”) can alter parameters to see which alterations bring the two closer together. Once altered, the model can then be further tested in contexts other than the one which led to its retuning, and to the extent it continues to do better, the new parameter values have received some confirmation. This distinction between tuning and testing has sometimes been lost in discussions of model skill. There is never a final result from this, but rather an incremental gain in confidence about the values of real world phenomena used in the models. This is not unlike experiments in other scientific disciplines, where conclusive results from individual experiments are the exception rather than the norm.

    There is clearly much more to models than this, but many of the other aspects have been addressed in previous threads, including the enormous topic of verification and validation, with insufficient room here to revisit them within the space of a few comments. In addition, most basic climate principles are derivable without complex models, although without quantitative detail.

    Are model runs experiments? By certain narrow definitions, they are not. In a broader sense, when models are used to test hypotheses about the climate variables used in their simulations, they conform to the concept of an experiment as a means of performing tests to gain knowledge about the world around us.

    • Fred,
      The confusion is on Lacis’ side of the table.
      He thinks his models not only predict the climate, not only shows that a gas that responds after temperature rises is in fact a thermostat, but also tel him the motives of those who dare to disagree with him.

    • K Scott Denison

      Please Fred, provide a link to the paper that shows the output of climate models is validated and verified by observations. Otherwise, the modelers are missing the point and the models are nothing more than games.

      • I have a sawbuck that says you will say it’s hindcasting and doesn’t count, but here it is.

        http://atoc.colorado.edu/~dcn/ATOC6020/papers/Soden_etal_727.pdf

        It’s well cited, and there is lots more where that came from.

        Do you know how to use google?

      • Stirling English

        It is hindcasting. They wrote a paper in 2002 that looked at one small aspect of an event that occurred in 1991, and managed to get a result that matched the observations. And all their chums sad what clever boys they had been.

        Let me remind you of one thing about forecasting. You have to do it before the event. Not after. And to be a well-regarded forecaster,you have to get it right – in advance – pretty consistently.

        That you eed to dredge back nearly 10 years to find one paper that managed to get something right by using the benefit of that famous predictive tool – 100% hindsight – shows the complete paucity of acheievement in this field.

        The worry is that modellers and their followers are so deldued as to have genuinely persuaded themsleves that their work is of authentic predictive value. Poor deluded souls

      • So it comes down to this,

        They have to not only model the climate properly, they also have to model the world economy at the same time.

        That’s whay I think we should let the modelers determine their own validation and verification procedures.

        And the models are not of predicitve value?
        Global temperature has been rising since Hansens predictions in the early 1980’s, and considering the PDO hadn’t been discovered then, much less modeled, I think he got it right well enough in advance.

        And it took me like 2 seconds to find that paper.

      • K Scott Denison

        That’s what you have. LOL.

      • K Scott Denison

        Exactly which temperatures did Hansen forecast and for what timeframe? Ever heard of Nostredamous (sp?). He wa pretty good at being vague enough to ensure some of his predictions would be interpreted as correct too.

      • That’s your problem, you want exactly, when the best nature can give you is within the range of year to year natural variability.

        And since when is LOL a scientific argument?

        What’s more important, the trend in temperature or the actual temperature itself?

        I wouldn’t trust any V&V that didn’t have hindcasting as an important part.

      • K Scott Denison

        Bob, tell me which climate “scientist” forecast the current lack of warming. Anyone? Anyone? Beuller?

      • K Scott Denison,

        You got another problem, here it is with statistics.

        The current lack of warming is not a statistically significant trend.
        Any statistically significant trends to the current date show warming.

      • That’s right. hind casting only doesn’t count. Do you get it?

    • Fred,

      You ask “Are model runs experiments?” I’d say they weren’t and that “simulations” would be a better term.

      Its probably only a minor quibble on my part but I would say that it is important to be clear that there is a difference between these two terms. Climate science, like other branches of science such as astronomy, relies on observation rather than experimentation.

      • Latimer Alder.

        To name but two pretty obvious areas where astronomy uses teh ol idea of theiory –> experiment –> confirmation or not

        1. The Apollo missions were pretty good experiemental confirmations of astronomical theories of the composition of the Moon and the rejection of some others.

        2 We can use astronomy to make successful predictions of the poistions of the heavenly bodies for future times.

        There are plenty others.

        Please remind the aduience of any area at all where theories climatology have ever made successful predictions that have been actually subsequently veirified by going and looking and being found to be correct.

        Because if you cannot demonstrate this, you are nowhere near being a science…little better than astrology with lots of sciencey words attached.

      • Successful Predictions? I first remember reading about a potential AGW problem in the mid to late 80’s. I can’t remember if that was directly related to James Hansen’s warnings at about the same time. Since then despite talk of AGW stopping in 1998 there has been a steady upward climb.

        If you accept that CO2, CH4 etc are GH gases, and accept the basic principles of the GH theory there is no getting away from the simple truth that increasing the concentrations of these is going to make the Earth warmer.

        I would suggest the “Skydragons” know this too; and, which is why they are still plugging away trying to deny the link.

      • Latimer Alder.

        I don’t dispute that Arrhenius got it about right in 1907. Double CO2 and you get about 1.2C warming. Fine, no probs with that. A piece of squared paper, a slide rule and some simple sums tell us that. And I have seen no reason at all to doubt that – on balanc e- a warmer world will be a better world.

        But what happened with the remaining 104 years? What about all teh work of all the climatologists and teh liek beavering away for the last 30? What did we get for the estimated $100 billion spent in the US alone? What is it about climate that we know now (by experiment, observation and/or demonstration) that we didn’t know in 1907?

        Have we developed a whole new climate theory and by rigorous teting shown that it has predictive skill? Can we convincingly and numerically explain all the ups and downs of the recent temperature record? Can we explain all the observed sea-level changes?

        Has there ever been a climate prediction made since Arrhenisus that has been demonstrably shown to be accurate over a reasonable period (10-25 years)? (Please note that predictions are made before the event, not aftwerwards. If the latter they are called ‘hinsdsight’. Hindsight is not prediction. Do not confuse the two).

        Becasue if the best you can come up with is ‘it’ll get a bit warmer if we put more GHGs into the atmosphere’, then I think we need our money back. Cliamtologists are no better than palm readers if this is the best they can do.

        PS – Arrhenius won the Nobel Prize for Chemistry. Chemistry is an experimental science.

      • Latimer,

        You write “I don’t dispute that Arrhenius got it about right in 1907. Double CO2 and you get about 1.2C warming. ”

        You should do. You’re supposed to be a sceptic. Being a genuine sceptic, and there’s is nothing wrong with that, doesn’t just mean accepting the results you like and rejecting rest. It means looking at all results to see if they are valid.

        In this case, being sceptical of both this result and Arrhenius’s previous much higher result of 6 degC of warming isn’t a criticism of Arrhenius’s methods. He surely did the best with what information he had at hand at the time. However, science has moved on in 100 years and the the opinion now is that the true answer is somewhere in between. However it is worth noting that Judith has herself suggested figures of the likely range of warming which almost exactly match Arrhenius’s two estimates.

      • Latimer Alder.

        @tempterrain

        Arrhenius’ prediction is not complicated. It does not rely on supercomputers to solve, It is a simple equation and it is very easy to check if it has any predictive skill. You can see it here

        ΔF = α ln(C/C0)

        Today, we know delta F from global mean temperature readings. We know C and Co from Manua Loa raedings. Hence we can solve for alpha from our observations. Once we know alpha, it is a simple matter to derive delta F for a doubling of CO2.

        And the answer (1.55) is not far from Arrhenius’s answer of 1.2. Try it and see. The numbers are readily available from Google. and you need no more than rudimentary (11 plus level) skill in manipulating equations. It works. It has reasonable predictive skill for the future. You could have sat in 1970, and predicted the temperatures in 2010 reasonably well with it.

        If you wish to claim that Arrhenius is not a good predictor and we should use a much higher value than he did form an immensely complicated model, then you really have to come up with something a lot lot better than ‘opinion has moved on’. Like soem actual numbers. And some way of checking that thise numbers correpsond to reality.

        The sums do not lie. Arrhenius reasonably well describes the temperature history of the last 50 + years (since good CO2 numbers were available). IMO no other explanation comes even close. If you have compelling evidence that it does, please show it.

        And thanks for the little lecture on the nature of scepticism. I’m sure you’ll be delighted to know that my support for Arrhenius’s ideas is based on something more than just the appeals to authority and post-hoc rationalisation that you so admire.

        PS – I still cannot get persudaed that lots of bad things will happen if the average global temperature increases from say 288.4K to 289.9K. Especially when most of the increase seems to come from slightly warmer nights,

        I like Arrhenius. He was a great chemist and his insights helped to found my own onetie specialty – physical chemistry. His work is clear and stands up today. You will, I am sure, forgive me if I am more inclined to believe in his work than in the convoluted and weasel words of the climatology mafia. And even more especially when the numbers show Arrhenius to be on the right lines.

      • LA,

        Is ΔF supposed to be the forcing or the temperature change? And α is a constant of proportionality. And, yes, we know that there is a logarithmic relationship with CO2 concentrations.

        I’m not convinced you know what you are doing here, so perhaps you’d like to complete your calculation?

      • If you do the sums correctly for the last 20 or 30 years, you get a sensitivity near 2.5 degrees per doubling. This is only assuming the CO2 rose as it did and the temperature rose at least .5 degrees. The values near 1 degree sensitivity fall short and only give 0.2 degrees warming. This alone should give pause for the proponents of low sensitivity, but I suspect they haven’t made this simple calculation yet.

      • Stirling English

        @tempterrain

        I’m sure you don’t need me to do elementary sums for you. The equation is quite clear. There are only three things you need to know to work out alpha. Once you know alpha, the temperature change for a doubling of CO2 is trivial to work out.

        Go find the figures from Google for Manua Loa and for the temperature anomaly change and do your own. Tell me if, and how, you come up with something far different for a temperature change of 1.5C for a doubling of CO2. Show your working.

        Helpful hint – the first reliable CO2 measurements for ML start in 1959. It might be a good idea to calcluate C/Co for 1959 vs 2010 and do the same for the temperature change. That way you get a nice long timescale to work with and it will smooth out any fluctuations..

        Look forward to hearing your answer. Do tell me if you get stuck anywhere and, as ever, I will give you another helpful hint.

      • Latimer Alder

        @jimd

        C02 (1959) = 316ppm, CO2 (2010) = 390ppm
        Temp change (1959–>2010) = 0.47 degrees

        Result = sensitivity for doubling = 1.55C

        If yours differ, please show where.

      • LA,
        CO2 in 1980: 340
        CO2 in 2010: 390
        Temperature rise 1980-2010: 0.5 degrees at least
        Sensitivity: 2.5 degrees per doubling.
        Before 1980 there was global dimming due to aerosol production growth, so a few tenths C was lost due to that.

      • JimD

        Also you need to consider that the Earth is not in equilibrium at present. In other words the Earth will take a finite time to warm, given the different forcing conditions. The current rate of warming is quite consistent with a climate senistivity of 3 deg (for 2x Co2)

        CO2 will double from pre-industrial levels under a BAU scenario by 2100.
        Current warming ~0.8 deg
        Warming at 0.15 deg per decade for next 9 decades ~ 1.35 deg
        Warming to follow even if levels stabilise ~ 1 deg
        Would make a total of over 3 deg C

        Latimer and Stirling,

        Are you different people or the same person? Anyway, yes, I, and I’m sure others, do need you to do some “elementary sums”!

        If you can’t, people might then think you do not really know what you are talking about.

      • tempterrrain, agreed, this is an underestimate by neglecting lag in an accelerating forcing, and neglecting possibly further increasing aerosol effects.

      • Latimer Alder

        @tempterraain etc.

        I did the sums a la Arrhenius accordig to the data observed and I got 1.55.

        You added a bit here for aerosols (non-quanitfied), ‘corrected’ for non-equilbrium at the end (non-quantified and ignores non-equilibrium at the beginnig). One of you didn’t even bother to look for real data – just stated ‘at least 0.5C).

        and lo and behold you came up with a higher number. Plus a lot of unquantifed hand-waving guff about future perils.

        Arrhenis works. It reproduces the observed temperatures pretty well. I don’t state his work is perfect or the last word, but until you acn coem up with a better theory that you can show by comparison with actual observational data works better, then I’ll go with Svente rather than you.

        @tempterrian – that’s what I mean about experiemental science. You go and measure things, not just pontificate about them ‘being consistent with’. Savvy?

      • I would add that 0.15 degrees per decade, which is the current rate, is somewhat lower than it is expected to be when the CO2 production rate gets up to double what it is now by mid-century, so we could easily see 3 degrees between 2000 and 2100.

      • Latimer Alder

        Since you guys are determined to frighten yourslees stupid with lots of predcitions about predictions about what might happen and to add mysterious and unquantified corrections to the simple bit of mathematics that actually looks at real data, then I’ll leave you in fantasy land from here on this thread.

        Just to remind you..Arrhenius gives a good description of the actual observed data. Everything else is guesswork.

        Without real data, you are just handwaving wildly. Ciao

      • Latimer,

        You’ve still not got the right answer. If you can show your working , maybe I’ll be able to spot where you’ve gone wrong.

      • tempterrain

        Climate science, like other branches of science such as astronomy, relies on observation rather than experimentation.

        Not really, tt.

        Climate science (as practiced by the mainstream purveyors of IPCC) relies on neither, but rather on model simulations based on theory and hypothetical deliberations.

        That’s the problem.

        Max

    • An ‘experiment’ on a model can tell you about the model. It cannot tell you anything about the real world, except insofar as the model has been rigidly matched and linked to the world at its component and assumption level by prior testing. Even matching of results to observations cannot tell you anything about the objective world, since there is a large, perhaps conceptually infinite, number of models that can emulate real world behavior over limited ranges without any correspondence elsewhere, and depending on processes which do not match real processes.

      A model can extend. It cannot discover.

  65. Dr. Curry,

    You posted a comment above as follows: “The fact that Andy Lacis reads the blog and provided a guest post demonstrates to me that he has an open mind.”

    Posting a guest post here does not in my opinion show an open mind. Responding to the questions raised by that post in the comments that follow, however, would.

    I realize this was posted on a Sunday, so the absence of any comments by Andrew Lacis so far is not so surprising. But I wonder if we may expect any participation by its author in resolving some of the questions regarding his post raised in the comments above in the next day or so?

  66. “You posted a comment above as follows: “The fact that Andy Lacis reads the blog and provided a guest post demonstrates to me that he has an open mind.”

    A good host is always gracious.

  67. I do assume that this is a typical consensus opinion.
    Thank you for posting this. It is good to read the Consensus Climate Theory Position, from time to time. That does more to support our skeptic Theories more than anything we can post.

  68. I’m really struggling with Lacis’s above introduction to this paper.

    Andrew Montford quoted Lacis as saying in his 2005 AR4 review suggestions:-

    There is no scientific merit to be found in the Executive Summary. The presentation sounds like something put together by Greenpeace activists and their legal department. The points being made are made arbitrarily with legal sounding caveats without having established any foundation or basis in fact. The Executive Summary seems to be a political statement that is only designed to annoy greenhouse skeptics. Wasn’t the IPCC Assessment Report intended to be a scientific document that would merit solid backing from the climate science community – instead of forcing many climate scientists into having to agree with greenhouse skeptic criticisms that this is indeed a report with a clear and obvious political agenda.Attribution can not happen until understanding has been clearly demonstrated. Once the facts of climate change have been established and understood, attribution will become self-evident to all. The Executive Summary as it stands is beyond redemption and should simply be deleted.

    Lacis now attempts to explain his criticism by saying:-

    I was irked by the persistent use of wishy-washy terminology such as ‘likely’ and ‘very likely’ that was totally uncalled for. One example: “It is likely that there has been a substantial anthropogenic contribution to surface temperature increases in every continent except Antarctica since the middle of the 20th century.”

    Such ‘social sciences’ terminology might be allowable if there was no other available evidence for global warming except for the statistical analysis of a relatively short global temperature time-series (on which there is superimposed a substantial natural variability component). But the physical evidence for global warming is quite overwhelming, and it is downright irresponsible (and stupid) not to make use of it.

    It’s very hard to enter into a discussion of the detailed science when the raison d’etre of the paper seems to be founded in a complete piece of doublethink.

    Have I misunderstood something here?

    • Foxgoose,

      If you have misunderstood, it could be that you’d not previously considered the possibility that criticism of aspects of IPCC assessment reports isn’t at all the same thing as a complete rejection of them.

      • tt

        criticism of aspects of IPCC assessment reports isn’t at all the same thing as a complete rejection of them.

        Correct. Not a “complete rejection” but a “partial rejection”.

        I’d say that fits pretty well for any of the skeptical posters here – they only reject a “part” of the IPCC reports.

        Whether that is 50% or 90%, it still remains only a “partial rejection” rather than a “complete rejection:

        Max

      • Max,

        Well I’m pleased to see you are making some, albeit slow, progress. Even if you now accept 10% of the IPCC reports, it’s 10% more than it was a few years ago. Maybe you’ll get there in the end.

        Mayy

  69. I do not understand why non-condensing gases act (net) as forcings and condensing gases (net) act as feedbacks. Why doesn’t water vapor act as a forcing as well? Why wouldn’t we all bubble away? What phase of the water cycle does water dominate feedbacks and not forcings?

    • Condensing gases can’t exceed their saturation point, which is a function of temperature, so the temperature acts like a ceiling.

      • I thought that condensing gases saturation points were a function of both temperature and pressure; hence, in a particular atmosphere, or in a particular GCM grid cell, adjacent cells may have different quantities of water because of different pressures even at the same temperature. Nevertheless, saturation points do not describe the phase of the water cycle where water can be considered a feedback instead of a radiative forcing. Water, to my understanding can absorb IR in multiple bands and should be acting as a forcing along with non-condensing gases. Is there a specific phase of water that dominates and becomes a feedback?

      • I didn’t mention pressure because that is not a variable for a column. An Arctic column holds less water than a tropical one. Water vapor is not a free variable in the climate system because it depends on ocean evaporation and air temperature. As Lacis mentioned, they tested doubling and removing water vapor and it just returned to its equilibrium state without a lasting climate effect, which proves it is not an independent forcing, but a result of the climate temperature.

    • Condensing gases, primarily water vapour, do make up a large part of the greenhouse effect. If the temperature falls, they will condense out. Then there is less of them. If the temperature rises, more evaporation will occur , and there will be a greater concentration in the atmosphere.

      This is what is meant by positive feedback.

      • They do not necessarily condense out of the atmosphere.
        They may change phase states and stay in the atmosphere as water or ice clouds.
        This obtuse excursion by you believers is rather tedious.
        The lack of reliance on observations is what is going to finally finish unraveling the nasty social mania of AGW.
        Reality is the ultimate skeptic, and AGW fails reality.

      • The clouds are important. It is good you remembered them. They contribute to the albedo.

      • Jim D

        Yes. Clouds contribute to the albedo, i.e. they are, in themselves, an important forcing (Soencer, Palle, Svensmark, et al.)

        We still do not know exactly what makes them grow or recede (CERN may give us more knowledge on this question), but it appears pretty clear that it is not simply a function of temperature.

        Max

      • Yes, I give up on this being a technical thread

      • tt,
        Here is the definition of positive feedback:
        http://en.wikipedia.org/wiki/Positive_feedback
        This does not seem to fit your definition.
        Care to clarify?

  70. There is a film coming out called ‘Anonymous’. It has the premise that Edward de Vere, 17th Earl of Oxford was the true author of the works of we attribute to William Shakespeare. The hypothesis is that William Shakespeare. was a front, and as nobility could not be associated with the theater, Oxford needed subterfuge to have his work played.
    Now the people who present such an hypothesis do so, in the same manner that climate scientists present forcings and feedbacks.
    Shakespeare was an ‘oink’, a peasant, a no body and yet Oxford had Royal blood in his veins. Obviously, a genius cannot appear out of common, base, stock and so therefore; Oxford wrote the plays.
    The logic is the same here. The temperature is rising, humans MUST be involved, human emission of CO2 is the mechanism. Like assuming that only nobility can produce noble works, These spoiled children of the 60’s think the world is about them and their species; it is not.

    Horatio:
    O day and night, but this is wondrous strange!

    Hamlet:
    And therefore as a stranger give it welcome.
    There are more things in heaven and earth, Horatio,
    Than are dreamt of in your philosophy.
    Hamlet Act 1, scene 5, 159–167.

  71. Arfur Bryant

    Dr Lacis,

    [“Noncondensing greenhouse gases, which account for 25% of the total terrestrial greenhouse effect…”]

    Can you confirm this means you think that ‘noncondensing greenhouse gasses’ (NCGG), which amount to less than 0.04% of the atmosphere, contribute appx 8.25 deg C of the (appx) 33 C Greenhouse Effect (33/4)?

    Can you also confirm that, therefore, back in 1850 when the NCGG amounted to appx 0.028% of the atmosphere, the NCGG would have been responsible for 8.025 C of the GE (32.1C/4)? Where 32.1 represents the current GE less the 0.9 C warming since 1850.

    Can you therefore explain why a 40% increase in NCGG (mostly made up of “the single most important climate-relevant greenhouse gas in the Earth’s atmosphere…” has only contributed an unknown portion of the 0.9 C warming observed in the last 160 years?

    I would appreciate your explanation.

  72. I don’t see any lack of writing skills – I think you’re wriggling a bit there.
    What I do see is a complete logical and ethical failure in presenting his reasons for writing the paper – which, taken with his own statement that there’s nothing new in it makes it quite clear that the paper was only written for propaganda purposes.

    Just a tour d’horizon of climate science’s “greatest hits” – cobbled together to get him off the hook of his previous injudicious (but presumably honestly meant at the time) remarks after they were dug out and circulated by the Good Bishop Hill in 2010.

    • What I see is an attempt to label information as propaganda because you don’t like it.

      Still wanted to go around claiming water vapor made up 98% of the greenhouse effect did you?

      • Come on, Lindzen hasn’t corrected his comments. I;m sure he knows the science. Noone clings to this idea. It’s just an incorrect comment. Rather like scores of others, like he Himalayan glaciers will be gone in 30 years. The issue is how to make climate science more believable to the Chinese and Lindzen has some great suggestions along these lines. It is a shame how he has been marginalized by the team. We need better methods and better science. The line at RC is just ridiculous and a “denial” of he problem.

  73. My last comment of 7.04 was a reply to Brandon’s timestamped at 6.47 – it seems to have shot back up the running order for some reason.

  74. Dear Andrew,

    It is really not very helpful to label people who disagree with your highly politicized view as:
    Quote:Unfortunately, such subtle misinformation is being actively promoted by the fossil fuel lobbyists and their growing multitude of dupes and minions. End quote.

    If all you have to show is the outcome of your models, for which you know what went in en should come out, this is not science. It is garbage, IMHO. It is a shame that this has been published in Science. A model can never be used to prove that your hypothesis is right and that your theory is the only explanation for an observed phenomenon. Many other theories might do a similar or even better job, based on completely different principles. Nice examples are the recent revelations about a possible influence of the activity of the sun in combination with cosmic rays on cloud formation. No CO2 needed to explain the warming/cooling in recent history. Only a different model is needed. No “overwhelming evidence” for AGW, rather than an overwhelming proof of the singlemindedness of climate research, IMHO. The butcher testing his own meat, so to say.

  75. Judith,

    Congratulations for inviting Andrew Lacis to make this contribution. Not because I happen to agree with him, but because he has the credentials to express a qualified opinion.