Consequences of being over-concerned

Recently, the world celebrated an International Day of Climate Action, called “350”, which is based on lifting public awareness on the need for an international climate treaty to reach a 350 parts per million CO2 level as a target threshold. I didn’t really join in on the fun or follow it in any detail, but from what I understand it was a pretty big deal, and I hope that they had some success in raising awareness.

In any case, I just wanted to say a word about the communication of climate science. It is very easy to justify, scientifically, that the globe is warming and that anthropogenic (human-induced) activities are responsible for at least a large part of that warming trend. It is easy to justify that continued use of fossil fuels under “business-as-usual” scenarios will eventually lead to consequences which can be dangerous to socio-economic and ecological welfare. The first two Working Groups of the IPCC 2007 report have an extensive background into these issues, as does many other reports and papers. It is therefore not necessary to over-inflate the consequences of climate change or to assume “worst-case” scenarios in analysis, and I urge people to consider this, since the consequences of this for a public attention, policy, and scientific viewpoint can be just as bad as those who downplay or misrepresent the urge to take climate action.

This brings me to a report online entitled The Economics of 350: The Benefits and Costs of Climate Stabilization (PDF file). The report is written by a group of economists (Ackerman et al.) who focus on the subject of emission targets, which urge quick action, and while I agree with much of what they write (and their concern about climate change and the urgency to act), much of the science in the paper is flawed or incomplete to emphasize their point that “climate change is occurring faster, and its consequences could be more severe, than previously expected” (Pg. 3). Such broad statements should be much more detailed (e.g., sea ice loss might be going up faster than expected, but temperatures are not) and the Copenhagen Synthesis report is a suitable citation for post-AR4 findings on this topic. I would just like to touch upon some points:

— Ackerman et al. describe climate sensitivity values cited in the IPCC AR4 (2 to 4.5 C per doubling of CO2) and sensitivity values in Hansen et al (2008) (~ 6 C per doubling of CO2) in “Target Atmospheric CO2: Where Should Humanity Aim?” in The Open Atmospheric Science Journal 2: 217-231. Ackerman et al. believe these these values are inconsistent, and specifically “That is, [Hansen et al] argue that the global warming likely to result from any given atmospheric concentration of CO2 is approximately twice as great as AR4 projected.”

This is not correct and is an apples-to-oranges comparison. IPCC 2007 uses the so-called Charney sensitivity, which refers to an equilibrium state in which CO2 is doubled. This accounts only for so-called “fast feedbacks” which respond relatively rapidly to climate change, such as sea ice, or water vapor content. The Hansen et al. value refers to a much longer term sensitivity value which takes into account slower feedbacks such as ice sheet and long-term vegetation changes. Hansen et al does not argue for a sensitivity outside the IPCC range when you compare the two appropriately.

— The assumption of a 6 degrees per 2x CO2 sensitivity is too high and unwarranted. The authors do explore alternative scenarios, however.

–Ackerman et al. continue to assert that scientific findings are becoming too troublesome. For instance,

The “climate sensitivity,” that is the amount of warming that will result from a doubling of the atmospheric concentration of greenhouse gases, may be inherently uncertain — because in a system such as the earth’s climate with strong positive feedbacks, small errors in estimating the size of the feedbacks inevitably cause large errors in the outcome (Roe and Baker 2007).

However, Ackerman et al ignore Hannart et al (2009) which suggests the Roe and Baker analysis may be an artifact of a strange use of the word ‘uncertainty.’

— Ackerman et al state:

Low-level clouds, one of the least understood aspects of the climate system until recently, may be a source of additional positive feedback to the warming process; of the major climate models, the one that simulates clouds most accurately is also the one that predicts the most rapid warming (Clement et al. 2009).

Although it may very well be true that clouds act as a positive feedback, Clement et al. can only be taken as a very small part of the literature on this topic. In particular, they only focus on a very small region of the globe (roughly 115° to 145°W, 15° to 25°N) and focus only on lower-level clouds that are important for albedo, and not higher ones which also can have a very large impact on sensitivity due to their impact on outgoing terrestrial radiation. A more comprehensive discussion of the literature, or at least a reference to more comprehensive discussions (e.g. Bony et al 2006) should be included.

–Ackerman et al. state,

There are also some lesser known, serious threats (Lenton et al. 2008; Weitzman 2009). For example, rising temperatures could trigger abrupt, massive releases of methane from undersea geological formations (clathrates) or from permafrost; this could lead to a runaway greenhouse effect (Hall and Behl 2006).

A runaway greenhouse effect is not something that is taken seriously as a possibility right now, and it has a very precise meaning in the study of climate physics and in the evolution of planetary atmospheres. It does not simply refer to a “tipping point” or dangerous amount of warming. Certainly, I can find no support for such a proposal in the reference by Hall and Behl (I cannot even find the word ‘runaway’ in that document).

–Ackerman et al state

Hansen’s assertion that 300–500 ppm CO2 corresponds to a 25 percent chance of harm is consistent with Harvey’s results under the assumptions that non-CO2 gases either remain at their current levels or decline, and that aerosols have no effect on temperature

There’s some sketchiness about what exactly “harm” means here, but Hansen et al only quote this CO2 range once, and they simply do it in the context of referencing Harvey’s results for background on the topic. It should not be taken to be “consistent” with Harvey’s reference.  It came from Harvey’s reference!

— Ackerman et al. summarize the strategy by Hansen et al (2008) to stabilize emissions, although I personally don’t feel they do a good job of error bars (there are essentially none in their descriptions or assumptions). A lot of numbers are given in this document which should have some brackets next to them. Another example of overselling certainty is the claim that “The combined radiative forcings from aerosols is -1.18 W/m2”.  It is not until a later graph that one can inspect a see a range of about 0.3 to 2 W/m2.

These are just some of the quibbles I have with this document.  I also would recommend that documents which go into even some detail about the science (and not just the economics) have better correspondence with scientists in that field.  I do agree with their focus on how to best stabilize emissions, although I find it difficult to get quantitative information from this piece.


44 responses to “Consequences of being over-concerned

  1. Ugh. If they thought Hansen was giving a higher sensitivity, they could have at least checked with him to see whether they understood that correctly.

  2. Chris,

    Thanks for another nice thread – you keep providing me great resources. Here is another paper that I think does a nice job of discussing clouds:

    Trends in Observed Cloudiness and Earth’s Radiation Budget: What Do We Not Know and What Do We Need to Know?

    Joel R. Norris and Anthony Slingo (2009)

    Click to access 02_Norris%20and%20Slingo.pdf

  3. You say “It is very easy to justify, scientifically, that the globe is warming”. It clearly has been but is it any longer? On WuWT today, Pielke Snr has commented “the climate system has not cooled even in the last 6 years. Moreover, on the long time period back to 1880, the consensus is that the climate system has warmed on the longest time period. Perhaps the current absence of warming is a shorter term natural feature of the climate system. However, to state that the “[t]he Earth is still warming” is in error. The warming has, at least temporarily halted.”. Is the globe warming or isn’t it? If it isn’t, then why not given the increasing level of CO2? I appreciate that this might be a naive question but as a layman I have no axe to grind. like everyone else I merely want to know because apart from anything else, some of those promised trillions of dollars of expenditure will come out of my pocket.

    • Alleagra, CO2 is not the only forcing factor. It’s annual forcing is weak compared to several other natural factors, meaning that you should not expect a linear warming. You can have several natural factors favoring cooling, superimposed on a ‘linear’ warming due to CO2 forcing. As a result, you can have a period, even a long period (decade), in which the temperatures don’t really go up (and perhaps even go down).

      • Thanks! I realize that mostly technically competent people comment here but this is an opportunity for me to learn something. I now understand the ‘if it cools or stays the same, it’s global warming but if it gets hotter it’s global warming’ mantra. I have to say I don’t like post hoc analysis – it looks shifty and suggests special pleading but I can see that your explanation may nevertheless be correct provided the magnitude of CO2 climate forcing is still sufficiently large in the context of those other variables. As I understand it, tthis is the nub of the AGW argument. Am I correct? CO2 has the wherewithal to be a significant member of the gang, so to speak, in the observed warming or it hasn’t. Can you please tell me ‘within what range of values should the CO2 forcing parameter be located, given the other factors, in order for it to be a candidate for the proposed draconian legislation? Armed with that data I can then assess for myself (or try to assess: see below) the need for action given estimates of the actual CO2 forcing factor.

        As a layman trying to form a judgement I am reduced to taking account of the opinion of people obviously qualified to make authoritative assessments on the specific topic of interest. I simply have to rely on arguments from authority though not arguments from ‘consensus’. Hate to do it but what choice do I have? And there’s a problem for me here because it appears that experts don’t agree. Are people like Roy Spencer and Richard Lindzen qualified to pronounce on this subject? Seems they are. But maybe you disagree? Lindzen says (in strong terms) that forcing due to CO2 is very small and insignificant. Well, you can see my difficulty. Please be clear I am not making an argument from authority to you. I’m saying that that procedure is the only one available to me. Before trillions of dollars are taken out of the economy, a proposal mostly argued, and that vehemently, by people in the main who like me merely rely on the testimony of others I’d like to see some measure of agreement on the part of the peer-agreed experts as to the value of this climate sensitivity factor. When they’ve finished their debate they can come out and tell me the result and I’ll go along with it. Meanwhile I’ll reserve judgement.

        Response– The fact is that in a warming planet, weather still happens. Contrarian noise is not going to get rid of El Ninos, La Ninas, other oceanic and atmsopheric phenomena, the possibility of volcanic eruptions, solar changes, etc. Ironically, it is these people who fail to consider anything except CO2, and then put up a straw man attack that a few years of cooling is somehow a danger to “the theory,” when in fact they just created their own phantom theory. Because weather happens, you don’t expect a monotonically increasing temperature from year to year. You expect a long term warming trend, but over shorter timescales (years to a decade or two) then you can see a lot of wiggles and bumps in a plot of Global T vs. time (se here ). That is what you see in observations and in models. However, increasing CO2 means an increase in energy available, so eventually global warming is going to win against the background noise of the climate system. Whether it takes a decade or two or three to really detect that trend is another subject (and a much more interesting one) but suffice to say that the globe is getting warmer, and cherry-picking a few years of steady temperatures to refute this just displays ignorance in climate and statistics.

        Concerning Lindzen, Spencer, etc, they are more than qualified to comment on the subject…but they are also strong outliers in the field and have a large body of peer-reviewed literature which is not consistent with their claims. So, at the very least, it should not be taken to be self-evident that they are correct. There is really no way to argue for a low climate sensitivity (which is not the same as the CO2 forcing) given the constraints by the paleoclimate record. Several decades worth of study have gone into this, and while it would be nice if Lindzen et al. were correct, wishful thinking is not science– chris

  4. The International Day of Climate Action got barely a mention in the media and even that was far more press than it deserved. Luckily everyone is starting to wake up to the fact that the “science” the alarmists have been pushing isn’t science at all.

    As for the rest of your post, you must not have received the memo. Those on the Climate Alarmism Gravy Train do no get into more detailed accounts. Mentioning specifics in projections leads to embarrassment. When James Hansen predicted in 1989 that in 20 years New York City’s West Side Highway would be under water, he looks bad in 2009.

    This is their livelihood. Looking incompetent or fraudulent isn’t good for the bank account. It is best to stay vague in the proclamations, peddle closely held computer models as “evidence”, play up any anecdotal pieces that can be twisted into supporting the pitch, bury the failures by claiming complexities have just deferred your correctness, and enjoy the money while it lasts.

    Chris, happy to see you back. I was hoping you’d pop up during the whole Yamal controversy. Would have loved to get your take on that steaming pile.

  5. “It is therefore not necessary to over-inflate the consequences of climate change or to assume “worst-case” scenarios in analysis, and I urge people to consider this, since the consequences of this for a public attention, policy, and scientific viewpoint can be just as bad as those who downplay or misrepresent the urge to take climate action”

    In the same line [subscription required, abstract available]:
    O’Neill, S. & Nicholson-Cole, S. (2009). ‘Fear Won’t Do It’: Promoting Positive Engagement with Climate Change through Visual and Iconic Representations. Science Communication. 30(3): 355-379

    And also related [pdf available here]:
    Lorenzoni, I. & Hulme, M. (2009). Believing is seeing: laypeople’s views of future socio-economic and climate change in England and in Italy. Public Understanding of Science. 18:383-400

    The press releases for both should be available here soon, but they aren’t yet (I received it through a webmail subscription).

  6. Alleagra,

    Yes, it is true that in the uppermost layer of the oceans, warming has apparently halted if the data is accurate. However, one cannot just look at that and declare a halt to warming. See my page at:

    There I show a variety of observations that do show warming. These include:

    1) Arctic sea ice extent declining
    2) Arctic se ice thickness declining
    3) Glacier mass balances declining
    4) Glacier retreat increasing
    5) von Shuckmann, Gaillard, and Le Traon (2009) show that the heat content of the upper 500 m of ocean are subject to strong seasonal and interannual variations. However, when considering the heat content of the upper 2000 m of ocean, global mean heat content and height changes are clearly associated with a positive trend during the 6 years of measurements between 2003 and 2008.
    6) Murphy et al. (2009) examined the Earth’s energy balance since 1950 including ocean heat content, radiative forcing by long-lived trace gases, and radiative forcing from volcanic eruptions. They show that the heat gained since 1950 is already quite significant.

    The best analogy I can come up with is to imagine climate change as a staircase. There are “flat steps” where there is no eleavation change but even if one steps on each of those flat areas, one is still climbing overall (upward trend). The uppermost layer of the ocean heat content is on a flat step now but its stairs are still climbing.

  7. Sources:

    von Schuckmann, K., F. Gaillard, and P.-Y. Le Traon (2009), Global hydrographic variability patterns during 2003–2008, J. Geophys. Res., 114, C09007, doi:10.1029/2008JC005237.

    Murphy, D. M., S. Solomon, R. W. Portmann, K. H. Rosenlof, P. M. Forster, and T. Wong (2009), An observationally based energy balance for the Earth since 1950, J. Geophys. Res., 114, D17107, doi:10.1029/2009JD012105.

  8. Do you have the full citation for Clement (2009)?

    Response– — chris

  9. Alleagra (and others),

    Here’s an excellent review article that summarizes the lines of evidence for climate sensitivity estimates, with many references to individual studies. Studies like these are a far better place to go for complete objective science than politically-oriented blogs like wuwt.

    Click to access knutti08natgeo.pdf

    Good post, Chris.

  10. Thanks to you and MarkB for your comments but as a layman with no axe to grind, in responding to people like me I don’t want to hear you bitching about your peers in the field ‘displaying ignorance of climate and statistics’ and accusing people like Lindzen of ‘indulging in wishful thinking that is not science’. I’m not interested in assertion-loaded quarrels whatever the status of the participants. This is precisely the kind of thing that looks like resulting in Copenhagen as a damp squib.

    Just think for a minute about what you’ve written. In establishing the truth or not of the AGW thesis, as a neutral observer, how many points do I award on the pro-AGW side for your assertion that ‘these people display ignorance of climate and statistics’? The answer is ‘none’ because this is an opinion and valueless in the grand scale of things. Again I see experts bickering and abusing each other while the AGW-side ask politicians to exact trillions of dollars in taxes. This is a bizarre situation. Constructing apposite on-the-bulls-eye invective is intensely pleasureable but should be resisted in this kind of debate. If we can’t counter a point specifically and dispassionately we should shut up if we seek to persuade the uncommitted.

    You talk about the ‘mass of peer-reviewed papers and decades of research’. Give me a break. Science is littered with the wreckage of abandoned theories supported by countless ‘peer-reviewed papers’. It’s your blog to do as you will of course but if you want to persuade people like me of the correctness of your conclusions you’d better sharpen up your act or merely preach to the converted which appears to be (I’m happy to be corrected) is what you mostly do.

    You may have noticed that the electorate out there is becoming increasingly less convinced of the AGW case. As it happens. I can at least see the power of your central argument and I’ll keep focused on that. So isn’t it time for you to regroup, strip out the invective and special pleading, remain dispassionate, keep to the facts and at least pretend that you are only swayed by the evidence and haven’t adopted (as the sceptics do as well) a bigoted stance.

    You say ‘increasing CO2 means an increase in energy available, so eventually global warming is going to win against the background noise of the climate system’. But you add that it would could it be ‘nice if Lindzen were correct’. I suppose you mean that the problem becomes a tiny one if the CO2 sensitivity is small? What range of values should the CO2 climate sensitivity factor be within, to skip that trillion dollar expenditure? The rest of us on this planet are dying to know even if some of us don’t know that we’re dying to know. And that’s exactly the point. The AGW brigade have so far utterly failed to get their very simple central argument out into the mediasphere. They (and their opponents) can’t resist cluttering up the discussion with irrelevant data about temperature trends, hurricanes, sea levels, and heck know what else. From their point of view this is a tragic disaster. The remedy is obvious.

    Response– The more and more you say ‘you have no axe to grind’ the more it looks like it just ain’t so, so you can drop the intro line to make me think you are really after the truth. Your very tone, and uses of phrases like “AGW crowd” and “they want us to spend trillions of dollars in taxes” and apparent denial of the bulk of literature out there is disturbing. If you feel you have the ability to “wreck” all of the science available, you can try– chris

  11. Alleagra , have you ever stopped to consider that a gross ignorance of science and the scientific method is behind you and your associated band of AGW deniers?

    The level of science literacy in NA (and elsewhere) is deplorable. This is what allows the misinformation, lies and distortions of the “anti-AGW brigade” to flourish. I would suggest that you spend some time on reading elementary texts on basic science and climatology before making your ill-informed pronouncements.

  12. Chris, back in September you made a few comments on Australian Senator Steve Fielding’s blog (Note 7) but quickly dropped out when confronted by arguments showing that your reasoning was flawed. In one of the exchanges I asked you QUOTE: BTW, when checking up on your pedigree I could only find one Chris Colose, a 21-year old student college student, with an A.S. in Environmental Studies and interest in the atmospheric sciences. Apart from on blogs I could find out nothing. Would you be good enough to let us know a bit about your background? UNQUOTE but you never did get back to me on that. Do I take it that you are in fact this “21-year old college student”? If so then it surely was rather impertinent of you to suggest (Note 8) that QUOTE: At the very least, there’s no obvious reason why positive feedbacks shouldn’t be real, as if this were some obvious fact of nature, as Dr. Burns feels so confident about. Unfortunately just about everything emanating from his posts are completely wrong, and the style of arguments shows he’s been getting too much info from wingnut sources UNQUOTE.

    On the matter of your QUOTE: need for an international climate treaty to reach a 350 parts per million CO2 level as a target threshold UNQUOTE there is no need to waste any of our much needed money chasing after a lower carbon economy. The efforts of the UN to force its climate change propaganda down our throats in order to impose a system of wealth redistribution from developed to developing economies are despicable, as is the support being given to this by our elected representatives. The UN’s Climate Change Conference in Copenhagen will do nothing to reduce our use of fossil fuels, but this is not the real objective. Redistribution of wealth and the setting up of a framework for global government are the major objectives, but countries like China and India have seen through the propaganda and will not do anything to damage their own growing economies (powered by fossil fuel).

    As for the QUOTE: International Day of Climate Action, called “350″ UNQUOTE this was another failed attempt to get large numbers of climate change activists out on the global streets, this time in support of reducing atmospheric Co2 levels to below 350ppm. It seems that it was “hockey stick” Hansen who created the illusion that 350ppm or less should be our target, just as he created the illusion of the hockey stick. In his 2008 paper (Note 1) “Target Atmospheric CO2: Where Should Humanity Aim?” Hansen pushes the need for a target level of 350ppm or less, saying QUOTE: If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm, UNQUOTE. Politicians and environmentalists have seized upon this as perfectly fitting their propaganda, without any mention of any uncertainty surrounding this hypothetical figure. They choose to totally ignore the uncertainties covered in Section 4.5. Caveats: Climate Variability, Climate Models, and Uncertainties

    Hansen says QUOTE: The largest uncertainty in the target arises from possible changes of non-CO2 forcings. UNQUOTE and does that surprise any of us here? It shouldn’t, since Roger Taguchi has clearly shown (independently substantiating the findings in papers by Drs, John Nicol, Heinz Hug and Jack Barrett) that the IPCC figures for climate forcing are far higher than demonstrated by empirical evidence. On climate models Hansen says QUOTE: Climate models have many deficiencies in their abilities to simulate climate change .. UNQUOTE then covers his backside with QUOTE: However, model uncertainties cut both ways: it is at least as likely that models underestimate effects of human-made GHGs as overestimate them UNQUOTE. There was I thinking that Hansen is a scientist when all the time he’s a politician in scientists clothing.

    It is interesting to note that one of Hansen’s close assiciates, Dr. Joanna.Simpson, ex-NASA scientist, is reported on numerous Internet sites as saying QUOTE: “Since I am no longer affiliated with any organization nor receiving any funding, I can speak quite frankly. …. But as a scientist I remain skeptical.” UNQUOTE. I now add the bit that is reported (Note 2) to have been left out (to save you from complaining about me cherry-picking) QUOTE: What should we as a nation do? Decisions have to be made on incomplete information. In this case, we must act on the recommendations of Gore and the IPCC because if we do not reduce emissions of greenhouse gases and the climate models are right, the planet as we know it will in this century become unsustainable. UNQUOTE. The most significant part of that extract is “if .. the climate models are right”. The problem is that the models are most probably WRONG because of the very poor level of scientific understanding of climate processes and drivers.

    I thought that it might be worthwhile looking a bit closer at the likely impact of increasing CO2 levels. I knew of research that has shown how plants grow better in an atmosphere with higher levels of CO2 than we have at present but was surprised by the extent of the improvement. I was also surprised to find that improved growth is experienced along with a lesser demand for water. What a boon for those drier countries. It turns out that many greenhouse operators force the CO2 level up to levels above 1000ppm and patented systems abound for doing this. Even more interesting was the use of exhausted coal mines as sources of methane and CO2 for powering and feeding the plants in greenhouses and the support given to these techniques by governments. (Notes 3, 4, 5). As the National Centre for Policy Analysis said in its 1998 bulletin “Who’s Afraid of CO2? “(Note6) QUOTE: Carbon dioxide is not a pollutant. UNQUOTE and concluded QUOTE: According to government mine safety regulations, atmospheric CO2 would have to rise as high as 5000 ppm before it posed a direct threat to human health. Since no scientist predicts a rise of this magnitude in the next century, the anticipated rise in CO2 levels should be viewed as beneficial. Even if temperatures increase slightly, life on earth will thrive. UNQUOTE.

    Let me offer a bit of advice for you r considerastion (from someone who has been around for 72 years and seen no evidence of significant climate change) don’t believe everything that you read. Keep enjoying life on this lovely planet of ours, which has withstood numerous changes in global climates in the past and will no doubt do so on numerous occasions in the future, all natural changes having nothing to do with our use of fossil fuels..

    1) see
    2) see
    3) see
    4) see
    5) see
    6) see
    7) see
    8) see

    Best regards, Pete Ridley, Human-made global climate change agnostic.

    Response– Did you have something specific you wanted me to address? I can’t see much from you that is rooted in fact (just the same old ridiculous talking points), and certainly nothing that caused me to leave a forum in shame a while back. The time I spend on random forums is limited, and I usually leave quickly if people insist on intentionally not understanding information given to them. For my background, I am indeed a 21-year old college student pursuing an Atmospheric and Oceanic Science degree.– chris

  13. Chris, with your vast experience behind you, try identifying any flaws in Roger Taguchi’s analysis. You’ll find it at but you’ll be unable to shoiw that there is anything significantly wrong with the analysisi or the obvious conclusions.

    Oh, I forget. You did try once and failed.

    Best regards, Pete Ridley, Human-made global climate change agnostic.

    Response– No, I was successful. Let the dead rest in peace– chris

  14. Chris,

    You write about climate science as if you were a PhD holding faculty member. Kudos!

  15. Chris, I have challenged you try identifying any flaws in Roger Taguchi’s analysis following your failed attempt (Note 1) but all that you could do was respond feebly with QUOTE: Response– No, I was successful. Let the dead rest in peace– chris UNQUOTE. Not at all convincing Chris.

    As Roger said (Note 2) QUOTE: When it appears to you that the article “just a few more molecules” seems to support the IPCC position, I say, yes of course! chris c, who is very familiar with the MODTRAN model, was a staunch defender of the IPCC which uses his model as the basis of their report. We haven’t read much recently from him, perhaps because my stinging criticism of his arguments and beliefs in an earlier post has forced him to re-examine his assumptions and beliefs, and he hasn’t been able to come back with a logical reply.
    Why did I refer you to this article, then? Because, yes, I believe that chris c did a good job in explaining without detailed calculations the idea of “saturation”. If you want an accurate, detailed explanation, please see Appendix 2 of my article at , .. I do not automatically reject everything that chris c writes as wrong, and I do not want to appear to demonize him. .. I try to be fair to the opposite side’s valid points, something that all sides ought to do in an honest debate. .. I do not agree with the IPCC’s numbers, because (1) their estimate of the sum of all feedbacks is too large, by a factor of 5 to 10 (depending on whether the solar constant change results in zero or 0.1 degree C temperature change from 1750 to today) and (2) the IPCC report’s prediction of a 6 degree rise on quadrupling CO2 from 300 ppm to 1200 ppm shows a lack of physical understanding, by assuming equal temperature increases on each doubling of CO2. As I have repeatedly stated, each doubling produces exactly half of the previous doubling (for a proof, see Appendix 2 of my long blog article). I am not sure if chris c knew this, as he has not responded. UNQUOTE.

    So come on Chris, respond to Roger with your criticisms of his paper (Note 3) IF YOU CAN. You must have heard the saying “actions speak louder than words”. Roger would love to hear from you.

    1) see
    2) see
    3) see

    Best regards, Pete Ridley, Human-made global climate change agnostic.

    Response– I have already outlined many of the problems with the “mistakes in the IPCC” web posting. I assure you that thousands of the worlds climate scientists are not all ignorant to the things you think they are. In particular, everyone already knows about the saturation effect of greenhouse gases, and this is already included in the physics…indeed, it must be, or small changes in CO2 would result in extremely radical changes in climate. In the “calculations of climate sensitivity section,” the author simply assumes (with no evidence whatsoever) that feedbacks are exactly net neutral, since he achieves the Stefan-Boltzmann feedback (in the same way I did on the Radiative Forcing/Feedback posting) and then declares with confidence that “Therefore all literature predictions of climate temperature changes will be too high by at least a factor of 3.” Unfortunately, simply asserting something with a back-of-the-envelope calculation (which doesn’t even include feedbacks) is not convincing either.

    This is enough. The rest of his essay is just as bad, especially his triangle experiment of a pure CO2 atmosphere, his tutorial on Venus, and everything else. It is rare that I see such fundamental misunderstandings of the physics involved. So if you want a serious discussion, you’re going to need to do some real research and cite refereed sources.– chris

  16. Pete,

    Here is a discussion of where Taguchi’s claims are false:

    As Chris stated, if Taguchi were correct then how do thousands of physicists miss the obvious?

  17. Chris, I’ve passed on your comments to Roger and hope that he will be inclined to spend some of his valuable time using his award-winning science teaching skills to help educate you.

    An invaluable lesson that the more mature among us have learned is that the more we learn the more we recognise how little we know.

    Best regards, Pete Ridley, Significant humnan-made global climate change agno(scep)tic

  18. Chris, you are an arrogant young fellow, aren’t you. I was amused by your parting comment of 24th October on your “Re-visiting climate forcing/feedback concepts” thread QUOTE: Please, I am not interested in absurd and unsupported opinions.- chris UNQUOTE. What you should have said is “I am not interested in absurd and unsupported opinions OTHER THAN MY OWN”. Have you tried to read your own words impartially in order to identify any occasions when you express “absurd and unsupported opinions”? Have a go. It could open your mind.

    Perhaps your response to my comment of 1st November that “This is enough. The rest of his essay is just as bad, especially his triangle experiment of a pure CO2 atmosphere, his tutorial on Venus, and everything else. It is rare that I see such fundamental misunderstandings of the physics involved” fits into the category of “absurd and unsupported opinions”.

    Roger Taguchi does much more than merely express “absurd and unsupported opinions”. He backs up his opinions with sound scientific analysis based upon many years experience. Roger is well aware of the attempt by Sylas to refute his analysis (the link provided by Scott A. Mandia). He has sent me a very long response to both what Sylas says and what Chris says which I can post here if you like, but it is quite detailed – 4500 words). Would you like me to submit his latest offering?

    Best regards, Pete Ridley, Human-made global climate change agnostic.

    Response– It is a bit more arrogant to imagine that a bit of basic high school algebra has revealed mass insights into the climate system which thousands of physicists and climate experts are unaware of, and of which is not captured in state of the art GCM’s. You are welcome to post what you want, but it’s very easy to see right away that his post is fraught with misunderstandings and errors. I really cannot imagine how any of this is in dispute or what the need for a “middle man” is.– chris

  19. Chris, “State of the art GCMs” eh! Have you read the recent peer-reviewed paper “Validity of climate change forecasting for public policy decision making” by Willie Soon et al (Note 1). It says QUOTE: Our validation exercise illustrates the importance of determining whether it is possible to obtain forecasts that are more useful than those from a simple benchmark before making expensive policy decisions. .. Our intent in this paper is not to assess what might be the true state of the world; rather, it is to illustrate proper validation by testing the IPCC projections against the benchmark model. UNQUOTE. Hopefully this is the start of a serious attempt to try to validate the General Circulation and Coupled Ocean- Atmosphere climate models that supporters of The (significant human-made global climate change) Hypothesis rely upon as substantiation of their alarmist position. One of the major concerns that sceptical scientists have about these models is that they have never been subjected to independent and professional Verification, Validation and Test (VV&T) procedures.

    A major criticism of many papers purporting to support The Hypothesis is their frequent references to “uncertainty” and the use of lots of “if”s, “but”s, “might”s and “maybe”s. It is noticeable that there is not a single mention of “uncertainty” in that paper, which only uses “if” and “might” three times each, all in relation to uncertainty about support for The Hypothesis. “But” is used once in QUOTE: Speculation is not sufficient for forecasting. The belief that “things have changed” and that the future cannot be judged by the past is common, but invalid. UNQUOTE and “maybe” does not appear at all.

    The paper concludes QUOTE: .. The benchmark forecast is that the global mean temperature for each year for the rest of this century will be within 0.5 _C of the 2008 figure. … While the Hadley temperature data .. drifts upwards over the last century or so, the longer series .. shows that such trends can occur naturally over long periods before reversing. Moreover, there is some concern that the upward trend observed over the last century and half might be at least in part an artifact of measurement errors rather than a genuine global warming .. Even if one accepts the Hadley data as a fair representation of temperature history, our analysis shows that errors from the benchmark forecasts would have been so small that decision makers who had assumed that temperatures would not change would have had no reason for regret. UNQUOTE.

    You’re obviously extremely knowledgeable on the subject so please would you point me to the independent and professional VV&Tevidence of showing that those GCMs are an improvement on crystal balls.

    1) see

    Best regards, Pete Ridley, Human-made global climate chhange agnostic

    Response– Crystal balls don’t generally include the physics of momentum, continuity equations, thermodynamic equations, etc. A detailed analysis of model evaluation requires being a bit more specific about the variable, statistic, timescale, etc of interest and the uncertainty in observations. There are lots of books, papers, reports, etc on how models work or how well they are doing in simulating various characteristics of the present and past climate. IPCC 2007 offers a good summary of climate model evolution and assessment, and the USCCP has a recent report on the Strengths and Limitations of climate models. Those might be good starts.

    Back to the actual conversation topic though, I assure you that models could faithfully represent climate sensitivity if the whole problem were reducible to a simple algebra step and a derivative, as Roger thinks it does. But it doesn’t.– chris

    • Chris, allow me to add that Pete Ridley oddly places a lot of emphasis on the absent of typical scientific qualifiers, such as “uncertainty”, “Maybe”, “if”, and “but”. It actually is more indicative of the unscientific nature of the paper by Soon et al. Should we be surprised? No, anyone submitting a paper to the Journal of American Physicians and Surgeons (on global warming…) isn’t concerned about good science, but only about good politics.

      • Some very politically-motivated “physicians and surgeons” I might add…

        It’s rather naive to think anything printed in that “journal” (that has printed things like “humanists have conspired to replace the “creation religion of Jehovah with evolution”) as a valid peer-reviewed scientific publication.

        Response– It doesn’t, but it is the only venues people can get into who think they are going to show that “AGW is all a hoax.” — chris

  20. Kesten Green is an oil industry hack with no science degrees:

    J. Scott Armstrong has no science credentials:

    Willi Soon is a real scientist with a real fossil fuel funded agenda:

    This paper cannot be taken seriously nor can you. Show us something from Nature or Science or J. Geo Res., etc.

  21. Wow, you’ve certainly got people popping up promoting old, long-refuted mistakes as though they were new.
    You’re being far more patient than I would be

  22. MarkB and Scott (A Mandia), thanks for those interesting links giving background to the people involved in the paper to which I linked.

    Marco, I fully appreciate that there is far far too much politics driving BOTH sides of this debate, with the UN at the forefront. If you were being honest you would admit that too. I will keep on emphasising all of the “if”‘, “but”s, “might”s and “maybe”s until many of the enormous uncertainties that presently surround the numerous disciplines involved in the science of climate processes and drivers have been removed by the enormous amount of research that is in progress.

    One research activity that is of particular interest to me is the CERN CLOUD09 program. Another is that of Keith Shine, Professor of Physical Meteorology at the University of Reading, recently elected to the Fellowship of the Royal Society. He continues his research into the role of water vapour in the Earth’s energy balance, one of the major areas of uncertainty about the impact on global climates of our use of fossil fuels.

    Any scientist who supports the opinion that the scientific debate is over is doing nothing but playing politics and their are important personal incentives for doing so which I should not need to spell out for you.

    The debate will continue, but both sides need to be much more open-minded. Exchanging ridicule about individuals and organisations does not move the debate along at all. It is the science that is important, theory verified by empirical data. At the present time The (significant human-made global climate change) Hypothesis has not been validated by empirical data.

    Best regards, Pete Ridley, Human-made global climate change agnostic.

    BTW Scott (A Mandia) am I correct in thinking that you are teaching or have taught Chris (Colose)?

    Response– But what is being debated? You seem to think that remaining uncertainties equates to a big “debate” on whether human beings can influence climate. It doesn’t. Uncertainties exist in all fields of science. That’s why people become scientists and study different things. That doesn’t mean we know nothing or that every little thing in life is in a mass debate. And no, Prof. Mandia has not taught me– chris

    • Pete, don’t expect much from the Cloud09 programme. The initial report has been criticised heavily for failing to take wall effects into account. The latter are likely so large that the proposed (very small) effect of GCR will be extremely difficult to discern from the expected wall effects.

      Regarding politics: I don’t see any mainstream climatologists publishing in crackpot journals and making crackpot claims.

  23. Scott A. Mandia, I took a look at your Web-site to find climate science research papers of yours but drew a blank. Can you provide me with some links? Looking at your “Climate Change (Global Warming) Links:” there is an apparent bias towards sites supporting The (significant human-made global climate change) Hypothesis. Don’t you think a bit more exposure to some of the many sceptical sites would help your students to be more open-minded, as all good scientists should be.

    Hank (Roberts), I like to find out a bit about the people that I’m debating with so did a bit of research into your climate science pedigree and found lots and lots of your contributions to numerous blogs. I have been accused of being an Internet virus but I think you beat me.
    It is quite clear from the comments of yours that I have read that your knowledge of climate processes and drivers is, like my own, QUOTE: just from what I’ve gathered as an ordinary reader UNQUOTE (Note 1). I started researching this subject in 2007 following a scare after reading environmentalist Mark Lynas’s propaganda booklet “Six Degrees ..”. You and I have been researching climate change as laymen for several years yet have arrived at opposing conclusions. I don’t find this to be at all surprising, merely reflecting the extend of the scientific uncertainty about climate processes and drivers. I must say that I agree with Roger Pielke Jnr when he says (Note 2) that QUOTE: Hank Roberts is very incorrect UNQUOTE but then Pielke is also a sceptic.

    I see that back in 2006 you were doing a bit of research on the effects of Cosmic Radiation on clouds. Have you learnt anything since then that you’d like to pass on or are you, like myself, eagerly awaiting the outcome of the CLOUND09 experiments? The most recent that I can find is Jasper Kirkby’s 4th June Colloquium, in which he concluded QUOTE:
    • Climate has continually varied in the past, and the causes are not well understood – especially on the 100 year timescale relevant for today’s climate change
    • Strong evidence for solar-climate variability, but no established mechanism. A cosmic ray influence on clouds is a leading candidate
    • CLOUD at CERN aims to study and quantify the cosmic raycloud mechanism in a controlled laboratory experiment
    • The question of whether – and to what extent – the climate is influenced by solar/cosmic ray variability remains central to our understanding of anthropogenic climate change
    If you unearth anything more up-to-date then I’d appreciate a link.

    You have made comments on RealClimate. Many sceptics claim that Realclimate refuse to publish anything that contradicts their support of The (significant human-made global climate change) Hypothesis if they can’t refute it in a convincing manner. I recall that they staunchly defended Hocky-stick” Mann’s misleading temperature graph (Note 3) which the UN depended so much on as part of its IPCC propaganda, despite convincing evidence that it was a misrepresentation (Note4). I can see why now. – when chasing up your “climate science” pedigree I was directed to RealClimate (Note 5) and what’s there at the top? Under the heading “Communicating Science: Not Just Talking the Talk” is “Michael Mann and Gavin Schmidt”. Birds of a feather? Perhaps that title should be understood as “Communicating Dubious Science”.

    BTW, I did like your link yesterday to Critical Thinking (Note 6). We should all try to practice it.

    1) see
    2) see
    3) see
    4) see
    5) see
    6) see

    Best regards, Pete Ridley, human-made global climate change agnostic.

  24. Pete,

    I am a meteorologist that teaches weather and climate courses at the freshman and sophomore level. I hold an M.S. and B.S. degree in Meteorology. Chris was not a student of mine but I am quite convinced I could be a student of his. 🙂

    I am not a publishing climate scientist. My site speaks for the scientific consensus and the information there is well documented. As I state on the home page: The result is that the misinformation is reaching more people than the real science. This Website tries to bridge the knowledge gap by summarizing some of the key research that has led scientists to their overwhelming consensus while also addressing some of the unfounded claims by climate change denialists.

    I do not represent the view of the skeptics because there is essentially little skepticism in the peer-reviewed journals. We need to move forward to debating mitigation of global warming and not whether it is happening or why it is happening.

    Analogy: An artery is gushing and nine of ten doctors describe the emergency and to use a tournaquet as mitigation. One doctor claims that it is not really blood or that the blood loss is normal so nothing should be done. Are we to assume that these doctors should debate?

  25. Marco, thanks for the link. At a first glance it doesn’t tell us much more than the earlier reports but I may have missed something that you spotted so I’ll get back.

    Scott A. Mandia, thanks for being honest. You are entitled to your opinion, like the rest of us. At least I know that you are simply parroting what the supporters of The (significant human-made global climate change) Hypothesis are saying, so I won’t expect you to add anything to the debate.

    Best regards, Pete Ridley, human-made global climate change agnostic.

  26. Pete Ridley, the only person not adding anything to the discussion (I won’t even call it a debate since the scientific evidence is overwhelming) is you.

    You are apparently suffering from a bad dose of Dunning Kruger syndrome.

    I hear that a good way to overcome that affliction is spending a considerable amount of time studying real science in well written text books and in the scientific journals. Denier web sites are not the place to seek a cure for DKS.

  27. Pete,

    Do you publish in climate-related journals? If not, then how is your position different than mine? Yet you believe you have something to offer. Strange.


  28. Ian (Forrester), are you one and the same as he of desmogblog/grist fame, self-established enlightener of the world’s climate sceptics, denigrator of all who dare to challenge supporters of The (significant human-made global climate change) Hypothesis (with words like “stupid”, “dishonest”, “nonsense”, “untruths”, “obfusction”, “quote mining”)? Methinks “yes”.

    I suspect that you are the same Ian Forrester who commented (Note 4) on a paper by Keppler et el (Note 5) that says QUOTE Most of the methane from natural sources in Earth’s atmosphere is thought to originate from biological processes in anoxic environments UNQUOTE. That Ian Forrester said QUOTE Methane production is limited to a very narrow group of bacteria UNQUOTE and chose not to mention that enormous amounts of methane are produced by biological processes involving termites and livestock.

    This comment sums you up (Note 1) QUOTE: I know your policy on your blog is not to silence competing views. Normally, I would not ask that anyone not be allowed to present deferring views of the science and the studies that support their claim. I do however want to post a complaint about Ian Forrester. So far he has not discussed the science or presented studies to support any position. All I see is him making demeaning personal attacks on anyone he does not agree with. This is a science blog, so could you enforce a limit on these attacks and move the focus back to the science. I do not mind if people get caught up in the moment and the conversation gets a little emotional, after all most everyone posting here is passionate about the science. I know we rarely agree on scientific issues but I have always found you to be a civil opponent. Can we get the pointless personnel attacks eliminated? Posted by: Vernon | May 27, 2009 2:17 PM UNQUOTE.

    You exclaim (Note 2) QUOTE: I am a scientist UNQUOTE with a QUOTE: BSc in chemistry and PhD in Biochemistry UNQUOTE but your comments here and elsewhere suggest that this is a serious distortion of fact (something that you repeatedly accuse others of – Note 3). A good example of your distortions is your QUOTE: Secondly, close to 100% of climate scientists agree that AGW is real UNQUOTE (Note 6). There is a reference (Note 7) to QUOTE: Dr Ian Forrester, NZ CS (New Zealand Chief Scientist), 1990-91 UNQUOTE but I cannot believe that you are he. You throw insults at scientists who can demonstrate competence in their discipline but despite searching very hard I can find not a single peer-reviewed paper of yours so have to assume that your scientific writings are limited to blogs like this. If you are scientifically qualified then the scientific community may well wish to disown you.

    Staunch UK environmentalist Jonathan Porritt complained in one of his propaganda booklets about the arrogance of scientists. Bsed upon my experience working with scientists in the Telecommunications R&D my reaction to that was “rubbish”, but he may have been unfortunate only to have encountered scientists like yourself.

    Scott (A Mandia) as I said earlier “You are entitled to your opinion, like the rest of us”.

    1) see
    2) see
    3) e.g. see
    4) see
    5) see
    6) see
    7) see

    Best regards, Pete Ridley, human-made global climate change agnostic.

  29. Peter Ridley said:

    and chose not to mention that enormous amounts of methane are produced by biological processes involving termites and livestock

    So good of you to show everyone here just how ignorant of science you are. You also show a level of arrogance that puts you in the good company of most deniers who, as you, suffer from DKS.

    For your edification, it is a population of bacteria (methanogens) in the guts of termites and in the rumen of ruminants that produce the methane, not the organisms themselves.

    I must admit I had a good laugh while reading your post. I can assume that the rest of your posts are as full of elementary mistakes as this one.

    You are a joke. Get a life or if you have so much time on your hands (you seem to post the same garbage on a large number of blogs) do some reading of real science as I alluded to above. You may even learn about the inner workings of termites and cows.

    I call a spade a spade. I hate people like you who, while being ignorant of science, denigrate science and scientist with your lies, distortions, obfuscation and other forms of scientific malfeasance.

    You can believe what you like about who I am and what my qualifications are. I know exactly what you are and it is not nice and I will not lower myself to put a description of you and your ilk on this blog.

  30. Guys, let’s stop with the back and forth attacks now. I think it’s safe to say at this point that Pete does not have any contributions to make to the science, nor does he really understand the subject, but rather he has just made up his mind that everyone who “believes in AGW” is delusional or a liar. So, I’m not sure anything more useful can come out of this.

  31. One suggestion for Pete Ridley would be to attempt to confine his various talking points to one or two distinct assertions post and try very hard to substantiate them, making sure a citation directly addresses the claim being made.

    While I understand that what contrarians tend to lack in robust scientific arguments they often make up for with rhetoric and repetition, I believe most readers of this blog are a bit more astute on average and are not easily fooled by such things.

    As for a bit of humor…

    – MarkB, Heliocentrism Agnostic (too many uncertainties to follow Heliocentrism religion, scientists need the grant money and makes me suspicious, it makes me further skeptical that they are dismissive towards unbelievers, claims that the issue is “settled” is evidence of a religion, not science, etc.)

  32. Ian (Forrester) it is unfair to Chris and others involved here to subject a students blog to puerile exchanges of insults. Please join us at a politicians blog (Note 1) where I have posted a comment about you. I will not respond to any more of your comments here.

    MarkB, thanks for the suggestion but if you’re interested do check around and you’ll find that (in my opinion) I do that most of the time.

    Chris, I said earlier that Roger Taguchi is updating his paper showing that The (significant human-made global climate change) Hypothesis is flawed. Until he completes this I have about 6000 words of updates in 3 E-mails from him which I could pass to you if you like. Let me know.

    Best regards, Pete Ridley, human-made global climate change agnostic.

    Response– You are welcome to post them in a comment. I’ll review them and either leave it as a comment or paste them into a new post– chris

  33. Chris, thanks for that. I’ll post them as you suggest after I’ve stripped out irrelevant stuff, probably next weekend. Are you able to access my E-mail address used when posting comments? If so I’m happy to receive direct communication.

    Scot (A. Mandia) if we had as much understanding and worthwhile experience of the effect of the emission of carbon dioxide into the atmosphere from our use of fossil fuels on global climates as we have of the effect of losing substantial amounts of blood, then I would agree with your analogy. Of course the difference is the degree of uncertainty about the outcome. As the Australian Government’s chief climate science advisor Professor Barry Brook said back in April (Note 1) QUOTE: There are a lot of uncertainties in science, and it is indeed likely that the current consensus on some points of climate science is wrong, or at least sufficiently uncertain that we don’t know anything much useful about processes or drivers. UNQUOTE. He then went on to try to suggest, without any substantiation whatsoever, that we understand 95% of climate processes and drivers with QUOTE: But EVERYTHING? Or even most things? Take 100 lines of evidence, discard 5 of them, and you’re still left with 95 and large risk management problem. UNQUOTE. I believe that this comment is highly significant and repeatedly but unsuccessfully tried to get Professor Brook to clarify what he was saying. He refused to discuss it, despite normally responding to comments within a couple of days, sometimes even minutes.

    This is a scientist who can reasonably claim having a high level of expertise in biology, but does it justify him being considered to be an “expert” in climate science? He appears to claim expertise in QUOTE: climate change; global change biology; ecology; tropical biology; extinction; habitat loss; invasive species; palaeontology; modelling; conservation biology; endangered species; climate policy; sustainability; conservation genetics UNQUOTE (Note 2).

    In June 2008 Professor Emeritus of Physics, James Cook University, Australia Dr Nicol presented a paper (Note 3) “Climate Change (A Fundamental Analysis of the Greenhouse Effect)” challenging the “scientific consensus” revered by supporters of The (significant human-made global climate change) Hypothesis. There have been the usual screams from supporters of The Hypothesis that “it hasn’t been peer reviewed” but a rejection of the argument on that basis is not acceptable to many of us. It is the argument itself that is relevant and if it is claimed to be flawed then such claims need to be justified. The reason for this is that arguments such as his fit in with what we lay people experience. Many of us accept that there may have been a slight increase in global temperatures and that changes in weather conditions take place repeatedly around the globe. We can see no evidence that using fossil fuels is causing this or any significant global climate change beyond what has been experienced in the past.

    In December 2008 Dr. John Nicol was involved in exchanges on Professor Brook’s blog (Note 4). Dr Nicol tried very hard but unsuccessfully to have a reasonable debate with Professor Brook. In his final contribution Dr Nicol said QUOTE: So whether GHGs warm or cool depends on some difficult calculations. It has not been properly treated and having written to Barry Brooks, various modelers including our CSIRO Climate Science Group, I have not been able to obtain any information on a modern treatment of the Green house effect upon which our future economy will stand or fall. Barry, to his credit, replied to me saying he was a biologist and therefore unable to help, but to try a physicist. UNQUOTE.

    So, is my questioning of the degree of climate science expertise enjoyed by those who set themselves up as experts fair? That last quote from Dr. Nicol in the previous paragraph appears to be Professor Brook’s answer to the question about the extent of his expertise in climate science. Perhaps my questioning is fair after all.

    For anyone who is interested, I comment in more detail on this in early September at the blog that I invited Ian Forrester to visit (Note 5).

    1) see lead item, but see also comments on 8 June 2009 at 1.24, 12 June 2009 at 20.42, 21 June 2009 at 0.09, 23 June 2009 at 5.02, 24 June 2009 at 6.12
    2) see!ProfessorBarryBrook!_8478.aspx
    3) see
    4) see
    5) see

    Best regards, Pete Ridley, human-made global climate change agnostic.

    PS: Ian Forrester, I forgot to post the link.
    NOTE 1) see

  34. Hi Chris,

    I posted a reply to you (and to Gavin) on the thread ‘Muddying the peer reviewed literature’, but it looks like the RealClimate moderators may not let through (although they did let through another post I made at the same time, thanking you for your article on forcings & feedbacks).

    I’ve posted my reply for you below. I would of course greatly appreciate your thoughts on it. I can be reached via email at ‘oneuniverse’ at ‘’ .

    — Start Paste —

    #145: Chris, and Gavin (re: #130)

    For a given quantity of water vapor in a tropospheric column, different distributions of the water vapor will result in different magnitudes of the ‘greenhouse’ effect from the radiative absorption of IR by the water vapor.

    From IPCC AR4 Chapter 8, Box 8.1: Upper-Tropospheric Humidity and Water Vapour Feedback :

    “Tropospheric water vapour concentration diminishes rapidly with height, since it is ultimately limited by saturation-specific humidity, which strongly decreases as temperature decreases. Nevertheless, these relatively low upper-tropospheric concentrations contribute disproportionately to the ‘natural’ greenhouse effect, both because temperature contrast with the surface increases with height, and because lower down the atmosphere is nearly opaque at wavelengths of strong water vapour absorption.”
    “The radiative effect of absorption by water vapour is roughly proportional to the logarithm of its concentration, so it is the fractional change in water vapour concentration, not the absolute change, that governs its strength as a feedback mechanism.”

    The 3 papers under discussion found that the models do well at reproducing the total column integrated water vapor profile but have a systematic tendency to overestimate the moisture levels in the upper troposphere, and to underestimate them in the lower troposphere.

    Since the total amount is the nearly the same in models and observations, the presense of any extra water vapor in the upper troposhere (compared to observations) must correspond to a decrease of that quantity of water vapor in the lower troposphere.

    Since water vapor is present at much greater concentrations in the lower troposphere, a decrease of water vapor in the lower troposphere will diminish the greenhouse radiative effect in the lower troposphere by a much smaller amount than the greenhouse radiative effect in the upper troposphere will be increased for an increase of the same quantity of water vapor.

    This seems to show that models are overestimating the greenhouse warming from water vapor?

    — End Paste —

    Best regards,

  35. Chris, here is the abstract from Roger Taguchi’s revised paper. Roger has sent me a Wordperfect version of the entire document but I only have Word so cannot open it fully (the first few pages were OK).

    I’ll try and get the whole thing converted and pass on to you.

    Regards, Pete R

    According to “Without any feedbacks, a doubling of CO2 (which amounts to a forcing of 3.7 W/m2 ) would result in 1oC global warming, which is easy to calculate and is undisputed. The remaining uncertainty is due entirely to feedbacks in the system, namely, the water vapor feedback, the ice-albedo feedback, the cloud feedback, and the lapse rate feedback.” Here we show that the IPCC estimate of net feedback, namely 2oC (giving a total climate change of 3oC on doubling CO2 from 300 ppm to 600 ppm), is at least a factor of 4 too large when its prediction for climate change when CO2 increases from 300 ppm to 400 ppm is compared with real world temperature increases from 1750 to today. The generally accepted explanation for the greenhouse effect, which involves radiative exchange between CO2 molecules until infrared (IR) radiation can escape from a “220 K black body” layer in the upper troposphere, is seriously flawed. An alternative explanation is proposed for the outgoing IR radiation at the 667 cm-1 CO2 frequency measured by the NIMBUS satellites. It involves absorption by CO2 of incoming solar radiation at 2μ and 1.6μ, which excites molecules to higher vibrational levels of the bond-bending mode, followed by a downward cascade to the ground vibrational state. The most probable quantum jumps involve a change of 1 in the vibrational quantum number, resulting in emission of IR centered around 667 cm-1 and slightly lower frequencies (for v=3 to v=2 and for v=4 to v=3 transitions). In particular, this mechanism can explain the emission measured over Antarctica, which cannot possibly be explained by the standard textbook treatment and its variants. Once this is recognized, it becomes clear that the absorption by CO2 (as measured by the truncated spectrum) is underestimated by about 33%. Therefore the temperature change caused by CO2 alone (without feedbacks) is even higher, reducing the net feedback compatible with the historic record to nearly zero.

  36. I need your help. I am working on a blog post called How to Talk to a Conservative about Climate Change and would enjoy your comments to make this a better tool to use when faced with a conservative-leaning skeptic. The goal is to end up with something that we can all use. I need no credit – I want this to be a goup effort.

  37. Atmospheric CO2 levels have stayed higher than 350 ppm since early 1988.
    It is at 385.899 ppm during nov 2009.

  38. Hi johnroger, that’s an interesting number but I can beat it with 390.101 from – where was yours from? and what does it prove?

    Happy New Year to all.

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