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Good news for the earth’s climate system?

Filed under: — group @ 6 February 2010

Guest Commentary by Jim Bouldin (UC Davis)

How much additional carbon dioxide will be released to, or removed from, the atmosphere, by the oceans and the biosphere in response to global warming over the next century? That is an important question, and David Frank and his Swiss coworkers at WSL have just published an interesting new approach to answering it. They empirically estimate the distribution of gamma, the temperature-induced carbon dioxide feedback to the climate system, given the current state of the knowledge of reconstructed temperature, and carbon dioxide concentration, over the last millennium. It is a macro-scale approach to constraining this parameter; it does not attempt to refine our knowledge about carbon dioxide flux pathways, rates or mechanisms. Regardless of general approach or specific results, I like studies like this. They bring together results from actually or potentially disparate data inputs and methods, which can be hard to keep track of, into a systematic framework. By organizing, they help to clarify, and for that there is much to be said.

Gamma has units in ppmv per ºC. It is thus the inverse of climate sensitivity, where CO2 is the forcing and T is the response. Carbon dioxide can, of course, act as both a forcing and a (relatively slow) feedback; slow at least when compared to faster feedbacks like water vapor and cloud changes. Estimates of the traditional climate sensitivity, e.g. Charney et al., (1979) are thus not affected by the study. Estimates of more broadly defined sensitivities that include slower feedbacks, (e.g. Lunt et al. (2010), Pagani et al. (2010)), could be however.

Existing estimates of gamma come primarily from analyses of coupled climate-carbon cycle (C4) models (analyzed in Friedlingstein et al., 2006), and a small number of empirical studies. The latter are based on a limited set of assumptions regarding historic temperatures and appropriate methods, while the models display a wide range of sensitivities depending on assumptions inherent to each. Values of gamma are typically positive in these studies (i.e. increased T => increased CO2).

To estimate gamma, the authors use an experimental (“ensemble”) calibration approach, by analyzing the time courses of reconstructed Northern Hemisphere T estimates, and ice core CO2 levels, from 1050 to 1800, AD. This period represents a time when both high resolution T and CO2 estimates exist, and in which the confounding effects of other possible causes of CO2 fluxes are minimized, especially the massive anthropogenic input since 1800. That input could completely swamp the temperature signal; the authors’ choice is thus designed to maximize the likelihood of detecting the T signal on CO2. The T estimates are taken from the recalibration of nine proxy-based studies from the last decade, and the CO2 from 3 Antarctic ice cores. Northern Hemisphere T estimates are used because their proxy sample sizes (largely dendro-based) are far higher than in the Southern Hemisphere. However, the results are considered globally applicable, due to the very strong correlation between hemispheric and global T values in the instrumental record (their Figure S3, r = 0.96, HadCRUT basis), and also of ice core and global mean atmospheric CO2.

The authors systematically varied both the proxy T data sources and methodologicalvariables that influence gamma, and then examined the distribution of the nearly 230,000 resulting values. The varying data sources include the nine T reconstructions (Fig 1), while the varying methods include things like the statistical smoothing method, and the time intervals used to both calibrate the proxy T record against the instrumental record, and to estimate gamma.

Figure 1. The nine temperature reconstructions (a), and 3 ice core CO2 records (b), used in the study.

Some other variables were fixed, most notably the calibration method relating the proxy and instrumental temperatures (via equalization of the mean and variance for each, over the chosen calibration interval). The authors note that this approach is not only among the mathematically simplest, but also among the best at retaining the full variance (Lee et al, 2008), and hence the amplitude, of the historic T record. This is important, given the inherent uncertainty in obtaining a T signal, even with the above-mentioned considerations regarding the analysis period chosen. They chose the time lag, ranging up to +/- 80 years, which maximized the correlation between T and CO2. This was to account for the inherent uncertainty in the time scale, and even the direction of causation, of the various physical processes involved. They also estimated the results that would be produced from 10 C4 models analyzed by Friedlingstein (2006), over the same range of temperatures (but shorter time periods).

So what did they find?

In the highlighted result of the work, the authors estimate the mean and median of gamma to be 10.2 and 7.7 ppm/ºC respectively, but, as indicated by the difference in the two, with a long tail to the right (Fig. 2). The previous empirical estimates, by contrast, come in much higher–about 40 ppm/degree. The choice of the proxy reconstruction used, and the target time period analyzed, had the largest effect on the estimates. The estimates from the ten C4 models, were higher on average; it is about twice as likely that the empirical estimates fall in the model estimates? lower quartile as in the upper. Still, six of the ten models evaluated produced results very close to the empirical estimates, and the models’ range of estimates does not exclude those from the empirical methods.

Figure 2. Distribution of gamma. Red values are from 1050-1550, blue from 1550-1800.

Are these results cause for optimism regarding the future? Well the problem with knowing the future, to flip the famous Niels Bohr quote, is that it involves prediction.

The question is hard to answer. Empirically oriented studies are inherently limited in applicability to the range of conditions they evaluate. As most of the source reconstructions used in the study show, there is no time period between 1050 and 1800, including the medieval times, which equals the global temperature state we are now in; most of it is not even close. We are in a no-analogue state with respect to mechanistic, global-scale understanding of the inter-relationship of the carbon cycle and temperature, at least for the last two or three million years. And no-analogue states are generally not a real comfortable place to be, either scientifically or societally.

Still, based on these low estimates of gamma, the authors suggest that surprises over the next century may be unlikely. The estimates are supported by the fact that more than half of the C4-based (model) results were quite close (within a couple of ppm) to the median values obtained from the empirical analysis, although the authors clearly state that the shorter time periods that the models were originally run over makes apples to apples comparisons with the empirical results tenuous. Still, this result may be evidence that the carbon cycle component of these models have, individually or collectively, captured the essential physics and biology needed to make them useful for predictions into the multi-decadal future. Also, some pre-1800, temperature independent CO2 fluxes could have contributed to the observed CO2 variation in the ice cores, which would tend to exaggerate the empirically-estimated values. The authors did attempt to control for the effects of land use change, but noted that modeled land use estimates going back 1000 years are inherently uncertain. Choosing the time lag that maximizes the T to CO2 correlation could also bias the estimates high.

On the other hand, arguments could also be made that the estimates are low. Figure 2 shows that the authors also performed their empirical analyses within two sub-intervals (1050-1550, and 1550-1800). Not only did the mean and variance differ significantly between the two (mean/s.d. of 4.3/3.5 versus 16.1/12.5 respectively), but the R squared values of the many regressions were generally much higher in the late period than in the early (their Figure S6). Given that the proxy sample size for all temperature reconstructions generally drops fairly drastically over the past millennium, especially before their 1550 dividing line, it seems at least reasonably plausible that the estimates from the later interval are more realistic. The long tail–the possibility of much higher values of gamma–also comes mainly from the later time interval, so values of gamma from say 20 to 60 ppm/ºC (e.g. Cox and Jones, 2008) certainly cannot be excluded.

But this wrangling over likely values may well be somewhat moot, given the real world situation. Even if the mean estimates as high as say 20 ppm/ºC are more realistic, this feedback rate still does not compare to the rate of increase in CO2 resulting from fossil fuel burning, which at recent rates would exceed that amount in between one and two decades.

I found some other results of this study interesting. One such involved the analysis of time lags. The authors found that in 98.5% of their regressions, CO2 lagged temperature. There will undoubtedly be those who interpret this as evidence that CO2 cannot be a driver of temperature, a common misinterpretation of the ice core record. Rather, these results from the past millennium support the usual interpretation of the ice core record over the later Pleistocene, in which CO2 acts as a feedback to temperature changes initiated by orbital forcings (see e.g. the recent paper by Ganopolski and Roche (2009)).

The study also points up the need, once again, to further constrain the carbon cycle budget. The fact that a pre-1800 time period had to be used to try to detect a signal indicates that this type of analysis is not likely to be sensitive enough to figure out how, or even if, gamma is changing in the future. The only way around that problem is via tighter constraints on the various pools and fluxes of the carbon cycle, especially those related to the terrestrial component. There is much work to be done there.


Charney, J.G., et al. Carbon Dioxide and Climate: A Scientific Assessment. National Academy of Sciences, Washington, DC (1979).

Cox, P. & Jones, C. Climate change – illuminating the modern dance of climate and CO2. Science 321, 1642-1644 (2008).

Frank, D. C. et al. Ensemble reconstruction constraints on the global carbon cycle sensitivity to climate. Nature 463, 527-530 (2010).

Friedlingstein, P. et al. Climate-carbon cycle feedback analysis: results from the (CMIP)-M-4 model intercomparison. J. Clim. 19, 3337-3353 (2006).

Ganopolski, A, and D. M. Roche, On the nature of lead-lag relationships during glacial-interglacial climate transitions. Quaternary Science Reviews, 28, 3361-3378 (2009).

Lee, T., Zwiers, F. & Tsao, M. Evaluation of proxy-based millennial reconstruction methods. Clim. Dyn. 31, 263-281 (2008).

Lunt, D.J., A.M. Haywood, G.A. Schmidt, U. Salzmann, P.J. Valdes, and H.J. Dowsett. Earth system sensitivity inferred from Pliocene modeling and data. Nature Geosci., 3, 60-64 (2010).

Pagani, M, Z. Liu, J. LaRiviere, and A.C.Ravelo. High Earth-system climate sensitivity determined from Pliocene carbon dioxide concentrations. Nature Geosci., 3, 27-30

378 Responses to “Good news for the earth’s climate system?”

  1. 251
    Jimi Bostock says:

    Hey folks, could we get some more regular posts here, you seem to have dropped off. Perhaps a post on the BBC Q&A with Phil Jones. What do you all make of his answers?? Us deniers would really like to know what you make of all of this.

  2. 252
    Neil says:

    Seriously Jim, I enjoyed the class candor and humility of your post. I care a lot that we are not buggering the place up. I hope one day to take my kid to see these little critters–
    TO share the joy of discussing whatever evolution or creation narrative works for his inquisitive mind. When he asks, “Will they be there when I grow up?” Will my “yes of course” be a lie? Probably… Because, sadly, the siltation and pesticides will get them long before AGW does. But the money that could have created near shore refuges has gone to computer toads in dehra dun.
    Anyway, thanks again.

  3. 253
    Ray Ladbury says:

    Steckis cites Miskolczi’s defense of his clearly wrong paper and says:

    “I would respect him and his theory well above your amateurish attempts to discredit him.”

    See, now Richard, this is what I don’t understand. Miskolczi’s paper contains many absolutely amateurish mistiakes. His expertise is simply too narrow to take on the problem he took on. The real experts on climate modeling have pronounced his work not only wrong, but laughably so. He had to publish in an obscure journal on meteorology. And yet, Steckis, you, with absolutely zero understanding of the science, pronounce his theory has merit.

    Don’t you think that if this were so that at least one modeller somewhere would have seized on the result and thereby kicked the collective butts of his competition? Or that if Miskolczi were sufficiently knowledgeable to understand what he was writing about that he would have developed his own model and similarly kicked butt. And yet…bupkes.

    Two questions, Steckis.
    1)Why, if the research has merit, has it led nowhere?

    2)Is there any piece of denialist crap you won’t swallow?

  4. 254
    Jiminmpls says:

    #37 Ed

    You don’t counter a well-organized and well-funded disinformation campaign with more disinformation. Current weather patterns are consistent with an El Nino. The El Nino effects may be attenuated by global warming, just as gw may contribute to the increased intensity of hurricanes and other major weather events, but to say that the warmth in Vancouver is proof of global warming is every bit as wrong as the assertion that the cold and snow in the southeastern USA if proof of the absence thereof.

    I think making the NCDC State of the Climate reports more widely publicized would be a better means to counter the conspirators. Each monthly update should result in a series of press releases, blog articles, news program appearances, letters to the editor, etc. These efforts should be short on hyperbole and alarmism and long on the facts. Just a simple graphic like can have a very powerful effect if the general public would just see it.

    Bryan Walsh’s recent article in Time Magazine was quite good. Readily understandable and based on rational science.,8599,1962294,00.html Indeed, several recent articles in Time magazine have been quite good.

    Unfortunately, real news sources like Time have been largely drowned out by pop news like Fox. So yes, step up the publicity and public relations, but not with sensationalist lies and distortions.

  5. 255
    dhogaza says:

    Hey folks, could we get some more regular posts here, you seem to have dropped off. Perhaps a post on the BBC Q&A with Phil Jones. What do you all make of his answers?? Us deniers would really like to know what you make of all of this.

    You can’t read plain english?

    Denierthought is odd …

    Jones states his opinion that there’s insufficient proxy evidence for the SH to say for certain that there was not a global, synchronous MWP. Other scientists disagree.

    Denialists conclude: the existence of a global, synchronous MWP is hereby proved due to the previously loathed Jones stating uncertainty. Jones has admitted that AGW is false.

    Jones states that yes, there have been two relatively recent warming periods, mid-1800s and early 1900s, similar to the current one. He says nothing about attribution. However, later he says that warming in current decades differs because it can’t be explained in terms of changes in solar output or a period of reduced volcanic activity.

    Denialists conclude: Jones has admitted that AGW is false.

    It’s hilarious.

    So, Jimi Bostock, why don’t *you* tell *us* what you, personally, conclude. Help us with a little insight into the denialist mind. I really do not understand why a mainstream scientists making uncontroversial, conventional responses to questions has denialists in such a tizzy of excitement.

  6. 256
    L. David Cooke says:

    RE: 247/248

    Hey Uli,

    The main point to my limiting zones was to attempt to make it more representative of the Earth’s atmospheric heat content flow. With attempting to model every 10 degrees of latitude you may be enabling heat transfer; but, at the cost of modeling the source and sink, hence the flow path/rate.

    By reducing the zones and specifying the primary convective heat content source at Solstice at approximately 20 degrees and at the Equinoxes at roughly 0 degrees, it should be more accurate then a zone to zone hand off, IMHO. (Going further to suggest a heat flow block in the region of about 45 degrees goes towards splitting the heat flow both towards the Polar region and into powering the northern jet stream at the Polar convergence zone. I suspect the Ferrel Cell is the Earth’s answer to bridge this condition.)

    My main focus was to offer the suggestion of a simple Earth atmospheric model. To accomplish a Earth model: I was suggesting a reduction to a three zone model at the Solstices intended to model a “stable” state; Along with a five zone model which would be intended to model the Equinoxes or the “transition” state.

    The intent is to attempt to run eight different quarterly models, with one model run for the each season for each condition. Meaning, we would start with a winter “steady” state run and then advance the model through each quarter, each with seasonal initial conditions which includes a heat flow transition vector. You then perform a similar run of the “transition” state each with seasonal initial conditions, (such as differing heat content flow rates).

    With this data it should be possible to model source and flow more readily. If we were to go further to add the modeling of the changing zonal transfer based on the state of the seasons that should provide an even greater resolution to the model without complicating it.

    To incorporate the data into a fairly sophisticated model, the ability to interpolate and hand off or incorporate a bridging between a “steady state” and a “transitioning” model run might offer an easy way to replicate why you might get unusual conditions if the heat flow were delayed or increased and the zonal implications they might wrought.

    I guess the intent on my part was to model with the end in mind, with the intent being to create a simple model that would more readily provide a “trouble shooting” tool. As you may be the expert here I bow to your expertise.

    Dave Cooke

  7. 257
    Anton says:

    To talk about “sceptics” as the ones who will “seize” upon “evidence” of flaws is unwittingly to make global warming into a matter of religion and not science. It’s not the skeptics who look bad. “Seize” sounds willful, but science should motivate us to grab at evidence. It’s the nonskeptics who look bad. It’s not science to be a true believer who wants to ignore new evidence. It’s not science to support a man who has the job of being a scientist but doesn’t adhere to the methods of science.

  8. 258
    Ike Solem says:

    In other interesting news, the state of Utah is going the Kansas route on science, and has just passed a bill declaring fossil fuel emissions to be “essentially harmless.”

    A respected professor once told me, “science is politics” but I don’t think this is what she was talking about… more the struggle for grants and tenure, I think – not the actual determination of fact.

    It’s really strange, psychologically – as if the members of the Utah legislature think they can control nature and physics via the deliberative legislative process… is it mass insanity?

  9. 259
    simon abingdon says:

    #249 Completely Fed Up “[Water] will precipitate out of an airmass that is on average about 60% RH.”

    This sounds to me like a by-and-large figure applicable to airmasses of considerable extent. I should like to know if precipitation can occur when the local RH is less than 100%. Sorry if this is elementary.

  10. 260
    Ike Solem says:

    RE this discussion:

    A couple of folk have made the point that both the value of gamma and it’s time dependence depend on starting conditions eg level of glaciation, which makes me wonder to whether attempting to reduce CO2 feedback to a single constant is a simplification too far. Certainly seems to have confused me…

    [Response:Few parameters are scale independent. As long as you define the scale, you're fine--Jim]

    Yes, but if you’re making projections outside of your defined region of reliability, then you have to at least consider what might have been left out. Making careful measurements of the biosphere response to CO2 changes of a 5-10 ppm and expecting that response to remain constant as CO2 changes reach 100-500 ppm – that doesn’t seem to make much sense.

    [Response: They weren't making, or attempting to make, predictions, they were just providing a best estimate of the parameter for 1050-1800.--Jim]

    Anyone able to answer the point about what value of gamma is assumed in or derived from coupled climate/carbon cycle models and to what extent this study informs model development ?

    [Response: The models' average are just slightly higher than the median reported by the authors. About 6 of the 10 are within a couple ppm of it. Pretty good correspondence overall--Jim]

    Ah, the carbon models are all over the place, from 20-200 ppm,

    [Response: You're confusing the analyses by Friedlingstein et al., 2006, with my statement regarding the results of the analyses the authors did.--jim]

    and they appear to have different systematic biases as well – they can’t even agree on the role of the terrestrial biosphere vs. the oceanic biosphere when it comes to the carbon cycle.

    [Response: What's the point? There's lots of uncertainty in how these fluxes behave, yet the authors got quite good correspondence between empirical and modeled analyses.--jim]

    In reality, not only is there regional variability in gamma, there is temporal variability

    [Response: Of course there are spatio-temporal variations in gamma--I've made that point several times now. They're trying to estimate it at policy relevant scales given the best empirical data at hand.--jim]

    even species variability – the gamma factor for pines and for oaks and for tropical jungle all vary widely.

    [Response:What? We are talking about the global system here--there isn't even any such thing as a gamma for individual taxa, and if there were it wouldn't even apply here--completely wrong scale.--jim]

    Ask yourself this: What will a tree do in response to higher temperatures? Some will die, some will flourish – and the key variable might actually not be temperature, but rather water or nutrient issues, and the hydrological response to global warming is expected to vary hugely with region, right?

    [Response: Of course. None of this means you can't estimate a global average T effect on CO2.--jim]

    The conclusion from that and similar considerations is that a catch-all gamma is a pretty useless variable, and is poorly defined as well.

    [Response: Completely wrong! It is clearly defined--the change in ppm CO2 per degree T change. And how can you call useless something which indicates how much additional CO2 is likely to accumulate???--jim]

    Even the Charney sensitivity is of little use outside of benchmarking model performance, because it’s a global average – hence, if you try to make predictions of permafrost behavior based on Charney, you’re ignoring the fact that Arctic temperatures are rising far faster than equatorial and midlatitude temperatures

    [Response: I suppose, but who is doing so?--jim]

    - and there are further effects that could start to play major roles in biosphere feedback processes, including ocean anoxia, insect invasions, and Amazonian drought. Unlike the Charney estimate, the gamma estimate is confounded heavily by the biological response – so physical models that claim to produce estimates of “gamma” are just about useless.

    [Response: You really seem to have completely missed the point of this paper--jim]

    This is a long-standing problem in modeling in Earth Sciences, by the way – modelers would rather not deal with biological complexity, and so they often just ignore it or assume it doesn’t matter to long-term geological processes – hence, you get serious oversimplifications more often than not. Modeling an ecosystem has proven to be far more difficult than modeling a purely physical system (say, Mars or Venus), because of the highly variable behavior of living systems – and in such situations, real life data is more reliable.

    [Response: ??? What do you think the authors' data was, made up? You're against the very concept of gamma, against the models, and against these empirical analyses as well. I wonder how you think the science is supposed to procede?--jim]

    For an example of a data-based approach, see Zimov et al 2006, a separate Science paper on permafrost responses, which seems to indicate a feedback significantly greater than the 20-200ppm reported in the models. To me, it seems to be the more reliable paper:

    [Response: As I said elsewhere, it takes a village. Permafrost is but one element, and possibly not even the most important one, on the scales the authors are addressing--jim]

  11. 261
    Don Shor says:

    259 simon abingdon says:
    14 February 2010 at 11:35 AM
    #249 Completely Fed Up “[Water] will precipitate out of an airmass that is on average about 60% RH.”
    This sounds to me like a by-and-large figure applicable to airmasses of considerable extent. I should like to know if precipitation can occur when the local RH is less than 100%. Sorry if this is elementary.

    RH is 100% where the rain is forming, but not necessarily where you are measuring it on the ground. Or, as Wikipedia puts it:
    “For clouds to form, and rain to start, the air doesn’t have to reach 100% relative humidity at the Earth’s surface, but only where the clouds and raindrops form.”

  12. 262
    Tom Dayton says:

    cce has got his excellent site The Global Warming Debate back up, but in a new place: The link to it in the RealClimate sidebar needs updating to that address.

    (Sorry for the off topic comment, but the Unforced Variations was closed. Don’t hesitate to delete this comment.)

  13. 263
    Ray Ladbury says:

    Science requires us to consider evidence. Anthropogenic climate change has evidence in thousands of peer-reviewed papers and over a period of about 110 years. Where is yours?

  14. 264
    Ray Ladbury says:

    Ike Solem says: “In other interesting news, the state of Utah is going the Kansas route on science, and has just passed a bill declaring fossil fuel emissions to be “essentially harmless.””

    Next up, they’ll pass a bill declaring pi to have the value of 3, following up on the Indiana legislature…

  15. 265
    Martin Vermeer says:


    what’s pi in Utah?


  16. 266
    flxible says:

    Simon – This sounds to me like a by-and-large figure applicable to airmasses of considerable extent. I should like to know if precipitation can occur when the local RH is less than 100%
    “Can occur” doesn’t mean “will occur”. Do you pay any attention to your local weather report [not "prediction"]? Where I live, we regularly register less than 100% RH in the rain, and sometimes show 100% when it’s not raining. Although of course, those reports may be for areas of “considerable extent” and is much tied up with other factors. Watch the dew point, and see here

  17. 267
    Ken W says:

    Ian (225),

    You seem to be embracing the fallacy that a consequence can only have 1 cause. That’s simply not true. Yes, we know there have been hot times on our planet before we ever had SUV’s or coal power, but that in no way discounts the evidence that the current warming is caused by SUV’s and coal power …

    We are quite certain that many forest fires (natural events) were caused by lightening before humans ever migrated to North America. Does that mean we can’t attribute human cause to any modern forest fires? Of course not! Such an idea is clearly silly. Yet the same concept is embraced by many deniers of global warming.

  18. 268
    matt says:

    DARPA just released a game-changer! Algae-Diesel produced for less than $3 a gallon and its only 2 years away from full-scale deployment.

  19. 269
    NoPreview NoName says:

    simon: Ray suggests there’s a convergent infinite series somewhere (where exactly?)

    A completely made up example: Say a 1 K increase in temperature raises the water vapor content of the atmosphere by 1%, and that increase raises the temperature by 0.1 K, which then increases the water vapor by 0.1%, etc. This is a convergent series, and the additional warming due to water vapor feedback from the initial 1 K will be 0.111…, or 1/9 K. Positive feedback, but not runaway.

  20. 270
    Jim D says:

    Re: 238. Simon, it is established that water vapor alone does not have a sufficient feedback factor to cause a runaway effect, but instead leads to about a doubling of the initial temperature forcing. Mathematically a feedback factor of f, gives a feedback of 1/(1-f), which is the sum of the infinite series. For f<1 it is not a runaway effect. For water vapor it might be about 0.4 globally-averaged (Held and Soden 2000), assuming RH is fixed. Global mean RH is established by dynamics (distribution of ascending and descending areas), and as a percentage is unlikely to change as much as water vapor with increasing temperature, so the fixed RH assumption is a good approximation, leaving the Clausius-Clapeyron effect dominant. (I might even argue that RH could decrease slightly as the oceans warm more slowly than land areas, but that is just my opinion).

  21. 271
  22. 272
    Doug Bostrom says:

    Ike Solem says: 14 February 2010 at 11:16 AM

    ‘In other interesting news, the state of Utah is going the Kansas route on science, and has just passed a bill declaring fossil fuel emissions to be “essentially harmless.”’

    The unequivocal definition of C02 as a pollutant will be a major defeat for fossil fuel interests. They’re acutely aware of the stepwise shift in perceptions that will arise from identifying C02 as an effluent needing active management. That’s why we’re seeing such an exaggerated response to this issue in the Senate and elsewhere.

    Unlike CFC management, C02 is neatly amenable to muddying in the public mind as it’s a natural constituent of the atmosphere.

    C0 is also present in the atmosphere as a naturally occurring component, but that did not stop us from recognizing excessive quantities as a pollutant and thus engaging in a major engineering effort to fix the problem of tailpipe emissions of C02.

  23. 273
    Matt says:

    Not entirely sure where I should post this, but as a non-scientist I’m having trouble providing counter-arguments to my friend, who is a left-wing sceptic.

    He has just made his case here:

    If someone with more scientific knowledge can help rebut some of his claims, I’d be grateful. Thanks!

  24. 274
    Brandon Sheffield says:

    Phil Jones of the CRU admits their is no warming, and has recently discredited Mann (Hockey Stick). I fear the world will swing the other way on Global Warming now that this has happened.

    [Response: Baloney, he has said no such things.--Jim]

  25. 275
    Lynn Vincentnathan says:

    RE #230 & others, OK, so the sun will not go supernova, but only become a big red hot ball before it self-destructs, and it will take some 5 billion years to do that, the earth going Venus in 1 to 2 billion years (thanks, Edward, for the heads up on this),…

    …the general idea is what’s important, that the sun is slowly getting hotter, and in that respect things are different from the end-Permian great warming or even the PETM, compared to what we are triggering now (among other differences).

    Now on to the real issue — we humans are likely causing a horrible mass extinction event, perhaps even total life-on-earth extinction. And people are busy critiquing others for not dotting their i’s and crossing their t’s, sort of fiddling while the earth burns, so to speak, or worse, totally denying the whole thing.

    “Evil” might not be a term used in psychology, but I feel funny about “medicalizing” or “psychologizing” away into some cubby-hole our human behavior and human nature — a nature that has probably always been there, only our toys were not as dangerous in the past.

    Even “evil” seems to fall short of what we are in this context. So too “diabolical.” It’s some form of “bad,” but we just don’t have a word for it. Sort of like “global warming” and “climate change” totally fail as words to describe what’s happening.

  26. 276

    BPL: If you think there is any scientific merit at all to Miskolczi’s jackass paper, you are a scientific illiterate.

    RS: Miskolczi argues his point at

    I would respect him and his theory well above your amateurish attempts to discredit him.

    BPL: Can you point out a mistake in my calculations or arguments? If not, why should I care what you think?

  27. 277

    RS: Human nature is not inherently evil.

    BPL: Wasn’t created that way, but we fell.

  28. 278
    Completely Fed Up says:

    ” I should like to know if precipitation can occur when the local RH is less than 100%.”

    [edit], do you know that it gets colder as you rise through the air?

    Did you know that as the temperature of the air drops, the amount of water it can hold is reduced?

    Did you know that RH is the amount of vapour held in water compared to the maximum amount of water that such vapour could hold?

    See those rain clouds [edit]?

    Up there, in the sky?

    With the rain coming from them?

    It’s 100% RH there.

    But not where you’re standing.

    Because the clouds are “up there” (cf earlier about it being colder the higher up you are) and you’re “down here” (ditto).

    [edit - if you are going to answer a question, just answer a question. Juvenile name-calling and excessive sarcasm are not required. If you don't want to answer a question, then don't]

  29. 279
    Completely Fed Up says:

    Sniffle. Neil’s heartwarming story. Sob.

    “But the money that could have created near shore refuges has gone to computer toads in dehra dun.”

    Oh, how about instead of spending billions on armaments (including nuclear), how about creating a near shore refugee for the poor little things?

    Heck, not spending 0.1% would given plenty of dosh for such a sad, heartrending tale of woe to be avoided.

  30. 280
    L. David Cooke says:


    Hey JimD,

    I suspect though that RH will not be stable. Just as the Dew Point rises in the face of seasonal change so will the global dew point rise in the face of GW as well as a slight drop in vapor pressure. The point is unless you change the physics of water, everything else around it will change… If you lift the GAT you would likely lift the Dew Point and the RH. Looking at the Devonian, Carboniferous and Permian relationships between GAT, Ocean Depths, RH, CO2 and O2 it is likely that RH is not stable in the face of changing GAT. (Worst case Ocean Level estimates?: Haq, B. U. (2008). “A Chronology of Paleozoic Sea-Level Changes”. Science 322: 64–68. doi:10.1126/science.1161648 )

    As the main balance of the Carbon in the atmosphere being introduced to the atmosphere today was laid down in the Carboniferous, at best we might return to the climate then when the CO2 levels were near 800ppm CO2 and the GAT was 14 Deg. C greater then current. When we look at the carbon recovery in from most mineral/fossil carbon mining/drilling running about 50% and coupled with the millennial of sequesteration of CaCO3 in the oceans, it is likely that the CO2 that will be returned to the atmosphere by man in this epoch may not exceed 35-50% of the carbon that was present in the Devonian period.

    (This as opposed to the Devonian with 2200ppm CO2 and a 20 Deg. C greater GAT and the Permian with 900ppm CO2 and 16 Deg. C GAT greater then current.) 540 – 65 Myr BP : Royer, Dana L. and Robert A. Berner, Isabel P. Montañez, Neil J. Tabor, David J. Beerling (2004) CO2 as a primary driver of Phanerozoic climate GSA Today July 2004, volume 14, number 3, pages 4-10. , )

    If you have better references that the RH would be stable I would be interested…

    Dave Cooke

  31. 281

    kai: the attribution to CO2 by default (because we can not find something else) is much less convincing.

    BPL: Nobody’s doing that. We expect global warming because CO2 is a greenhouse gas and CO2 is rising. Ditto methane and nitrous oxide. It’s a matter of radiation physics, not climate correlations.

  32. 282


    Thanks, I’ll look into that. I think you’ve hit the nail on the head–the weakness in the model is the parameterization I’m using for inter-latitude heat exchange. If I can make that more realistic, it should help.

  33. 283
    simon abingdon says:

    #270 Jim D

    Jim, thanks for your reply. I’m too far out of my depth on this to have an informed opinion, but when you say “Global mean RH is established by dynamics … and as a percentage is unlikely to change as much as water vapor … so the fixed RH assumption is a good approximation. [But] RH could decrease slightly as the oceans warm … that is just my opinion” I do not get the comfortable feeling that I’m listening to the confident findings of a well-established scientific discipline. Sorry if I sound like a Doubting Thomas.

  34. 284
    David B. Benson says:

    L. David Cooke (223) & simon abingdon (240) — Yes, there are all those other factors but CCNs are in more than ample supply everywhere except maybe Antarctic interior, where it doesn’t matter. It does seem than globally and averaged over a year that RH has remained nearly constant as has global precipitation.

    What little I know about this began with reading CaltechWater.pdf, available from Ray Pierrehumbert’s web site. If you read that you’ll know what I do (other than some preciptation products).

  35. 285
    David B. Benson says:

    For quite a variety of commenters here today, it would help if they carefully read the decadal averages from the GISTEMP global temperature anomaly product. BPL computed these and I added the plus signs to remove any ambiguity.
    1880s -0.25
    1890s -0.26
    1900s -0.27
    1910s -0.28
    1920s -0.16
    1930s -0.03
    1940s +0.04
    1950s -0.02
    1960s -0.01
    1970s +0.00
    1980s +0.18
    1990s +0.32
    2000s +0.51
    Do note that it has been really warming up for the past 30 years.

  36. 286
    Doug Bostrom says:

    Matt says: 14 February 2010 at 2:01 PM

    That’s a pretty funny writeup and indeed shows how science is not fundamentally political. Arguments parroted by a person leaning right are equally hollow when regurgitated by a left winger.

    Dr. Easterbrook, again. What a hoot.

    There’s nothing new there, the only novelty is the perspective of the author.

  37. 287
    Completely Fed Up says:

    “Even “evil” seems to fall short of what we are in this context. So too “diabolical.” It’s some form of “bad,” but we just don’t have a word for it. Sort of like “global warming” and “climate change” totally fail as words to describe what’s happening.”

    How about “inhumane”?

    We’re supposed to be “seriously wise man”.

    Definitions of wise on the Web:

    * having or prompted by wisdom or discernment; “a wise leader”; “a wise and perceptive comment”
    * a way of doing or being; “in no wise”; “in this wise”
    * judicious: marked by the exercise of good judgment or common sense in practical matters; “judicious use of one’s money”; “a wise decision”
    * knowing: evidencing the possession of inside information
    * wiseness – wisdom: the quality of being prudent and sensible
    * wiseness – wisdom: the trait of utilizing knowledge and experience with common sense and insight

    Ergo the opposite of this is the opposite of “seriously wise man”.

    Ergo, inhumane.

  38. 288
    Completely Fed Up says:

    Matt says:
    14 February 2010 at 2:01 PM

    Not entirely sure where I should post this”

    Get him to read this


  39. 289
    Edward Greisch says:

    254 Jiminmpls: No dispute. I agree with you. I think the RC people are smart enough to add all the caveats, tell only the truth and STILL attract attention to the subject of global warming with a headline that involves the olympics and Vancouver. For example:
    Don’t you think the Olympic Committee should have picked Resolute Bay or Yellowknife? ;) ;) Not. But they could have picked a place that was more certain to be colder.

  40. 290
    Completely Fed Up says:

    And reading that “story” I wonder who could possibly be reading this with an open mind and not find it completely vacuous.

    Starts off with “there is a consensus that AGW is happening and this shows you need good evidence to say it isn’t”.

    Meanders into nothing about the science, just how you should be scared if you state openly that AGW is happening.

    ‘cos you could be *wrong*.


    Then it states that there are some scientists against AGW.

    Proposes that this is good enough to make you skeptical of the consensus. Yet this is not (as he earlier stated you had to have) good evidence that AGW is wrong.

    Then complains that the idea has been heavily politicised.

    Well duh.

    Those against AGW have gone running to the public and the politicians calling out how they’re being joe-jobbed. This politicisation happened not from the IPCC scientists, but from the political pundits against AGW mitigation.

    And is nonetheless not a reason why the science is wrong.

    Then brings up a few choice and unsupported statements about how temperatures have peaked (which, even if it were true, is correlation, not causation. But it’s not even true).

    Still not a reason why AGW is wrong.

    Then states of his own violition:

    “The HadCRUT3 data on global temperature actually shows a halt in global warming in this decade. That is to say, the trend line in temperature is flat.”

    When this is not seen.

    Unless you cherry pick your points just as he cherry-picked his dataset (GISS would have shown 2005 warmest. Hardly supportive of a peak in 1998).

    Then states that one dissenter is right, when many others say he’s wrong. Yet he stated right at the beginning that a consensus was the right thing and that ignoring it required solid proof.

    Yet here one lone non-consensus voice is not undermined by a greater number of voices counter to his.

    Strange how the undermining only happens one way, isn’t it?

    “I can’t stress enough the last sentence I quoted above:”

    Indeed he can’t.

    is entire thesis is based on misrepresenting others words as long as they are ones that can be led to say AGW is not happening.

    In no ways is a pause a peak in temperatures.

    He didn’t stress his own collection of statements enough, did he.

    Like contrasting his “it’s peaked” story with “even the AGW scientists say it’s paused”.

    I guess he can’t emphasise denialist talking points enough, because he doesn’t want you to hear what he’s saying, he wants you to buy what he’s selling: Be Scared Of Stating AGW Is Real.

    Again back to his own statements:
    “The IPCC predicted a 0.2 °C temperature rise in this decade. That has not happened. ”

    And the last decade was 0.17C warmer than the previous one.

    Indeed this is not 0.2C, but I don’t see it as proof the prediction was wrong.

    “Nor did the climate computer models predict the flat trend.”

    No, because there hasn’t been one.

    Adding weather on to climate you can get years where there has been no higher temperature some years after a local peak. But if we looked at 1935 and said that it was now cooling, would we have looked stupid today?


    Weather is not climate.

    And a trend is not the difference between two data points.

    Something else he refrained from emphasizing.

    He rounds up with:

    “These developments are clearly a completely legitimate argument for questioning the current consensus on global warming.”

    Except he hasn’t actually shown, as he stated was necessasry to do this at the beginning that:

    “the burden of proof is squarely on you to try and justify criticism of an accepted theory”.

    I also note he still doesn’t have one to explain the temperature history nor his future prediction of no more warming.

    Einstein didn’t say “Newton was wrong ‘cos Mercury’s orbit is well bent”.

    Einstein came up with a theory that explained Newton’s laws and Mercury’s orbit BETTER.

    To *appear* even handed, he dismisses solar changes. But then comes out with this humdinger:

    “But there are dissenting scientists who have proposed that ocean oscillations – notably, the El Niño-Southern Oscillation (ENSO) and, above all, the Pacific Decadal Oscillation (PDO) – are the major causes of climate change”

    So where does that extra energy come from to engender century long changes in total energy budget of the earth’s atmosphere?

    And how does ENSO/PDO cool the stratosphere?

    Funny how he’s all over “problems” with AGW science but he’s completely blind here.

    He then brings up Roy Spencer, a man willing to let the bible trounce his science if they come into conflict.

    He then rounds up with three damning pieces of “evidence”:

    (1) it is widely reported that there has been a flat trend in global temperatures since 1998 (which is recognised in the peer-reviewed scientific literature);

    Except it isn’t recognised:

    or the APS’s blind test on statisticians

    (2) the IPCC’s predictions for the 2000s are wrong, and

    Except we’ve already seen that, except in the trivial sense of wrong, they weren’t/

    (3) a major study by climate scientists attributes one third of the warming of the 1990s to water vapour and the stall in the temperature rise from 1998 to less water vapour in the atmosphere.

    Doesn’t give a climate change, only weather changes.

    He tries to play the even-handed card again:

    “Note that this does not mean that long-term warming of the planet has stopped. ”

    So what are we supposed to be sceptical of from the IPCC, then?

    “But that falls far short of the warming predicted by the IPCC”

    Uh, we’ve already done that.

    ” – and it will not be catastrophic.”

    Can ***anyone*** say where this is shown by anything in his tale or the linked papers he applies as his argument?

    ‘cos I can’t see it.

    “In view of all this, it seems perfectly legitimate to question the AGW thesis. ”

    May I contrast this with his statement only a few lines earlier:

    “Note that this does not mean that long-term warming of the planet has stopped.”

    I’m getting tired of reading this pish, but he goes on about how the hockey stick is broken and cites three papers or blogwrites that say so but none of the reports that show it’s still solid.

    He’s turned off now into full-on dittoheading.

    I suspect he knows that anyone still reading from this point on is a believer like him and don’t care to think about what he’s saying, they’ve bought the message.

  41. 291
    Jim D says:

    Re: 283. Simon, water vapor may change about 6% per degree C. The only way RH changes could be significant is if they change by similar amounts as a global average. While the water vapor response has a solid scientific base, there is no reason to think RH could change significantly enough in either direction to affect this 6% much. Changes in RH would have consequences for cloud cover, and this is all part of the cloud feedback issue, which is far from quantified, and independent of the somewhat established water vapor feedback. Is the cloud feedback as large as the vapor feedback? It is hard to even say what sign it is, since it is opposite for high and low clouds, so I suspect not, but this is where the debate continues.

  42. 292
    Jim D says:

    Re: 280. David, yes, but the context about RH being near constant is relative to the water vapor increase of 6%/degree, and for near-future climate change amounts of a few degrees. So we can take Clausius-Clapeyron as a good guideline for water vapor feedback.

  43. 293
    Jim D says:

    Re: 273. Tell your friend to look at decadal averages (e.g. post #285 here). The 2000′s is the warmest decade, despite the so-called plateau. The 2010′s are quite certain to be warmer still. The earth is warming and the increasing CO2 can explain it very well. Denialists first have to explain (i) why CO2 isn’t, then (ii) explain what else has been, causing it. The first of these is going to be hardest to refute since it is deeply rooted in physics. If we already have an explanation for observed warming in terms of observed CO2, why look for something else? Can it really be that simple? Yes. Can we use this to help predict the future in some way? Why not?

  44. 294

    What Jones should have said (BBC interview) about the 19th century is that there is no statistically significant trend over that period (1850-1899 t-test on correlation coefficient p = 0.44).

    On decadal trends, if you really want to cherry-pick your data, HadCRUT3 shows a 4.4K per century decline over 1878-1887.

    Start of an ice age? No, more like an indication of how sharp short-term variation can be compared with the scale of the long-term trend we are looking at today, around 1.5K per century. Add that trend on to the 19th century, and you’d still have a decline of 2.9K/century over that period. Even if you double the current trend to 3K/century and add it to that period, you still get “cooling” of 1.4K/century.

    Relate that now to the rather trivial slowdown in warming we’ve seen over the last decade. Clearly this sort of “analysis” is rubbish.

    Meanwhile the last issue of Guardian Weekly (which I subscribe to as a counter to the dross that passes for news in Australia) to reach me reprinted the atrocious Fred Pearce article. This really is substandard: it’s hard to believe they had not picked up feedback from its publication in the daily that it’s severely flawed. I blasted them with a letter ending “PS: has Rupert Murdoch bought The Guardian?”. The letter’s a bit long to post here but if anyone’s interested I’ll put it up on my blog.

    [Response: I'm working on a longer piece on the Guardian series. Some time this week. - gavin]

  45. 295
    David B. Benson says:

    Jim D (292) — Well, global precipitation seems to be holding constant so far, or nearly so, despite the prediction from water vapor increase of about 6%/K. So possibly RH has been declining slightly so far? No evidence for that AFAIK.

    Under some scenarios, this is all supposed to change, rathr drastically, by 2080 CE; see IPCC AR4 WG1 chapter 10.

  46. 296
    Jim says:

    Ike Solem: inline comments to #260 added.

  47. 297
    Jim D says:

    Re: 295. David, precipitation is a throughput (or flux) measurement of water, while atmospheric water vapor is a reservoir, so it is quite possible for the water flux from/to the atmosphere (precip and surface evaporation) to remain near constant while water vapor increases. The reservoir change would result from surface evaporation exceeding precip by a probably imperceptible amount relative to their sizes. Even 6% would amount to only about a 1 or 2 mm extra liquid equivalent in the atmosphere. I don’t think this can tell us anything about RH.

  48. 298
    David B. Benson says:

    Jim D (297) — That was clarifying, thanks.

  49. 299
    L. David Cooke says:

    RE: 297

    Hey Jim D,

    I don’t know, given the difference in vapor pressure and the mass/m^3 it would look like the 6%of RH/1K value may be worth revisiting. To see an 800% in water mass/m^3 change for doubling the GAT of say around 20 Deg. C would seem to suggest 40%/Deg. C. (Based on; ref: 2-14-2010) In essence, something must be happening in the atmosphere if as David Benson suggests that the RH actually seems to be decreasing in the atmosphere with the generally accepted 0.5+/-.15 Deg C GAT increase over the last 30 years. (At least in the Stratosphere… We also have to be careful of the assumption that precipitation started where the dew point and the adiabatic temperature of water vapor match up, coming out of the atmosphere. As we have the potential of partial to complete evaporation of the precipitation such as Virga…; but, I digress…)

    The point I was wanted to point to in my earlier references of the Paleozoic Sea Levels were that as a reservoir there appeared to be 120 meters below current. If the difference between 2000ppm CO2 and 800ppm CO2 is 120 meters would that suggest 10ppm of CO2 equates to the reduction of the Sea Level of one meter. Given this and the gamma of 10ppm/deg. K, would this then suggest 10ppm CO2 to 1 meter of Sea Level loss and not gain? This would seem to suggest a addition of 1000kg of water to the atmosphere for every square meter of the Earth’s Oceans surface. Is this estimate accurate, I do not think so; however, if my macro comparison were accurate it would seem to suggest the 6%RH/1 Deg. K is questionable. As I am unfamiliar with Clausius-Clapeyron would you care to discuss it in more depth?

    Dave Cooke

  50. 300
    Lynn Vincentnathan says:

    #277, Barton &

    RS: Human nature is not inherently evil.
    BPL: Wasn’t created that way, but we fell.

    Yes, that’s right. Even from a purely evolutionary science pt of vw, nonhuman animals are not evil — they just act according to their intincts and nature, which is amoral.

    We humans KNOW BETTER. We have evolved to the point of being able to create moral systems. We understand right and wrong, tho these be culturally defined, but most of world’s peoples I imagine subscribe to cultures that consider willy nilly killing and harming people, children, future generations to be wrong; many would considering killing off (causing to go exinct) other life forms in such a way also to be wrong.

    Language has helped us discuss and consider the past and imagine and project into the future. We have developed science to help us understand all the more what’s going on. We have Pascal’s wager to help us decide and avoid the false negative on this issue (even if one does not accept the science on AGW completely). We have our mothers who told us to be good. We have our children and progeny who need us to leave them a viable world.

    So there’s absolutely no excuse for us not to mitigate AGW, especially no economic or political excuse (not to mention no moral loopholes), since a large portion of measures make good economic sense, and any political remedy (in the form of taxes, incentives, or structural facilitation, better public transportation) would be like some beneficial innoculation to prevent a terrible disease, and would (if AGW can be mitigated enough) help prevent the political upheavals — war, warlords, totalitarian clampdowns, amid chaotic conflicts, a vicious, killer musical chairs over diminishing life-sustaining resources — the very political and economic ruinous things the denialists fear.

    So it really beats me what the problem is in accepting the AGW science and mitigating AGW. If it isn’t fallen, evil human nature, it must be the devil. And the only weapon effective against the devil is humility, but our fallen human nature makes humility really tough. It’s like the evil syndrome meets the Venus syndrome.

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