Yet another denier talking point melts down

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"Yet another denier talking point melts down"

Denier talking points are harder to kill than vampires. They keep rising from the dead no matter how many times scientists try to drive a stake through their heart.

t1000.jpgSometimes they take on a slightly different form, like a relentless, indestructible liquid-metal android assassin from the future that constantly switches appearance in an effort to fulfill its mission of ruining life on this planet for homo “sapiens.”

And so it is with one of the most enduring denier myths, that the satellite data didn’t show the global warming that the surface temperature data did. When this myth was exposed as bad data analysis by scientists at the University of Alabama in Huntsville, it morphed into a narrower claim about supposed discrepancies between the modeled and observed rate of warming in the tropical troposphere — a claim which itself was quickly debunked (see “Should you believe anything John Christy and Roy Spencer say?“). But since that debunking did not come in a peer-reviewed publication, the myth lived on for hard-core deniers.

The fatal blow has come in the form of a new paper, “Consistency of modelled and observed temperature trends in the tropical troposphere,” (subs. req’d, RealClimate post here, and a fact sheet with everything you could possibly want to know about the study in laymen’s language here). The International Journal of Climatology article has 17 authors, including some of the top climate scientists in the country. Its bottom line:

Using state-of-the-art observational datasets and results from a large archive of computer model simulations, a consortium of scientists from 12 different institutions has resolved a long-standing conundrum in climate science — the apparent discrepancy between simulated and observed temperature trends in the tropics. Research published by this group indicates that there is no fundamental discrepancy between modeled and observed tropical temperature trends when one accounts for: 1) the (currently large) uncertainties in observations; 2) the statistical uncertainties in estimating trends from observations. These results refute a recent claim that model and observed tropical temperature trends “disagree to a statistically significant extent”. This claim was based on the application of a flawed statistical test and the use of older observational datasets.

I would say “Ouch” or “D’oh” but since the “et al” in the original flawed Douglass et al paper included the likes of John Christy and S. Fred Singer, the more appropriate one word response is probably “Duh.”

The fact sheet has a very interesting figure:

tropics.jpg

Estimates of observed temperature changes in the tropics (30°N-30°S). Changes are expressed as departures from average conditions over 1979 to 2006. The top panel shows results for the surface and lower troposphere. The thin red and black lines in the top panel are 12-month running averages of the temperature changes for individual months. The thick straight lines are trends that have been fitted to the time series of surface and tropospheric temperature changes. The warming trend is larger in the tropospheric temperature data than in the surface temperature record, in accord with computer model results. The bottom panel shows a commonly-used index of El Ni±o and La Ni±a activity, consisting of sea-surface temperature changes averaged over the so-called Ni±o 3.4 region of the tropical Pacific. The bottom panel shows that much of the year-to-year variability in surface and lower tropospheric temperatures is related to changes in El Ni±os and La Ni±as.

In short, “El Ni±os and La Ni±as introduce considerable year-to-year variability [or noise] in surface and tropospheric temperature” superimposed on the underlying warming trend. The authors note:

The underlying “signal trend” is what we really want to compare in climate models and observations. Any meaningful statistical test of the differences between modeled and observed temperature trends must therefore account for the statistical uncertainty in estimating this “signal trend” from noisy observational data. The Douglass et al. test did not account for this uncertainty.

Ouch D’oh Duh.

The Real Climate post ends by noting:

Taking a slightly larger view, I think this example shows quite effectively how blogs can play a constructive role in moving science forward (something that we discussed a while ago). Given the egregiousness of the error in this particular paper (which was obvious to many people at the time), having the initial blog posting up very quickly alerted the community to the problems even if it wasn’t a comprehensive analysis. The time in-between the original paper coming out and this new analysis was almost 10 months. The resulting paper is of course much better than any blog post could have been and in fact moves significantly beyond a simple rebuttal. This clearly demonstrates that there is no conflict between the peer-review process and the blogosphere. A proper paper definitely takes more time and gives generally a better result than a blog post, but the latter can get the essential points out very quickly and can save other people from wasting their time.

Blogs rule!

Kudos to Gavin Schmidt and all of the authors of this excellent paper. Jeers to the climate terminators deniers.

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17 Responses to Yet another denier talking point melts down

  1. albert says:

    Regarding your putting “sapiens” in quotes:

    I think maybe it was author Sue Hubbell who suggested we be renamed “Homo mutans” because we insatiably change everything — without thinking.

  2. Rick says:

    “bad data analysis by scientists”

    thats the sort of phrase that makes people shrug and say “who knows about this whole global warming thing anyway?”

  3. Joe says:

    They are scientists, but they are among the ranks of the few remaining discredited global warming deniers. If you had read any of the links, you would have seen that it just so happens that they screwed up their analysis in precisely the fashion that needed to confirm they are mistaken views about global warming.

  4. Joe says:

    Albert — We’re so insecure or egotistical that we called our subspecies Homo sapiens sapiens.

    I suppose it bears repeating that we are the only species that got to name itself. is there any doubt that if other species had to vote on the name for us, it wouldn’t have one “sapiens” let alone two!

  5. Brian D says:

    Rick: The “but they are scientists!” claim is one of the easier ones to debunk, should that show up. (Check the comments on that link too; it’s quite a good read.) I do agree that Joe should probably have used a qualifier, though I can’t think of any which would be both (indisputably) accurate and appropriate.

  6. David B. Benson says:

    Joe — ‘Homo sapiens sapiens’ is an older term for modern humans; the current term is just ‘Homo sapiens’. The earlier forms of humans now have their own species name; the Latin form for ‘Heidelberg man’ comes to mind as an example, but I don’t recall how to spell it.

  7. Mark Hadfield says:

    Fatal blow? If only. You underestimate the indestructibility of liquid-metal android assassins from the future. In this case I expect the response will be, “You’re saying the models agree with the observations only because of the large uncertainties in both? What sort of proof of the models is that?” (Cf Pielke Jr.)

  8. john says:

    David — so we’ve dropped a sapiens from our name? — None too soon, I’d say.

  9. Raven says:

    Mark hit the nail on the head. Defending the models by insisting that virtually any possible temperature profile is ‘consistent with’ the models only demonstrates that the models have no useful predictive value.

  10. Dano says:

    Defending the models by insisting that virtually any possible temperature profile is ‘consistent with’ the models only demonstrates that the models have no useful predictive value.

    Poor Raven needs to move the goalposts to keep his ideology viable.

    Young Raven, please go here and tell us specifically which models (or ensembles) have no predictive value.

    And let us all know when you are going to publish your Galileo-like paper stating such, and showing those darn dirty warmers a thing or two!!!!!!

    Best,

    D

  11. Raven says:

    Poor Dano,

    Has to trot out phrases like “moving the goal posts” to cover his own ignorance. I have long said the models have no predictive value and the only think that has changed is there is peer reviewed research that admits that too.

    The paper in question simply rehashes the argument originally presented on RC when the Douglass paper came out. The RC argument was debunked here: http://www.climateaudit.org/?p=3058#comment-305420

    The important step that Douglass followed which RC left out was he first removed all model runs which are obviously wrong because they could not get the surface temperature trends right.

  12. Dano says:

    I have long said the models have no predictive value and the only think that has changed is there is peer reviewed research that admits that too.

    The world anxiously awaits this Galileo-like paper that you, young Raven, surely are ready to publish, right? After all, you have knowledge that others don’t. You have a duty to teach the world, lad. And shut up all those green nazi warmer eh-gee-dubya religious priest adherent something-or-others.

    Like I said, let us all know here when your manuscript is accepted. Because as we all know (except for a brave young lad, apparently), that is how knowledge is shared with the world.

    Best,

    D

  13. Raven says:

    Dano,

    A number of papers have been published on the limitations of the models. The only issue is too many people ignore these papers and insist that the models should be assumed to be useful despite these rather glaring problems.

    In any case, the ultimate test for a model is if it can predict the future and the models used in AR4 are doing a pretty poor job since all of the real data suggests they have significantly overpredicted the amount of warming. Of course it is possible that it nothing more than an 8 year blip and warming will resume soon but we won’t know until it happens. Until then the only reasonable position is to wait and see before betting trillions trying to solve a problem that may not actually exist.

  14. David B. Benson says:

    Raven — Here are the five year averages from the HadCRUTv3 global surface temperature product:

    http://tamino.files.wordpress.com/2007/12/5yrave.jpg

    (The flock of ravens around here all seem to understand that.)

  15. David B. Benson says:

    john — Ouhgt to be even shorter:

    Homo sap

  16. Mark Hadfield says:

    Me: I expect the response will be, “You’re saying the models agree with the observations only because of the large uncertainties in both? What sort of proof of the models is that?”

    Raven: Mark hit the nail on the head. Defending the models by insisting that virtually any possible temperature profile is ‘consistent with’ the models only demonstrates that the models have no useful predictive value.

    Well, my prediction wasn’t falsified on this occasion!

    I’d just like to make it clear I do not agree with Raven. The models (meaning ensembles of global climate models) have made predictions that could have been falsified and haven’t. (By, for example, tropospheric cooling, or lower stratospheric warming, over the last few decades.) In this sense they are consistent with observations.

  17. Dano says:

    Until then the only reasonable position is to wait and see before betting trillions trying to solve a problem that may not actually exist.

    Simplistic binary argumentation: what planet uses this for policy decisions?

    Saaaaaay, Raven, are you from Jupiter? Betelgeuse? Do we have an honest to goodness alien in our midst? Can I get your autograph? DNA? A piece of your ship?

    Eppur si corvo!

    Best,

    D