The Island of Doubt

What the science cited by the Cato Institute really says about global warming

Posted by James Hrynyshyn on April 7, 2009
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I was going to ignore the open letter-to-the-president advertisement placed in major papers recently by the Cato Institute. You’ve probably heard of it — the one that says Obama should ignore global warming alarmism because the science says it isn’t happening. The one signed by “over 100 scientists.” But the response elsewhere has been interesting. It focuses almost exclusively on the expertise of those who signed the letter, not the merits of the argument it makes. I find myself agreeing — ever so slightly, with the Cato Institutes’ Jerry Taylor, who defended the letter last week in the National Review Online. Only slightly, though, and only on the abstract notion of ad hominem logical fallacies.

First, let me just say that I disagree with Taylor that the president shouldn’t take the credentials of his advisers into account. In scientific endeavors, it would be foolish to pay more attention to laypeople than those who have devoted their professional lives to studying the subject. And I disagree with Taylor’s contention that it doesn’t matter how many experts you have arguing your side. Although it is a falsehood, as Taylor writes, that “that truth can be reliably determined by a show of hands. Nothing — especially in science — could be further from the truth” when the numbers are so lopsided against you, it is usually wise to at least consider why that’s the case.

But Taylor is correct, in principle, when he claims that “An argument’s merit has nothing to do with the motives of the arguer, the credentials of the arguer, or the popularity of the argument. Full stop. No exceptions.”

So let’s look instead at the scientific basis for the argument, which is laid out in the letter with the help of four footnotes backing up three claims.

1. Surface temperature changes over the past century have been episodic and modest and there has been no net global warming for over a decade now.

Supporting literature: Swanson, K.L., and A. A. Tsonis. Geophysical Research Letters, in press: DOI:10.1029/2008GL037022.
and
Brohan, P., et al. Journal of Geophysical Research, 2006. DOI:10.1029/2005JD006548

Here’s what Swanson and Tsonis actually conclude:

…we caution that the shifts described here are presumably superimposed upon a long term warming trend due to anthropogenic forcing…. If the role of internal variability in the climate system is as large as this analysis would seem to suggest, warming over the 21st century may well be larger than that predicted by the current generation of models, given the propensity of those models to underestimate climate internal variability.

and here’s what Brohan et al. say about the subject: Nothing. The paper is about uncertainties in 19th century data. But here’s what they do write:

Since the mid twentieth century the uncertainties in global and hemispheric mean temperatures are small, and the temperature increase greatly exceeds its uncertainty. In earlier periods the uncertainties are larger, but the temperature increase over the twentieth century is still significantly larger than its uncertainty.

So that does support the Cato letter’s contention that “there has been no net global warming for over a decade now.” No. Even if it did, (as Taylor likes to say), “so what? Ten years is not enough to come to any conclusions about long-term climate changes, as I explain in detail here.

2. After controlling for population growth and property values, there has been no increase in damages from severe weather-related events.

Supporting literature: Pielke, R. A. Jr., et al. Bulletin of the American Meteorological Society, 2005: DOI: 10.1175/BAMS-86-10-1481

This has become a contentious issue. Al Gore recently pulled a sequence of slides from his climate change presentation because of exactly this problem. But note what Pielke et al. include in their short article, which isn’t original research, just a reply to some:

Concern about the possibility of abrupt climate change, whether human caused or not, is well justified.

In other words, this is red herring. Just because we’ve been unable to see a signal of climate change in property damage trends is no reason to question the science behind anthropogenic global warming. Again, the authors are worried about what’s going on with the climate.

3. The computer models forecasting rapid temperature change abjectly fail to explain recent climate behavior.

Supporting literature: Douglass, D. H., et al. International Journal of Climatology, 2007: DOI: 10.1002/joc.1651. Which says:

Model results and observed temperature trends are in disagreement in most of the tropical troposphere, being separated by more than twice the uncertainty of the model mean.

Here we have a single paper that takes issue with an enormous volume of literature based on computer models that actually do explain recent climate behavior. It’s a paper about temperatures in the tropical troposphere, not the planet as a whole. Remember, we’re supposed to be examining “global” warming, not warming in Cost Rica and Ghana. The fact the some of the models fail to accurately predict what some parts of the atmosphere are experiencing does not invalidate AGW.

It turns out that climatologists have been remarkably accurate for decades now when it comes to anticipating global average temperature rise. There’s a nice piece in the New York Times of 1983 that shows how little the science has had to change despite a quarter century of observations.

So what does that leave the Cato Institute with? Not much. Zippo in fact. Just a list of more than 100 non-climatologists who think that several thousand climatologists are wrong, based on three research papers and one commentary that do absolutely nothing to undermine the consensus of the genuine experts.

And what does that tell you about those who signed on to the letter?

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Comments

  1. #1 frog
    April 7, 2009

    But Taylor is correct, in principle, when he claims that “An argument’s merit has nothing to do with the motives of the arguer, the credentials of the arguer, or the popularity of the argument. Full stop. No exceptions.”

    Balderdash. Unless it’s a very simple logical argument, that’s untrue. Most arguments rely to some extent on the credibility of the arguer — whether they are or are not hiding key facts, whether they actually did the experiments claimed, whether their argument has been fully vetted. Even in mathematics proofs have become computer generated, and to some extent whether you’ll even bother to investigate the kernel that produced it depends on the credibility of the mathematician.

    Reputation is everything in science. That’s why PI’s get the cash and not the grad students doing the work. Most arguments for the last 100 years have been too complicated to be fully vetted individually. The irrelevance of the speaker is only true in courts of law — where the lawyer is simply an agent — and in 300 BC Greece, when cutting edge science was limited to comparing the number of teeth between the genders. Taylor’s position is not only utopian, it’s simply a false reflection of the nature of modern arguments.

    Let’s leave the putative “fallacies” from before the time that logic was fully formalized in freshmen history of philosophy courses.

    Of course, none of this is to say that the primary basis of judging an argument shouldn’t be the argument itself; but there is no full-stop there, no no exceptions there except in the hands of the naive or a medievalist. Your approach of attacking the arguments one by one should be primary; but then again, your credibility is always part of your argument.

  2. #2 MeToo
    April 7, 2009

    “And what does that tell you about those who signed on to the letter?”

    It tells me exactly what I have been contending all along: For those who are not climatologists or who have not educated themselves in the science, the issue is a political one, not a scientific one.

    Even for those who agree with the conclusions of the climatologists, if they cannot explain the reasons why the climatologists have reached their conclusions, then their agreement is politically motivated.

  3. #3 bi -- IJI
    April 7, 2009

    Thanks Hrynyshyn! As I point out in my other blog entry, there’s also another problem: if the petition is only about the merits of its scientific arguments, then why did Cato even need to find 100+ signatories — since one person would be enough?

    Clearly, even the Cato people themselves think there’s some sort of validity in counting votes among scientists.

    – bi

  4. #4 qetzal
    April 7, 2009

    What frog said.

    The truth of an argument is what’s independent of the arguer (at least, for those of us who accept the notion of objective truth).

    Also, I disagree with MeToo’s last paragraph. I accept that climatologists’ scientific conclusions are likely to be the best approximation of reality re global warming, simply because they have the training and data to reach the best scientific conclusions. I don’t consider that a political judgment on my part.

  5. #5 D. C. Sessions
    April 7, 2009

    WRT argumentum ad hominem, they can’t have it both ways: either the credentials of their “100 scientists” are immaterial (in which case, why not just poll 100 people on the street?) or else they are — in which case, questioning those “scientists” is apt. Since they pulled the argumentum ad verecundiam, the argumentum ad hominem is in fact a direct rebuttal.

    Likewise with regard to the argumentum ad populum: if numbers aren’t relevant, then why round up “100 scientists?” They could just ask Bill Oreilly and be done with it.

  6. #6 brandon
    April 7, 2009

    peer-reviewed scientific research is blind to a researcher’s credentials (this is of course arguable, but at least in the fantasy applied physics world i live in, it works most of the time); so in that sense, the science is free to live beyond its author’s reputation.

    this is qetzal’s “truth” and it is good.

  7. #7 Brodie
    April 7, 2009

    Since all of their possible claims have been thoroughly and repeatedly debunked, what else is there to do except point to the lack of credibility of the names they’ve exploited? If their argument is from authority then revealing how baseless that authority is is entirely relevant.

    also, if the argument has already been won, it is not ad hominem to then declare those still arguing to be fools – and then in proclaiming this new argument (the foolishness of said denialists) you must support it with valid evidence.

  8. #8 MeToo
    April 7, 2009

    “Also, I disagree with MeToo’s last paragraph. I accept that climatologists’ scientific conclusions are likely to be the best approximation of reality re global warming, simply because they have the training and data to reach the best scientific conclusions. I don’t consider that a political judgment on my part.”

    qetzal,

    OK. If not political, then at least subjective.

    I’m not certain how one could argue that the climate scientists are reaching valid conclusions unless one has a pretty high level understanding of the science. Sure, one could trust that those who have been granted the credentials of climatologists are more likely than the rest of us to get the science “right,” but we all come to the argument with preconcieved notions of what we expect the climate scientists to say.

    Most of those notions come from our political beliefs about the role of government in protecting the environment, the level of control government should have over the actions of businesses and private citizens, and our biases about the motiviations of those on the various sides of the argument.

    For example, the laypeople who think AGW is true argue that the climate scientists who argue in support of the idea of AGW are pure in heart and just doing good science, wherease any other scientist who disagrees with the “yes it’s AGW”-scientists is either unqualified to judge, or the patsy of evil business people.

    On the other hand, those who disagree with the verity of AGW claims believe that the other side are just trying to gain control of the means of production (environmentalism is just the wedge for communism, don’t you know?) or woo-woo nature lovers who think humans are inherently evil and just a blight on “Mother Earth.”

    Assuming that humans are the major cause of the current increase in world temperatures, there is a very important consequence: If we caused it, then we are able to solve it.

    What methods people propose to solve it is a direct result of their political biases. Free-market types will argue for entrepreneurial solutions. Big Brother types will argue for government solutions. What we will come up with will be an ever-changing mixture, since the two are not mutually exclusive.

  9. #9 D_E_R_M_A_N
    April 7, 2009

    thankyou

  10. #10 bi -- IJI
    April 8, 2009

    MeToo:

    False. We don’t need to know every nuance of climatology to tell that the global warming ‘skeptics’ are peddling complete nonsense — see e.g. D. C. Session’s rebuttal. Nonsense which is so complete, in fact, that anyone with at least half a brain can easily tell that it’s nonsense.

    Simple logic is ‘biased’ towards the climate activists. Get over it.

    – bi

  11. #11 MeToo
    April 8, 2009

    bi – Get over what? I never said that logic wasn’t required to tell the AGW skeptics were “peddling nonsense.”

    Your biases are showing, in that you pretend that I’m disagreeing with the idea of AGW.

    What I’m pointing out is that for you to claim that you believe human action is the primary cause of global warming without being able to explain the science means you are relying on something else, most likely your political biases.

    The same goes for the AGW “deniers.” Whithout a demonstrated understanding of the science, then politics is their motivation.

    But pointing out that the “deniers” are politically motivated is not an argument for the verity of AGW. Any more than showing that ID proponents have no valid argument is a support for evolution.

    The only way to prove or disprove AGW is scientifically. If you cannot show that you understand the science, then you are just guessing.

  12. #12 bi -- IJI
    April 8, 2009

    MeToo:

    I never said that logic wasn’t required to tell the AGW skeptics were “peddling nonsense.”

    No, you were suggesting that simple logic is not sufficient to tell that AGW ‘skeptics’ are peddling nonsense.

    But it is sufficient.

    The fact that the Cato Institute felt it necessary to find 100 signatories with impressive-sounding credentials, and then turn around and complain about ‘argument by numbers’ and ‘argument by authority’ (!), is enough indication that they’re peddling complete nonsense.

    The fact that you tried to misrepresent your own argument — and mine — when I pointed this out, is also enough indication that you’re peddling complete nonsense.

    – bi

  13. #13 MeToo
    April 8, 2009

    “No, you were suggesting that simple logic is not sufficient to tell that AGW ‘skeptics’ are peddling nonsense.”

    Nothing like that at all. Not even in the ballpark. What I have been writing all along is this:

    “…for you to claim that you believe human action is the primary cause of global warming without being able to explain the science means you are relying on something else, most likely your political biases.”

    and

    “The only way to prove or disprove AGW is scientifically. If you cannot show that you understand the science, then you are just guessing.”

    So go back and check your preconceptions.

  14. #14 bi -- IJI
    April 8, 2009

    I said:

    you [MeToo] were suggesting that simple logic is not sufficient to tell that AGW ‘skeptics’ are peddling nonsense.

    MeToo replies:

    Nothing like that at all. Not even in the ballpark. What I have been writing all along is this:

    and it turns out to be the same thing.

    It’s simple. People point out elementary flaws in logic present in the Cato petition and reply — flaws which are plain for everyone to see. You respond by insinuating that they’re guilty of “political bias” or “preconceptions” and various variants of these crank code phrases.

    Sorry, but the Cato petition is still bogus, and so are you.

    – bi

  15. #15 MeToo
    April 8, 2009

    Where did I write that the Cato petition was not bogus?

    Show me where I agreed with anything they wrote, as quoted anywhere in this post and the discussions, then we can continue the discussion.

    Until then, I’m writing you off as one who believes:

    “Me saying it makes it true.”

  16. #16 bi -- IJI
    April 8, 2009

    MeToo:

    I stand by my words.

    – bi