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What do climate scientists think?

Filed under: — gavin @ 24 June 2010 - (Español)

by Gavin and Eric.

… and why does it matter?

There is a lot of discussion this week about a new paper in PNAS (Anderegg et al, 2010) that tries to assess the credibility of scientists who have made public declarations about policy directions. This come from a long tradition of papers (and drafts) where people have tried to assess the state of the ‘scientific consensus’ (Oreskes, Brown et al, Bray and von Storch, Doran and Zimmerman etc.). What has bedevilled all these attempts is that since it is very difficult to get scientists to respond to direct questions (response rates for surveys are pitiful), proxy data of some sort or another are often used that may or may not be useful for the specifics of the ‘consensus’ being tested (which itself is often not clearly defined). Is the test based on agreeing with every word in the IPCC report? Or just the basic science elements? Does it mean adhering to a specific policy option? Or merely stating that ‘something’ should be done about emissions? Related issues arise from mis-specified or ambiguous survey questions, and from the obvious fact that opinions about climate in general are quite varied and sometimes can’t easily be placed in neatly labelled boxes.

Given these methodological issues (and there are others), why do people bother?

The answer lies squarely in the nature of the public ‘debate’ on climate. For decades, one of the main tools in the arsenal of those seeking to prevent actions to reduce emissions has been to declare the that the science is too uncertain to justify anything. To that end, folks like Fred Singer, Art Robinson, the Cato Institute and the ‘Friends’ of Science have periodically organised letters and petitions to indicate (or imply) that ‘very important scientists’ disagree with Kyoto, or the Earth Summit or Copenhagen or the IPCC etc. These are clearly attempts at ‘arguments from authority’, and like most such attempts, are fallacious and, indeed, misleading.

They are misleading because as anyone with any familiarity with the field knows, the basic consensus is almost universally accepted. That is, the planet is warming, that human activities are contributing to the greenhouse gases in the atmosphere (chiefly, but not exclusively CO2), that these changes are playing a big role in the current warming, and thus, further increases in the levels of GHGs in the atmosphere are very likely to cause further warming which could have serious impacts. You can go to any standard meeting or workshop, browse the abstracts, look at any assessment, ask any of the National Academies etc. and receive the same answer. There are certainly disputes about more detailed or specific issues (as there is in any scientific field), and lots of research continues to improve our quantitative understanding of the system, but the basic issues (as outlined above) are very widely (though not universally) accepted.

It is in response to these attempts to portray the scientific community as fractured and in disagreement, that many people have tried to find quantitative ways to assess the degree of consensus among scientists on the science and, as with this new paper, the degree of credibility and expertise among the signers of various letters advocating policies.

It is completely legitimate to examine the credentials of people making public statements (on any side of any issue) – especially if they make a claim to scientific expertise. It does make a difference if medical advice is being given by a quack or the Surgeon General. The database that Jim Prall has assembled allows anyone to look this expertise up – and since any new source of information is useful, we think this can be generally supported. Prall’s database has a number of issues of course, most of them minor but some which might be considered more problematic: it relies on citation statistics, which have well-known problems (though mostly across fields rather than within them), it uses Google Scholar rather than the standard (ISI) citation index, and there are almost certainly some confusions between people with similar names. Different methodologies could be tried – ranking via h-index perhaps – but the as long as small differences are not blown out of proportion, the rankings he comes up with appear reasonable.

So it is now possible to estimate an expertise level associated with any of the various lists and letters that are out there. Note that it is worth distinguishing between letters that have been voluntarily signed and lists that have been gathered with nothing but political point scoring in mind (the Inhofe/Morano list was egregious in its cherry picking of quotes in order to build up its numbers and can’t be relied on as an accurate reflection of peoples opinions in any way, and similarly contributing to RealClimate is not a statement about policy preferences!). Additionally, it isn’t always clear that every signatory of each letter really believes every point in the statement. For instance, does Lindzen really believe that attribution is impossible unless current changes exceed all known natural variations (implying that nothing could be said unless we got colder than Snowball Earth or warmer than the Cretaceous or sea level rose more than 120 meters….)? We doubt it. But as tests of political preferences, these letters are probably valid indicators.

So, do the climate scientists who have publicly declared that they are ‘convinced of the evidence’ that emission policies are required have more credentials and expertise than the signers of statements declaring the opposite? Yes. That doesn’t demonstrate who’s policy prescription is correct of course, and it remains a viable (if somewhat uncommon) position to acknowledge that despite most climate scientists agreeing that there is a problem, one still might not want to do anything about emissions. Does making a list of signers of public statements, or authors of the IPCC reports, constitute a ‘delegitimization’ of their views? Not in the slightest. If someone’s views are widely discounted, it is most likely because of what they have said, not who they sign letters with.

However, any attempt to use political opinions (as opposed to scientific merit) to affect funding, influence academic hiring, launch investigations, or personally harass scientists has no place in a free society – from whichever direction that comes. In this context, we note that once the categorization goes beyond a self-declared policy position, one is on very thin ice because the danger of ‘guilt by association’. For instance, one of us (Eric) feels more strongly that some of Prall’s classifications in his dataset cross a line (for more on Eric’s view, see his comments at Dotearth).

But will this paper add much to the ‘there [is/is not] a consensus’ argument? Doubtful. People are just too fond of it.

But there really is.


427 Responses to “What do climate scientists think?”

  1. 101
    Ray Ladbury says:

    Barry Woods,
    Perhaps they should link to Astrology blogs and Velikovsky advocates and conspiracy theorists, too. After all, we want to be inclusive and make sure we don’t hurt anyone’s feelings.

    Get real. If you challenge the peer-reviewed science in a non-peer-reviewed venue, you are doing anti-science, not science. Your inability to tell the difference tells us all we need to know.

  2. 102
    Reasonable Observer says:

    I guess I am surprised that RC is being so supportive of what appears to be a pretty poorly thought out paper.

    At its heart, what this paper says is that if you look at the cite lists of the AR4 WG1 Contributors they are longer than the cite lists of those signing a number of statements skeptical of CAGW. This conclusion is obvious but it doesn’t really mean much. Specifically:

    1) It is not surprising that the IPCC contributors have long cite lists. The whole point of the IPCC is to gather the best and brightest climate scientists to update policy makers.

    2) Climate scientists want to be contributors to the IPCC (and have their work cited by the IPCC) as it increases their prestige and professional advancement.

    3) On the other hand, signing a statement critical of the IPCC can be very harmful to a climate scientist. At a minimum, it reduces their chances of being picked to be a contributor in the future. It likley has a series of other negative impacts on a career.

    4) Just because someone is a contributor to the IPCC doesn’t mean they agree with everything in it or even the central points. It generally means that they are part of a process on a very small part of the IPCC and they may not even agree totally with the small part they are part of.

    5) As has already been pointed out, it is also possible to sign some of the statements in this paper and still support some part of the CAGW hypothesis.

    In short, this paper says almost nothing of value.

  3. 103
    Grunt says:

    forgive me i have not read all of the comments here. but one thing i have been surprised at generally is the lack of official surveys done on the matter (i have seen all that is available). Anonymous surveys could have been carried out – to be completed by all IPCC contributors for example. OK so getting the wording right in a questionnaire is always difficult but surely it is worth having a go? Perhaps this can be done for the next IPCC report – contributing authors are required to fill out a questionnaire based on the reports final version, to establish their degree of agreement with the core findings. this can include a box for ‘do not feel qualified to comment’.
    this sounds too easy or am i being stupid or something?

  4. 104
    Walter Crain says:

    want to demonstrate the consensus? in a funny, memorable way?

    skeptics have plenty of lists, and it’s time mainstream scientists get one of their own a la “project steve”: http://ncse.com/taking-action/project-steve

    ‘cept the one for AGW would be called

    ***PROJECT JIM***

    in honor of james hansen. the catch is you can only sign it if you’re PhD scientist named “jim”… it might read something like:

    *anthropogenic global warming (AGW) theory is well-supported by numerous lines of evidence. [insert best lines of evidence]. there are uncertainties about some details, and discussion about consequences and policy, but there is no serious scientific debate about whether the earth is warming and the cause is human co2 emissions.”

    or something like that. you guys might be able to tweak “serious scientific debate”?

  5. 105
    Chris G says:

    I made this same comment over at Skeptical Science, but I think it would be more telling if the change in the state of consensus were shown over time, say, about 100 years. Some people act as though the current consensus has been the tradition, when it appears to me that proponents of AGW were the outliers some decades ago, much as the anti-AGW, or no-problem, proponents are the outliers today. The amount of change of state, and the rate of change, would be more informative for those who can’t directly access the depths of the science. If you start talking about Stefan-Boltzmann or Planck’s to the average Joe, who the politicians listen to, and are for the most part, their eyes glaze over and you loose them.

  6. 106
  7. 107
    Ike Solem says:

    Are we harkening back to some kind of chivalric era of science – from a perhaps mythical past? Science these days is heavily beset by propaganda efforts aimed at distorting scientific results and analysis in the name of economic gain (rather short-term economic gain at that). It’s all been spelled out numerous times – the leaked 1998 American Petroleum Institute memo being a classic example:

    Upon this tableau, the Global Climate Science Communications Team (GCSCT) developed an action plan to inform the American public that science does not support the precipitous actions Kyoto would dictate.

    It’s worth listing the specific steps they suggested that relate to scientists, specifically their effort to develop a “white list” of approved scientists for media quotes – so, if a media PR organization develops a list of scientists who will repeat their talking points, and then someone else does a study that exposes this list, and people complain about “blacklisting scientists in a free society” – no, that doesn’t hold much water, does it?

    The American Petroleum Institute effort certainly involved the development of this “blacklist”, or as they would call it, a white list. From their 1998 memo:

    “…identify and recruit as many as 20 respected climate scientists to serve on the science advisory board.”

    “…cooperative relationships with all major scientists whose research in this field supports our position.”

    “…developing opportunities to maximize the impact of scientific views consistent with ours with Congress, the media and other key audiences.”

    Translation: They paid a bunch of low-quality scientific quacks to go on speaking tours for them. The tobacco industry employed their ilk for decades to cloud the cancer link to tobacco.

    Here’s a very good comment on the issue from Andy Revkin’s DotEarth blog:

    This paper largely makes a very simple point-if you have 100 scientists, 97 of them agree with the tenets of anthropogenic climate change and their research is well supported. Three do not and are poorly represented in the relevant literature. Thus, there is no “debate” about the main points of climate change. All kinds of papers get published that revolutionize fields or upend the current paradigm, but they’re based on solid science. The exceedingly competitive nature of scientific research and publishing ensures that there are incentives for well-researched game-changers to be published. However, from the climate skeptics we see a consistent pattern of disinformation funded by corporations with claims that do not hold up under scrutiny. What this paper shows is that the vast majority of scientists qualified to make assessments about the status of climate science believe in the core IPCC tenets, and those who do not are poorly qualified to do so.

    The only plausible objection to the PNAS paper, logically speaking, is that this entire issue falls under the “appeal to authority” fallacy. This requires a rethinking of what it is the ‘expert’ is really doing for the public – and the best kind of expert is the one who helps you understand how they came to their conclusions, not the one who delivers said conclusions from on high in the ivory tower, with no questions allowed. Any educated person should then be able to consider the arguments and come to their own conclusions, sans authoritarian guidance. Those arguments involve the radiative physics of planetary atmospheres, the effect of adding CO2, the complexities of the global oceanic and atmospheric circulation, and the chemistry of fuel combustion.

    I don’t see that exposing the scientists who’ve put their personal prestige or economic interests ahead of scientific accuracy is a problem in a free society, though. The PNAS paper doesn’t even do that, it just points out the general trend, so it’s actually very gentle criticism. Now, if the authors would just apply the same methodology to Stanford’s Exxon-financed “Global Climate and Energy Project” (GCEP) – who knows what they’d find?

  8. 108
    MarkB says:

    Eric can correct me if I’m wrong, but part of his beef is likely with the use of the term “activist”, which tends to have negative connotations (scientists being corrupted by politics or what not).

    This was the same phrasing used in a dubious textbook written by political hacks that distorted climate science, casting the “debate” between “activists” and “skeptics”.

    http://www.centerforinquiry.net/uploads/attachments/CFI_Textbook_Critique.pdf

    http://pr.thinkprogress.org/2008/04/pr20080414

    Another problem is Eric is listed in the “activist” category, with the only justification being that he’s affiliated with this blog RealClimate, which is a pro-science blog, not an activist one. Since this blog doesn’t characterize itself as “activist”, and rarely/never discusses policy, the characterization seems unfair.

    Eric’s categorization seems to be the exception. Most others identified as “activists” have signed a public declaration indicating agreement with the usual consensus position, and sometimes indicating explicit support for emissions reductions. But again, “activist” is too strong a word and certainly doesn’t apply to everyone. It gives some the impression that they’re all out there actively doing what Hansen’s doing (which I’m not saying is wrong), or being wined and dined by Al Gore. Some phrase to the effect of “expclitly agrees with the consensus positions outlined…and indicated by signing a public declaration” would be better than this poor choice of a word.

  9. 109

    The “blacklist meme” is (IMHO) a pure attempt to change the subject from the overwhelming agreement in the climate science community to, well, a pure and utterly unsubstantiated smear worthy of the tin hat brigade.

    I know it’s tempting to take a potshot at such a sitting duck, but let’s keep the focus where it belongs–on the piles of science that say that we are not on a good track today, and we should seriously attempt to change direction.

  10. 110

    A boycott list exists by Journalists, of which a great deal of them are pro-contrarian:

    http://www.telegraph.co.uk/…/Climate-change-sceptic-scientists-less-prominent-and-authoritative.html

    Regular cast of skeptics make ink, the vast majority of scientists successful in predicting rising temperatures, don’t…. Its a wonder correct science somehow gets through!

  11. 111
    Edward Greisch says:

    79 & 88 Scott A Mandia: I agree.

  12. 112
    Jim Eager says:

    Grunt @106, great time line compilation, there are many entries that are new to me. Thanks for the link.

  13. 113

    …. Journalists who fancily dont know the colour of ice or sea:

    http://www.theprovince.com/technology/Scan…/story.html

    never bother looking at graphs and stuff, so much easier to quote a scientists without further background research a few google seconds away:

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.arctic.png

    2010 just about reached 2008 anomaly minima 2 months early…. It seems like this:write the opposite of what is happening and everyone will worry about something else ?

  14. 114
    Edward Greisch says:

    Eric: Reference “Storms of My Grandchildren” by Gavin’s boss, James Hansen. Dr. Hansen is clearly an activist and it isn’t hurting him any. I agree completely with Dr. Hansen’s reasoning.

    103 Grunt: Yes. Stop commenting and go study physics.

    [Response: I'm not placing any value judgements on what it means to be an 'activist'. I am objecting to the false impression provided by this 'list' that some sort of objective criteria has been used to classify me. I would object just as much if I had been classified as "not an activist".--eric]

  15. 115
    Chris G says:

    Grunt @ 106,
    Not sure if you were responding to my comment, but what I had in mind was actually more like adding a third axis to the graph, that showed snapshots of the same type of data, perhaps taken every 10 years. I’d be surprised if the researchers mentioned in the timeline did not have contemporaries who dissented with them.

  16. 116
    Timothy Chase says:

    A Response to Eric Steig, Part I

    Eric Steig responded inline to 49:

    … If Pielke Sr. gets classified as a skeptic, or contrarian, or whatever, it is due to this sort of misleading rhetoric. It may not purposefully intend to mislead, but it is misleading nevertheless, and in quite substantive ways (because it implies that the mainstream view that we probably ought to cut CO2 emissions is based on faulty science). Note, however, this none of this has anything to do with Andregg et al., except that, if in fact he gets classified as a ‘denier’ in their analysis, this is probably why.

    I found the last sentence to be somewhat informative.

    You state, “… if in fact [Pielke Sr.] gets classified as a ‘denier’ in their analysis, this is probably why.”

    Apparently you do not know whether Pielke gets classified as a denier in their analysis. However there is only one place in the entire paper that the term “denier” gets used: the last sentence of the first paragraph.

    In that one sentence, Anderegg et al. (2010) states:

    This group, often termed climate change skeptics, contrarians, or deniers, has received large amounts of media attention and wields significant influence in the societal debate about climate change impacts and policy (7, 9–14).

    http://www.pnas.org/content/early/2010/06/04/1003187107.full.pdf+html

    Beyond that, they simply refer to such individuals as researchers who are unconvinced by the evidence (UE) of [anthropogenic climate change] ACC. I refer you to the first sentence of the second paragraph:

    This group, often termed climate change skeptics, contrarians, or deniers, has received large amounts of media attention and wields significant influence in the societal debate about climate change impacts and policy (7, 9-14).

  17. 117
    Timothy Chase says:

    A Response to Eric Steig, Part II

    Now I had been told that Roger Pielke Sr. was the individual who first alerted you to this paper and that it could be used to blacklist people. Looking at the material quoted from your email at DotEarth, you state:

    The idea of listing the names of those people analyzed is disturbing for reasons that should be obvious. In this respect I completely agree with Roger that the “blacklist” metaphor is appropriate.

    http://dotearth.blogs.nytimes.com/2010/06/24/notes-from-the-whaling-and-warming-wars/

    … it appears that my informant was right. But then based upon past experience I had every reason to think my informant trustworthly. Nevertheless I checked for myself.

    However, you admit that Pielke Sr. uses misleading rhetoric. You did so in your inline comment in 49:

    Both 2a and 2b are correct depending on what part of the system you are talking about. Pielke Sr. makes it sound like the ‘mainstream’ is missing something when they aren’t. Hence the definition of a loaded question: one that presupposes something that has not been proven or accepted by all the people involved. If Pielke Sr. gets classified as a skeptic, or contrarian, or whatever, it is due to this sort of misleading rhetoric.

    Therefore you know that Pielke Sr. is misleading. And he has been misleading for quite a while during which no doubt a great many people told him what — given his intelligence and education — he no doubt was able to figure out for himself: that his rhetoric is misleading. As such we have very good reason to believe that he is deliberately misleading. Given your intelligence I have every reason to believe that you can see this.

    Thus when you state:

    It may not purposefully intend to mislead, but it is misleading nevertheless, and in quite substantive ways (because it implies that the mainstream view that we probably ought to cut CO2 emissions is based on faulty science).

    … I can only assume that you are trying to be polite and maintain a modicium of civility. But if this is the case then I have to wonder — Why did you trust Pielke’s interpretation of the paper? And why didn’t you read the paper for yourself prior to having your critique — which appears to have been Pielke’s critique once removed — printed in part in DotEarth?

    [Response: Tim, thanks for your thoughts. The idea that I would trust Pielke's interpretation of anything, without checking the facts first, is laughable, given his history of inflammatory accusations against me and RealClimate, not to mention many other people. Having read the paper, and the web site that it is linked with, I formed my own view, and I happen to largely agree with Roger on this. (This doesn't alter my view that Roger consistently and engages in much worse tactics, but that is really beside the point.) My view on the 'list' is that it is a terrible mistake politically, highly questionable ethically, and dubious scientifically. My view on the paper is largely that it should have not been linked to the list, but it was, and not be me, nor by Pielke, but by the authors. I have huge respect for Steve Schneider (I am not familiar with the other authors' previous work), but I think this paper and its explicit linkage with the web list was a very big mistake. --eric]

  18. 118
    Timothy Chase says:

    A Response to Eric Steig, Part III

    Now you are also quoted at DotEarth as having written:

    The methods appear suspect, because of the difficulty of separating ‘association’ from ‘opinion,’ and the requirement to put people in only one of two categories.

    What did you mean by “association”? In the context of a “blacklist” which you (or rather, Pielke Sr.?) seemed to think was somehow applicable to this peer-reviewed paper appearing in the Proceedings of the National Academy Sciences, normally this would conjure up by means of association the notion of “guilt by association”? Is this what you meant? Or is did you mean by “association” that the criteria was subjective?

    In either case, I would like to point out that who got counted and who did not was entirely determined by who chose to voluntarily sign statements and who did not. I quote:

    We defined UE researchers as those who have signed statements strongly dissenting from the views of the IPCC. We compiled UE names comprehensively from 12 of the most prominent statements criticizing the IPCC conclusions (n = 472; SI Materials and Methods).

    Anderegg et al. (2010)

    Furthermore, if you go to the Supporting Information linked to by the phrase “SI Materials and Methods”, you will see that they are quite explicit about what lists were used.

    We define UE researchers as those who have signed reputable statements strongly dissenting from the views of the IPCC. We compiled UE names comprehensively from the following 12 lists: 1992 statement from the Science and Environmental Policy Project (46 names), 1995 Leipzig Declaration (80 names), 2002 letter to Canadian Prime Minister Jean Chretien (30 names), 2003 letter to Canadian Prime Minister Paul Martin (46 names), 2006 letter to Canadian Prime Minister Stephen Harper (61 names), 2007 letter to U.N. Secretary General Ban Ki-Moon (100 names), 2007 TV film The Great Global Warming Swindle interviewees (17 names), NIPCC: 2008 Heartland Institute document “Nature, Not Human Activity, Rules the Climate,” ed. S. Fred Singer (24 listed contributors), 2008 Manhattan Declaration from a conference in New York City (206 names listed as qualified experts), 2009 newspaper ad by the Cato Institute challenging President Obama’s stance on climate change (115 signers), 2009 Heartland Institute document “Climate Change Reconsidered: 2009 Report of the Nongovernmental Panel on Climate Change (NIPCC)” (36 authors), and 2009 letter to the American Physical Society (61 names). After removing duplicate names across these lists, we had a total of 472 names.

    http://www.pnas.org/content/suppl/2010/06/07/1003187107.DCSupplemental/pnas.201003187SI.pdf

  19. 119
    Timothy Chase says:

    A Response to Eric Steig, Part IV

    Now you are quoted at DotEarth as having stated:

    2) The idea of listing the names of those people analyzed is disturbing for reasons that should be obvious….

    3) Some colleagues of mine have rightly pointed out that if names were not listed, then the authors would be accused of ‘refusing to divulge data.’

    However, the names are neither listed in the the paper itself nor in the SI Materials and Methods. The SI Materials and Methods do contain a link to a website where names are given — but it is also made clear that the people listed there are not necessarily the same as those that are counted in the paper itself. Moreover, even at the website where names are actually given, the statements signed by each individual are identified — and where possible linked to. (Some are no longer online.)

    So while you give the impression that the names are listed in the paper itself, they are not. And given that they are not listed in the paper, the term “blacklist” seems quite inappropriate. Furthermore, primarily, the lists that actually exist are the lists created by the individuals named in those lists — when they signed the statements. So if these lists are blacklists then we must conclude that the individuals on the lists voluntarily put themselves there — with the full understanding that the lists would be widely publicized. If these are blacklists they are very strange ones.
    *
    Now in the above essay that you coauthored, it states:

    To that end, folks like Fred Singer, Art Robinson, the Cato Institute and the ‘Friends’ of Science have periodically organised letters and petitions to indicate (or imply) that ‘very important scientists’ disagree with Kyoto, or the Earth Summit or Copenhagen or the IPCC etc. These are clearly attempts at ‘arguments from authority’, and like most such attempts, are fallacious and, indeed, misleading.

    They are misleading because as anyone with any familiarity with the field knows, the basic consensus is almost universally accepted….

    This is a point that we are in basic agreement on — and to me at least this suggests an alternative reason why the individuals who voluntarily put themselves on the lists would be opposed to PNAS paper.

    In an earlier comment (47) I stated in part:

    what the “contrarians” are really upset about is that they were trying by means of their lists to create the appearance that the climatology community is evenly divided — but now those lists and lists by scientists that affirm the conclusions of mainstream science have been used to show just how un-divided the scientific community actually is.

    The contrarians are a tiny but vocal and well-financed minority, similar to the libertarian/industry-funded scientists that opposed the regulation/phasing-out of dioxins, CFCs, asbestos, and cigarettes.

    I believe that this is the main reason why contrarians are so opposed to the analysis given by the paper, that and that is shows that they, “publish less often, are cited less often, typically they are much closer to retirement as opposed to the concerned scientists, …” (ibid.)

    There is another point on which we both agree. The classification could have been more finely-grained, distinguishing between climatologists who agree with the science but who are opposed to attempts to reduce the effects of climate change and those who actually deny the science. However, as the individuals who voluntarily signed their names to the various declarations were counted if and only if, judging from their publication record, they had expertise in climatology, it would seem that it was their expertise that was being counted on to give their judgment weight in the declarations themselves. As such, while I take the failure to make such a distinction to be important, I do not consider it to be a major failing — particularly if it results in a more conservative estimation of the strength of the consensus that exists regarding the science itself.

  20. 120
    J says:

    RE:>>>>>>[Response: There is, however, no evidence that 'skeptics' are being shut out of journals. There is indeed much evidence to the contrary.

    Not in the study that is the subject of this thread. That's the point. The study, by itself, logically proves a skeptic point as equally as it does its touted conclusion.

    [Response: That's a fair point of course, but it is strictly academic. No paper should ever be read in isolation, out of context with other with other evidence.--eric]

  21. 121
    MapleLeaf says:

    Eric, I understand that you object to the label. But with respect, you are missing the point. Those in the UE category elected to sign politically motivated, FF funded lists. They classified/labeled themselves, that the scientists in question did so is not the fault of the authors of the PNAS paper. I find it hypocritical how the contrarians accuse the IPCC and scientists involved in writing the reports of being politically motivated, and when the contrarians elect to sign politically-motivated and industry funded petitions.

    Could better methods been employed by the authors on how to group the scientists in the PNAS paper? Absolutely, there is always room for improvement. For example, the paper does not deal well with people like Pielke Snr. (who did sign at least one petition), but does not, as far as I know, dismiss AGW as a non-issue. Perhaps they needed a third category for fence sitters or ambiguous cases. But maybe they or whoever runs with this can get around to tackling that the next time round. I still find the findings insightful and revealing, and the results are pretty devastating for the contrarians. They also confirm (quantitatively) what people in the know have known or suspected for a long time. I suspect their findings are quite robust (they do corroborate earlier, independent analyses), no matter how one chooses to slice and dice or group the data. But perhaps a subsequent study can rigorously test that hypothesis.

  22. 122
    David B. Benson says:

    This grows ever more bizarre. I’m going to life a quotation from Michael Tobis’s Only in it for the Gold blog:

    “The system of scholastic disputations encouraged in the Universities of the middle ages had unfortunately trained men to habits of indefinite argumentation, and they often preferred absurd and extravagant propositions, because greater still was required to maintain them; the end and object of such intellectual combats being victory and not truth.

    “No theory could be too farfetched or fantastical not to attract some followers, provided it fell in with popular notions…”

    — Charles Lyell in “Principles of Geology” (1830)

  23. 123
    Timothy Chase says:

    CORRECTION to A Response to Eric Steig, Part I

    Where I stated:

    Beyond that, they simply refer to such individuals as researchers who are unconvinced by the evidence (UE) of [anthropogenic climate change] ACC. I refer you to the first sentence of the second paragraph:

    … then repeated the earlier quote, I should have stated:

    … third sentence of the third paragraph…

    … and quoted:

    We provide a broad assessment of the relative credibility of researchers convinced by the evidence (CE) of [Anthropogenic Climate Change] ACC and those unconvinced by the evidence (UE) of ACC…

  24. 124

    One of the most commonly identified alleged weaknesses of the PNAS paper is the choice of friends/enemies dichotomy, instead of several categories ranging from outright denial of a warming trend to more nuanced objections to attribution all the way to full embrace of the IPCC consensus. That was my first thought, too.

    But upon further reflection, it’s clear that a binary categorization was the least problematic way to go. The use of multiple categories of skepticism/denialism/agreement would only produce countless objections about who belongs where. As it is, only Pielke Sr. is proving challenging to assign to the convinced or unconvinced division. Imagine if there were five or six categories…

  25. 125
    MapleLeaf says:

    James @125. Good points.

    IMO, with this kind of paper you are damned what you do or damned what you don’t do. Either way the “skeptics’ will squeal and spin it as has been done by Pielke Jnr and Roy Spencer.

  26. 126
    Floccina says:

    I like Robin Hanson’s idea or having betting markets on climate change.

  27. 127

    Gilles 96: are you sure that they aren’t very poor people in the world that would be very happy to use the spared 25 Mbl/d ???

    BPL: Are you sure there aren’t very hungry people in the world that would be very happy to eat human beings of other ethnic groups?

    Are you sure there aren’t very tired people in the world that would be very happy to have slaves?

    Just because a resource would help some people doesn’t mean it’s ethical for them to use it. The cash in the nearby Parkvale Bank would help me a lot, but that doesn’t mean I’m justified in drilling in through the wall and taking it.

  28. 128
    Ryan T says:

    “Average person” (#40), your omission of the science supporting the radiative power of CO2 and it’s feedbacks aside, you’d need to define “dramatic change” and the context in which it occurred. The key issue seems to be the relatively stable holocene climate and ecology that has greatly benefited humanity, and could well do so for thousands of years more (some much-needed growing-up time). When during the holocene has global climate shifted 3+ degrees C in the space of a century? Heck, even REGIONAL climate change has been disruptive to past societies. Societies that, although less technological, weren’t nearly as populous or as interconnected. So why risk accelerating things when we can try spurring an orderly transition from fossil fuels? The answers frequently seem to be greed, ignorance, and convenience.

  29. 129
    Doug Bostrom says:

    Gerard Harbison says: 25 June 2010 at 9:11 AM

    All in all, this paper, published under the rubric of ’social science’ by a biologist, an engineer, a climate scientist and an MBA, is a pretty sad showing — not so much for the authors, but for PNAS, who are now publishing political rhetoric from unqualified amateurs as ’social science’.

    Actually, if you bother to look at Schneider’s CV and list of publications you’ll see he’s been dealing with social science aspects of climate change for some time, including decision making in the face of uncertainty which squarely straddles the province of social sciences. He’s an excellent case-example of the fruitful practice of interdisciplinary research, as for that matter is Roger Pielke Jr.

    The paper is largely a statistical exercise in any case. Perhaps involving a statistician would be helpful but then tens of thousands of papers have been published by scientists with functional application knowledge of stats that did not require such special assistance and yet involved much more thorny statistical challenges.

  30. 130
    Doug Bostrom says:

    Regarding the Prall list, it was an existing and potentially useful compendium of data that unfortunately was not composed for the explicit purpose of Anderegg’s paper and as such carried with it some historical baggage having to do with its original purpose.

    Ideally a “clean” list might have been created. This could have been accomplished by “sanitizing” Prall’s list, removing the germane content and isolating it from what people perceive as politically charged but is there much doubt that the same objections would have been raised, seeing as how the ultimate provenance of the data would still need to be indentified?

    Or an application specific survey could have been created but that would of course entail cost as well as inevitably carrying the usual liabilities of survey design, response rates etc. One could also argue that such an instrument would never capture attitudes as authentically as does Prall’s list, composed as it is of people who have spontaneously volunteered information about their attitudes as opposed to being solicited for a survey.

    Anderegg leaned on a self-selected measure of attitudes that was already preexisting and not intended for research purposes, somewhat akin to using drivers license data to tease out attitudes to organ donation versus age or the like. Was Anderegg’s choice to use this data an aggressive act, an intentional direction of attention to Prall’s list for the purpose of condemnation? Folks on the list might feel otherwise but ascribing some nefarious purpose to the use of an existing collection of data for analysis when that data is so plainly useful seems quite a stretch of imagination.

    [Response: I won't speak for others, but in criticizing the Prall list and its connection with the paper, I by no means implied 'nefarious intent'. But then, those in the 1950s that told government authorities about suspected communists at work, or at school, didn't 'intend" anything either. The point, once again, is that the list of names by *any* category is objectionable. I simply reject the notion that this list should have been made public in detail, before, but especially after, the publication of the Anderegg paper. This is indeed a very example of why Steve McIntyre, George Monbiot, Ralph Cicerone and everyone else are wrong when say all the code, data, and minutae of every study should be made public and readily accessible on the web. These sorts of shrill proclamations aren't thought out, and here is a nice example of just how wrong that sort of generalization can be. Again, in medical studies names are never included, but no one accuses the medical researchers of 'refusing to divulge the data'. There is simply no justifiable purpose for having the list of names available anywhere, except possibly to the confidential peer reviewers of the paper. Why most of my colleagues on the left, right, and center fail to see this is completely baffling to me (other than the obvious explanation that they have not read up on history or have their heads in the sand).--eric]

  31. 131

    Doug:

    Could you provide a link or citation to a single piece of social science research that Schneider has published, prior to this?

  32. 132
    Doug Bostrom says:

    Gerard Harbison says: 25 June 2010 at 4:22 PM

    “Interdisciplinary”, Gerard.

    Uncertainty and Climate
    Change Policy

    Go ahead and quibble over what constitutes “social science research” or qualifications to employ social science methods but if you read work he’s coauthored it’s obvious that Schneider has a good working knowledge of social science research as it applies to thinking about climate change.

    What social science technique do you believe Schneider bungled, by the way? Or is this discussion focused on the person as opposed to the work product?

  33. 133
    Timothy Chase says:

    Eric Steig wrote inline to 118:

    Having read the paper, and the web site that it is linked with, I formed my own view, and I happen to largely agree with Roger on this. (This doesn’t alter my view that Roger consistently and engages in much worse tactics, but that is really beside the point.)

    Then why did you make the following statement?

    Eric Steig responded inline to 49:

    Note, however, this none of this has anything to do with Andregg et al., except that, if in fact he gets classified as a ‘denier’ in their analysis, this is probably why.

    The paper only mentions the term “denier” along with “skeptic” and “contrarian” in passing — as terms which get used elsewhere — and instead chooses to frame things in terms of those who are convinced or unconvinced by the evidence. Moreover, the paper does not speak of Roger Pielke Sr., he is not mentioned in the supporting information, and it is only by following a link from the paper itself to the supporting information, then from the supporting information to the website that you will find Roger Pielke mentioned — and there you will also find that he is listed because he signed:

    Statement by Atmospheric Scientists on Greenhouse Warming (1992)
    http://www.sepp.org/policy%20declarations/statment.html

    Furthermore even at that website, Jim Prall himself speaks in terms of “skeptics”, not “deniers” — although in truth the latter would usually seem to be far more appropriate of those who choose to call themselves “skeptics” — but at present I will simply speak of them as contrarians.
    *
    It would be absurd to claim that the lists created by the contrarians are blacklists. It is equally absurd to claim that a paper that analyzes those lists but does not actually include them or any of the names that are on those lists itself constitutes a blacklist.

    The contrarians themselves created those lists in order to create the appearance the scientific community is largely divided — and thus that there is no consensus. The paper analyzes this in terms of the authors that actually count and the degree to which they should be counted — given how prolific the authors are and how often they are cited. It demonstrates that what few climatologists disagree with the consensus constitute a tiny fraction of scientists working in climatology — and thus that the consensus is quite real.

    Contrarians have no argument against this — and therefore have come up with the absurd claim that the authors were creating a blacklist. And in the New York Times — you gave that claim something that they themselves were entirely incapable of: an air of legitimacy.

    I have a great deal of respect for your work and no doubt will continue to do so. However, on this point I must most vehemently disagree.

    [Response: Tim. I understand your pionts, but please do not climategate me. By that I mean, do not make me explain each and every word I write and how they may or may not relate to something else you think I meant to say. Again, I think the claim that the paper and the web site that it links to (yes, it does link to it) are totally separate entities is not justifiable. I'm sorry if you think I've given the 'skeptics' ammunition, but first of all, I simply cannot be silent about something that I think is quite egregious. I bite my tongue quite often on minor issues, but in this case I frankly thought the Prall (specifically) stepped over a very serious ethical line. I have gotten enough questions about why I think this that I suppose I need to write something up on this, but it won't be here at RealClimate. It'll be an opinion piece for the Times or something. And it will take me a while to write it. As I've discovered recently, just about anything I say can and will be used against me -- and indeed against scientists in general -- by very adept crafters of rhetoric. I won't name names. ;) --eric]

  34. 134
    Gilles says:

    #BPL128 “BPL: Are you sure there aren’t very hungry people in the world that would be very happy to eat human beings of other ethnic groups?”

    sorry BPL, I don’t catch the comparison. Naturally if half of the world were eating other human beings, it would be totally unfair to forbid the other half to do so for moral reasons.

    The consumption of oil wouldn’t be forbidden – it would still be burnt at a pace of 25 Mbl/d in my example. So my question is : who would be entitled to burn these 25 Mbl/d and who couldn’t do it, if we are able to produce 50 Mbl/d ? how concretely would you prevent them to do it ? (of course the question applies as long as there is a decrease of oil production : for instance the current oil production has slightly decreased because of the crisis, but is slowly recovering : if there is no geological constraint on it (I think there are actually, but no more in my example), how can you prevent the economic growth to raise naturally the need for oil ? I think there are enough people who want even a hybrid car to buy happily all the oil that can be economically extracted !

  35. 135
    Former Skeptic says:

    Gerard Harbison:

    You could, for instance, use your search engine of choice, type “Stephen Schneider” and click on his website.

    From there, you can click on his publications page yourself.

    I think you can find at least one “social science” based paper/book chapter in there.

    You may also wish to click the header bar – it’s right on top – and see the “Climate Policy” link for more of Schneider’s writings that are not based on the “non” social sciences.

    Lastly, some freely given advice. Try lowering your puerile snarkiness both here and in James’ blog. This, combined with your laziness in a task as simple as searching for Schneider’s social science publications, is really beneath someone who (ironically?) claims to be a professor.

  36. 136

    So to cut through the waffle, he’s never done any social science research.

    The theme of the PNAS paper is that CEs are more qualified than UEs to comment of climate science policy because they’ve published more research papers in the field. The PNAS paper is published in a field in which none of the authors have ever published a single piece of prior research. This is beyond irony; we have here a paper invalidated by its own premise.

    Substantive criticisms have already been pointed out here: determining current attitudes to AGW based on past signatures to a very diverse series of letters/petitions over twenty years is methodologically suspect, and it is my understanding that this is not an accepted sociological method of determining attitudes. The methods for assessing productivity are also suspect. I highly doubt this paper would have survived actual peer review.

  37. 137
    Timothy Chase says:

    Eric Steig wrote inline to 134

    As I’ve discovered recently, just about anything I say can and will be used against me — and indeed against scientists in general — by very adept crafters of rhetoric. I won’t name names. ;) –eric

    They always seem to have some sort of spin they can put on things, don’t they? Take care…

  38. 138
    David B. Benson says:

    Following the title of this thread, but certainly not the comments so far, here is an article about some important people who rather deeply want to know what climatologists think:
    http://www.nytimes.com/cwire/2010/06/24/24climatewire-defense-experts-want-more-explicit-climate-m-35887.html

  39. 139
    Average Person says:

    #63

    Climate change is nothing out of the ordinary. It been occurring for millions of years, and you are asking “if there is a consistent long-term trend in the climate data.”

    It would be surprising if the was no change, given the context I provide in my answer.

    Others, however, have a different view @70

  40. 140
    Doug Bostrom says:

    Gerard:

    I highly doubt this paper would have survived actual peer review.

    Gerard, you’d be more credible if you were aware of some elementary facts, such as that Anderegg’s paper was in fact reviewed prior to publication according to PNAS’ normal process.

  41. 141
    MapleLeaf says:

    Gerard @137,

    I think what I posted over at Spencer’s page addresses your complaint, at least in part. And I do not concur that the paper is invalidated by its own premise, that sounds like some pretty fancy spin to me— this paper is not a climate science paper. Contrarians/”skeptics” want it both ways– first they make the excuses that publications are not a good metric of expertise (see below) and then they use the fact that the authors have few publications to dismiss this paper. Please do make up your mind!

    Anyhow, here is what I wrote to Spencer:

    “This from the BBC concerning the paper in question:

    “Sceptical groups, however, argued that publication in scientific journals was not a fair test of expertise.”

    So I find it rather bizarre that people here are lamenting about the alleged “ivory tower” in climate science, yet here you are here claiming that someone with “only” a MSc and no prior publications is incapable of doing research. That strikes me as not only contradictory, but also rather hypocritical. You also allege that Anderegg made “serious allegations”, but provided no evidence of such allegations.

    You might also be surprised how many scientists having Master’s degrees do publish (and very successfully I might add) in reputable peer-reviewed journals. Some of them even prior to completing their degrees (whether it be a MSC or PhD).

    Instead of making baseless ad hominem attacks [edit], please at least try tackle their work. And please remember that all young scientists have to start somewhere, and rather than attacking them as you are doing here one should be encouraging/supporting them.”

    You also conveniently ignore the inconvenient fact that the findings made in this paper corroborates findings made by previous efforts.

    I encourage you to read the views of Dr. Michael Tobis on this.

  42. 142
    David B. Benson says:

    gain off-topic, but this happens to be about what happened at a particular time long ago of great inerest to me:
    Higher Wetland Methane Emissions Caused by Climate Warming 40,000 Years Ago
    http://www.sciencedaily.com/releases/2010/06/100624144105.htm

  43. 143
    J says:

    Re:>>> “I like Robin Hanson’s idea or having betting markets on climate change.”

    Here you go, offer your wager:

    http://www.longbets.org/bets

  44. 144
    Ray Ladbury says:

    Gerard Harbison, This paper is not really a piece of “social science” so much as it is sociology of science. It is not saying much different from what I have been saying all along. That is: that publication in scientific journals on a subject and citations are good metrics of a scientist’s expertise in a field. There are good reasons to expect this–namely that the scientist with the most fruitful ideas is likely to be the one publishing most frequently and having the most influence in advancing the field. On the other hand, if a researcher is unproductive, it may be a sign that their ideas are not fruitful.

    This is clearly the case in climate science: you simply cannot understand Earth’s climate without CO2 providing significant forcing.

  45. 145
    Gerard Harbison says:

    @141

    Doug: you’d be more credible if you knew how the PNAS ‘peer review’ scam works. Have you ever published in PNAS? No? I have. Schneider, as a member, selected his own two reviewers. One of the could have been his mom, for all we know.

    [edit]

  46. 146
    Walter Crain says:

    what will be the worst effects of global warming?

    sea level rise? species extinction?

    ***PROJECT JIM!***

  47. 147
    Gerard Harbison says:

    Gerard Harbison, This paper is not really a piece of “social science” so much as it is sociology of science.

    When you’re counting angels on pinheads, Ray, you’ve lost contact with the real world.

    FWIW, I am not a climate skeptic. I am a scientist who cares about the integrity of science.

  48. 148
    caerbannog says:


    FWIW, I am not a climate skeptic. I am a scientist who cares about the integrity of science.

    Then certainly, you have expressed concerns about global-warming “skeptic” papers like McLean/de Freitas/Carter 2009, Soon/Baliunas 2003, etc., etc. that were published in spite of the fact that they contained errors that an undergraduate would be dinged for at any respected university…

  49. 149
    Former Skeptic says:

    Gerald Harbison:

    Strike two.

    Anderegg et al. was peer reviewed in the proper manner. In fact, one of the reviewers (a noted social scientist) even posted his comments.

    A little bit of research – which you appear reluctant to do, in spite of your incessant harrumphing – would have told you that.

    Instead of pontificating about the integrity of science, or trying to impress us about the PNAS review process, which most of us here know about…how about thinking before you post next time?

  50. 150
    Frank Giger says:

    Eric’s response in 147:

    “As I’ve discovered recently, just about anything I say can and will be used against me — and indeed against scientists in general — by very adept crafters of rhetoric.”

    And it should be! The very second anyone begins writing on the opinion page of the Times they’ve crossed the rubicon into politics. Sorry, one does not get untouchable status within the political realm due to a Ph.D.

    [Response: A fair point. But I'm not objecting to people criticizing me, disagreeing with me, or even calling me an idiot. I'm objecting to people twisting my words to mean something different from what was obviously intended.--eric]


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