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The Continuing Denial of the Scientific Consensus on Climate Change

Posted on 16 August 2012 by Andy Skuce

One of the perennial Skeptical Science top ten climate myths is “There is no consensus” (currently at number 4 in popularity). Consensus means the elements of knowledge that research scientists tend not to discuss or actively investigate any more. Consensus is the stuff that fills textbooks and is the established knowledge that teachers try to cram into high school and undergraduate students’ heads. It doesn’t mean an impregnable bastion of knowledge—there are many well-known examples of consensus-changing revolutions in the history of science—and even school textbooks have to get updated every now and then.

Consensus doesn’t mean unanimity, either. There is always a minority of gadfly scientists who decide to take on the consensus: scientists who challenge the biotic origin of oil or medical researchers who doubt HIV as a cause of AIDS. In such cases, the contrarian scientists don’t typically deny the existence of the consensus; they just think that the content of it is wrong.

Nor does consensus mean that everybody is happy with every single element that others believe to be settled. Consensus in any field has a hard core but fuzzy edges.

There have been a few studies that have attempted to measure the degree of scientific consensus on climate change. Naomi Oreskes in 2004; Doran and Zimmerman in 2009; Anderegg et al in 2010; and the Vision Prize in 2012. All found evidence for a very strong consensus among climate scientists for the idea that recent climate change can mostly be attributed to human activities (see the recently updated rebuttal written by Dana Nuccitelli for details).  Most of the world’s scientific academies have made explicit affirmations of the consensus on climate, along with numerous scientific associations.  The IPCC reports are a major effort to define the extent of general agreement and to identify the areas of remaining uncertainty.

Yet, contrarians persistently deny that a consensus exists among climate scientists. In particular, they maintain that climate scientists are deeply divided even over the high-level conclusions to be found, for example, in the Summary for Policymakers sections of the IPCC reports.  The consensus-denial tactics involve minor criticisms of sample size and methodology of the published consensus studies, hyping the work of the few dissenters and citing surveys of non-specialist scientists and engineers. None of this criticism makes a dent on the massive and obvious evidence for consensus.

For example, see a recent article debunked by the blog Watching the Denierswhere somebody had cherry-picked skeptical quotes from a few scientists who responded to the Doran and Zimmerman study (Eos, January 20, 2009). This only reveals that some people confuse consensus with unanimity

A recent Wall Street Journal op-ed by Roger Cohen, William Happer and Richard Lindzen was headlined 'Climate Consensus' Data Need a More Careful Look. They dismiss the consensus with the straw-man argument that consensus is simply the repetition of a single fib, while making the false claim that:

It is increasingly clear that doubling CO2 is unlikely to increase global temperature more than about one degree Celsius.

As if there was an emerging body of literature or multiple lines of evidence pointing in that direction: their claim seems to be based on a single publication, Lindzen and Choi 2011. As Dana Nuccitelli wrote here in his article on that paper:

Since the body of research using multiple different approaches and lines of evidence is remarkably consistent in finding an equilibrium climate sensitivity of between 2 and 4.5°C for doubled CO2 (whereas a 'low' sensitivity would be well below 1.5°C), climate contrarians reject the body of evidence by (falsely) claiming it is based on unreliable models, and attempt to replace it with this single study by Lindzen and Choi under the assertion that it is superior because is observationally-based.

At least Cohen, Happer and Lindzen do not deny the existence of a scientific consensus, even if they disagree with its content. That's more than can be said for some commentators, as we shall see.

Larry Bell in Forbes

A recent article by Larry Bell in Forbes went over the now-familiar ground of denying the consensus on climate change. He criticized the Doran and Zimmerman study for having too small a sample size and for asking vague questions (although, as I will discuss below, he is forgiving of similar questions and  sample sizes of a study done by the Association of Professional Engineers, Geologists and Geophysicists of Alberta (APEGGA)). He cited the Oregon Petition, debunked here, while ignoring the work of Oreskes (2004) and Anderegg et al (2010). He cited the Polish Academy of Sciences PAN Committee of Geological Sciences, while ignoring the position of the General Assembly of the Polish Academy of Sciences, which endorses the IPCC conclusions, along with many other national science academies.

Most of Bell’s arguments have been debunked before and there’s little point in discussing them here again in detail. However, I have some personal familiarity with APEGGA, having been a member of this organization for many years, so I will look at that case of a supposedly dissenting scientific organisation in more detail.

APEGGA and climate science

APEGGA (now APEGA) is a professional body that regulates the practice of engineering and geoscience (previously geology and geophysics) in the Canadian province of Alberta. Approximately 90% of the professional members are engineers and 10% geoscientists. By provincial law, anybody who works as an engineer or geoscientist in Alberta must be a member of the association, including academics. As might be expected in a province that employs thousands to exploit the largest deposit of bitumen on the planet, there is widespread “skepticism” of anthropogenic climate change among the membership. These views frequently manifest themselves in the organization’s newsletter, sometimes associated with accusations of fraud directed at climate scientists, along with pseudo-science on climate change and, sometimes, young-Earth geochronology. I protested about this in a letter published in the June 2010 edition of the association's news magazine (page eight).

Larry Bell wrote:

 A March 2008 canvas of 51,000 Canadian scientists with the Association of Professional Engineers, Geologists and Geophysics of Alberta (APEGGA) found that although 99% of 1,077 replies believe climate is changing, 68% disagreed with the statement that “…the debate on the scientific causes of recent climate change is settled.”

The survey report is here. Note that just a self-selected 2% of the membership responded to the survey, only 15% (about 160) of whom were professional geoscientists. Many of these engineers and geoscientists would likely be oil industry employees with little professional knowledge or expertise in climate science.  The survey reported:

There is even less agreement as to the cause: 27.4% believe it is caused by primarily natural factors (natural variation, volcanoes, sunspots, lithosphere motions, etc.), 25.7% believe it is caused by primarily human factors (burning fossil fuels, changing land use, enhanced water evaporation due to irrigation), and 45.2% believe that climate change is caused by both human and natural factors.

Bell’s conclusion that:

Only 26% of them attributed global warming to “human activity like burning fossil fuels.”

is not correct; in fact, 71% accepted at least some degree of a human role by selecting either “primarily human” (25.7%) or “both human and natural” as causing global warming. The problem here is that even mainstream climate scientist would have been able to vote for “both human and natural”. Nobody denies that solar variations and large volcanic eruptions have played a measurable role in modern climate change. The question is poorly worded, a problem Bell skips over in this case, perhaps because he approves of the result.

The main problem, however, is in citing the opinions of a small, self-selected group, predominantly of engineers, on a subject in which they have little professional expertise. We should heed this survey to the extent that Alberta’s engineers might be expected to pay attention in the unlikely event that atmospheric scientists try to  tell them how to build pipelines.

The hallmark of a professional engineer or scientist is in knowing his or her limits of competence. When APEGGA’s then executive director, Neil Windsor, quoted in the Forbes article, declared as a result of the 2008 survey, that: “There is no clear consensus of scientists that we know of”; we should perhaps read it as a confession of ignorance rather than the comment of an informed expert.

Why is the climate science consensus important? 

The public understanding of science is not, alas, very good. When it comes to understanding basic science, even Harvard graduates, for example, may have difficulty explaining why the Earth has seasons. In a recent study by Daniel Kahan, "scientific literacy" was determined by asking rather simple questions, in this case, only 32% knew that the Earth goes around the Sun one time per year. See also the study Americans' Knowledge of Climate Change (pdf 8MB).

Climate science can be very difficult to understand, with many people, even experts, occasionally struggling to explain a consensus concept such as an anthropogenically cooling stratosphere. Nobody can grasp it all; we all have to accept parts of the subject largely on trust. Even though consensus doesn’t logically entail certainty, it’s a good enough indicator for most of us to accept the scientific consensus as the most reliable knowledge available.

On the other hand, if somebody rejects the consensus view, they are claiming that they can see flaws and weaknesses where the majority of experts sees none. Convincing others (and perhaps themselves, first) that there’s actually no scientific consensus may help deflect charges that their opinions are merely fringe views.

The reality, of course, is that there is indeed a very well-documented consensus on climate change. The public is misinformed of this fact through the deliberate dissemination of manufactured doubt by fake skeptics, which is amplified by false balance reporting in the media (Boykoff and Boykoff, 2004). For most non-scientists, their decision to accept or reject the scientific consensus on climate change is inseparable from their awareness of the existence of the consensus itself. For this, the general public is largely at the mercy of the media. 

A survey of 1010 American adults conducted in 2011 by Yale and George Mason Universities, revealed (Question 31) that only 15% of those polled believed that 81% or more of "climate scientists think that global warming is caused mostly by human activities". Although it may be asking too much of today's financially stressed print and broadcast media to report on the complex details of climate science, surely reporters could at least write accurate stories on the state of the scientific consensus. 

Nobody has to take the media's word for it, though. Anyone can spend a day at a big scientific conference, like the AGU Fall Meeting, listen to some talks, question scientists in the hallway and eavesdrop at discussions in the poster sessions. The visitor will see scientists engaged in heated discussions about almost everything. What they won't observe are scientists wasting time debating any of the most used Skeptical Science climate myths

Taking timely action to avert the worst consequences of climate change requires good public policy. Policy change requires widespread public support. That support will not be sufficient until the broad scientific consensus on climate change is recognized as a fact.

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Comments 1 to 24:

  1. Another one is American Institute of Professional Geologists, whose tagline is "competence, integrity, ethics."

    Read pp.78-81 of the PDF @ Fake science, .... basically, a subgroup got their information from Heartland, synthesized it, passed it to legislators. The effort's leader got an award from the national organization.
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  2. Forbes has really become a mouthpiece for Heartland Institute climate misinformation. If you see a climate-related article on Forbes, odds are very good that it's written by somebody with zero climate expertise, whose salary is paid by the fossil fuel industry, and that the content of the article is entirely wrong.
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  3. Steve Forbes gets info from his buddy George Gilder (or his daughter). Gilder got it from Art Robinson. See first few minutes of this video. So, no surprise.
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  4. Just to re-emphasize the points you make in the final section "Why is the climate science consensus important?", and your closing paragraph...

    cf. Support for climate policy and societal action are linked to perceptions about scientific agreement, Nature Climate Change, November 2011.

    Abstract: "Although a majority of US citizens think that the president and Congress should address global warming, only a minority think it should be a high priority. Previous research has shown that four key beliefs about climate change - that it is real, human caused, serious and solvable - are important predictors of support for climate policies. Other research has shown that organized opponents of climate legislation have sought to undermine public support by instilling the belief that there is widespread disagreement among climate scientists about these points — a view shown to be widely held by the public. Here we examine if this misperception is consequential. We show that the misperception is strongly associated with reduced levels of policy support and injunctive beliefs (that is, beliefs that action should be taken to mitigate global warming). The relationship is mediated by the four previously identified key beliefs about climate change, especially people’s certainty that global warming is occurring. In short, people who believe that scientists disagree on global warming tend to feel less certain that global warming is occurring, and show less support for climate policy. This suggests the potential importance of correcting the widely held public misperception about lack of scientific agreement on global warming."

    And from the closing paragraphs:

    "Importantly, these findings are actionable: the myth of widespread disagreement among climate scientists over whether global warming is happening has little to no basis in truth, and it emerged, at least in part, as the result of a concerted effort to deceive the public. Purposive campaigns can be mounted to correct important misperceptions.

    "... efforts to `debias' audiences should repeatedly assert the correct information for example, `the vast majority of climate scientists agree that human-caused global warming is happening' because repeated assertions, in time, become more familiar and therefore more likely to be deemed true. This strategy is consistent with the literature on public information campaigns, which has long emphasized the importance of the repetition of simple, clear messages to communicate effectively with the public."
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    Moderator Response: [AS] Fixed broken link
  5. If deniers have their doubts about Doran & Zimmerman, how hard would it be for them to try to duplicate the study, "correcting" the methodologies they find fault with, and perhaps expanding the participation? It certainly wouldn't be expensive for them - they could pay for it with the money found in the Koch brothers' couch. That they haven't even attempted to do so speaks volumes, and in fact strikes me as another nail in the coffin.
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  6. Rust@4. Thanks. That paper led me to this study: Americans' Knowledge of Climate Change (pdf 8MB), which I have added a link to in the main text.
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  7. jimspy@5

    Well, it has been tried with the Oregon Petition.

    As has been pointed out by John Cook, some skeptics like to claim that "31,487 American scientists have signed this petition" (against mainstream climate science), while in the next breath they decry the logical fallacy of argumentum ad populi (popular vote). Of course, contradictions and climate skeptic arguments have never been strangers.

    In fact, no good scientist would ever claim that something is logically true because many other people believe it. It's just that most researchers know that there are certain areas of knowledge that are so well supported by evidence that it would be a waste of effort to try to refute them.
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  8. Unfortunately there's now a media consensus that climate change is boring.

    "...surely reporters could at least write accurate stories on the state of the scientific consensus."

    Newspapers only really want to print headline grabbing stories and therefore love to report tales of scandal or the opinions of the latest eminent loon to come out with a contrarian rant. Reporters aren't encouraged to do in-depth research anymore - only to churn out copy.

    Sadly this is what informs public opinion.

    Am I being overly pessimistic? ;(
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  9. Bodhod @8 touches on a very important point. Newspapers (and other news media) value stories only on the basis of how many readers they will attract. A story about the IPCC being wrong will interest people far more than, for example, a story about Anthony Watts being wrong. The former is a "Man bites dog" story, the latter is "Dog bites man". The result is that people whose only source of information will read detailed coverage of the few errors by the IPCC, but nothing about the innumerable errors by deniers. The picture they inevitably gain is of an inaccurate IPCC, and of deniers who make few or no errors - ie, the exact opposite of the truth. This institutional bias works to miseducate the public on climate change in a number of ways. Studies that can be construed as contradicting the IPCC will get more attention than those that confirm it (even if they have to be misconstrued to contradict the IPCC). Studies that confirm the IPCC will be ignored. Those studies that give results "alarmist" enough to generate controversy will have their "alarmist" conclusions exaggerated out of all proportion to make them more news worthy; and then the same reporters will happily run stories about failed predictions, never noticing that the failed predictions are not those of the scientists, but their own distortions.

    The media make strong claims of the rights of freedom of speech, of the press, and to the right to protect their sources. There claims, however, are premised on the notion that a free press contributes to the strength of democracy. Repeated recent experience shows that a commercial press driven only by commercial considerations cripples democracy rather than strengthens it.
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  10. An article that is somewhat relevant to BodHod and Tom's comments is the paper by Freudenberg and Muselli (2010). The Asymmetry of Scientific Challenge concept (discussed in this SkS post) deals mostly with an effect that tends to draw research towards being more conservative rather than 'alarmist', but the concept is a bit similar to the media effect described above. Research that shows results to be 'about what we thought' get less attention. The closing paragraph of the SkS post is worth quoting:
    "If the intention is to offer true balance in reporting, the scientifically credible ‘‘other side’’ is that, if the consensus estimates such as those from the IPCC are wrong, it is because the physical reality is significantly more ominous than has been widely recognized to date".
    Will we see a point at which the media realises that it might be "worse than we thought" rather than the existing pseudodebate between "it's happening" and the misinformation of "it's not happening"?
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  11. By the way, Andy, your good friend Matt Ridley is at it again, this time at Wired: .

    His argument? False alarms have happened before, and lukewarmers don't get published; therefore, technology will save the day.
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  12. Thanks, DSL. That has spoiled my entire day. ;-b

    Here's a clickable link:
    Apocalypse Not: Here’s Why You Shouldn’t Worry About End Times

    Your characterization of his article is pretty good. It's mostly a polemic, cherry-picking the most extreme alarmist statements from the past and then helpfully reminding us that the world did not, in fact, end. He glosses over the fact that at the same time as these alarmist comments were made on HIV/AIDS, acid rain, DDT and the ozone layer, others were busy making unscientific and false claims that these things posed no threat at all. These counter-consensus claims were all given undue press attention and were embraced by reactionary political factions, indulging in wishful thinking in an attempt to preserve the status quo. Draw your own parallels with the climate crisis, because Matt Ridley won't do it for you.

    In the case of AIDS, for example, HIV denialism to contributed to what can only be described as an apocalypse in Southern Africa. Thanks to AIDS, there are an estimated 30 million people who no longer have to worry about the end times.


    It would be a disgraceful rhetorical sleight-of-hand to associate Ridley with the disaster made worse by fringe HIV/AIDS denialists. Nevertheless, he seems to think it is a legitimate tactic to associate anyone worried about the prospect of doubling the amount of CO2 in the atmosphere with the very worst alarmists, including Harold Camping and the Mayans.

    Ridley used to be a fine science writer. It is a shame to see him fallen to the level of a partisan hack.
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  13. "In a recent study by Daniel Kahan, "scientific literacy" was determined by asking rather simple questions, in this case, only 32% knew that the Earth rotates around the Sun one time per year"

    Oops, some unintended irony here - "revolves" is the word you want.
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  14. Some of the questions in the US survey are a bit narly, even for well-informed people.

    In the past, the Earth's climate always shifted gradually between warm and cold periods

    The answer is given as 'False', but how do you parse 'gradually'? I would have answered True, thinking that even the PETM event was a slower temp rise than current, and gotten that one wrong.
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  15. barry@14: Yes, my use of "rotate" is not right. The Kahan Study questionnaire actually said "How long does it take for the Earth to go around the Sun?" I'll change it. Thank you.

    barry@15: I agree, when I read the questions in the Yale project, there were a few instances where my initial reaction was "well, it depends what you mean".
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  16. Response to vrooomie from here, about the term "climate ostrich":

    I like "ostrichism," but the term I actually used was "ostrichitis."

    Climate deniers suffer from ostrichitis.
    It causes them to exhibit ostrichism.
    They are, in fact, climate ostriches.

    There... the climate ostrich lexicon is complete!
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  17. Of course, all that is left for debate is the precise definition, spelling and usage of ostrichcised/ostrichsized/ostricheyed.
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  18. Daniel@17: Taken over to the Dark Side = ostrichcated?...;) I think all forms must have the 'h'!
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  19. Andy, somewhat tangential, but in line with your post at 12.

    And The Band Played On

    I *lived* through those dark years, lost more than a few friends to the inactions of He Who Shall Not Be Named (as documented by Shilts, that name rhymes with Kagan), and now, ever so depressingly (except now I *are* a scientist) I'm seeing he same denialist claptrap about an issue that may well have much further effect on the planets' population, as a whole.

    Make no mistake, I do not minimize the importance of HIV/AIDS in the entire pantheon of humanity's ills, but if we make the planet hostile to just everyday life, HIV/AIDS will pale in comparison. I find it a ~very~ difficult thing to remain in my scientists' 'face of calm,' when engaging in a debate with a spittle-spewing denialist, irrespective of what verifiable scientific fact or rationale s/he may be railing against.

    I have found SkS' articles, easily-linkable and -searchable, to be an invaluable boon to my psyche.
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  20. Ostrichcised is what Pat Michaels and other deniers do to inconvenient data.

    Ostrichsized is what deniers do to the MCA (MWP for you ostriches out there), the importance of bristlecone pines, or the hockey stick.

    Ostricheyed is what deniers are when they look at rising temperatures and see natural variation, or they look at melting arctic ice and see natural variation, or they look at an ostrich-load of extreme weather events and they see... you guessed it, natural variation.

    Ostrichfied is what deniers do to any science that they choose to willfully misinterpret (such as the 2nd Law of Thermodynamics).
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  21. In the way that bovine means "like a cow", the word for "like an ostrich" is struthian (or struthious). May I suggest that when we encounter a climate, er, contrarian putting his head where the light of reason and empiricism does not shine, we now exclaim: "Struth!" (with apologies to our Australian friends).
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  22. Call me a traditionalist, but in my book one who denies a thing is a denier, pure and simple.

    And if that denial involves actively ignoring, dissembling, and/or otherwise misrepresenting pertinent content of the subject at hand, especially for the purposes of promoting to others the denialism of said subject, then that individual is a denialist.

    I'm all for enriching lexicons, but not for impoverishing them. As Tom Curtis notes, and as George Orwell classically described in his novel 1984, controlling language provides a tool for controlling thought - there's a decent little essay about it here.

    Allen Ginsberg observed a similar thing - "[w]hoever controls the language, the images, controls the race".

    So don't be afraid to recognise and announce a denier or a denialist when one ecncounters such. A spade is a spade, even when it demands to be called a manually-operated earth-restructuring/relocating implement.
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  23. When a spade is a MOERRI

    Sorry, Bernard...couldn't resist! I agree wholeheartedly, and it's this--timidity, for lack of a better term--that science/scientists ofttimes exhibit that allow denialISTS [mod: if you wish, please italicize my caps; not sure how to code for italics] to win the day. I see it over on WUWT *all the time*, where they ~whinge and whine~ about having the terrible, dastardly ad hom term "denier" flung at them, in the same breath the astonishing attacks, verifiably ad homs, get flung at The Inconvenient Data and its Messengers.
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  24. And, of course, I just discovered the link leading to the 'how to italicize schtuff', right after hitting 'send.'

    I'm just a geologist...;-)
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