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No matter how strong the evidence on climate change, deniers will keep denying

When President Obama last week tweeted that “97% of scientists agree: climate change is real, man-made, and dangerous” it drew the attention of his 31 million followers to the most recent study pointing…

Sometimes even the clearest signs of change are ignored. Flickr/baldeaglebluff

When President Obama last week tweeted that “97% of scientists agree: climate change is real, man-made, and dangerous” it drew the attention of his 31 million followers to the most recent study pointing to the consensus in climate science.

The study, by John Cook and colleagues, gathered all 12,000 scientific articles published on “global climate change” or “global warming” between 1991 and 2011. The authors then focused on the studies that expressed a position on the basic premise that humans are causing climate change. Of those roughly 4,000 papers that took a position, more than 97% endorsed the consensus. (The articles that did not express a position addressed other issues such as new measurement techniques for polar ice.)

The same figure was obtained when the original authors were asked to classify their own work. Again, more than 98% of authors classified their articles as having endorsed the consensus.

On one hand this result is old news because we have known about the overwhelming consensus in climate science for many years. Study after study points to more than 95% agreement among scientists or publications.

But it is important to periodically underscore this because there is evidence that the public is quite sensitive to the breadth of a scientific consensus. If people believe scientists agree on an issue, then their own belief follows suit. If people perceive disagreement among scientists, they withhold their endorsement of the issue, and fail to demand action from governments.

Notably, this association between perceived consensus and the acceptance of scientific findings appears to be causal. In one of my studies, when participants were explicitly informed about the scientific consensus on climate change, they became significantly more likely to endorse the basic premise of global warming. They also attributed a larger share of the observed warming trend to CO2 emissions than people in the control group who hadn’t been informed.

Underscoring the consensus in public communication of climate science is therefore an important tool to counter the disinformation that suffuses the media and the internet.

Debate is debate, but facts are facts

But what exactly is a consensus? If science really is debate, then how can there be scientific debate in the presence of a consensus? Does a consensus imply hegemony and rigidity?

The answer is simple. Scientific debate continues in the peer-reviewed literature and at scientific conferences, where the impact of ocean acidification, the rate that ice sheets and glaciers melt, and the prevalence of hurricanes, drought and disease are debated. Indeed, there is debate about the likely range of climate sensitivity, the temperature rise expected with a doubling of CO2 levels. But established facts - like gravity, evolution, or global warming from greenhouse gas emissions - are not debatable.

In the social sciences the debate has moved on as well. There is now considerable research focus on the variables that explain why some people choose to deny the overwhelming scientific consensus on climate change.

If 97 out of 100 scientists and 97% of peer-reviewed articles oppose your view that the climate is just fine and we have nothing to worry about, what can you do? How would you “explain away” that consensus?

It appears that in those situations dissenters often resort to the belief that the inconvenient scientific consensus is the result of a nefarious conspiracy. If a scientific consensus cannot be accepted as the result of researchers independently converging on the same evidence-based view, the idea of a complex and secretive conspiracy among researchers — often accompanied by claims that dissenting voices are censored — presents an alternative explanation for that consensus. And so 97 out of 100 climate scientists conspire to create a “hoax” called climate change. The idea that science is a conspiracy also facilitates the framing of dissenters as the unrecognised geniuses who resist a “dogma” by heroically posting the truth on their blogs.

This is why those who cannot accept the overwhelming evidence that greenhouse gases are warming the globe claim scientists fake evidence to support their political point - calling it “Lysenkoism”. Hence the tobacco industry’s insistence that medical research into the health effects of smoking is the effort of “a vertically integrated, highly concentrated, oligopolistic cartel” that “manufactures alleged evidence.” And perhaps that is why a sitting US Senator has entitled his recent book “The Greatest Hoax: How the Global Warming Conspiracy Threatens Your Future.”

How widespread is this reframing of an overwhelming scientific consensus as conspiracy? According to a recent poll, 37% of American voters believe global warming is a hoax. This figure likely represents an upper bound. My own recent data, also based on a representative sample, suggest a figure of 20%. In comparison, 10% believe US agencies intentionally created the AIDS epidemic and 15% believe that the evidence for a link between second-hand cigarette smoke and ill-health has been invented by a corrupt cartel of medical researchers.

How can scientists respond?

By definition, conspiracy theories are largely impervious to increasing amounts of evidence. Indeed, in the case of climate change, we have arguably reached the point where it is the strength of the overwhelming scientific evidence that is compelling some people to accept a conspiracy theory in preference to a price on carbon or other government regulations.

Additional evidence will not find any traction among those who think of science as a conspiracy. Instead, communicators should focus on the vast majority of people who know that when medical scientists pointed to the health risks of tobacco, they did not conspire against smokers but sought to keep them alive. And that vast majority of people also understand that, when climate scientists say that the globe is warming from greenhouse gas emissions, they are not attempting to create a World Government but are alerting us to a risk to humanity’s most basic life support system.

Join the conversation

28 Comments sorted by

  1. Bob Ashworth

    logged in via Twitter

    97% is just not a big enough scientific consensus for some. The wonderful denier machine that is the Heartland Institute, has just sent out around100,000 copies of a booklet, trying to argue against the science. Amazingly they have sent it to scientists in an apparent attempt to convince them that the 3 % have the answers!

    http://www.guardian.co.uk/environment/climate-consensus-97-per-cent/2013/may/20/heartland-institute-scientists?commentpage=1

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    1. William Hughes-Games

      Garden weed puller

      In reply to Bob Ashworth

      Scientific consensus is a pretty poor argument for any scientific subject. It has been wrong so often in the past that I am surprised we even mention it. The plain visible evidence is so overwhelming that we would be better to just keep pointing this out. What will convince the public is a few more extreme weather events despite the fact that individually, they are also a very poor argument that climate change is happening. The stats regarding the frequency of these events is a much better argument but so much less visceral for most of the public. We need some more mini disasters before we are overcome be a huge climate shift which will really trash our society. It is probably too late anyway.
      http://mtkass.blogspot.co.nz/2013/04/the-beauford-gyre.html

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  2. Lauren Hodgson

    Spatial Ecologist

    Thanks for this article, especially for the 'how can scientists respond' section.

    Has there been any work to tease out why this figure of those who believe climate change to be a hoax is so high in comparison to other similar, popular beliefs?

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    1. Sean Lamb

      Science Denier

      In reply to Lauren Hodgson

      Funny you should mention that because there is a 2nd rate academic who passed a link to an online survey to a handful of blogs.
      IIRC he found around 500 people who hold free market ideology also denied AGW. He also found around 10 people who disbelieved the Moon Landing that denied AGW - these 10 people were apparently so significant that he made them the focus of his paper. He also found more people who believed the US administration had prior knowledge of the 9/11 attacks believed in climate…

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  3. Darren Kay

    Private trader

    It's good to see the results of this study corroborating the earlier work done by N. Oreskes. However I'm skeptical how much of an impact this study will have on climate change deniers whose views are firmly entrenched. Two reasons:

    1. Motivated reasoning and confirmation bias means they will continue to discount or avoid news which doesn't reinforce their current beliefs.

    2. Recent studies have linked conservative thought with low-effort thinking and a need for closure. This corroborates…

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    1. Stephan Lewandowsky

      Chair of Cognitive Psychology at University of Bristol

      In reply to Darren Kay

      The World Government certainly features in conservative thought, but then again the "9/11 was an inside job" theory is primarily anchored on the political left. There tends to be no consistent association between political leanings and endorsement of theories in general. Some studies go one way, some the other, but overall I do not believe it's reliable either way. Some specific theories are favoured by one or the other political side, sure, but not the overall propensity to endorse theories.

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    2. Glenn Tamblyn

      logged in via Facebook

      In reply to Darren Kay

      Darren

      This study will have no impact on the hard-core deniers. Their thinking processes have been described as 'self-sealing' and they have used multiple tubes of superglue to do the sealing.

      The point of the study, as a communications exercise, is to influence the opinions of the much larger number of folks who are only mildly skeptical, or are disengaged, or have actually been conned into thinking that there is still an active debate about the science.

      Surveys of the public suggest that many people think the views amongst the scientific community about AGW are more like 50/50 rather than 97/3. The paper is attempting to give the general public a better understanding of how much consensus there is.

      But the hard core deniers? They are unreachable.

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  4. Chris Devery

    logged in via email @tpg.com.au

    An eroding island in Chesapeake Bay is no evidence for climate change, in spite of the title "Sometimes even the clearest signs of change are ignored".

    In fact, the erosion of the island started in 1914, and the island was more or less abandoned by 1918, so events there have no relevance for the current debate. Not a good start to this article, which is more of the usual from Lewandowsky.

    "The land of the island has been subsiding as a result of post-glacial rebound, the return to normal of bulges created by the weight of glaciers elsewhere during the last ice age. This process has caused a major loss of land on the island." Courtesy of Wikipedia.

    In fact recent research regarding sensitivity of climate change to CO increase is rather supporting the skeptical case.

    You can see a summary here:
    http://bishophill.squarespace.com/blog/2013/5/20/reactions-to-otto-et-al.html

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    1. Mike Hansen

      Mr.

      In reply to Chris Devery

      Pretty sad if the only criticism you are able to make of Stephan's article is the graphic that the editors would have added.

      But it is good to see that you are keen on the new sensitivity study. I gather that you would endorse the author's comments.

      "We would expect a single decade to jump around a bit but the overall trend is independent of it, and people should be exactly as concerned as before about what climate change is doing," said Dr Otto.

      Is there any succour in these findings for climate sceptics who say the slowdown over the past 14 years means the global warming is not real?

      "None. No comfort whatsoever," he said.
      http://www.bbc.co.uk/news/science-environment-22567023

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    2. Chris Devery

      logged in via email @tpg.com.au

      In reply to Mike Hansen

      Well, Stephan has his own problems getting his own studies published, and Cook's paper is also very questionable. However, the graphic is a clear attempt to frame the article's message and the fact that it is irrelevant and questionable immediately undermines it. Come to think of it, the metaphor of a crumbling building is quite a nice one given the increasing uncertainty which is becoming apparent in the AGW story.

      That's why the Otto paper is significant. It makes a great deal of difference…

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    3. Mike Hansen

      Mr.

      In reply to Chris Devery

      So to recap Chris.

      Firstly I should drop my scientific skepticism because, out of the many papers on climate sensitivity published each year some higher than the IPCC, some lower - this is the anointed one - in your words the "significant" one.

      And secondly I should not listen to what the paper's lead author says about the paper - I should listen to a failed banker's interpretation.

      OK got that.

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    4. Mike Hansen

      Mr.

      In reply to Michael Craig

      This is Annan's comment in the discussion. Which has been his position for a while.

      "2.5 [for ECS] is still fine by me, though I wouldn't be surprised by a value a bit lower or higher. I don't think the recent decade really changes the best estimate all that much, but it helps to confirm what sensible people were saying several years ago about extremely high values"

      You may be interested in Dr Otto's article on the Met web site.
      http://www.metoffice.gov.uk/research/news/alex-otto-article

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    5. Barry Woods

      logged in via Twitter

      In reply to Chris Devery

      Actually the title of the article is problematic.. and comes across as polarising and politicised rhetoric by a psychologist who should absolutely understand the problem with it.

      Ie who denies the fact that climate changes.

      Papers like Cook's just seem another thinly disguised attempt to persuade the public of a 'false consensus' ie making claims beyond what the paper actually surveyed.. for the purpose of encouraging policy action (which Cook describes as the purpose in his leaked forum emails…

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    6. Glenn Tamblyn

      logged in via Facebook

      In reply to Barry Woods

      Barry

      You have missed Jo Codling (Nova), Climate Audit and Climate Depot. Anyone else you have missed out on in your shopping trip across the Denialosphere?

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    7. Barry Woods

      logged in via Twitter

      In reply to Glenn Tamblyn

      Hi Glenn
      The most critical comments of Cook's and Lewandowsky's work I quoted were by 2 very well respected professors, (tol & Betts) both longstanding IPCC lead authors and contributing lead authors, perhaps you could address there criticisms.

      As you brought up those other blogs, perhaps we should both declare interests to any casual reader.

      You presumably Glenn Tamblyn, a regular author at John Cook's blog sceptical science (did you contribute on this paper) and I write occasionally for…

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    8. Geoff Chambers

      retired

      In reply to Barry Woods

      Barry
      Perhaps you and I should also declare our interests!

      Like you, I was identified by name in the second article by Lewandowsky (and Cook) as being guilty of conspiracist ideation in five of its different forms, namely “nefarious intent; nihilistic skepticism; ‘must be wrong’; ‘no accident’; and unreflexive counterfactual thinking”.

      It’s also worth pointing out that this second article, which represents Lewandowsky’s latest word on the mindset of us denialists, has been twice revised…

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  5. Evan Keith Beaver

    logged in via Twitter

    Interesting piece, thanks.

    Further anecdotal evidence to the assertion that "facts won't change people's minds if they see a conspiracy". I have spent a good (or bad, depending on your POV) deal of time arguing with skeptics on the internet, with one thrust in mind: If CO2 emissions were really raising global temperatures, what would be evidence of this". And similarly "what evidence would convince you that climate change is real?". Not one has ever answered either question.

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  6. Josie

    logged in via Twitter

    Thanks for this. I would add a couple of things.

    a) I think that the important thing is not just the strength of the consensus, but the SIZE of climate science. Many past consensuses have been wrong, but most of them were only consensuses in the sense of "97% of papers support it, but that is, in total, 6 papers".

    b) Conspiracy theorists are immune to evidence

    I disagree with you here. They are certainly harder to get through to - they are difficult, at the far end of the distribution…

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    1. Stephan Lewandowsky

      Chair of Cognitive Psychology at University of Bristol

      In reply to Josie

      hmm. i dont think i said "completely immune" but "largely impervious"? Subtle distinction, perhaps, but i agree that "completely immune" would be far too strong. It's just as a first approximation, by definition, further evidence does not dislodge a conspiracy theory. One of the best papers on this is by Sunstein and Vermeule (Conspiracy Theories: Causes and Cures Journal of Political Philosophy, 2009, 17, 202-227). They spend quite a bit of time talking about how one might rebut such theories. I largely agree with their approach.

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  7. William Hughes-Games

    Garden weed puller

    Science unexamined is science debased. Most of the climate denier comments are laughable but some have come up with genuine chinks in the paradigm. They have forced us to re-examine the data, look for more information and basically have kept us honest. Humans have a sad inherent tendency to turn their beliefs into a religion and we are no less prone than they are. As annoying as they are, we owe the deniers. You might define science as a belief system that is not allowed to become a religion. What a true scientist believes can be changed as more information comes to light. Consensus has very little to do with science. It has been wrong time after time.

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  8. Geoff Chambers

    retired

    Professor Lewandowsky is too modest to say so, but the research which demonstrates (in the case of climate change denial) that “dissenters often resort to the belief that the inconvenient scientific consensus is the result of a nefarious conspiracy” is contained in two papers of which he is the lead author. These can be found at
    http://websites.psychology.uwa.edu.au/labs/cogscience/documents/LskyetalPsychScienceinPressClimateConspiracy.pdf
    and
    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3600613

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  9. Thomas Fuller

    Managing Director

    Depending on how the question is phrased, 97% of skeptics would agree with the proposition. Almost all skeptics acknowledge that the globe has warmed and almost all skeptics understand that an increase in CO2 concentrations has contributed to that warming.

    How much and to what end is a different story.

    IPCC Lead Author has pretty much shown how hollow Cook's compendium of climate change papers is. Hence, the conversation needs to move past it--it is not even wrong, and it is certainly not useful…

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  10. William Hughes-Games

    Garden weed puller

    We are only a week at most away from the date when, last year, the ice extent took a sharp down turn. Then on Aug6, the force 2/3 hurricane (964mb) occurred and sent the graph plummeting even more quickly. After an extreme event like this one, a random system would be expected to revert to be closer to the mean. A system with a feedback towards melting, by contrast would be expected to be very similar or worse than last year. It will be a brave or foolhardy climate denier that will put his head above the parapet if this year results in even more melt than last year.

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  11. Geoff Chambers

    retired

    Ten days ago I asked if it would be possible to have the basic demographic information on the respondents to this survey, but there has been no reply.

    All we know about respondents is that they were obtained from seven blogs and some tweets, that about 15% of the sample was discarded for attempted cheating, and a further sixty responses obtained from people contacted at the University of Western Australia were also discarded, because sixty is a small number. (Though ten wasn’t considered too…

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