On the value of consensus in climate communication
After our Consensus paper was published with extensive media coverage, law professor and climate communicator Dan Kahan posted an emotive blog post (he characterised it as a "haughty outburst"). He questioned the value of a study measuring consensus and whether consensus is something climate communicators should be emphasising.
Once Dan had a chance to calm down, we corresponded about his post and he suggested he summarise his views in a 4-point article that I could respond to. Dan's 4 point critique of Cook et al. and my response have now been posted on his blog. He also included a response from science journalist Scott Johnson. I recommend you head over to Kahan's blog post summarising all three viewpoints, but here are a few choice excerpts.
In his four points critiquing Cook et al. (indulge me in a paraphrase), Kahan questions how much scholarly value there is in our paper, suggests that the reason for the consensus gap is not a lack of information but cultural and that consensus messages can be polarizing. Here are a few excerpts:
The Cook et al. study, which in my view is an elegantly designed and executed empirical assessment, doesn’t meaningfully enlarge knowledge of the state of scientific opinion on climate change.
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That message—that there is a scientific consensus on climate change—has been the centerpiece of climate-science communication for over a decade. There have thousands upon thousands of stories in the media reporting this contention. The divided state of U.S. public opinion hasn’t changed.
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Second, I think a science communication strategy that makes “getting the word out” on scientific consensus can easily aggravate the antagonistic cultural meanings that generate polarization.
In my response to Kahan's criticisms, I outline some of the scholarly contributions of our paper (there are plenty, IMHO), demonstrate with my own research how the consensus gap is a product of lack of information *and* cultural bias, explain how the consensus gap has persisted despite consensus being "the centerpiece of climate-science communication for over a decade" and look at research linking perception of consensus with support for climate policy. Here's some excerpts including a nifty new graph (if you're going to say I excerpt my own content more extensively than the others, well, guilty as charged):
The following graph plots perceived scientific consensus from a survey of a US representative sample versus support for free markets (-1 is equivalent to extreme liberal and 1 is equivalent to extreme conservative). I’ve included a green dotted line indicating the 97% consensus (I can never resist adding some bling to my graphs).
Several features jump out from this data. We confirm recent studies and public surveys that find a significant relationship between perceived consensus and free market ideology (p < .00001). Also, it’s hard not to notice the sharp drop in perceived consensus for participants with very strong support for free markets (e.g., extremely conservative).
However, the key feature for the purpose of this discussion is that even for liberals, there is still a large gap between perceived consensus and the 97% reality. This indicates that there is still a significant lack of awareness of consensus, even among those whose cultural values are predisposed to agree with AGW.
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If the public have heard ‘over & over & over that there is "overwhelming scientific consensus" on AGW’, then why is public perception of consensus so low, even among liberals? A significant contributor is a focused and persistent misinformation campaign designed tomanufacture doubt. Science communicators are not operating in a vacuum but competing in a marketplace of ideas.
As early as 1991, Western Fuels Association spent $510,000 on a campaign to “reposition global warming as theory (not fact)”. The infamous Frank Luntz memo urged Republican politicians to “…make the lack of scientific certainty a primary issue in the debate.” In an analysis of syndicated conservative opinion pieces, the most popular myth was “there is no consensus”. Lobbyists sought to undermine Obama’s climate policy by attacking the consensus, arguing “If we win the science argument, it’s game, set, and match.”
It’s becoming increasingly apparent that attacking the consensus has been a central strategy of opponents of climate action.
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A key point that mustn’t be overlooked is that two studies (Ding et al 2011 and McCright et al 2013) have shown that perception of consensus is linked to support for climate policy. When people understand that climate scientists agree on human-caused global warming, they are more likely to support climate action.
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This is not to say that consensus is a magic bullet that will solve all our problems and usher society into an environmental utopia. If only things were that simple! But by reducing the consensus gap, we are removing a significant roadblock to public support for climate action.
Lastly, Ars Technica science journalist Scott Johnson also submitted a response to Kahan's criticism of Cook et al. Here are some excerpts:
That brings me to the charge that if informing about the consensus was worth doing, it would have worked by now. (“Worked” here meaning a large shift in public opinion, I assume.) I can’t categorically agree. Einstein’s definition of insanity may have been “doing the same thing over and over and expecting a different result”, but in the business world, this behavior also goes by the name of “marketing”. (To some extent. It’s a stretch—just humor me.)
Repetition of a message can be beneficial. I could be wrong, but I’m not completely sold on the idea that all members of the public have received plenty of information about the scientific consensus before.
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Dan has agreed, I think, that information about the scientific consensus is important, so shouldn’t we be arguing about how to communicate it rather than whether to communicate it? If this story is really a waste of time, isn’t it the fault of the journalists who covered it poorly rather than the study itself? If the argument is that this study represents no value-added over previous ones, I think it’s at least the best study to date. (The tremendous transparency alone makes it valuable.) If so, its newness represents a news hook and a communication opportunity, which is why I felt it was important to cover it.
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It’s my feeling that “preaching to the choir” should get more respect. We’re worried about issues on which public opinion is out of sync with the existing science, so we’re naturally focused on the dissenting side of the opinion spectrum. I don’t think the concurring side of the spectrum is irrelevant.
One thing we all agree on is that the consensus message won't fix everything. It's not a magic bullet solution - closing the consensus gap is simply about removing a roadblock to climate action. I also agree with Scott that the issue is not whether we should communicate consensus but how we should communicate it. And that is an area of open research.
Check out all three responses in full at Dan Kahan's blog.
Note that a high-rez version of the graph of perceived consensus versus free market support is available in our collection of consensus infographics, which are all creative commons licensed and free to be reused.
Posted by John Cook on Thursday, 23 May, 2013
