Recently, we've discussed how the US public is confused about some of the basic factual aspects of climate change, from the clear indications that temperatures are rising to the fact that there's very little disagreement within the scientific community about the basic outlines of anthropogenic climate change. Now, a study suggests that there's a causal relationship between the latter and the former: people who don't understand how broad the scientific agreement is are less likely to accept what the scientists are agreeing upon.

On its face, this sounds like one of those "it took a study to show this?" moments. After all, there's a lot of literature showing that most people can't or don't understand issues in detail, and therefore they use some sort of mental shortcut to reach conclusions. In the case of scientific information, this will typically involve accepting what scientists are saying; many surveys place scientists as one of the most trusted professions in the nation.

But in many corners of the Internet, relying on expertise is dismissed as an argument from authority. And a number of science communicators (including, to some degree, the Ars staff) have suggested that the basic outlines of greenhouse warming are so simple and intuitive that the public shouldn't necessarily be forced into relying on experts. Finally, it's always dangerous to assume that you can simply reason your way to conclusions without bothering with supporting evidence.

To get some actual evidence, researchers surveyed a representative group of 750 US adults, asking them to rate their acceptance of various aspects of climate change, along with some basic demographic and political information. To an even greater degree than in other polls, this population doesn't realize that there's a scientific consensus on climate change. A full half fell into that category, with most of them thinking that there was a lot of disagreement among scientists and five percent thinking that scientists don't even think global warming is happening. Another 16 percent didn't know enough to answer.

Controlling for things like political orientation and cultural worldview didn't change the results, suggesting that people don't misunderstand the scientific consensus because they are ideologically predisposed to do so. There was also no indication that people believe there's a scientific controversy because they are mistaken about the details of climate science.

As a result, the authors suggest that people start off being confused about what the scientific community actually thinks, and that leads to confusion about the factual details of climate change. Unsurprisingly, confusion about the factual details leads to an indifference about policy solutions. Although the data don't provide a clear demonstration of causation, they're clearly not consistent with the sort of motivated reasoning that some have suggested drives climate confusion.

A couple of things are worth noting about these results. One is that they're largely consistent with the study linked in the top paragraph, which suggested that a misleading picture of the science and scientific consensus leaves at least some segments of the society confused about climate science. The second is that, although there are clearly people out there who make painstakingly detailed attacks on the actual science, the results suggest that this effort is only effective in aggregate, as it probably contributes to the sense that the scientific community is badly divided.

Do we have a strategy here?

Most of the authors are based in communications departments, so a fair portion of the paper is devoted to discussing the communications strategies involved. For one, it appears that the whole confusion about the scientific community may be the product of an approach first proposed in 2002 by a Republican strategist named Frank Luntz. In a memo to then-President Bush, Luntz wrote, "Voters believe that there is no consensus about global warming in the scientific community. Should the public come to believe that the scientific issues are settled, their views about global warming will change accordingly. Therefore, you need to continue to make the lack of scientific certainty a primary issue in the debate."

Whether a conscious strategy or not, on the face of it, this should be easy to counteract; as the authors note, "The myth of widespread disagreement among climate scientists over whether global warming is happening has little to no basis in truth." However, the authors advise caution in going about this. People who are already inclined to believe inaccurate information actually have their belief in it strengthened when it's repeated, even if that repetition takes place in the context of a thorough debunking.

A short bit of editorializing

Frequently, discussions of the scientific community's consensus attract comments that echo Michael Crichton's claims that a consensus is antithetical to science. As a scientist, these comments always confused me, since I've seen consensus form on everything from what constitutes statistical significance in DNA chip experiments to the role of a specific signaling molecule in nerve cells.

But the survey results suggest that these arguments don't make a difference to the public, either. People clearly think they know what the majority of experts believe (even when they don't), and it influences how they view the underlying science. The survey didn't use the word "consensus," but I expect the results wouldn't have been any different if it had.

The other thing that strikes me as significant is that, if the authors are right, certain events will drive public opinion that strategy can't touch, and I think this is a testable prediction. Next year, the new IPCC report will be released, and it will almost certainly be accompanied by extensive coverage filled with terms like "highly likely" and "95 percent certainty." If the authors are right, this should drive up public acceptance of the science behind climate change, despite all the arguing that will undoubtedly ensue.

Nature Climate Change, 2011. DOI: 10.1038/NCLIMATE1295 (About DOIs).