The Washington PostDemocracy Dies in Darkness

Yet another survey suggests the climate change ‘debate’ is settled among scientists

Smoke billows from chimneys at a chemical factory in Hefei, Anhui province, in this March 10, 2010 file photo.  UN-CLIMATECHANGE-CARBON/ REUTERS/Stringer/Files
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There’s a statistic that climate activists are fond of repeating: 97 percent of climate scientists agree that human-caused climate change is a real thing. But while it makes a convincing case, some doubters have argued that the case for climate change is far from settled in the scientific community at large — and, indeed, there have been few investigations into how other scientists, aside from just climate experts, feel about the issue of anthropogenic climate change.

A survey published Thursday in the journal Environmental Research Letters attempts to put the case to bed. Using responses from nearly 700 biophysical scientists, the survey finds that approximately 92 percent of them believe that human-caused climate change is really happening.

“These results show again that climate science is trusted, is mature, is reliable,” said Stuart Carlton, a coastal ecosystem and social science specialist at Texas Sea Grant (formerly at Purdue University, while the survey was being completed) and the study’s lead author.

Carlton and his colleagues sent surveys to nearly 2,000 biophysical scientists at universities in the Big 10 conference (which primarily includes universities in the Northeast and Midwest). The scientists surveyed included experts in a broad range of disciplines, including biology, chemistry, physics and geosciences, and also included some climate scientists.

The inspiration for the survey came partly from the idea that many prominent climate change doubters in the scientific sphere come from disciplines other than climate science. The driving question, according to Carlton, was, “Are these people representative of what scientists believe about climate science?”

The surveys included questions about four major issues: what the scientists believed about climate change, what they believed about climate science, where they got their information and what kinds of cultural and political values they had. Out of the sample, 698 scientists responded.

The survey results indicate that a firm majority of scientists believe in anthropogenic climate change. The researchers found that 93.6 percent of respondents believe that global temperatures have risen since their pre-1800s levels. Out of these, 98.2 percent said they believe that human activities are contributing to the rise in temperatures, meaning that altogether 91.9 percent of the respondents believe in anthropogenic climate change.

The survey also reported that respondents who believed that temperatures have risen since pre-1800s levels were more certain in their beliefs than those who did not believe this was true. In other words, “among the scientists we surveyed, those who believe in climate change are more certain in their beliefs than those who do not,” said Carlton in a follow-up email to The Post. “I wouldn’t have expected that. I’m not sure why that is the case, but it may be a sign that the climate change skepticism is weakening among this population.”

The researchers also used the survey to gauge how personal cultural and political values might influence scientists’ thinking on climate change. Past research has found that these values have significant influence on climate change perceptions in the general public. In fact, a 2012 study in Nature Climate Change found that the most scientifically literate members of the public were likely to be the most culturally polarized. So the researchers wanted to find out if scientists were “also affected by some of the same things that we know affect the public’s belief in climate science,” Carlton said.

In fact, cultural and political values do seem to play a role among scientists. Those who believed that global temperatures are rising were more egalitarian, more communitarian and more liberal than those who did not, the survey revealed. There were also differences among those who said they believed in anthropogenic climate change. For instance, 100 percent of egalitarian communitarians said they believed in a human contribution to climate change, compared with 90.3 percent of hierarchical individualists.

“There is this idea that something like belief in climate change is purely a rational or knowledge-based thing,” Carlton said. “These results show that it’s not. It’s the intersection of knowledge, your values, your identity — it’s somewhere in the intersection of all these things.”

That said, Carlton pointed out that the effects of cultural values on climate beliefs were less pronounced than past research has indicated they are in the general public. This is an effect he also found unsurprising, given that many biophysical scientists do “interact with climate change indirectly or directly.”

And Dan Kahan, a professor of law and psychology at the Yale Law School, said in an email to The Post that these results “show how radically dissimilar scientists and members of the public are in this regard.” Kahan was not involved with this survey, but conducted the 2012 study in Nature Climate Change, along with several other studies on cultural cognition.

“For me the take away is that scientists, unlike ordinary members of the public, are not meaningfully affected by cultural worldviews,” Kahan said. Past research, including his own 2012 paper, found vastly larger gaps between different cultural and political identities and the climate beliefs associated with them in the public at large.

For Carlton, the most important point is that climate change should no longer be viewed as a controversy within the scientific community, a perspective that he says distracts people from the more important issue of what should be done to mitigate it.

“The debate that is going on about the existence of climate change is noise,” he said. “What people should be discussing, the policy issues that people should be evaluating, are what to do about climate change.”