NEW HAVEN, Conn. — A new study led by Yale University researchers has found that the depth of Americans' understanding of climate science has little bearing on whether they accept the reality of human-caused global warming. The findings, published in the journal Advances in Political Psychology, indicate that the most scientifically literate citizens are often the most politically polarized on the issue.
The research, based on a nationally representative sample of 2,000 U.S. adults, measured participants' knowledge of climate science using questions derived from reports by the U.N. Intergovernmental Panel on Climate Change, the U.S. National Oceanic and Atmospheric Administration, and NASA. Participants were also asked whether they believe human activity is responsible for recent global temperature increases.
Results showed the public is almost evenly split, with roughly 50% accepting human-caused climate change and 50% rejecting it. But notably, this division did not narrow among those who scored higher on the climate-literacy test. Instead, the gap widened, with the highest scorers showing the most pronounced partisan split.
“The study participants were deeply divided along partisan lines,” said Dan Kahan, the Elizabeth K. Dollard Professor of Law and Psychology at Yale Law School and the lead researcher. “Those with the highest scores were even more politically polarized.”
The climate-literacy test revealed widespread misconceptions, even among those who accepted the scientific consensus. For instance, while most participants correctly identified carbon dioxide as a greenhouse gas, many mistakenly believed that rising atmospheric CO2 levels would reduce photosynthesis in plants. Kahan noted, “If you know carbon dioxide is a ‘greenhouse gas’ but think it kills the things that live in greenhouses, then it’s safe to say you don’t know much about climate science.”
Similarly, participants often recognized that climate change could increase coastal flooding but also associated it with risks unsupported by evidence, such as a higher incidence of skin cancer.
Cultural Identity Over Scientific Understanding
Kahan and his colleagues found that participants who excelled on a general science literacy test also performed well on the climate-specific questions. Yet this did not translate into agreement on the causes of global warming. “Despite consistently giving the correct answers to climate-literacy questions, the most science literate study participants were even more politically polarized,” Kahan said.
These findings align with previous research suggesting that greater science literacy can exacerbate polarization, but this study goes further by showing that even those with high climate-science knowledge remain divided. Kahan dismissed the idea that the results undermine the value of climate education, stating, “We need even more research on how to communicate climate science effectively, so people can make informed individual and collective decisions.”
However, he argued that the study calls for a reassessment of some popular communication strategies. “One conclusion is that it’s misguided to fixate on what percentage of the respondents in an opinion survey say they ‘believe in’ climate change,” he said. “What people say they believe about global warming is not a measure of how much they know, or even how worried they are about it; it is an expression of their cultural identities.”
Kahan also questioned the effectiveness of campaigns emphasizing that “97% of climate scientists” accept human-caused climate change. “Republicans and Democrats alike already understand that climate scientists have shown we face huge risks from global warming,” he said. “Just telling people that over and over — something advocacy groups have been spending millions of dollars doing for over a decade — misses the point: Positions on climate change have become symbols of whose side you are on in a cultural conflict divorced from science.”
As a counterexample, the study highlights efforts by local political leaders in southeast Florida to depoliticize climate discussions, which have shown some success in fostering bipartisan cooperation.
The study was jointly sponsored by the Cultural Cognition Project at Yale Law School, the Annenberg Public Policy Center of the University of Pennsylvania, and the Skoll Global Threats Fund.
