Communicating consensus strengthens beliefs about climate change, study finds

Climate scientists have long agreed that humans are largely responsible for climate change. However, people often don’t realize how many scientists share this view. A new study conducted in 27 countries and published in the journal Nature Human Behavior finds that communicating consensus among scientists can dispel misperceptions and reinforce beliefs about climate change.

The study is co-led by Bojana Većkalov of the University of Amsterdam and Sandra Geiger of the University of Vienna. Kai Ruggeri, professor of health policy and management at Columbia University’s Mailman School of Public Health, is the corresponding author.

The scientific consensus identifying humans as the main cause of climate change is not new and was formed as early as the 1980s. Today, 97 to 99.9% of climatologists agree that climate change is occurring and that human activity is the main cause.

Over the past decade, researchers have begun to study the effects of communicating this overwhelming consensus, with promising results. They found that Americans who read a short statement about this scientific consensus perceived it as more convinced about human-caused climate change and were more concerned about it than those who read an unrelated expert statement.

However, as with many findings in behavioral science, we know little about the effects of communicating this consensus beyond the United States. Now a new study provides an answer.

An international research team of 46 people showed different consensus scientific messages to more than 10,500 people around the world and asked them for their opinions on climate change. They found that the results obtained in the United States were valid in 27 countries spread across six continents. People in these 27 countries responded similarly to the scientific consensus on climate change.

Geiger, co-lead author, explains: “In response to reading the 97% consensus, people adjusted their perceptions of the scientific consensus, became more convinced about climate change and more concerned about it, but they did not increase their support for public action on climate change, although other research has shown that support for action can be boosted indirectly by changing the way people think and feel about climate change.”

Climate scientists now agree on more than just the existence and causes of climate change: 88% agree that climate change is a crisis. How do people react when they learn of this additional consensus about the crisis? Oddly enough, this additional information has had no effect.

“We think that the gap between actual and perceived consensus may have played a role,” says study co-lead author Većkalov. “This gap was much smaller for the crisis consensus than for the 97% consensus. A smaller gap means that people already perceived a high crisis consensus before they learned about it, which could have prevented any further changes in beliefs about climate change.”

These new findings show that it is still important to emphasize consensus among climate scientists, whether in the media or in our daily lives when we discuss climate change and its consequences.

“Especially in the face of increasing politicization of science and misinformation about climate change, cultivating a universal awareness of scientific consensus will help protect public understanding of the problem,” adds lead author Sander van der Linden.

Beyond climate change communication, these findings also highlight the importance of testing previous behavioral science findings on a global scale.

“Such initiatives are only possible if we bring together researchers from around the world. What is particularly unique about this work is the participation of students and early-career researchers from Columbia University’s Junior Researcher Program (JRP) and Global Behavioral Science (GLOBES) program,” Ruggeri said.