Communicating the overwhelming scientific consensus about climate change – at least 97% of climate scientists agree that climate change is happening and human activity is the main cause – can strengthen people’s climate beliefs, according to a massive new study with global reach.

Members of the public often underestimate this agreement among scientists, and those who do are less likely to believe in or be concerned about climate change themselves. What’s more, many past studies have found that communicating the consensus can strengthen climate beliefs, but most have been conducted in the United States, with a handful in other wealthy, industrialized countries.

The new study “represents a first large-scale multi-country test of this climate change communication strategy,” says Bojana Većkalov, a graduate student at the University of Amsterdam in the Netherlands and part of an international team of 46 researchers who conducted the study.

Većkalov and her collaborators administered an online survey to more than 10,500 people in 27 countries on 6 continents, recruiting several hundred people from most of the countries. Participants were asked to estimate the proportion of scientists who agree that climate change is real and human-caused and queried about their own climate beliefs.

Then, participants were shown one of three statements: one stating that 97% of climate scientists agree that climate change is real and human-caused; one stating this consensus and also that 88% of climate scientists agree that climate change is a crisis; or a third statement not related to climate change. After this participants answered questions about their climate beliefs again.

Across all countries, communicating the consensus about the reality and causes of climate change made survey respondents more likely to endorse such views themselves, the researchers report in Nature Human Behaviour.

Those who read the statement about scientific consensus perceived the consensus to be greater, believed more in human-caused climate change, and were more concerned about it than those who read the unrelated statement, although they did not show greater support for public action on climate change.

“Overall, our work shows that it is important to continue emphasizing the existing consensus among climate scientists – be it in the media or in our everyday lives when we have conversations about climate change and its impacts,” says study team member Sandra Geiger, a graduate student at the University of Vienna in Austria.

The statement that also included the scientific agreement about climate change being a crisis was equally effective at strengthening people’s climate change beliefs, but had little additional effect – which surprised the research team, Većkalov reports. “We had indications this might be effective from pilot data in the U.S. and hoped this could be used as a strategy to strengthen climate change consensus messaging,” she says.

“We believe that the gap between the actual and the perceived consensus might have played a role,” Geiger says. People greatly underestimated the scientific consensus about the existence and cause of climate change, but underestimated the agreement about it being a crisis to a lesser degree. In the case of climate crisis perceptions, “This gap was likely not large enough to subsequently change personal climate change beliefs.”

Both messages were more effective at shifting the beliefs of people who were less familiar with the climate consensus, less trusting of climate scientists, and those on the right of the political spectrum. The findings suggest that consensus messaging is a non-polarizing approach that can help move the needle on climate beliefs across different audiences, without causing blowback.

However, the best ways to roll out consensus messaging in different places will require more detailed investigations tailored to particular countries, the researchers say. More studies are also needed to find out more about how to increase not only belief in climate change but support for climate policies.

Source: Većkalov B. et al. “A 27-country test of communicating the scientific consensus on climate change.” Nature Human Behaviour 2024.