Yale University’s Program on Climate Change Communication has published a new study on the effectiveness of communicating the links between climate change and extreme weather. Study authors Laura Thomas-Walters, Matthew H. Goldberg, Sanguk Lee, Aidan Lyde and Anthony Leiserowitz conclude that the connection may be most effectively communicated using percentages (“the heat wave was made at least 400% more likely by climate change”) than using equivalent magnitudes (“the heat wave was made at least 5 times more likely by climate change”). They also found that “just talking about [a] heatwave, without mentioning climate change, was enough to change beliefs.”
The study was “a message experiment with 3,902 Americans, focused on the July 2023 heat wave that occurred in much of the United States.” The authors explain, “We found that prior to exposure to the attribution message, a majority of research participants thought climate change made the July 2023 heat wave more likely (53%), and that it is making heat waves generally more likely (58%). All messages then increased the belief that climate change made the July 2023 heat wave more likely and is making heat waves in general more likely as well. Expressing the magnitude as a percentage was more effective…, leading to a 6 percentage point increase in the belief that climate change made the July 2023 heat wave more likely, compared to a ‘pure control’ message (i.e., a message unrelated to climate change and extreme weather), or a 1 percentage point increase compared to the standard Climate Shift Index (CSI) treatment.”
Why does this matter?
“Extreme weather, including heat waves, poses a significant threat to human health and ecosystems. As global temperatures continue to rise, heat waves are becoming more frequent and severe. Because of this, communicating heat-related risks to the public is increasingly important for both their own protection and to encourage mitigation policies.”
In conveying the urgency of climate action, different modes of messaging can clearly impact the belief that climate change is making heat waves more likely and worse.
The study was published in the American Meteorological Society Journal, June 19, 2024
