Watson Institute for International and Public Affairs
Climate Solutions Lab

Cass Sunstein — ​Polarization and Beliefs about Climate Change

Tuesday, October 25, 2022

5:00pm – 6:30pm

Joukowsky Forum, 111 Thayer Street

Reception to follow.

​How do people update their beliefs about climate change? We find that people who are not sure that man-made climate change is occurring, and who do not favor an international agreement to reduce greenhouse gas emissions, show a form of asymmetrical updating: They change their beliefs in response to unexpected good news (suggesting that average temperature rise is likely to be less than previously thought) and fail to change their beliefs in response to unexpected bad news (suggesting that average temperature rise is likely to be greater than previously thought). By contrast, people who strongly believe that manmade climate change is occurring, and who favor an international agreement, show the opposite asymmetry: They change their beliefs far more in response to unexpected bad news (suggesting that average temperature rise is likely to be greater than previously thought) than in response to unexpected good news (suggesting that average temperature rise is likely to be smaller than previously thought).

The results suggest that exposure to varied scientific evidence about climate change may increase polarization within a population due to asymmetrical updating. We explore the implications of our findings for how people will update their beliefs upon receiving new evidence about climate change, and also for other beliefs relevant to politics and law.

Moderated by
Eric M. Patashnik
Julis-Rabinowitz Professor of Public Policy
Professor of Political Science
Chair, Department of Political Science

Cass R. Sunstein is currently the Robert Walmsley University Professor at Harvard. He is the founder and director of the Program on Behavioral Economics and Public Policy at Harvard Law School. In 2018, he received the Holberg Prize from the government of Norway, sometimes described as the equivalent of the Nobel Prize for law and the humanities. In 2020, the World Health Organization appointed him as Chair of its technical advisory group on Behavioural Insights and Sciences for Health. From 2009 to 2012, he was Administrator of the White House Office of Information and Regulatory Affairs, and after that, he served on the President’s Review Board on Intelligence and Communications Technologies and on the Pentagon’s Defense Innovation Board. Mr. Sunstein has testified before congressional committees on many subjects, and he has advised officials at the United Nations, the European Commission, the World Bank, and many nations on issues of law and public policy. He serves as an adviser to the Behavioural Insights Team in the United Kingdom.

Mr. Sunstein is author of hundreds of articles and dozens of books, including Nudge: Improving Decisions about Health, Wealth, and Happiness (with Richard H. Thaler, 2008), Simpler: The Future of Government (2013), The Ethics of Influence (2015), #Republic (2017), Impeachment: A Citizen’s Guide (2017), The Cost-Benefit Revolution (2018), On Freedom (2019), Conformity (2019), How Change Happens (2019), and Too Much Information (2020). He is now working on a variety of projects involving the regulatory state, “sludge” (defined to include paperwork and similar burdens), fake news, and freedom of speech.