How risk communication shapes individual response to climate change: an experimental study.

We examine the theoretical prediction that early contributions can be crucial for managing uncertain collective risk successfully and study how different ways of presenting or understanding climate risk affect people's willingness to work together. Participants played a repeated Collective Risk Dilemma game in which they decided how much to contribute towards avoiding a collective loss. In one version of the game, catastrophic losses could occur only at the end of multiple interactions (last round), while in the other, partial losses could occur in every round (every round). We measured when contributions were made, how closely participants' expectations matched the actions of others, and whether a shared social norm emerged. The results indicate that, contrary to predictions, subjects in the last-round setting reached the contribution target more often and earned higher individual rewards, even though their contributions were less evenly distributed and were made only at the very end of the game. We did not find support for social norms having a role in shaping the participants' decisions. These findings suggest that framing risk as a single, catastrophic event may lead to a clearer understanding and more effective cooperation than presenting it as a series of smaller, uncertain risks. In terms of policy, the study highlights the importance of clear and consistent communication in motivating collective action to address climate change, particularly if early contributions are needed.