For many countries which produce high emissions, climate policy starts at the ballot box. This study presents the first causal evidence on the electoral response to a climate disaster based on microdata.

Using a large-scale survey, we investigated how the experience of the catastrophic flood disaster of 2021 in western Germany influenced citizens’ voting decisions. Our results show that respondents who live in areas affected by flooding and did not vote for the Green Party (Die Grünen) in the last election are around 4 percentage points more likely to vote for the Green Party in the next election due to their flood experience. The tendency to vote for the Greens is determined to a large extent by those respondents who have left the affected regions or moved to the region. These results show the importance of voter persuasion over mobilisation due to a ceiling on climate salience.