Climate Barriers to Democratic Participation

Extreme weather events can undermine political representation by preventing vulnerable populations from voting. Using georeferenced polling-station records from eight Brazilian elections (2010–2024) matched to daily river discharge, we exploit within-polling-station variation to show that historically low river discharge on election day increases voter abstention in communities dependent on river transportation. The effects are larger in polling sections with higher illiteracy rates and married voters. These shocks also shift electoral outcomes by reducing the vote share of parties whose bases overlap with affected populations. Our findings show that climate change can systematically weaken the political voice of the populations most exposed to climate damages.