** **AEA Papers & Proceedings Vol. 114, May 2024** ** This study uses historical conflict and weather data for the period 1400–1900 CE to investigate the long-run effects of climate change on political instability in a context that suffered extensive cooling. The results show that temperature changes have little effect on conflict if they are isolated events but that consecutive periods of cooling are associated with increased conflict. This is consistent with the conventional wisdom that societies and economies are able to adapt to a certain amount of environmental change. But if climate change is prolonged, then the disruptions they cause can cumulate and lead to political instability. [[pdf]](https://www.aeaweb.org/articles?id=10.1257/pandp.20241058)