Rainfall anomalies are a significant driver of cropland expansion

Significance Rainfall anomalies are known to have deleterious impacts on agricultural yields, but the resulting consequences on cropland expansion remain uncertain. We study the differential scale of these impacts around the world. We find that repeated dry anomalies increase cropland expansion specifically in developing countries, which are characteristically dominated by small-holder farming, implying that cropland is expanded to compensate for lower yields. Two tests corroborate the results. First, comparable reductions in forest cover due to repeated dry anomalies are found in the same regions where cropland expands. Second, in places where infrastructure buffers yields from rainfall anomalies, cropland expansion halts. Understanding the synchronous challenges facing agriculture and the environment will be critical to inform appropriate policy interventions.