Abstract

This paper studies how global warming affects deforestation and agricultural land use. Using global, high-resolution data on temperature, deforestation, and land cover from 2001 to 2019, we find that extreme heat causes large and persistent forest loss on the world’s agricultural frontier. This effect is strongest in the tropics, in areas with the most temperature-sensitive crops, and in regions with the most inelastic demand for agricultural products, and we find no evidence that it is offset by global spillovers. Deforestation in response to extreme heat can be explained almost entirely by cropland expansion. We corroborate these findings using agricultural census data from Brazil, where extreme heat leads to productivity declines, cropland expansion, and limited additional input adjustment or land reallocation. Our estimates imply that extreme heat has already driven substantial forest loss and that projected warming through 2100 could lead to an additional 28 million hectares of deforestation. These findings challenge the view that economic reallocation will necessarily soften the economic and environmental consequences of climate change, suggesting instead that farmers double down and expand cropland locally in response to lower productivity.