Nonlinear temperature effects on GDP. Higher temperature may reduce GDP in Mediterranean agricultural countries more than non-agricultural countries. Extreme heat over 30℃ significantly reduces the GDP of agricultural countries but not the non-agricultural ones. GDP is a main determinant of international migration. The nonlinear relationship between GDP and temperature in agricultural countries provides indirect evidence for the agricultural linkage between temperature and migration.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report