Evidence of climate and economic drivers affecting migration in an unequal and warming world

Abstract Climate conditions, in complex interrelations with other socioenvironmental, economic, political and cultural factors, significantly play a key role in shaping population density and movement. However, the impacts of climate change on global human migration remain poorly understood. This study assesses the sensitivity of international migration to climate change across 160 countries and regions, focusing on temperature-related climate indices. The results show that migration patterns are strongly influenced by a country’s baseline climate and economic conditions. Under global warming, countries in mid- to high-latitudes with lower baseline temperatures are projected to experience substantial increases in migration inflows, while low-latitude countries are likely to see rising migration outflows. This climate sensitivity is especially pronounced in higher Gross Domestic Product (GDP) countries, whereas lower-GDP countries show little dependence on baseline climate. A simple predictive model based on projected changes in climate and GDP suggests that populations in low-GDP, low-latitude countries will face worsening conditions and increasing migration pressure by the end of the 21st century. The results underscore the growing influence of economic factors on migration and call for urgent integration of climate justice into migration policy to support vulnerable populations in a warming world.