Empirical evidence for climate migration from a global panel of subnational regions

Abstract: Climate change-induced migration poses socioeconomic and political risks, yet quantitative evidence of such effects at global scales, including within-country and cross-border migration, remains lacking. Here, we combine migration data for more than 3,000 subnational regions worldwide and 20 years with assessments of local climate conditions including extremes. Fixed-effects panel regression analysis provides strong and robust evidence that rising temperatures as well as temperature and rainfall extremes induce outward migration in low-income regions. Explicit assessment of spatial spill-overs confirms that temperature increases and extremes generate cross-border flows towards high-income countries. We project that - ceteris paribus - 180 million people will migrate from low-income regions due to climate change across emission scenarios by mid-century.