Conference Agenda

Human migration is increasingly recognized as a critical response to anthropogenic climate change, with far-reaching societal, economic and geopolitical implications. However, quantitative evidence linking climate conditions to both, internal and — in particular cross-border — migration at the global scale remains limited. Here, we show that higher temperatures, along with temperature and precipitation extremes, significantly increase outward migration from low-income regions worldwide. This conclusion is based on a robust causal analysis that integrates migration data from over 3,000 subnational regions across two decades with high-resolution climate metrics, using fixed-effects panel regression models. A complementary spatial spillover analysis, adapted from trade economics, reveals that temperature-driven migration is primarily directed toward high-income countries, while precipitation extremes predominantly drive movement between low-income regions. We project that — ceteris paribus — 422 million people might migrate from low-income regions by mid-century due to climate change-induced temperature and precipitation effects, across emission scenarios. However, effective emissions reductions could half migration pressures by 2060. These findings highlight the need for integrated policies that reduce greenhouse gas emissions while also strengthening the agency of climate migrants.