The impact of climate change on migration, particularly internal migration, has become a topic of significant interest among both the public and policymakers in recent years. A new study led by IIASA has provided the first comprehensive analysis of how climate factors, specifically drought and aridity, affect internal migration. While much attention is often given to international migration, the study focused on migration within national borders, using census microdata from 72 countries spanning from 1960 to 2016.
The analysis revealed that internal migration increases in regions affected by drought and aridification, especially in hyper-arid and arid regions. This trend is most pronounced in agriculturally dependent and rural areas where livelihoods are highly vulnerable to changing climate conditions. Many climate-induced migrants tend to move to urban areas, contributing to the accelerated urbanization observed in many countries. The effects of drought and aridification were found to be particularly strong in parts of Africa, the Middle East, South America, South Asia, and Southern Europe, where agricultural livelihoods are prevalent and the climate is already dry.
Overall, the findings suggest that wealthier areas tend to experience more mobility, with poorer regions often having higher outmigration rates toward wealthier areas when affected by climatic stress. In less developed countries, younger working-age adults with medium levels of education are most likely to migrate in response to drought and increased aridity. In wealthier countries, older populations across all education levels show stronger migration patterns. As climate change continues to exacerbate droughts and water scarcity, more populations will face pressures to seek better living conditions, highlighting the need for policies that address both the drivers of migration and the consequences for destination regions.
The study underscores the importance of supporting vulnerable populations, including those who cannot migrate due to resource constraints. Policies that promote livelihood diversification, social safety nets, and resilience-building in affected communities can help mitigate forced migration and displacement while also protecting those who remain. Despite the progress made in understanding the links between climate change and internal migration, the authors acknowledge challenges posed by limited and non-comparable migration data. The dataset used in the study provides a robust longitudinal view on internal migration for a large number of countries but does not capture other forms of movement, such as temporal or short-distance mobility.
As climate change continues to reshape migration trends, comprehensive data and continued research will be essential for developing targeted interventions and policy solutions to address the complex relationship between environmental factors and human mobility. The study highlights the urgent need for a holistic approach to policy development that accounts for both spatial and social differences, recognizing the complex and context-dependent nature of migration dynamics. With climate change increasing the frequency and severity of droughts and water scarcity worldwide, it is crucial to address the implications of climate-induced migration and implement policies that support both migrants and host communities.