In recent years, particularly over the last decade, the impact of climate change on migration has attracted considerable interest from both the public and lawmakers. A recent study led by IIASA has delivered an in-depth analysis of how climate elements—especially drought and aridity—impact internal migration patterns.
While discussions often emphasize international migration, scientific evidence suggests that climate-related migration usually involves shorter moves within a country. However, studies investigating climate-driven internal migration across various nations remain limited. The new research, published in Nature Climate Change, utilized census microdata from 72 countries, covering the years from 1960 to 2016, to offer the first global evaluation of how environmental pressures influence migration within national boundaries.
“Our findings indicate that internal migration—which we define as movement between different regions within a country—tends to rise in areas impacted by drought and aridification, especially in extremely dry regions. These effects are especially significant in rural areas that rely on agriculture, where livelihoods are susceptible to changing climatic conditions. Many people who migrate due to climate factors end up in urban centers, further accelerating urbanization trends in various countries,” states lead author Roman Hoffmann, head of the Migration and Sustainable Development Research Group at IIASA.
The analysis uncovered regional variations in the effects of climate change. Drought and aridification were notably more severe in regions like Africa, the Middle East, South America, South Asia, and Southern Europe, where agriculture is a key economic activity and the climate is already arid. In these areas, the combination of environmental degradation and economic struggles provides strong motivations for migration.
Overall, the study found that wealthier regions tend to show greater mobility, as migration barriers are often lower there. Within individual countries, poorer regions generally experience higher out-migration to wealthier areas when faced with climate stress. The research also highlighted differences in migration patterns among various demographic groups. In less affluent countries, young adults (aged 15-45) with moderate education levels are the most likely to relocate due to drought and increased dryness. Conversely, in wealthier nations, older individuals across all educational backgrounds exhibit stronger migration tendencies.
“As climate change continues to exacerbate the frequency and severity of droughts and water scarcity globally, more communities will feel the urge to migrate for better living conditions. Our findings highlight the importance of developing policies that address the causes of migration as well as the impacts on the receiving regions. Providing sufficient infrastructure, healthcare services, and social support in urban areas that are increasingly welcoming climate-displaced migrants is vital,” adds coauthor Guy Abel, a researcher in the IIASA Migration and Sustainable Development Research Group.
The research also emphasizes the need to support vulnerable communities, particularly those unable to migrate because of limited resources. Policies that encourage livelihood diversification, social safety nets, and resilience-building in affected areas can help reduce involuntary migration and safeguard those who remain behind.
Although this study marks a significant advancement in understanding the connections between climate change and internal migration, the authors acknowledge the hurdles posed by insufficient and incomparable migration data. The dataset used in this research, derived from census microdata, offers a solid long-term perspective on internal migration for many countries. Nevertheless, it does not encompass other forms of movement, such as temporary or short-distance migration, which are also critical in the context of climate change.
“As climate change continues to alter migration patterns, obtaining more comprehensive data and ongoing research will be crucial for creating targeted interventions and policy solutions that address the intricate relationship between environmental elements and human movement. Our study emphasizes the urgent need for a comprehensive approach to policy development that considers both geographical and social disparities, acknowledging the complex and context-specific nature of migration dynamics,” concludes coauthor Raya Muttarak, a researcher in the IIASA Migration and Sustainable Development Research Group and a professor of Demography at the University of Bologna, Italy.
