Options Magazine, Winter 2023: There has been much debate around the impact of climate change on migration. The international discourses around this topic, however, have often been more politically charged and less backed by science.

In a recent IIASA Working Paper, Roman Hoffmann, who leads the Migration and Sustainable Development Research Group of the IIASA Population and Just Societies Program and his coauthors, used a novel internal migration dataset built on 107,916 migration flows between subnational region pairs over time to analyze climatic impacts on internal migration worldwide. The researchers then combined this migration data with data on drought and aridity in the subnational regions to estimate whether changes in climatic conditions have affected migration.

Their results show that drought and aridity have a considerable impact on internal migration. The strongest migration impacts were observed in hyper-arid and arid areas of Southern Europe, the Middle East and North Africa, Southern Asia, and South America. Additionally, the results show that within individual countries, it is the relatively poorer regions where populations respond strongest to environmental stress.

“Drought and aridity are found to increase internal migration worldwide with considerable heterogeneity across regions as well as age and education groups,” explains Hoffmann. “Our study provides new comparative evidence on the impacts of climatic factors on internal migration using novel longitudinal census migration data for 72 countries. The findings highlight the importance of differential mobility patterns across population subgroups in different contexts.”

By Jeremy Summers


Hoffmann, R., Abel, G. , Malpede, M., Muttarak, R., & Percoco, M. (2023). Climate Change, Aridity, and Internal Migration: Evidence from Census Microdata for 72 Countries. IIASA Working Paper. Laxenburg, Austria: WP-23-008