A new global study has found that extreme weather events like severe heat and floods can both increase migration for some groups while simultaneously trapping others in place. Published in Nature Communications, the research found that age and education are the key factors determining who is most likely to move in response to climate shocks.
A “Double Penalty” for the Vulnerable
The study, led by Hélène Benveniste of the Stanford Doerr School of Sustainability, reveals a “double penalty” for some populations. The people who are most exposed to the negative impacts of climate change and have the least resources to adapt are also the least likely to be able to migrate.
The researchers analyzed over 125,000 cases of cross-border migration and more than 480,000 within-country moves, correlating them with daily weather data. Their findings show that while a small percentage of overall migration is tied to weather, the demographic response is significant:
• Older, less educated adults are more likely to migrate internationally in response to high heat.
• Children and the youngest, least educated groups are less likely to move across borders.
• Adults with higher education are largely unaffected by weather when it comes to international migration.
This research resolves previous conflicting findings by showing that migration patterns are highly dependent on the demographics of the population. The study’s model, which accounts for these differences, is up to 12 times better at predicting cross-border migration patterns than previous models that assumed a uniform response.
No Evidence of Mass Border Surges
The study cautions against common narratives of “mass migration.” When projecting future migration under a high-warming scenario, the study did not find evidence for surges in international migration. Instead, it predicts a change in the demographics of migrants. For example, if all other factors remain constant, rising global temperatures could increase migration rates by about 25% for older, less educated adults, while decreasing them by up to a third for the youngest and least educated.
The authors emphasize that migration decisions are influenced by a wide array of factors beyond climate, such as conflict, politics, and job opportunities. They hope their findings will help policymakers address the specific needs of different demographic groups, particularly those who are likely to be trapped in place and face the most severe consequences of climate change.