Some experts believed that by 2010, up to 50 million “environmental refugees” would flee their lands due to the dramatically negative effects of climate change. Such claims, however, are not based on the actual responses of households and communities to climate change but on broad estimates of the number of people “at risk” from the changing climate.

In a recent IFPRI brief that explores the relationship between climate and migration, Jean François Maystadt and Valerie Mueller challenge the assumption that climate change is the driving force behind migration in the 21st century. They specifically show that people migrate to places where they can expect better prospects for their family—and not necessarily to flee from climate change risks.

The authors discuss recent findings from migration studies in Nigeria, Ethiopia and Bangladesh—three countries particularly vulnerable to natural disasters. They also incorporate findings from a global analysis for Sub-Saharan Africa. These results reveal that climate change sometimes—but not always—drives poor people to move.

• The 20-year Nigeria study, the longest study on climate conducted in Africa, found that men were more prone to move after they experienced hot weather spells for the past five years or less.
• A 15-year study in Ethiopia shows there is a “strong relationship between severe droughts and the movement of males for employment reasons.” Male migration rates in the country rose from 1.4% to 2.6% during times of extreme drought.
• Conversely, the study in Bangladesh indicates that flooding, (a crucial issue addressed by many researchers and aid organizations), tends to have modest effects on relocation. Instead, drought-related crop failure tends to be the most common reason for migration.
• The cross-country analysis suggests that rainfall and temperature variations are likely to increase the economic incentives to migrate in Sub-Saharan Africa. The phenomenon of environmental migration was so far limited to less than 150,000 migrants a year but is likely to magnify in the future (5 to 24 million people every year by the end of the 21st century).

In a recent Climate Nature editorial, Allan M. Findlay, a professor of Geography & Sustainable Development at the University of St. Andrews, discusses findings from the Bangladesh case study that were laid out in a new Proceedings of the National Academies of Sciences (PNAS) journal article by Clark L. Gray and Valerie Mueller. Findlay concluded that “immobility rather than mobility should be the focus of concern for policymakers worried about the impact of climate-related natural hazards on the livelihoods of rural populations.”

Read Findlay’s article here. Read the PNAS article, Natural disasters and population mobility in Bangladesh, here.