The link between extreme weather and migration remains ambiguous, despite the hype surrounding so-called climate refugees, but new research appears to bolster the connection.

A new study published this week in Nature Climate Change (paywall) explores the effects of different disasters on human migration patterns in rural Pakistan. In light of the severe floods that have affected Pakistan in recent years, particularly the historic 2010 floods that affected 20 million people, the authors focused on the impact that extreme rainfall and temperatures have on patterns of migration in the country. The study examines the relationship over a 21-year period (1991-2012), relying on data from three longitudinal surveys.

The authors analyze several key weather variables, including rainfall during the monsoon season, average temperatures during the Rabi (winter wheat) season, flood intensity, and a 12-month moisture index measurement.

The various measures of rainfall have no significant effect on the mobility of men or women, either within or outside of the villages surveyed. In fact, the results suggest that periods of high rainfall actually decrease out-migration within the villages, perhaps due to the fact that farm and non-farm incomes increase significantly during these periods.

These results correspond with previous studies examining the relationship between rainfall and migration. Afifi and Warner examined the influence of 13 different forms of environmental degradation on patterns of international migration. They found that only one of the 13 – flooding – failed to increase international migration flows. In addition, Raleigh, Jordan, and Salehyan (PDF) concluded in 2008 that Bangladeshis affected by flooding migrated just two miles from their homes, on average, and that the vast majority of those displaced returned home shortly after the flood waters receded.

For the complete article, please see timkovach.