Climate Migration at the Height and End of the Great Mexican Emigration Era.

Previous research has linked increasing climate-change-related variability to Mexico-US migration, but only under particular climatic/social conditions and periods of high irregular migration. Using the 2000 and 2010 Mexican censuses, we examine this environment-migration nexus across a broader set of socioecological contexts and during periods of both increasing (1995-1999) and declining (2005-2009) migration. Consistent with the notion that climate can "trap" populations in place, we find that frequent/severe bouts of hot or dry conditions are associated with lower US-bound migration from most of rural Mexico. However, we do find higher climate outmigration during episodes hot and dry climate, or out of places with lower vulnerability. Our comparisons across periods suggest that climate migration is affected by conditions in the U.S. in a similar or slightly weaker manner as other forms of migration are. Altogether, our findings suggest that rural Mexico is unlikely to push large numbers of international "climate refugees" and that climate migration is indeed sensitive to conditions in sending and destination areas.