Through drought and flood: past, present, and future of climate migration

Abstract

Migration from low-income countries has doubled in the last 30 years, a flow increasingly associated with climate degradation in nations heavily dependent on agriculture. This process is often confounded with weak institutions, violence, and strife. Countries at the receiving end have also been affected. With an increasingly negative perception among the general population, migration has contributed to social and political polarization associated with the recent deterioration of the geopolitical landscape. However, the scale of migration thus far will likely pale in comparison with future pressures. As climate further deteriorates, the map of uninhabitable ecosystems—many of which house some of the largest concentrations of people today—will continue to expand. Regions that will suffer the most are often those already degraded, suggesting observed trends may soon become highly nonlinear.1 Thus, mass migration—the main adaptation mechanism of our species to survive climate change in the past—may constitute a key social tipping point in our modern, overpopulated societies.