Climate Change, Drought, and Potential Environmental Migration Flows Under Different Policy Scenarios

Abstract

Unmitigated climate change will likely produce major problems for human populations worldwide. Although many researchers and policy-makers believe that drought may be an important “push” factor underlying migration in the future, the precise relationship between drought and migration remains unclear. This article models the potential scope of such movements for the emissions policy choices facing all nation-states today. Applying insights from climate science and computational modeling to migration research, we examine the likely surge of drought-induced migration and assess the prospects of different policy scenarios to mitigate involuntary displacement. Using an ensemble of 16 climate models in conjunction with high-resolution geospatial population data and different policy scenarios, we generate drought projections worldwide and estimate the potential for internal and international population movement due to extreme droughts through the remainder of the 21st century. Our simulations suggest that a potential for drought-induced migration increases by approximately 200 percent under the current international policy scenario (corresponding to the current Paris Agreement targets). In contrast, total migration increases by almost 500 percent, should current international cooperation fail and should unrestricted policies toward greenhouse gas emissions prevail. We argue that despite the continued growth projections of drought-induced migration in all cases, international cooperation on climate change can substantially reduce the global potential for such migration, in contrast to unilateral policy approaches to energy demands. This article highlights the importance of modeling future environmental migrations, in order to manage the pressures and unprecedented policy challenges which are expected to dramatically increase under conditions of unmitigated climate change.