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Addressing Climate Migration Within Borders Helps Countries Plan, Mitigate Effects

By Alex de Sherbinin

Migration in response to climate change is a big topic in the media. But the focus is all too often on either international cross-boundary movements or short-term population displacement from major floods or droughts. While these forms of population movement are important, they are by no means the whole story. A new report by World Bank, CIESIN, CUNY, and PIK, Groundswell: Preparing for Internal Climate Migration, is the first to focus on longer-term climate impacts on crop and water resources and the ways in which they may influence internal migration.

International migration―a hot-button political issue―generally involves only about 3 percent of the world’s population, a proportion that has remained pretty constant since the 1970s. By contrast, as discussed in a major UNDP report, there are many more internal migrants. Finally, regarding displaced persons, they often (but not always) return home after the climate disaster subsides. Migrants, on the other hand, leave areas permanently.

The Groundswell report employs a novel modeling framework that provides estimates not only of future numbers, but also likely hotspots of climate out-migration and in-migration in three regions: Mexico and Central America, East Africa, and South Asia. Unlike other recent efforts to model the impact of future climate change on population movements, this effort models across entire regions rather than at local or subnational levels. It is also based upon impacts on crop production and water resources, using model outputs from PIK’s ISIMIP project, rather than projected temperature and precipitation from global climate models. This more closely approximates the impacts on people’s livelihoods—the way rural people in developing countries make a living through agriculture, livestock herding or resource extraction.

A major purpose of the Groundswell report is to help countries anticipate likely climate-induced migratory flows so that they can better plan for them. (Sample planning tools can be found in the map and chart for Mexico and Central America, below.)  In some cases they may also be able to avert the flows by implementing adaptation programs that make rural livelihoods more resilient.

Another message of the report is the need to reduce greenhouse gas emissions and improve wellbeing in the lowest income countries. Across all regions that were modeled, the modeling finds that climate migration levels are far higher under a pessimistic scenario—characterized by high emissions, large disparities in human development, and high population growth rates in low income countries—than under corresponding low emissions or more equitable development scenarios.

Map of Hotspots of climate-induced in-migration (red) and out-migration (blue) in Mexico and Central America
Hotspots of climate-induced in-migration (red) and out-migration (blue) in Mexico and Central America. A hotspot means that multiple scenarios agree that the area will see a significant increase or decrease in population relative to a scenario in which no climate impacts occur.


Projected climate and other (non-climate/development) migrants in Mexico and Central America between now and 2050: total (top) and as a percentage of the population in the region (bottom)
Projected climate and other (non-climate/development) migrants in Mexico and Central America between now and 2050: total (top) and as a percentage of the population in the region (bottom).

Strategies to anticipate internal migration and facilitate adaptation in place would be a win-win for crossboundary migration. If countries are able to get a handle on internal migration by helping people to move before their resources are depleted or to adapt in place, it is far less likely to result in the kinds of distress migration that have been witnessed in recent years.

In summary, migration may be considered a positive adaptation strategy, but only if it is managed well by development policies. Furthermore, it is possible to prevent distress migration. Groundswell urges attention to the phenomenon of longer term, slower and incremental changes to temperature and precipitation that are spurring internal climate migration. It makes a case for national and local level planning to develop livelihood strategies and supportive adaptations in place, rather than solely in response to migration.
Blog author
Alex de Sherbinin heads the Science Applications Division of the Center for International Earth Science Information Network. He is a co-author of the Groundswell report

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