Forecasts of environmental migration vary widely – the intergovernmental International Organization for Migration estimates that 200 million people will be displaced by 2050, while the respected charity Christian Aid predicts 700 million in the same time frame. More important than specific 40-year forecasts is the conclusion of In Search of Shelter that climate change is “already causing migration and displacement.”
The report, jointly produced by the United Nations University Institute for Environment and Human Security; CARE International, and Center for International Earth Science Information Network at Columbia University, says that the scope and scale of climate-induced migration will “could vastly exceed anything that has occurred before,” and that “people in the least developed countries and island states will be affected first and worst.”
- Climate change is already contributing to displacement and migration. Although economic and political factors are the dominant drivers of displacement and migration today, climate change is already having a detectable effect.
- The breakdown of ecosystem-dependent livelihoods is likely to remain the premier driver of long-term migration during the next two to three decades. Climate change will exacerbate this situation unless vulnerable populations, especially the poorest, are assisted in building climate-resilient livelihoods.
- Disasters continue to be a major driver of shorter-term displacement and migration. As climate change increases the frequency and intensity of natural hazards such as cyclones, floods, and droughts, the number of temporarily displaced people will rise. This will be especially true in countries that fail to invest now in disaster risk reduction and where the official response to disasters is limited.
- Seasonal migration already plays an important part in many families’ struggle to deal with environmental change. This is likely to become even more common, as is the practice of migrating from place to place in search of ecosystems that can still support rural livelihoods.
- Glacier melt will affect major agricultural systems in Asia. As the storage capacity of glaciers declines, short-term flood risks increase. This will be followed by decreasing water flows in the medium- and long-term. Both consequences of glacier melt would threaten food production in some of the world’s most densely populated regions.
- Sea level rise will worsen saline intrusions, inundation, storm surges, erosion, and other coastal hazards. The threat is particularly grave vis-à-vis island communities. There is strong evidence that the impacts of climate change will devastate subsistence and commercial agriculture on many small islands.
- In the densely populated Ganges, Mekong, and Nile River deltas, a sea level rise of 1 meter could affect 23.5 million people and reduce the land currently under intensive agriculture by at least 1.5 million hectares. A sea level rise of 2 meters would impact an additional 10.8 million people and render at least 969 thousand more hectares of agricultural land unproductive.
- Many people won’t be able to flee far enough to adequately avoid the negative impacts of climate change-unless they receive support. Migration requires resources (including financial, social, and political capital) that the most vulnerable populations frequently don’t have. Case studies indicate that poorer environmental migrants can find their destinations as precarious as the places they left behind.