Climate migrations could be biggest ever

By mid-century climate change could be causing migration and displacement on a scale never seen before. That's according to a report released by Columbia University, the UN University and CARE International, which says that people in the least developed countries and island states will be affected first and worst.

The report, In Search of Shelter: Mapping the Effects of Climate Change on Human Migration and Displacement was released at a news conference in Bonn, Germany, where negotiators have gathered in the run-up to Copenhagen.

"Societies affected by climate change may find themselves locked into a downward spiral of ecological degradation, towards the bottom of which social safety nets collapse, while tensions and violence rise," said CARE International in a statement. "In this all-too plausible scenario, large populations would be forced to migrate as a matter of immediate survival."

Climate change can exacerbate existing problems, such as political and economic conflicts, extreme weather events, population growth, human destruction of ecosystems and overuse of farmland. The report finds that, although economic and political factors are the dominant drivers of displacement and migration today, climate change is already having a detectable effect and contributing to displacement and migration.

It's not clear how many people will be uprooted, but previous estimates have ranged from 25–50 million by 2010 to almost 700 million by 2050. Breakdown of ecosystem-based economies such as subsistence herding, farming and fishing is likely to be the dominant driver of forced migration, while sea-level rise directly threatens the existence of some 40 countries and saltwater intrusion, flooding and erosion could destroy agriculture in the densely populated Mekong, Nile and Ganges deltas. The Maldives, a Pacific island nation with a population of 300,000 is already considering prospects for total relocation.

The authors believe that most people will relocate within their own country but others may cross borders to find better conditions. The use of adaptation measures could reduce the need for migration but poorer countries are underequipped to support widespread adaptation.

"Policy decisions made today will determine whether migration becomes a matter of choice amongst a range of adaptation options, or merely a matter of survival due to a collective failure by the international community to provide better alternatives," says the report.