The world's governments and relief agencies need to plan now to resettle millions of people expected to be displaced by climate change, an international panel of experts said on Thursday.
Resettlement is already occurring at the rate of some 10 million people a year, said the report's lead author, Alex de Sherbinin. Climate-related resettlement projects are under way in Vietnam, Mozambique, on the Alaskan coast, the Chinese territory of Inner Mongolia and in the South Pacific.
If global temperatures rise, as predicted, by as much as 7.2 degrees F (4 degrees C) this century, "resettlement would become virtually unavoidable in some regions of the world," the scientists wrote in the journal Science.
Warming of this magnitude would have a dramatic impact on water availability, agricultural productivity, ecosystems and sea level -- all of which in turn affect where and how humans can live.
Planning for millions of refugees will be challenging, but it is vastly better than the alternative, de Sherbinin said by telephone from The Earth Institute at Columbia University in New York.
"Are we just going to respond to the next 911 (emergency) call that comes out, or are we going to actually anticipate some of these things and in so doing hopefully avert the 911 call to some extent and maybe save some money in the process?" he said.
Procedures already in use to resettle victims of such natural disasters as droughts, floods and earthquakes could be used or adapted to prepare for resettlement of climate refugees, the authors said.
Lessons from Three Gorges
Past resettlement prompted by dams, mines or other development have not always produced the projected benefits for those who were moved, de Sherbinin said.
For example, in China 1.25 million people were displaced over 16 years for the giant Three Gorges dam on the Yangtze River, according to co-author Yan Tan of the University of Adelaide in Australia.
Those who were moved were supposed to be resettled locally, but 15 percent were resettled far from their original homes.
More than 200,000 rural residents, some of whom were resettled once due to the dam project, live in vulnerable environments near the shore of the Three Gorges reservoir and will have to be relocated again, Tan said in answer to emailed questions.
Learning from this experience could help those who will deal with communities forced to move by climate change, the authors said. One lesson is to ensure that assessments made before any resettlement reflect health and social effects.
Resettlement methods may need revision. Rather than moving farmers to less vulnerable farmland elsewhere, resettlement efforts for climate refugees will likely move rural residents to urban environments, de Sherbinin said.