Governments around the world must be prepared for mass migrations caused by rising global temperatures or face the possibility of calamitous results, say University of Florida scientists on a research team reporting in the Oct. 28 edition of Science.

If global temperatures increase by only a few of degrees by 2100, as predicted by the U.N. Intergovernmental Panel on Climate Change, people around the world will be forced to migrate. But transplanting populations from one location to another is a complicated proposition that has left millions of people impoverished in recent years.

The researchers say that a word of caution is in order and that governments should take care to understand the ramifications of forced migration.

A consortium of 12 scientists from around the world, including two UF researchers, gathered last year at the Rockefeller Foundation's Bellagio Center to review 50 years of research related to population resettlement following natural disasters or the installation of infrastructure development projects such as dams and pipelines.

The group determined that resettlement efforts in the past have left communities in ruin, and that policy makers need to use lessons from the past to protect people who are forced to relocate because of climate change.

"The effects of climate change are likely to be experienced by as many people as disasters," UF anthropologist Anthony Oliver-Smith said. "More people than ever may be moving in response to intense storms, increased flooding and drought that makes living untenable in their current location."

"Sometimes the problem is simply a lack of regard for the people ostensibly in the way of progress," said Oliver-Smith, an emeritus professor who has researched issues surrounding forced migration for more than 30 years.

But resettlements frequently fail because the complexity of the task is underestimated. "Transplanting a population and its culture from one location to another is a complex process - as complicated as brain surgery," he said.

"It's going to be a matter of planning ahead now," said Burt Singer, a courtesy faculty member at the UF Emerging Pathogens Institute who worked with the research group. He too has studied issues related to population resettlement for decades.

Singer said that regulatory efforts promoted by the International Finance Corporation, the corporate lending arm of the World Bank, are helping to ensure the well-being of resettled communities in some cases.

But as more people are relocated - especially very poor people with no resources - financing resettlement operations in the wake of a changing climate could become a real challenge.

Planning and paying for resettlement is only part of the challenge, Oliver-Smith said. "You need informed, capable decision makers to carry out these plans," he said.

A lack of training and information can derail the best-laid plans. He said the World Bank increasingly turns to anthropologists to help them evaluate projects and outcomes of resettlement.

"It is a moral imperative," Oliver-Smith said. Also, a simple cost-benefit analysis shows that doing resettlement poorly adds to costs in the future.

Wasted resources and the costs of malnutrition, declining health, infant and elder mortality, and the destruction of families and social networks should be included in the total cost of a failed resettlement, he said.

Oliver-Smith said the cautionary tales of past failures yield valuable lessons for future policy makers, namely because they point out many of the potential pitfalls than can beset resettlement projects.

But they also underscore the fact that there is a heavy price paid by resettled people, even in the best-case scenarios.

In the coming years, he said, many projects such as hydroelectric dams and biofuel plantations will be proposed in the name of climate change, but moving people to accommodate these projects may not be the simple solution that policy makers sometimes assume.

A clear-eyed review of the true costs of forced migration could alert governments to the complexities and risks of resettlement.

"If brain surgeons had the sort of success rate that we have had with resettling populations, very few people would opt for brain surgery," he said.