The bank's report underlines specific risks confronting climate change "hotspots," including megacities in coastal areas of Asia.

These hotspots of climate-induced migration face pressure from swelling populations as rural people seek new lives in cities, the report indicates. The problem is compounded by greater dislocation of people caused by flooding and tropical storms.

On the positive side, the report says that if properly managed, climate-induced migration could actually facilitate human adaptation, creating new opportunities for dislocated populations in less vulnerable environments.

The ADB report accords with the 2009 prediction of UN High Commissioner for Refugees Antonio Guterres, who said that "climate change will become the biggest driver of population displacements, both inside and across national borders, within the not too distant future."

"Today's challenges are interconnected and complex," Guterres warned again in December 2010. "Population growth, urbanization, climate change, water scarcity and food and energy insecurity are exacerbating conflict and combining in other ways that oblige people to flee their countries."

The Asian Development Bank will publish the report, "Climate Change and Migration in Asia and the Pacific," in early March as part of a broader ADB project aimed at increasing awareness of migration driven by changing weather patterns, and enhancing regional preparedness for this unprecedented type of migration.

The bank says that its project, Policy Options to Support Climate-induced Migration, is the first international initiative that aims to generate policy and financing recommendations to address climate-induced migration in Asia and the Pacific.