Governments in Asia and the Pacific need to prepare for a large increase in climate-induced migration in the coming years, says a forthcoming report by the Asian Development Bank.

Climate refugees displaced from Kutubdia Island on the coast of Bangladesh, April 2010. [Environment News Service]

Typhoons, cyclones, floods and drought are forcing more and more people to migrate, the bank said in a statement Monday announcing the report. In the past year alone, extreme weather in Malaysia, Pakistan, China, the Philippines, and Sri Lanka has caused temporary or longer term dislocation of millions of people.

The bank said it expects this process to accelerate in coming decades as climate change leads to more extreme weather.

"No international cooperation mechanism has been set up to manage these migration flows, and protection and assistance schemes remain inadequate, poorly coordinated, and scattered," the report states. "National governments and the international community must urgently address this issue in a proactive manner."

Speaking Saturday at the Delhi Sustainable Development Summit, Bart Edes, director of ADB's Poverty Reduction, Gender, and Social Development Division, said, "Climate-induced migration will affect poor and vulnerable people more than others."

"In many places, those least capable of coping with severe weather and environmental degradation will be compelled to move with few assets to an uncertain future," predicted Edes. "Those who stay in their communities will struggle to maintain livelihoods in risk-prone settings at the mercy of nature's whims."

Edes cited an article in the May 2009 issue of "The Lancet," a leading medical journal of record, that called climate change "the biggest global health threat of the 21st century."

Edes sketched a four-part scenario for the summit participants.

Climate change will increase extreme weather events, causing injuries and loss of life, water contamination, infectious diseases, food shortages, and mental health problems associated with disaster and tragedy.

During drought and heavy rainfall, a reduction in crop yield and subsistence agriculture leads to malnutrition and micronutrient deficiencies.

An increase in the number of very hot days in large cities will exacerbate urban air pollution, while forest fires and dust storms affect air quality over broad areas, both rural and urban.

Vector-borne diseases such as malaria and dengue are highly correlated with temperatures and rainfall patterns. Warmer temperature will increase the geographical habitat of vectors of diseases, such as mosquitoes and rodents. "The most at risk are people with infirmities and pre-existing health conditions that will be worsened by heat stress and extreme weather," Edes said.