Bangkok  - Climate-change adaptation is likely to cost developing countries 75 billion to 90 billion dollars annually from 2010 to 2050, according to a study released Wednesday by the World Bank.

Based on an assumption that global temperatures would rise at least 2 degrees Celsius over the next four decades, adaptation costs for the developing world in such sectors as infrastructure "climate proofing" are to cost 75 billion to 90 billion dollars a year, the organization said on the sidelines of United Nations climate-change talks being held this week and next in Bangkok.

"The gross costs will be highest in the Asia-Pacific region, followed by Latin America and Sub-Saharan Africa," said Warren Evans, World Bank Environment Department director.

The World Bank, in a first attempt to methodically quantify the costs of climate-change adaptation for developing countries, made its estimates based on two future climate scenarios that differ on the predicted increase in rainfalls, Evans said.

According to the study, adaptation costs for the Asia-Pacific under the so-called wetter scenario amount to about 25 billion dollars a year.

For Latin America, the estimated annual sum is 21.5 billion dollars, 18.1 billion dollars for Sub-Saharan Africa, 12.6 billion dollars for South Asia, 9.4 billion dollars for Europe and Central Asia, and 3 billion dollars for the Middle East and North Africa.

The two sectors requiring the lion's share of the adaptation costs are infrastructure and coastal zones, the report said, requiring investments of 29.5 billion and 30.1 billion dollars annually.

In the drier-case scenario, Asia-Pacific countries would need to spend an estimated 19.6 billion dollars, Latin America 16.9 billion dollars, Sub-Saharan Africa 16.9 billion dollars, South Asia 15.6 billion dollars, Europe and Central Asia 5.6 billion dollars, and the Middle East and North Africa 3 billion dollars per year.

"The infrastructure costs are for climate-proofing roads, drainage, hospitals, schools," said Urvashi Narain, a World Bank senior economist who helped compile the study. Coastal zone adaptation includes building dykes and saving mangroves, she said.

Much of the adaptation bill would have to be picked up by local governments, but the bank noted that the estimated costs were similar to amounts currently spent by industrialized nations on Overseas Development Assistance.

"Economic growth is the most powerful form of adaptation; however, it cannot be business as usual," Evans said, noting that in the future, all governments would need to factor in adaptation costs to their national development plans.

The study did not provide a breakdown of how much industrialized nations would have to contribute to help developing countries, one of the more controversial issues discussed at the UN Framework Convention on Climate Change in Bangkok.

The meeting has drawn about 4,000 country delegates and observers to finalize the negotiating text to be used in Copenhagen in December to agree upon a new global climate deal.

Key controversies include persuading developed countries to agree to drastic carbon emission cuts and assist the developing world to adapt to and help mitigate climate change. (dpa)