"If the sea level rises, most of the African large cities are going to be under threat," Ann Kajumulo Tibaijuka, executive director of UN-Habitat, Kenya, told a forum ahead of the annual African Development Bank meeting.

Some of Africa's largest cities, including Lagos, Mombasa, Dakar, Dar Es Salaam, are coastal, and by 2030, more than 50 percent of Africans are expected to live in urban areas.

"Of course, it is Africa that is least prepared to cope. And within these cities, it is actually the low income people and the poor who are most at risk," she said.

Better rail and road networks would make secondary cities more attractive to migrants and prevent the growth of coastal mega-cities, where slums in low-lying areas make the poor the most vulnerable to rising sea levels, Kajumulo Tibaijuka said.

China is hosting the AfDB's May 16-17 board meeting in Shanghai which will be attended by economic ministers and central bank governors from the 53 African states and 24 non-African members.

The bank's first board meeting to be held in Asia comes at a time when China is leading a global scramble for oil and raw materials that is propelling growth on the world's poorest continent.

PRIVATE SECTOR WOOED

Last month, climate experts issued their starkest warning yet about the impact of global warming, blamed on human emissions of greenhouse gases from burning fossil fuels, findings that are expected to spur governments to greater action.

With only 3 percent of the world carbon market in Africa, experts urged the African Development Bank to take a more active role in promoting the sector and in financing power projects that promote alternatives to greenhouse gas-emitting fuels like coal and oil.

"The African Development Bank is well-positioned to be a financier of greenhouse gas reduction projects," said Ogulande Davidson, a professor at the University of Sierra Leone and a co-chair of one of the UN Intergovernmental Panel on Climate Change's working groups.

Right now, officials said, there was no mechanism to make Africa attractive to carbon markets and African governments did not alone have the capacity to spearhead a low-carbon drive.

"Public funds are not sufficient. We need private sector involvement, and for that, we need new financial instruments," said Yogesh Vyas, head of the environment unit at the African Development Bank.

The effects of rising temperature are already clear across the continent.

The ice cap on Mount Kilimanjaro has almost completely melted and is expected to be gone by 2020 if warming trends continue, malaria is spreading to new areas and declining rainfall is affecting crop yields.