Tens of millions of Africans face increasing water scarcity by 2020, posing potential food shortages and a rise in disease, scientists say, and Africa must push hard for the finance and expertise to enable it to devise regional solutions, they say.

"It's critical for African countries to be sure that they have a strong and unified negotiating position when negotiations begin in Bali", Yvo de Boer, Executive Secretary of the Bonn-based U.N. Climate Change Secretariat, said.

"Africa should ensure that concerns about the continent are firmly on the negotiating agenda," he said at a meeting of African and Mediterranean nations in Tunis about climate change.

More than 100 of the world's environment ministers will meet in Bali next month to launch two years of talks on a broad international deal to succeed the U.N.'s Kyoto Protocol.

The Kyoto treaty obliges 36 industrial nations to cut emissions by at least 5 percent below 1990 levels by 2008-12. A new deal would aim to involve outsiders led by the United States and China, which have no Kyoto goals.

Experts say big developing countries, such as China and India, have won far more funds than Africa from rich nations to help cut greenhouse gases, for instance by investing in wind farms, hydropower dams or in cleaning up industrial emissions.

"We have non-skilled human resources and weak institutions which cannot address this important threat", said Youba Sokona, executive secretary of Sahara-Sahel Observatory, a Tunis-based body which campaigns against desertificiation in Africa.

"What we need is new and strong ways of cooperation between the institutions at national, sub-regional and international levels. We are in climate change and we have to adapt."

MORE DISEASES, MORE PESTS

The U.N. climate panel's final 26-page summary report, released in Spain on Saturday, says that Africa, the Arctic, the deltas of major rivers in Asia and small island states are likely to be especially affected by climate change.

For Africa, it says that between 75 and 250 million people on the world's poorest continent are projected to face increased water stress by 2020. In some African countries, it says yields from rain-fed farming could be cut by up to 50 percent by 2020.

Rajendra Pachauri, chairman of the U.N.'s Intergovernmental Panel on Climate Change (IPCC), said Africa had to act fast at sub-regional level to improve climate policy.

"Countries with geographical links should come up with a common action plan. Action has to start today."

"Climate change will obviously have an impact in the social sense, on the life of people dependent on farming ...

"There will be more diseases and more pests due to the rise in temperatures and heat waves. We have to worry about that."

He said solutions would include improving information systems and boosting local infrastructure "to know when and what to do if there is a heat wave."