Yvo de Boer told Reuters that damage projected for Africa by the U.N. climate panel would justify tougher world action to slow global warming even without considering likely disruptions to other parts of the planet.

"Africa has been the forgotten continent," in efforts to combat warming, de Boer, head of the Bonn-based U.N. Climate Change Secretariat, said by telephone from a meeting of African and Mediterranean nations in Tunis about climate change.

He noted that big developing countries, such as China and India, had 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.

Africa has won relatively little aid to help it adapt to ever more drought, desertification, changing ranges for diseases and rising seas.

"Africa is not getting a lot out of climate change policy at the moment," he said. "But climate change will affect Africa very severely."

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. "That in itself is enough for more world action," de Boer said.

AGRICULTURE

And in some African countries, it says yields from rain-fed agriculture could be reduced by up to 50 percent by 2020.

It also says the costs of adapting to rising seas in Africa could amount to at least 5 to 10 percent of gross domestic product towards the end of this century. It also projects an increase of 5 to 8 percent of arid and semi-arid lands in Africa by 2080.

More than 100 of the world's environment ministers will meet in Bali next month and de Boer said there seemed "general agreement" on a need to launch two years of talks on a broad international deal to succeed the U.N.'s Kyoto Protocol.

Kyoto binds 36 industrial nations to cut emissions of greenhouse gases, mainly from burning fossil fuels, by at least 5 percent below 1990 levels by 2008-12.

But Kyoto only caps a third of global emissions and top emitters led by the United States and China have no firm goals. U.S. President George W. Bush said Kyoto would damage the U.S. economy and wrongly omits 2012 goals for developing nations.