http://seattlepi.nwsource.com/opinion/270809_africa21.html

Africa on the brink of catastrophic change -- blame global warming

Africa is facing the greatest catastrophe in human history. Climate change represents a nightmare scenario for the future of the people of the world's poorest continent, according to the official preparing a top-level report due to land on the desks of British Prime Minister Tony Blair and Chancellor to the Treasury Gordon Brown later this year.

Emerging analysis seen by the Stern Review into the economic impact of climate change suggests one of the worst affected places on the planet also will be the poorest.

Global warming could cause temperature rises double those elsewhere. The consequences would be dramatic declines in rainfall and a fall in crop yields that could make previous famines look like small tragedies. Desertification could accelerate around the Sahara. There are likely to be severe water shortages in many parts of the continent..........

.......Two things give his conclusions added urgency, he said: The scientific evidence on global warming is strengthening daily, and there are risks over and above those that are usually considered. For example, the release of methane from the permafrost could bring an acceleration that is not factored into many existing models on climate change.

The disproportionate impact on Africa will be for a combination of reasons. Global warming will be greater over land than over sea because land retains heat more than water. But it will also be greatest in the tropics and in low altitudes. There is also increasing evidence that it will be particularly hit by the effect of vertical rises and falls in air currents.