Amazon rainforest 'could resist climate change'

Charles Clover, Telegraph 29 Nov 07;

The Amazon rainforest can withstand climate change and can help to mend the global climate as long as enough forest cover is protected, scientists said.

Previous computer simulations by the Meteorological Office's Hadley Centre suggested that if global average temperatures rose more than 3ºC - the amount predicted by the end of this century - the Amazon forest would be likely to dry out and the rainfall in the region would drop.

Researchers say there is mounting scientific evidence that intact Amazon forests are more resilient to drying out than was previously suggested because of their deep root systems and because plants would acclimatise to increased temperatures and lack of water.

However, where fragmentation and clearing has already occurred, forests are more vulnerable to drying out and the spread of fires, according to an article in the journal Science.

Scientists calculated that the zone with the highest drought risk is in the south east, with a 70-80 per cent risk, while the risk of drying out in the west is only 20 per cent.

Prof Yadvinder Malhi from Oxford university, which led the research with the Met Office in conjunction with some of the world's leading experts on the Amazon, said: "The latest science points to intact rainforests being fairly resistant to a possibly drier 21st century climate in the eastern half of Amazonia.

"However, this resistance breaks down when the forests are opened up and fragmented by roads, logging and agriculture, and become vulnerable to fires. Once burnt, a forest becomes even more vulnerable to the risk of fires.

"Once the forest starts breaking up, rainfall in the region is likely to decline. Hence maintaining sufficient forest cover in Amazonia is an effective means of protecting the region from climate change, as well as directly contributing to slowing down global warming."

Scientists involved in writing the paper will be among the experts attending next week's UN conference in Bali next week where new financial mechanisms for funding the protection of standing forest will be high on the agenda.