Tipping point ?

Woods Hole scientists tested the Amazon basins resilency this way-(begining in 2002) -Over an area the size of two football fields, plastic sheeting was laid down, preventing any rainfall from reaching the soil. After two and a half years, most of the trees began to fall over, dead. Another year, and the area would turn into savanna, then desert. Ecological processes in Amazonia are thought to control alot of the worlds weather patterns- by causing proper evaporation and thus determining ocean temperatures and hurricane formation, as well as affecting the trade winds, monsoons, and the Gulf Stream. A sudden loss of the forest cover in the Amazon basin would trigger a world-wide catastrophe. About 25% of the forest is gone, another 25% is seriously threatened- A 50% loss is assumed to be the point of no return, and we will reach this threshhold next year, if the rains don't come. Then about 90 billion tons of carbon will be released into the atmosphere, almost all at once. There will be unbearable heat, and finally a loss of our oxygen supply, and then we will all die.

- The New Zealand Herald, July 24, 2006.

Add to the problem the accelerating release of methane from melting permafrost bogs,