http://fromthewilderness.com/free/ww3/110705_world_stories.shtml#2 ........ But what is worrying some scientists even more than the growing scale of the humanitarian crisis is a suspicion that this year's drought may be the harbinger of a much greater disaster that could push the whole Amazon forest to a critical flip-over point and into an unstoppable process of self-destruction ....... What happens to the Amazon affects the rest of the planet, and scientists have long been aware that if too much forest is felled by loggers, cattle rearers and soya farmers, the convection process will be disrupted, with disastrous global consequences. "If the Amazon loses more than 40% of its forest cover, we will reach a turning point where the world's largest forest will begin an irreversible process of savannisation," says Carlos Nobre, a senior scientist at INPE, the Brazilian institute of space research, and a leading climatologist.