World’s biggest carbon sink approaches tipping point

The Amazon basin could pass a tipping point by 2050 beyond which it no longer sustains a rainforest with its own water cycle if global warming and deforestation aren’t brought under control. The warning is familiar – it’s already widely known that the Amazon’s ability to make its own weather and function as a carbon sink depends above all on its scale. But a new study in Nature says up to 47 per cent of the remaining forest is at risk if logging, burning and warming aren’t dramatically reduced. The smaller the surviving forest, the more of it is exposed to rising temperatures and drought conditions, and the less is protected by the self-sustaining moisture that is the defining feature of rainforest. So far, according to the study, 15 per cent of the historic rainforest has been lost. What survives hosts 10 per cent of the world’s biodiversity. Parts of what’s gone, according to one scientist not involved in the study, now resembles the American midwest.