No climate let-up

摘要

IS IT time to relax over global warming? The Intergovernmental Panel on Climate Change may be set to revise downwards its estimate of climate sensitivity-the extent to which the world will warm as carbon dioxide levels rise. But while lower climate sensitivity would be good news, we certainly shouldn't bet on it.The last IPCC report stated that climate sensitivity for a doubling in CO_2 levels was between 2 and 4.5 ℃, mostly likely 3 ℃. Now an article in The Economist, based on a leaked draft of the next report, due in September, claims it will give a figure between 1.5 and 4.5 ℃, with no most likely value.