Greenland poised on a knife edge

摘要

On 4 August 2010, the Petermann glacier in Greenland sounded a warning. A gigantic slab of ice broke off and the glacier retreated 15 kilometres, leaving it further inland than it has been since observations began a century ago. That warning went unheeded at the UN climate talks in Cancun, Mexico, last month. Delegates left without agreeing drastic cuts in greenhouse gas emissions, leaving the planet on course for 3.2 ℃ of global warming, and Greenland - the world's second largest ice cap - heading for a point of no return. The suggestion is that Greenland will reach a tipping point in the early 2040s.