Greenland ice sheet doomed: Richard Alley

While I was on vacation last week, nothing much seemed to happen. Oh, massive flooding in Pakistan, heat waves in Russian, but beyond disasters in foreign countries, no one I talked to recalled anything.

Today I come across a report in The Guardian that Richard Alley, perhaps this nation's premier expert in ice sheet formation and loss, told a House panel that if global temperatures rise by 2C, which is at the low end of estimates this half-century, that the Greenland ice sheet is doomed.

"Sometime in the next decade we may pass that tipping point which would
put us warmer than temperatures that Greenland can survive," Alley told a
briefing in Congress, adding that a rise in the range of 2C to 7C would
mean the obliteration of Greenland's ice sheet.

"What is going on in the Arctic now is the biggest and fastest thing that nature has ever done," he said.

If the Greenland ice sheet melts, world seas will rise by more than twenty feet, wiping numerous cities — including New Orleans, and much of lower Manhattan — off the map. 

For a more dramatic reporting, see former sceptic Michael Hanlon's story — The Crack in the Roof of the World:

Greenland is silent, almost. There is no wind, no birds, no insects;
apart from the scientists around me the world of Man is far away. But
there is sound, which you have to strain your ears to hear.

A gurgling sound, the tinkle-trickle of drains, and a deeper, Hadean roar  -  the noise of an icecap liquefying.

Sceptics
will argue that Greenland has always had moulins and meltwater rivers;
this is true. But what is new is these used to be confined to the very
edge of the icesheet, marginal, ephemeral features that lasted just a
few weeks in the height of the summer melting season. Now there are
lakes and moulins right on the centre of the cap, and persisting well
into August.