Wyrd - OE: that which has become; fate-shaping; destiny-unfolding

Tuesday, 18 October 2011

Skating on thin ice

If a picture paints a thousands words, then maybe a nicely-framed graph can sketch out a good few dozen. The one place on the planet where climate change isn't measured in tiny fractions of a Fahrenheit -- or in the remorseless millimetric lapping of sea-levels -- is the Arctic. Here, summer-on-summer, great wedges of sea-ice are swallowed back into the warming sea -- and winter isn't claiming them back:

The winter's sea-ice volume for the last 32-years 

And remember that's a zero-based graph - which is exactly where sea-ice volumes appear to be racing.

That isn't a measly chipping away -- something monstrous has caused the amount of sea-ice to crash by two-thirds over the last three decades, the time we've been tracking sea-ice by satellite. The numbers come from the satellite's daily mapping of sea-ice area; computer modelling fills in that all-important third dimension -- the ice thickness -- to give the volume figures above.

Mention computer models, and eyebrows are raised -- after all models are just best guesses, aren't they? And of course guesses can be wildly wrong. But these numbers match other ways of checking ice thickness, especially from those on the 'ground'. And those 'on the ground', are all at sea -- literally, as the ice has gone. Listen to Dr David Barber's description of unprecedented areas of 'rotten ice' on his expedition to the Arctic -- 22 mins into this video of the Oslo Science Conference.

A twenty-five year veteran scientist of the Arctic, he is shocked by what he found. If the Arctic is the 'canary in the coal-mine' of global warming, then the time for its tweeting is long past. The poor bird would seem to be heading for an imminent swan-dive to the cage floor.

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