As global warming melts unprecedented areas of ice, the Arctic's downward spiral is becoming well known, with the fabled Northwest Passage emerging for the first time in history and both sea ice and ice thickness shrinking to an unprecedented degree this summer.
Add to that, according to scientists quoted by the Toronto Star, unprecedented melting of permafrost. As the ice locked up in the spongy earth melted in Arctic permafrost this summer, the land sunk more than three feet -- 20 times more than usual. With water as lubricant, vast sloped areas just slid into valleys, burying streams and leaving hillsides bare, according to the Queensland University scientists that watched the events unfold over the course of hours in late July.
There was already good reason to watch the action of permafrost. In the Siberian Arctic, the melting of permafrost is being watched because it releases vast quantities of greenhouse gases that had been frozen -- making the connections between global warming and melting permafrost a potential positive feedback loop, wherein one reinforces the other. The melting of the Arctic sea ice is another such loop, because with less ice, dark water absorbs more heat, leading to additional melting, and so on.
At what point these feedback loops spiral past a tipping point at which the change can't be reversed is a huge unknown. Some say the Arctic is already there, and United Nations scientists agree that the world has already investing in years of additional warming based on the longevity of greenhouse gases it has already pumped into the atmosphere. Even if the Arctic has not tipped, the mudslides triggered by melting permafrost and the earthquakes -- yes, those too -- triggered by glaciers sliding more quickly to the sea are worrying signs that global warming is bringing amazingly vast changes to the Arctic that go beyond the melting of ice.
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