A three-year spell of exceptionally high temperatures has weakened the ice stream.
The last edge of the Greenland ice sheet that had resisted global warming has now become unstable, adding billions of tonnes of melt water to rising seas. In a study published in the journal Nature Climate Change, they said a surge in temperature from 2003 had eased the brakes on a long “river” of ice that flows to the coast in north eastern Greenland. Known as an ice stream, the “river” takes ice from a vast basin and slowly shifts it to the sea – in the same way that the Amazon River drains water. In the past, the flow from this ice stream had been constrained by massive build ups of ice debris choking its mouth.
But a three-year spell of exceptionally high temperatures removed this blockage – and like a cork removed from a bottle helped accelerate the flow, the study said. From 2003 to 2012, northeastern Greenland disgorged 10 billion tonnes of ice annually into the ocean, the study found.