Tuesday, January 27, 2015

Climate change responsible for super-charging winter storms, scientists say

Suzanne Goldenberg in the Guardian (UK): Winters may be getting shorter, but watch out when it does snow: climate change is super-charging storms like the blizzard engulfing the American north-east, scientists said on Monday.

The heavier storms of recent years – snowfalls that shut down cities and brought heavy flooding to coastal areas of New England – carried the imprints of climate change, as researchers get better at detecting the fingerprints of global warming – even from snow.

It was too soon to pin the current storm to climate change, but a trend line was emerging, the scientists said. “The snow season is getting shorter,” said Kevin Trenberth, a climate scientist at the National Center for Atmospheric Research. “But the interesting thing is you can end up with heavier snows in part because of climate change.”

In general, climate change produces more extreme precipitation in North America – and if it’s cold enough, that produces snow. ... Nor’easters pack their punch from the contrast between cold land temperatures at the warmer Gulf stream and surrounding waters. Five of New York’s biggest snow storms have occurred since 2000, and 2014 was the hottest year in 130 years of temperatures records.

...“You can easily get as much as 20% more snow out of a storm than you would otherwise, as long as it is cold enough so that all of that moisture gets converted into snow. And that is usually the case in the wintertime,” Trenberth said....

NASA image of the current visitor to Carbon Based headquarters, January 27, 2015

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