Warm Pacific may paradoxically cause US winter freeze, says a study

Reuters: Unusually warm western Pacific waters linked to global warming may be the paradoxical cause of a bone-chilling winter in parts of the United States this year, a scientific study said on Thursday. The theory contrasts with other experts' views, including that the freeze was simply a freak natural event or that it was linked to a thawing of the Arctic in recent years that sent a blast of cold air south.

"People's reaction when they sit under 10 feet of snow is to say 'this cannot be man-made climate change'," said Professor Tim Palmer of Oxford University, who published his research in the journal Science. "But there is a plausible link," he told Reuters.

He said a strengthening of trade winds had led to a build-up of warm water in the western tropical Pacific, aggravated in recent years by global warming from man-made emissions of greenhouse gases. Thunderstorms linked to the warmth in turn disrupted the jetstream, high altitude winds which flow in vast meandering loops around the northern hemisphere, and sucked cold air from the Arctic. Detroit, for instance, suffered record snows and the coldest January since 1977.

Pinpointing the causes of the U.S. chill, when climate change should make cold winters less likely, would help companies, farmers, city planners or even home owners wondering if they should invest in extra roof insulation. Two other experts were unconvinced by Palmer's study.

Jennifer Francis of Rutgers University, who wrote in 2011 that a melting of Arctic ice may cause cold snaps, said the Pacific had a similar pattern of heavy rainfall in 2011-12 but the winter was mild in the United States....

A winter storm in New York City, MTA of the state of New York, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license