Warming at the top of the world has gone into overdrive, happening twice as fast as the rest of the globe, and extending unnatural heating into fall and winter, according to a new federal report.
Study lead author Jeremy Mathis, NOAA's Arctic research chief, said it shows long-term Arctic warming trends deepening and becoming more obvious, with a disturbing creep into seasons beyond summer, when the Arctic usually rebuilds snow and ice.
Scientists have long said man-made climate change would hit the Arctic fastest. Mathis and others said the data is showing that is what's now happening.
"Personally, I would have to say that this last year has been the most extreme year for the Arctic that I have ever seen," said Mark Serreze, director of the National Snow and Ice Data Center in Boulder, Colorado, who wasn't part of the 106-page report. "It's crazy."