The signs of climate change were all over the Arctic this year - warmer air, less sea ice, melting glaciers - which probably means this weather-making region will not return to its former, colder state, scientists from the U.S. National Oceanic and Atmospheric Administration (NOAA) reported on Thursday.

"It's a bit of a paradox where you have overall global warming and warming in the atmosphere (that) actually can create some more of these winter storms," said Jim Overland, an oceanographer at NOAA's Pacific Marine Environmental Laboratory in Seattle. "Global warming is not just warming everywhere. ... It creates these complexities."