Yet even though there was slightly more ice overall across the northern latitudes this winter than during last year's record-breaking low, scientists saw several troubling trends during the winter of 2017-2018.
During February, temperatures skyrocketed to a wild winter high more than 45 degrees above normal in some areas, sending the North Pole—in the dead of winter, when the region is shrouded in darkness—above freezing for several days. Massive sections of Greenland, normally blanketed by thick, old ice, experienced open water for the first time on record. Much of the Bering Sea off Alaska, and, for a while, the whole of the Bering Strait, was also ice-free, "which is pretty remarkable," says NASA sea ice expert Alek Petty.
And despite not breaking last year's record, this winter continued a recent trend of being worse than scientists expected.
"These last few winters have all been above our projections for air temperature predictions and sea-ice declines," Petty says.
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"We recently looked back and were able to show that extreme warm periods have happened before in the Arctic, even 100 years ago," Petty says. "But what we're seeing is that there's an increase in the frequency of these incidents, they are lasting longer, and the impact on sea ice is even greater. The storms are simply eating away at the sea ice more than they used to."
The key, of course, is that all these ice declines are having immeasurable impact on the globe—increasing heat and moisture in the atmosphere, changing mixing and circulation of the Arctic ocean, affecting what and where things live, even altering the global climate system. And these shifts will only get worse until and unless humans dramatically scale back carbon dioxide emissions from the burning of coal, oil, and gas.
"The changes are just going to get more severe," Petty says.
Read more at Arctic Sea Ice Is Second-Lowest on Record
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