Record Low Arctic Sea Ice Extent Points to Irreversible Changes
Scientists at the National Snow and Ice Data Center (NSIDC) said on Monday that Arctic sea ice cover of 5.607 million square miles on March 24 represented the lowest winter maximum since records began in 1979. That’s 5,000 square miles less than last year’s record low. Contributing to the ice extent loss were record high air temperatures and relatively warm seawater.
“It is likely that we’re going to keep seeing smaller wintertime maximums in the future because in addition to a warmer atmosphere, the ocean has also warmed up,” said Walt Meier, a sea ice scientist at NASA’s Goddard Space Flight Center. “That warmer ocean will not let the ice edge expand as far south as it used to. Although the maximum reach of the sea ice can vary a lot each year depending on winter weather conditions, we’re seeing a significant downward trend, and that’s ultimately related to the warming atmosphere and oceans.”
After this winter’s record ice lows, scientists expect the Arctic could be ice-free in the summer months in the next few decades.
“Sometime in the 2030s or 2040s time frame, at least for a few days, you won’t have ice out there in the dead of summer,” said John Walsh, chief scientist of the International Arctic Research Centre. “The balance is shifting to the point where we are not going back to the old regime of the 1980s and 1990s. Every year has had less ice cover than any summer since 2007. That is nine years in a row that you would call unprecedented. When that happens you have to start thinking that something is going on that is not letting the system go back to where it used to be.”