In December, NOAA released an unsettling Arctic report card declaring that the North Pole had reached a “new normal,” with no sign of returning to a “reliably frozen region.” Rising temperatures have locked in a long-term trend of shrinking glaciers, receding sea ice, and warming permafrost.
Between October 2016 and September 2017, the area above the 60th parallel north experienced the second-warmest air temperature anomaly since 1900. In March, satellites recorded the lowest sea-ice winter maximum on record.
Melting glaciers and sea ice are particularly worrisome trends because they trigger critical secondary effects, notably including increasing rates of sea-level rise.
This development also sets up dangerous climate feedback loops as reflective white snow and ice turn into heat-absorbing dark-blue water. It means the Arctic will send less heat back into space, which leads to more warming, more melting, and more sea-level rise still.
“We see a major increase in temperatures in the high latitudes, in the area and coasts around the Arctic Ocean, so it seems like this process has already started,” says Vladimir Romanovsky, a professor of geophysics at the Permafrost Laboratory at the University of Alaska, Fairbanks.
He says another cause for concern is that permafrost is warming, approaching thawing temperatures in parts of the Alaskan interior. The problem there is that permafrost traps massive amounts of greenhouse gases beneath the surface. As it melts, those gases are released, forming a separate self-reinforcing cycle.
In early December, Lawrence Livermore National Lab researchers highlighted yet another potential effect of declining Arctic sea ice, concluding it may have played a crucial role in California’s extended drought this decade and could exacerbate future ones. Finally, though it seems counterintuitive, the warming Arctic could also amplify cold spells, much like the winter storm now enveloping the East Coast.