A new study finds that Arctic sea ice is thinning at a steadier and faster rate than previously thought. Sea ice extent has been fairly well observed by satellites, but observations of ice thickness have been relatively sparse until now.
The new research, published in The Cryosphere, shows that the ice in the central Arctic Ocean thinned 65 percent between 1975 and 2012, from 3.59 meters (11.78 feet) to 1.25 meters (4.1 feet).
“The ice is thinning dramatically,” said lead author Ron Lindsay, a climatologist at the UW Applied Physics Laboratory. “We knew the ice was thinning, but we now have additional confirmation on how fast, and we can see that it’s not slowing down.”
In addition to thinning, sea ice extent was well below average in February. In fact, it was the third lowest February ice extent in the satellite record.
PBI’s Senior Director of Conservation, Geoff York, said, “For those who have spent time on the sea ice, this change has been clear—more active sea ice year-round, less multi-year ice, and vast areas of broken rubble ice. The habitat for polar bears is not only decreasing in size, it’s also becoming less stable.”
According to the National Snow & Ice Data Center, arctic sea ice extent in February averaged 14.41 million square kilometers (5.56 million square miles). It is 940,000 square kilometers (362,900 square miles) below the 1981 to 2010 long-term average of 15.35 million square kilometers (5.93 million square miles).
Arctic sea ice is expected to reach its maximum size in the next few weeks. In previous years there has been a surge in sea ice extent in March, but “if the current pattern of below-average extent continues, arctic sea ice extent may set a new lowest winter maximum,” the NSIDC reported.
York said, “We can still turn this around, for polar bears and for people. Climate scientists and economists increasingly suggest we have a short and rapidly closing window of opportunity to harness the best technology and make informed policy choices to reduce green house gases. What we need is leadership to create this new economy—for polar bears and for the future of us all.”
Read more: livescience; Arctic Sea Ice 'Thinning Dramatically,' Study Finds
Read more: National Snow & Ice Data Center; Possibly low maximum in the north, a high minimum in the south