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Arc­tic sea ice shrinks: A ‘nail in the cof­fin’

Sec­ond-low­est level on record caps ‘crazy year’

- Doyle Rice Weather · Science · Ecology · Arctic · Arctic · Siberia, California · NASA · University of Washington · United States of America · National Snow and Ice Data Center · US National Oceanic and Atmospheric Administration · Goddard Space Flight Center · Cecilia

Fu­eled by un­usual warmth at the top of the world, Arc­tic sea ice shrank to its sec­ond-low­est level on record last week, sci­en­tists an­nounced Mon­day.

“It’s been a crazy year up north, with sea ice at a near-record low, 100de­gree (Fahren­heit) heat waves in Siberia and mas­sive for­est fires,” said Mark Ser­reze, di­rec­tor of the Na­tional Snow and Ice Data Cen­ter, which made the an­nounce­ment, along with NASA.

“The year 2020 will stand as an ex­cla­ma­tion point on the down­ward trend in Arc­tic sea ice ex­tent,” he said. “We are headed to­ward a sea­son­ally ice-free Arc­tic Ocean, and this year is another nail in the cof­fin.”

Sea ice is frozen ocean water that melts each sum­mer and re­freezes each win­ter. It af­fects Arc­tic com­mu­ni­ties and wildlife and it helps reg­u­late the planet’s tem­per­a­ture by in­flu­enc­ing the cir­cu­la­tion of the at­mos­phere and ocean.

Arc­tic sea ice typ­i­cally reaches its small­est ex­tent in Septem­ber and largest in March.

The min­i­mum was reached on Sept. 15 and mea­sured 1.44 mil­lion square miles. This is about 958,000 square miles be­low av­er­age, ac­cord­ing to a state­ment from NASA.

This ap­pears to be the low­est ex­tent of the year, the Na­tional Snow and Ice Data Cen­ter said. In re­sponse to the set­ting sun and fall­ing tem­per­a­tures, ice ex­tent will be­gin in­creas­ing through au­tumn and win­ter. How­ever, a shift in wind pat­terns or a pe­riod of late-sea­son melt could still push the ice ex­tent lower.

This year ranks be­hind only 2012, when the low­est level on record was mea­sured. Arc­tic sea ice has been mea­sured since 1979.

The amount of sum­mer sea ice in the Arc­tic has been steadily shrink­ing over the past few decades be­cause of man-made global warm­ing, ac­cord­ing to the Na­tional Oceanic and At­mo­spheric Ad­min­is­tra­tion and NASA.

A Siberian heat wave in the spring be­gan this year’s Arc­tic sea ice melt

“The year 2020 will stand as an ex­cla­ma­tion point on the down­ward trend in Arc­tic sea ice ex­tent.” Mark Ser­reze, di­rec­tor of the Na­tional Snow and Ice Data Cen­ter

sea­son early, and with Arc­tic tem­per­a­tures be­ing 14 to 18 de­grees Fahren­heit higher than av­er­age, the ice ex­tent kept de­clin­ing.

“It was just re­ally warm in the Arc­tic this year, and the melt sea­sons have been start­ing ear­lier and ear­lier,” said Nathan Kurtz, a sea ice sci­en­tist at NASA’s God­dard Space Flight Cen­ter. “The ear­lier the melt sea­son starts, the more ice you generally lose.”

The 14 low­est ex­tents on record have all oc­curred in the past 14 years.

“Sea ice keeps our planet cooler, so when we lose ice, the en­tire world warms,” said Cecilia Bitz, a pro­fes­sor at the Univer­sity of Wash­ing­ton. “Arc­tic sea ice is es­sen­tial for the sur­vival of po­lar bears and seals, and hu­mans rely on it, too – north­ern com­mu­ni­ties use it for travel and for hunting, and sea ice damps ocean waves, pro­tect­ing coastal com­mu­ni­ties from storm-in­duced dam­age.”

Bitz said that Arc­tic sea ice is an as­set for our planet, but it is dis­ap­pear­ing rapidly. “In my life­time, the sea ice at the end of sum­mer has de­creased by 50%, and now we’ve found that late sum­mers may be ice-free in a few decades. “When it is gone, we’ll have lost a sea ice area about equal to the area of the lower 48 states of the U.S.”

Ser­reze said the sec­ond-low­est ex­tent of sea ice on record is just one of many signs of a warm­ing cli­mate in the north, point­ing to the Siberian heat waves, for­est fires, higher-than-av­er­age tem­per­a­tures over the Cen­tral Arc­tic and the thaw­ing per­mafrost that led to a Rus­sian fuel spill.

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