Arc­tic’s year of crazy ex­tremes as warm­ing hits over­drive

Kuwait Times - - HEALTH & SCIENCE -

Warm­ing at the top of the world has gone into over­drive, hap­pen­ing twice as fast as the rest of the globe, and ex­tend­ing un­nat­u­ral heat­ing into fall and win­ter, ac­cord­ing to a new fed­eral re­port. In its an­nual Arc­tic Re­port Card , the Na­tional Oceanic and At­mo­spheric Ad­min­is­tra­tion on Tues­day tal­lied record af­ter record of high tem­per­a­tures, low sea ice, shrink­ing ice sheets and glaciers. Study lead au­thor Jeremy Mathis, NOAA’s Arc­tic re­search chief, said it shows longterm Arc­tic warm­ing trends deep­en­ing and be­com­ing more ob­vi­ous, with a dis­turb­ing creep into sea­sons be­yond sum­mer, when the Arc­tic usu­ally re­builds snow and ice.

Sci­en­tists have long said man-made cli­mate change would hit the Arc­tic fastest. Mathis and oth­ers said the data is show­ing that is what’s now hap­pen­ing. “Per­son­ally, I would have to say that this last year has been the most extreme year for the Arc­tic that I have ever seen,” said Mark Ser­reze, di­rec­tor of the Na­tional Snow and Ice Data Cen­ter in Boul­der, Colorado, who wasn’t part of the 106-page re­port. “It’s crazy.” NOAA’s peer-re­viewed re­port said air tem­per­a­tures over the Arc­tic from October 2015 to Septem­ber 2016 were “by far the high­est in the ob­ser­va­tional record be­gin­ning in 1900.”

The av­er­age Arc­tic air tem­per­a­ture at that time was 3.6 de­grees (2 de­grees Cel­sius) warmer than the 1981-2010 av­er­age. It’s 6.3 de­grees (3.5 de­grees Cel­sius) warmer than 1900. Other ex­tremes the re­port de­tailed: Ocean tem­per­a­tures were 9 de­grees (5 de­grees Cel­sius) higher than the 30-year av­er­age off the coasts of Green­land. Arc­tic sea ice didn’t set a record for the an­nual min­i­mum, but in October and Novem­ber when sea ice nor­mally starts grow­ing back, it didn’t.

Extreme in num­bers

Sea ice from mid-October through Novem­ber was the low­est on record. Dart­mouth Univer­sity pro­fes­sor Don­ald Perovich, au­thor of the chap­ter on sea ice, said sea ice con­di­tions have sunk from a Bplus grade 11 years ago to a D-mi­nus grade “and that’s be­cause I’m an easy grader.” Snow cover in North Amer­ica reached a record low for spring, fall­ing be­low 1.5 mil­lion square miles in May for the first time since satel­lite ob­ser­va­tions be­gan in 1967. Though not a record, Green­land’s ice sheet continued to shrink , start­ing early, on April 10.

It was the sec­ond ear­li­est start of the Green­land melt sea­son on record. What’s hap­pen­ing is due to both man-made warm­ing and a large El Nino that just ended, Mathis said. “Not only is it extreme in any num­ber of mea­sures - air tem­per­a­ture, loss of sea ice and on and on - but there are so many things we haven’t seen, par­tic­u­larly this ex­tremely warm fall,” said study coau­thor Bren­dan Kelly, ex­ec­u­tive di­rec­tor of the Study of En­vi­ron­men­tal Arc­tic Change at the Univer­sity of Alaska, Fair­banks.

In 1979, Kelly cruised the Ber­ing Straits re­gion with a na­tive hunter who told him dozens of Yupik words for sea ice. One was tag­negh­neq, for a char­coal grey thick mul­ti­year ice. That ice is pretty much gone, Kelly said. This is more than an Arc­tic prob­lem, be­cause the cold air es­cap­ing changes weather con­di­tions, such as weak­en­ing the jet stream, Mathis said. “What hap­pens in the Arc­tic doesn’t stay in the Arc­tic,” Mathis said. “The Lower 48 may have to deal with more extreme weather events in the fu­ture.”—AP

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