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A28    SCIENCE
                 Tuesday 15 augusT 2017


















            Science Says: Fast-melting Arctic sign of bad global warming



            By SETH BORENSTEIN                                                                                                  from  November  through
            AP Science Writer                                                                                                   March,   when    sea   ice
            WASHINGTON  (AP)  —  One                                                                                            reaches its peak spread.
            of  the  coldest  places  on                                                                                        BEYOND THE ARCTIC
            Earth is so hot it’s melting.                                                                                       Of  all  the  global  warming
            Glaciers,  sea  ice  and  a                                                                                         warning  signs  in  the  Arc-
            massive  ice  sheet  in  the                                                                                        tic, “it is the sea ice that is
            Arctic  are  thawing  from                                                                                          screaming  the  loudest,”
            toasty air above and warm                                                                                           Serreze said.
            water  below.  The  northern                                                                                        That’s  a  problem  because
            polar  region  is  heating  up                                                                                      a  growing  body  of  studies
            twice as fast as the rest of                                                                                        connects  dwindling  sea
            the  planet  and  that’s  set-                                                                                      ice to wild weather. The re-
            ting off alarm bells.                                                                                               duced winter sea ice inter-
            “The  melting  of  the  Arctic                                                                                      acts  with  warmer  oceans
            will  come  to  haunt  us  all,”                                                                                    to change conditions in the
            said German climate scien-                                                                                          air that then triggers a po-
            tist Stefan Rahmstorf.                                                                                              tent  noticeable  shift  in  the
            While  global  leaders  set  a                                                                                      jet stream, the giant atmo-
            goal  of  preventing  2  de-                                                                                        spheric  river  that  controls
            grees  Celsius  (3.6  degrees                                                                                       much of our weather, said
            Fahrenheit)  of  man-made                                                                                           Rutgers  University  climate
            warming  since  pre-indus-    In this July 21, 2017 file photo, researchers look out from the Finnish icebreaker MSV Nordica as the   scientist  Jennifer  Francis.
            trial  times,  the  Arctic  has   sun sets over sea ice floating on the Victoria Strait along the Northwest Passage in the Canadian   This  theory  is  still  debated
            already hit that dangerous   Arctic Archipelago.                                                                    by  scientists,  but  increas-
            mark.  Last  year,  the  Arctic                                                                    Associated Press  ingly more researchers are
            Circle  was  about  3.6  de-  Sea  ice  is  white  and  it  re-  Colorado.             more across the Arctic and  agreeing with Francis.
            grees (6.5 degrees Fahren-   flects  the  sun’s  heat  back  ROLE OF WINTER            get thicker in the winter so it  It’s  not  just  sea  ice  on  the
            heit) warmer than normal.    into  space.  But  when  it  Winter is crucial. Three times  can  withstand  the  warmth  decline.  Glaciers  in  the
            CAUSES OF WARMING            melts,  it’s  replaced  with  in  the  past  two  cold  sea-  of the summer. But a warm-  Arctic  are  shrinking.  And
            Earth  is  getting  hotter  dark  ocean  that  strongly  sons, air temperatures near  er  winter  means  less  pro-  the massive Greenland ice
            because  of  the  buildup  absorbs it, said former NASA  the North Pole were near or  tection when the heat hits.   sheet  is  slowly  but  steadily
            of   heat-trapping   gases  chief  scientist  Waleed  Ab-  even a shade above freez-   In  September  2016,  the  melting and that can add
            spewed into the air by the  dalati,  who  heads  the  en-  ing.  That’s  about  50  de-  time of year the spread of  a big dose to sea level rise.
            burning  of  coal,  oil  and  vironmental  research  pro-  grees warmer than it should  ice across the Arctic is at its  Since 2002, it has lost 4,400
            natural  gas,  according  to  gram  at  the  University  of  be.  From  last  November  lowest,  Arctic  sea  ice  was  billion  tons  (4,000  billion
            decades of peer-reviewed  Colorado.                       through  February,  Barrow,  the  second  lowest  day  on  metric tons) of ice.
            research.  Scientists  have  That  heat  gets  transferred  Alaska — the northernmost  record,  about  40  percent  Then there’s the Arctic car-
            long  predicted  the  Arctic  back up to the atmosphere  U.S.  city  —  was  7  degrees  below the lowest day mea-  bon  bomb.  Carbon  diox-
            would warm first and faster  in  the  fall  and  winter.  As  Celsius  (13  degrees  Fahr-  sured  in  1979  when  satel-  ide and methane — which
            than the rest of the globe.  that  happens,  water  va-   enheit)  warmer  than  the  lite  records  started.    Be-  traps  even  more  heat  —
            Real-time   measurements  por  —  a  greenhouse  gas  20th century average, and  tween  those  two  days  37  are stuck in the permafrost
            are proving them right.      —  hangs  around,  trapping  much of the Atlantic Arctic  years apart, the Arctic lost  in  places  like  Alaska  and
            The  Arctic  is  mostly  ocean  more  heat.  More  clouds  off Norway and Greenland  enough  sea  ice  to  cover  Siberia.
            covered  with  a  layer  of  form  around  that  time,  was as hot.                    Alaska,  Texas  and  Califor-  “Roast  the  Arctic  and  you
            ice;  changes  from  ice  to  also  acting  as  a  blanket,  Warm  winters  weaken  sea  nia combined.              create a mess everywhere
            water often kick in a cycle  said  Mark  Serreze,  director  ice,  which  floats  on  the  Then  it  didn’t  grow  back  on  Earth,”  said  Princeton
            that  contributes  to  global  of  the  National  Snow  and  ocean  surface.  It’s  sup-  that  much  this  winter,  set-  University  climate  scientist
            warming.                     Ice Data Center in Boulder,  posed  to  recover,  spread  ting  record  low  amounts  Michael Oppenheimer.q
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