itudes . ▁ ▁The ▁black ▁carbon ▁is ▁short - l ived , ▁but ▁such ▁routine ▁fl aring ▁also ▁em its ▁vast ▁quantities ▁of ▁sul ph ur . ▁▁ ▁Home ▁fires ▁in ▁India ▁also ▁contribute . ▁ ▁Rec ent ▁studies ▁According ▁to ▁Tim ▁Gar rett , ▁an ▁assistant ▁professor ▁of ▁meteor ology ▁at ▁the ▁University ▁of ▁Ut ah ▁involved ▁in ▁the ▁study ▁of ▁Ar ctic ▁ha ze ▁at ▁the ▁university , ▁mid - lat itude ▁cities ▁contribute ▁poll ution ▁to ▁the ▁Ar ctic , ▁and ▁it ▁mix es ▁with ▁thin ▁clouds , ▁allowing ▁them ▁to ▁trap ▁heat ▁more ▁easily . ▁Gar ret ' s ▁study ▁found ▁that ▁during ▁the ▁dark ▁Ar ctic ▁winter , ▁when ▁there ▁is ▁no ▁precip itation ▁to ▁was h ▁out ▁poll ution , ▁the ▁effects ▁are ▁strong est , ▁because ▁poll ut ants ▁can ▁warm ▁the ▁environment ▁up ▁to ▁three ▁degrees ▁F ahren heit . ▁ ▁Scient ific ▁predictions ▁European ▁clim at olog ists ▁predicted ▁in ▁ 2 0 0 9 ▁that ▁by ▁the ▁end ▁of ▁the ▁ 2 1 st ▁century , ▁the ▁temperature ▁of ▁the ▁Ar ctic ▁region ▁is ▁expected ▁to ▁rise ▁ 3 ° ▁Cel si us ▁on ▁an ▁average ▁day . ▁In ▁that ▁same ▁article , ▁National ▁Geographic ▁quoted ▁the ▁co - author ▁of ▁the ▁study , ▁Andreas ▁Sto hl , ▁of ▁the ▁Norwegian ▁Institute ▁for ▁Air ▁Research , ▁" Pre vious ▁climate ▁models ▁have ▁suggested ▁that ▁the ▁Ar ctic ' s ▁summer ▁sea ▁ice ▁may ▁completely ▁disappear ▁by ▁ 2 0 4 0 ▁if ▁war