Antarctic Sea Ice Paradoxically Growing
While Arctic sea ice continues to shrink as the world warms, the ice around Antarctica is actually growing, thanks to the influence of the ozone hole over the southernmost continent, scientists have reported.
But the south polar growth won't be permanent, they warn.
Though they are headed in opposite directions, the current conditions at both poles are affected by human impacts on the climate, said John Turner of the British Antarctic Survey, who presented these findings to the International Polar Year (IPY) conference held last week in Oslo, Norway.
In the Arctic, the buildup of greenhouse gases in Earth's atmosphere caused sea ice to melt to its lowest recorded area in 2007 and second lowest in 2008, but Turner said this summer is already surpassing data from those years and may take the record.
Meanwhile, at the other end of the Earth, sea ice — which melts and refreezes on the ocean's surface with the changing seasons — has been growing slightly over the last three decades, even while the Earth's climate has warmed.
Turner reported in a 2009 study in the journal Geophysical Research Letters that this mysterious ice increase is likely due to the huge rift in our planet's protective ozone layer, which has created what Turner called a "shielding effect." Essentially, a huge vent hole in the atmosphere — the famous ozone hole — causes cool winds to circle the continent, keeping Antarctica chilled. Currently, during the area's winter freeze, sea ice has expanded to an area roughly twice the size of Europe.
But this shielding will not last, Turner told OurAmazingPlanet. In 1989, the Montreal Protocol banned the use of ozone-depleting chemicals worldwide. The ozone hole has already stopped growing, and scientists expect it to heal itself by 2060 or 2070. Without the hole, the Antarctic should see more melting.