The appearance of significantly more open water in the summer months in the Arctic Ocean in 2007 created great apprehension in climatologists who make it their business to try to understand what influences global weather patterns.
Since 2007 we have has more open water in the summer months than what was seen previously, and a substantial change in the weather patterns in the Northern hemisphere possibly due to the observed changes in the Arctic.
It was clear from the outset to climatologists that open oceans water essentially should act like a heater. Water is usually warmer than the air above in as winter proceeds. The disappearing ice in the summer allows the water top warm in areas of the open Arctic notably in the Barents, Kara and Laptev seas lost significant ice first. High pressure systems could then form notably in Western Siberia and subsequently steer cold Arctic air into Europe sometimes bringing bitterly cold winds.
Major early losses of sea ice in summers since 2007 have been in thes areas and suggested that major altered weather patterns would more likely develop there. Losses have also occurred on the canadian-Greenland side of the Arctic Ocean opening increasingly passages for ships but new open water has been far greater on the Russian-European side of the Arctic.
Weather changes have nevertheless appeared on the canadian side all the way down to and inside the U.S. as well. Adding both areas together with Europe and Russia have resulted in record increases in snow cover through the winters of 2010 and 2011. However, the 2011-12 winter was particularly mild in the U. S. while Europe and Russia was less so.
How long such patterns will last is unclear, but additional warming and opening of the Arctic, particularly at the Russian-European end of the Arctic may be the most significant concern in the short term. Overall these ice melting patterns are expected to have effects on the pattern and intensity of the Arctic jet streams, and these altered patterns may have even more effect on global or Northern Hemisphere weather in the long run, especially to the extent these jet streams dip to lower latitudes. Such effects are not yet apparent.
The effects of increasingly open water and the ultimate disappearance of summer ice up to the North Pole are speculative . However, long term projections suggest an open, ice-free Arctic in summer may be possible as early as 2050-2070. Much will depend on the release of methane and other greenhouse gases from the permafrost and other sources.