Arctic ice is decreasing

CryoSat is a satellite built to study the thickness of the Earth's polar caps.  The first results from the satellite are disturbing.  The volume of ice in the Arctic is disappearing at a much faster rate than formerly thought.  

It seems as though summer ice is disappearing faster than winter ice.  In 2004 there was about 13,000 cubic kilometres of sea ice in the Arctic. In 2012, there is 7,000 cubic kilometres, almost half the figure eight years ago. If the current annual loss of around 900 cubic kilometres continues, summer ice coverage could disappear in about a decade in the Arctic.  And the ice is getting thinner. 

While the results are preliminary and may change, if the change holds, then ocean temperatures will rise and methane deposits on the ocean floor could melt, evaporate and bubble into the atmosphere.