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NASA ice expert Claire Parkinson does the math on global sea ice and confirms that small gains around Antarctica do not cancel out large losses in the Arctic.

(animation) Decades ago, the majority of the Arctic's winter ice pack was made up of thick, perennial ice. Today, very old ice is extremely rare.

The latest installment of NOAA's Arctic Report Card confirms that Arctic air temperatures are rising at more than twice the rate of the planet as a whole. This collection of images highlights some of the key changes in physical and biological conditions in the Far North.

 Arctic sea ice extent shrunk down to 2.0 million square miles (5.1 million square kilometers) in September 2013—18 percent below the 1981-2010 average, but larger than record low set in 2012.

Among the questions triggered by the entrapment of a Russian ship near Antarctica on Christmas Eve were whether the ice conditions were out of the ordinary, and, if so, whether long-term climate change was playing a role.

To be consistent with NOAA's use of 30-year periods for the official "climate normals," the National Snow and Ice Data Center switched its baseline period for sea ice analyses from 1979-2000 to 1981-2010.  Compared to the new normal, the low ice conditions of the recent past will appear less abnormal than they used to.