Top 10 global weather events of 2010

A panel of weather and climate experts ranked the the Top 10 global weather and climate events of 2010. Voters considered the scope and unusualness of the event, its immediate human and economic impact, and whether it is emblematic of climate trends or variability. They voted during the first week of December, so the following weeks' extreme winter weather in Europe, which may have deserved a spot in the Top 10, received an honorable mention.

- National Oceanic and Atmospheric Administration

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A polar bear crosses the Arctic National Wildlife Refuge in Alaska in this 2003 file photo. Polar bears live on the floating sheet of Arctic sea ice, which in September 2010 had shrunk to its third-smallest area on record. (Subhankar Banerjee / AP / File)

9. Shrinking Arctic sea ice

Arctic sea ice, the floating ice sheet that covers most of the Arctic ocean, shrunk to its third-smallest extent ever, measuring only 4.9 million sq. km (1.9 sq. miles). The last four years (2007-2010) are the four smallest on record.

For the first time in modern history, the Northwest Passage and the Northern Sea Route were simultaneously ice-free in September.

Arctic ice shrinks every summer and grows every winter, but this summer, it shrunk at the fastest rate ever measured – more than 50 percent faster than average, and breaking the 1999 record.