Arctic sea ice falls to record low. Global warming?  The decline
in sea ice coincides with warming at the top of the world that
has been occurring twice as fast there as it has for the
northern hemisphere as a whole as the global climate warms.  By
, Staff writer    • close     A polar bear in the Arctic
National Wildlife Refuge in Alaska. Arctic sea ice has reached
its lowest summer extent since satellites first began keep in
track in 1979     View Caption  Earth's icy skull cap, floating
atop the Arctic Ocean, has reached its lowest summer extent
since satellites first began keep in track in 1979, and by some
estimates its lowest reach in nearly 1,500 years.  As of Sept.
7, the Arctic Ocean's expanse of summer ice this month spanned
less than 1.54 million square miles, nearly six times the size
of Texas and some 45 percent less than for the average for the
same month through the 1980s and '90s, according to the National
Snow and Ice Data Center in Boulder, Colo. And the ice is still
retreating; the summer m