Bloomberg: Arctic sea ice shrank to the second- smallest area on record this year, U.S. scientists said in the latest measurement used to gauge the impact of climate change. Polar ice covered 4.52 million square kilometers (1.74 million square miles) on Sept. 12, the National Snow and Ice Data Center in Boulder, Colorado, said today in a statement. The agency, part of the University of Colorado, releases the figures annually at the lowest level the sea ice reaches before cooling …