북극해 얼음 면적 역대급 감소...관측 사상 두 번째로 작아<br /><br />Ice in the Arctic Ocean this summer melted to the second lowest level in the four decades since records began in 1979.<br />According to the U.S. National Snow and Ice Data Center, this year's sea ice minimum measured at 3-point-seven-four million square kilometers on September 15th.<br />The only time it was lower was in 2012, when ice shrank to 3-point-four-one million square kilometers.<br />Scientists warn the thickness of the Arctic sea ice has been on a continuous downward trend.<br />Experts attributed this year's melt to heat waves and forest fires, and stressed the need to combat global warming.<br /><br />
