Since 1979 , the arctic has lost an ice mass the size of nearly two alaskas , and last summer saw the second-lowest ice cover on record ( surpassed only by 2007 ) .

自1979年以来，北极的并已经减少了接近于两个阿拉斯加州那么大的面积，而去年夏天，北极覆盖的冰层达到了第二低的记录，仅比2007年多而已。