This year will see the second-biggest loss on record of Arctic sea ice Ã¢ÂÂ” a sign that the area of ice coverage is shrinking at a pace faster than once expected.
The trend also suggests that global warming is likely to increase, polar bear habitat will decline and previously icebound areas could be opened to oil and gas exploration.
Mark Serreze, a senior scientist at the National Snow and Ice Data Center, said Tuesday that the sea-ice minimum, which will be reached later this month, won't hit last year's record because the amount of daylight is decreasing in the Arctic and a new freeze is beginning.
But the minimum amount of ice at summer's end this year will be near last year's total. In 2007, the extent of Arctic ice was 23 percent lower than the previous record in 2005. That 2007 total, which set a record, was 1.65 million square miles. As of Monday, satellite observations showed 1.78 million square miles.
Arctic sea ice is important because it reflects most sunlight, keeping polar regions cool and producing a cooling effect at lower latitudes. Open water, in contrast, absorbs the sun's energy, and the warm ocean waters mean more ice melting, the National Snow and Ice Data Center says.