The amount of sea ice in the Arctic has fallen to the lowest level on record, a confirmation of the drastic warming in the region and a likely harbinger of larger changes to come.
Satellites tracking the extent of the sea ice found over the weekend that it covered about 1.58 million square miles, or less than 30 percent of the Arctic Ocean's surface, scientists said. That is only slightly below the previous record low, set in 2007, but with weeks still to go in the summer melting season, it is clear that the record will be beaten by a wide margin.
The National Snow and Ice Data Center, a government-sponsored research agency in Boulder, Colo., announced the findings Monday in collaboration with NASA. The agency bases its numbers on a slightly conservative five-day average of sea ice extent.
The amount of sea ice in summer has declined more than 40 percent since satellite tracking began in the late 1970s, a trend that most scientists believe is primarily a consequence of human activity.
"It's hard even for people like me to believe, to see that climate change is actually doing what our worst fears dictated," said Jennifer A. Francis, a Rutgers University scientist who studies the effect of sea ice on weather patterns. "It's starting to give me chills, to tell you the truth."
Scientific forecasts based on computer modeling have long suggested that a time will come when the Arctic will be completely free of ice in the summer, perhaps
"It's an example of how uncertainty is not our friend when it comes to climate-change risk," said Michael E. Mann, a climate scientist at Pennsylvania State University. "In this case, the models were almost certainly too conservative in the changes they were projecting, probably because of important missing physics."