Record ice melt reported in Arctic

WASHINGTON – Critical ice in the Arctic Ocean melted to record low levels this sweltering summer and that can make weather more extreme far away from the poles, scientists say.

The National Snow and Ice Data Center reported Monday that the extent of Arctic sea ice shrank to 1.58 million square miles and is likely to melt more in the coming weeks. That breaks the old record of 1.61 million square miles set in 2007.

The North Pole region is an ocean that mostly is crusted at the top with ice. In the winter, the frozen saltwater surface usually extends about 6 million square miles, shrinking in summer and growing back in the fall. That’s different from Antarctica, which is land covered by ice and snow and then surrounded by sea ice.

Normally sea ice in the Arctic reaches its minimum in mid-September and then starts refreezing. But levels on Sunday shrank 27,000 square miles – about the size of West Virginia – beyond the old record.

Figures are based on satellite records dating back to 1979. The ice center bases its figures on averages calculated over five days.

Data center scientist Ted Scambos said the melt can be blamed mostly on global warming from man-made emissions of greenhouse gases. There are natural factors involved too, including a storm that chewed up a significant amount ice earlier this month. But, he said, dramatic summer sea ice losses in all but one year since 2007, continuous thin ice and warm air temperatures show a pattern that can only be explained by climate change.

“It really does imply that the Arctic is moving to a new state,” said NASA ice systems program scientist Tom Wagner.

Wagner and Scambos said some people thought 2007 was just an odd year that caused the dramatic melt, but years like this one show something bigger is happening.

This milestone is a “substantial step” to the day when there will be no significant sea ice in the Arctic in the summer, said NASA chief scientist Waleed Abdalati.

Scientists say Arctic sea ice helps moderate temperatures farther south in the winter and summer. A study earlier this year in the peer-reviewed journal Geophysical Research Letters linked some of the factors behind Arctic sea ice loss to higher probabilities of extreme weather. Scientists also say sea ice is crucial for polar bears and other animals.