This image shows the extent of sea ice over the Arctic. (National Snow and Ice Data Center)

The good news on Arctic sea ice is that the bad news isn't as bad as in previous years. The bad news is that there's no reason to believe it won't get worse.

The extent of sea ice covering the Arctic Ocean fell to the sixth-lowest in the satellite record dating back to 1979, according to the National Snow and Ice Data Center in Boulder, in a report released Thursday.

All of the seven lowest extents for Arctic sea ice were recorded in the past seven years, according to the NSIDC. Sea ice cover reached its lowest point Sept. 13, the center reported, and the sea ice average for the month of September was also the sixth-lowest on satellite record.

Arctic sea ice had hit an all-time record low in September 2012.

"The Earth's cryosphere (snow and ice cover) in general is a variable thing," said Mark Serreze, NSIDC director and senior scientist. "The globe is warming. We know this. And the Earth's snow and ice cover is one of the most sensitive indicators of this trend."

Even in the face of a warming planet, he said, scientists expect to see temporary recoveries, or even a "few good years" here and there.

"This is exactly what we expect with climate change," Serreze said. "It's not going to be an even process. It's going to be filled with a lot of ups and downs. This year, the cryosphere got a little bit of a breather."

Julienne Stroeve, a scientist at the center, attributed the slowing of ice loss to a "relatively cool and stormy summer," compared to the last few summers.


On Sept. 13, the Arctic sea ice cover decreased to 5.10 million square kilometers (1.97 million square miles). Averaged over the month of September, according to the center, the ice extent was 5.35 million square kilometers (2.07 million square miles).

That made 2013 the sixth-lowest ice extent, in terms of both daily minimum extent and monthly average. And the September coverage was 1.17 million square kilometers (452,000 square miles) below the 1981-to-2010 average.

Despite the slight uptick in this year's summer sea ice coverage over 2012, Serreze is not forecasting a long-term improvement.

"What we call the climate-forcing network, the rise in greenhouse gases, is simply too strong now," he said.

"You can't go back to where you were in the 1970s. It's too late. We can have a little bit of a recovery like this year, but the long-term trend is quite clear. We're looking at losing that summer sea ice cover certainly in this century, and possibly in the next few decades ... . And it will be a new world -- certainly, in the Arctic."

The implications for decreasing sea ice cover in the Arctic -- and the decreasing thickness of that ice -- has implications through the food chain in that part of the world, he said, as well as for weather patterns there and beyond.

"The Arctic is not that far away," Serreze said. "What happens up there can influence what happens down here. That is one of the biggest research questions out there right now. How does the loss of sea ice up there affect the weather patterns down here?"

The NSIDC sea ice report comes on the heels of last week's release of the International Panel on Climate Change Fifth Assessment Report, from its first working group (the panel's second and third working groups' efforts will come early next year), which said it is "extremely likely" that planet warming is linked to human activity. The IPCC also raised projections of potential sea-level rise to 10 to 32 inches by the end of this century.

"It's in large part just restating what was in the previous report (in 2007) just a little more forcefully," Serreze said. "In other words, the details of the picture have changed, but the overall picture has not.

"We are not just headed for a warmer world. We are already in one. And it is just going to get warmer."
