Stunning record low for arctic sea ice in 2012

Yesterday, the extent of Arctic sea ice reached its minimum level for the year, and as predicted, it set a new record low, at just 3.41 million square kilometers, trouncing the 2007 record low of 4.17 million square kilometers.

"It didn't just beat the 2007 minimum, it beat it by a whole lot," said Julienne Stroeve, from the U.S. National Snow and Ice Data Center (NSIDC), who was on a Greenpeace ship, north of Greenland, this week to take stock of the ice and compare what she was seeing with satellite measurements.

According to Stroeve, her on-the-scene measurements suggest that the satellite data grossly underestimated the melt. Also, frequent clouds and fog in the images concealed the extent of the melt, so scientists believed there were still large, unbroken ice sheets. However, that isn't the case.

"There's quite a bit of open water between them," Stroeve said in a satellite-phone interview with CBC News.

"What's surprised me is how much open water there is. And how small the floes are," she said. "They're not large. We've been looking for floes that were at least 100 metres in length or width. And there's very few large floes. That surprised me. They're really broken up."

Stroeve hopes that the measurements she takes will help her to determine exactly how much the satellites underestimated and improve future monitoring. She predicts that the Arctic will have days completely free of ice by the year 2030, although other estimates have put that date as soon as 2022.

NISDC scientist Dr Walt Meir said, according to The Globe and Mail, that "in the 1980s summer sea ice would cover an area slightly smaller than the mainland United States. Now it is about half that."

"The record is unbelievable," said Dr. Andrew Weaver, a climate scientist at the University of Victoria. "This is a stunning loss of ice. To say that it is anything less than stunning would be an underestimate."

Sea ice isn't the only concern for melting in the Arctic, though. Dr. Weaver, along with two graduate students Andrew MacDougall and Chris Avis, recently published the results of their efforts to model permafrost thaw and its effect on climate change.

Permafrost is permanently frozen soil that underlies about half of Canada's landmass, and the study by Weaver, MacDougall and Avis predicts that this permafrost could release up to 508 billion additional tonnes of carbon into the atmosphere by the end of this century — roughly the same amount that humans have released into the atmosphere since the industrial revolution — raising global temperatures by an additional 0.4 to 0.8°C.

"Our analysis shows that limiting global warming to less than 2°C — as identified in the 2009 Copenhagen Accord — is less and less likely," says MacDougall in a UVic press release. "It's clear that if we want to avoid the more dire effects of climate change, we need to start reducing our emissions immediately and aggressively."

According to CBC News, Environment Minister Peter Kent wasn't shocked by the news, but he was definitely "perturbed", mostly about how the reforming ice could affect navigation patterns. He did say that the federal government was "bolstering its ice monitoring and Arctic meteorological services" and that Canada is "pushing for countries with large emission levels to join a global pact on climate change."

The ice extent is expected to grow from here, until it reaches its maximum sometime in March. However, the El Nino pattern developing in the tropical Pacific Ocean is expected to push warmer conditions into the Arctic from December through February, so it remains to be seen just how much the Arctic sea ice recovers this winter before the melting begins anew next year.