Arctic sea ice tied for smallest ever

The maximum reach of Arctic sea ice isn’t what it used to be, and global warming appears to be a culprit.

The National Snow and Ice Data Center reports that Arctic sea ice probably reached its maximum extent for the year on March 7, which was 5.65 million square miles.

“The maximum extent was 1.2 million square kilometers (463,000 square miles) below the 1979 to 2000 average of 15.86 million square kilometers (6.12 million square miles), and equal (within 0.1 percent) to 2006 for the lowest maximum extent in the satellite record,” the center, which is part of the University of Colorado-Boulder, reported Wednesday.

Walt Meier, a research scientist with the center, said the declining maximum reach is tied to global warming.

“I think one of the reasons the Arctic sea ice maximum extent is declining is that the autumn ice growth is delayed by warmer temperatures and the ice extent is not able to 'catch up' through the winter,” he said in a statement.

“In addition, the clock runs out on the annual ice growth season as temperatures start to rise along with the sun during the spring months,” Meier added.

The satellite records date back to 1979. The seven lowest maximum Arctic sea ice extents have all occurred within the last seven years, according to Meier.

The center said the ice’s reach had been in decline for five straight days as of March 22, but there is still a chance it could grow again.

“Sea ice extent in February and March tends to be quite variable, because ice near the edge is thin and often quite dispersed. The thin ice is highly sensitive to weather, moving or melting quickly in response to changing winds and temperatures, and it often oscillates near the maximum extent for several days or weeks, as it has done this year,” the center said on its website.