NASA: record low for sea ice

Nasa has reported the lowest levels of sea ice in the Arctic since it began monitoring in 1979.

A report from the US space agency said this week that sea ice calculations had reached the lowest total in more than 30 years, at 1.58m sq miles (4.1m sq km), compared to the previous low of 1.61m sq miles (4.17m sq km) seen in 2007.

Moreover, researchers say that the low point in 2012 came several weeks earlier than normal, as it usually occurs in late September.

According to Nasa scientist Joey Comiso from the Goddard Space Flight Center, the current melting trend comes as a result of several years of warmer weather that reduced the levels of perennial ice, giving way to instable melting conditions for sea ice worldwide.

He told the BBC, “Unlike 2007, temperatures were not unusually warm in the Arctic this summer. [But] we are losing the thick component of the ice cover. And if you lose [that], the ice in the summer becomes very vulnerable.”

It’s not just the surface area of the ice that is disappearing, however; experts say that the thickness of sea ice is being rapidly depleted.

Cambridge University Professor Peter Wadhams said, “Measurements from submarines have shown that it has lost at least 40 percent of its thickness since the 1980s, and if you consider the shrinkage as well, it means that the summer ice volume is now only 30 percent of what it was in the 1980s.This means an inevitable death for the ice cover, because the summer retreat is now accelerated by the fact that the huge areas of open water already generated allow storms to generate big waves, which break up the remaining ice and accelerate its melt,” the BBC reports.