This September, the extent of Arctic sea ice shrank to roughly 4.7 million square kilometres, as was determined by researchers at the Alfred Wegener Institute, the University of Bremen and Universität Hamburg. Though slightly larger than last year, the minimum sea ice extent 2017 is average for the past ten years and far below the numbers from 1979 to 2006. The Northeast Passage was traversable for ships without the need for icebreakers.
This September, the extent of Arctic sea ice shrank to roughly 4.7 million square kilometres, as was determined by researchers at the Alfred Wegener Institute, the University of Bremen and Universität Hamburg. Though slightly larger than last year, the minimum sea ice extent 2017 is average for the past ten years and far below the numbers from 1979 to 2006. The Northeast Passage was traversable for ships without the need for icebreakers.
The sea ice in the Arctic is considered a critical element in climate processes, and a valuable early-warning system for global warming. Accordingly, the September minimum extent is an important indicator of climate change. Despite an especially warm winter, the current extent of sea ice does not represent a new record low; nevertheless, the amount of ice loss is massive. As sea-ice physicist Marcel Nicolaus from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) explains, “This year’s sea ice extent is again on a very low level: the observed September value of the past eleven years has consistently been lower than in any of the previous years.”
This winter, the Arctic remained unusually warm, and the sea-ice coverage in March was lower than in any March before. “Thanks to the relatively cold summer, the sea ice managed to bounce back somewhat, but this year’s September minimum is by no means a good sign,” stresses Lars Kaleschke from Universität Hamburg’s Center for Earth System Research and Sustainability. “Though the amount of sea ice is of course subject to natural fluctuations, the long-term decline is obvious.” For comparison, the summertime minimums in the 1970s and 1980s were roughly seven million square kilometres.
Read more at Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research
Image: This is a polar bear on Arctic sea ice. (Credit: Alfred-Wegener-Institut / Stefan Hendricks)
