John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
The ice’s summer extent has tied for second-lowest in the modern record.
The Arctic’s sea ice has contracted to its smallest extent for 2016, and there’s some serious shrinkage on display. On September 10, the ice measured 1.6 million square miles which, at 911,000 short of the 1981–2010 average, makes it tied with 2007 as the second-lowest extent on the modern record.
The region’s sea ice contracts during the summer and packs it back on during the winter, although the long-term trend is more of the former and less of the latter. This year, it seemed poised for a comeback, with clouds obscuring sunlight during the normally melt-prone months of June and July. But then two large storms ripped across the Arctic, which seem to have contributed to an increased break-up and disappearance of ice.
That put the Arctic solidly back on track with the ice’s historic decline. “In the past, we had this remaining sea ice pack that was mostly thick, old ice,” NASA’s Walt Meier says in a press release. “But now everything is more jumbled up, which makes it less resistant to melt, so even late in the season you can get weather conditions that give it a final kick.” Here’s more about that:
Arctic sea ice cover has not fared well during other months of the year either. A recently published study that ranked 37 years of monthly sea ice extents in the Arctic and Antarctic found that there has not been a record high in Arctic sea ice extents in any month since 1986. During that same time period, there have been 75 new record lows.
“When you think of the temperature records, it’s common to hear the statement that even when temperatures are increasing, you do expect a record cold here or there every once in a while,” said Claire Parkinson, main author of the study and a senior climate scientist at Goddard. “To think that in this record of Arctic sea ice that goes back to the late 1970s, since 1986 there hasn’t been a single record high in any month of the year, and yet, over that same period, there have been 75 record lows. It’s just an incredible contrast.”
This visualization based on NASA research grimly illustrates the withering of the Arctic’s sea ice. Squares of medium-to-dark blue represent months with low ice cover: