The 2016 race downward in Arctic sea ice continued in May with a dramatic new record.
The average area of sea ice atop the Arctic Ocean last month was just 12 million square kilometers (4.63 million square miles), according to the National Snow and Ice Data Center (NSIDC). That beats the prior May record (from 2004) by more than half a million square kilometers, and is well over a million square kilometers, or 500,000 square miles, below the average for the month.
Another way to put it is this: The Arctic Ocean this May had more than three Californias less sea ice cover than it did during an average May between 1981 and 2010. And it broke the prior record low for May by a region larger than California, although not quite as large as Texas.
This matters because 2016 could be marching toward a new record for the lowest amount of ice ever observed on top of the world at the height of melt season — September. The previous record September low was set in 2012. But here’s what the National Snow and Ice Data Center has to say about that:
Daily extents in May were also two to four weeks ahead of levels seen in 2012, which had the lowest September extent in the satellite record. The monthly average extent for May 2016 is more than one million square kilometers (386,000 square miles) below that observed in May 2012.
In other words, for Arctic sea ice, May 2016 was more like June 2012 — the record-breaking year. Going into the truly warm months of the year, then, the ice is in a uniquely weak state.
“We’ve never seen anything like this before,” said Mark Serreze, who directs the center. “It’s way below the previous record, very far below it, and we’re something like almost a month ahead of where we were in 2012.”
Granted, the NSIDC called the May numbers “tentative” because of problems with the satellites that scientists rely on to observe the Arctic, but added that they are “supported by other data sources.”
The group also shared this NASA image, showing a highly broken-up field of ice in the Beaufort Sea above Canada, and a large gap of open water separating the ice from the coast:
The May record was driven, naturally enough, by significant warmth — Arctic air temperatures were 4 to 5 degrees Fahrenheit above average in the region, NSIDC said. Pockets of the Arctic had temperatures even more anomalously high than that.
Following an extremely warm winter for the Arctic, these temperatures suggest “that warmth has persisted through spring, and so we’re in a bad way right now,” Serreze said.
In 2016, Arctic sea ice has also experienced record low levels in January, February and April. In March, meanwhile, while the ice atop the Arctic Ocean was still growing rather than shrinking, it had the lowest peak extent yet observed in any winter since record-keeping began in 1979.
All of this has happened during a year that itself is blowing out old records for temperatures averaged across the globe.
And it matters so much because of the fear that we’ll see the warming of the Arctic continually feed upon itself — less sea ice, a darker ocean surface exposed to space, more heat absorbed, less sea ice … and so on, and so on.
Granted, Serreze says we still can’t be sure that 2016 will set an all-time-low sea ice record, besting 2012 — that still depends on summer weather.
“All we can say is that we are on a very bad footing,” he said. “However, this is also part and parcel of a longer trend … we’ve always known that the Arctic would be the place most sensitive to climate change, and that’s what we’re seeing.”
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