British researchers report today that Arctic Ocean ice is now so thin and fragile that it may be only a decade before the ocean is ice-free and navigable in summer.
The BBC:
The Arctic Ocean could be largely ice-free and open to shipping during the summer in as little as ten years' time, a top polar specialist has said.
Professor Peter Wadhams, of the University of Cambridge, has been studying the Arctic since the 1960s. He was speaking at the announcement of the findings of the Catlin Arctic Survey.
Explorer Pen Hadow led the expedition from the north of Canada. It found that, on average, the thickness of Arctic ice was characteristic of a single season's freezing, rather than the thicker ice characteristic of a multi-year buildup.
Professor Wadhams said: "The Catlin Arctic Survey data supports the new consensus view - based on seasonal variation of ice extent and thickness, changes in temperatures, winds and especially ice composition - that the Arctic will be ice-free in summer within about 20 years, and that much of the decrease will be happening within 10 years.
"That means you'll be able to treat the Arctic as if it were essentially an open sea in the summer and have transport across the Arctic Ocean."
That means open shipping routes, which could have some short-term economic benefits, although it also could lead to a lot of international tensions over access to and ownership of natural resources.
But in the longer-term, losing a permanent feature of the planet risked accelerated warming, changing patterns of circulation in the oceans and atmosphere, and having unknown effects on ecosystems through the acidification of waters.
Well, yeah. There's that...
The Survey's website can be accessed here. Meanwhile, our own National Snow and Ice Data Center reports the folllowing:
At the end of the Arctic summer, more ice cover remained this year than during the previous record-setting low years of 2007 and 2008. However, sea ice has not recovered to previous levels. September sea ice extent was the third lowest since the start of satellite records in 1979, and the past five years have seen the five lowest ice extents in the satellite record.
NSIDC Director and Senior Scientist Mark Serreze said, "It’s nice to see a little recovery over the past couple years, but there’s no reason to think that we’re headed back to conditions seen back in the 1970s. We still expect to see ice-free summers sometime in the next few decades."
Decades now sounds optimistic. As with so many studies of the effects of global warming, things are getting worse than was expected faster than was expected. Expect more of the same.