This just popped up at the NY Times a couple of hours ago. Justin Gillis and Kenneth Chang have the details.
The collapse of large parts of the ice sheet in West Antarctica appears to have begun and is almost certainly unstoppable, with global warming accelerating the pace of the disintegration, two groups of scientists reported Monday.emphasis added
The finding, which had been feared by some scientists for decades, means that a rise in global sea level of at least 10 feet may now be inevitable. The rise may continue to be relatively slow for at least the next century or so, the scientists said, but sometime after that it will probably speed up so sharply as to become a crisis.
A related story by Michael Slezak at New Scientist ties in with this report - Antarctic wind vortex is strongest for 1000 years.
If greenhouse gases really are contributing to the winds, it changes our expectations for what will happen to the climate in Australia and Antarctica.Meanwhile, Alister Doyle at Scientific American reports things aren't looking all that rosy on the East Side either.
The ozone hole is expected to heal in the coming decades, and if it was the only factor controlling the winds they would weaken and expand. So Australia would get its rain back, while the western parts of Antarctica might get some more protection against warming.
However, Abram says rising global temperatures will counteract this weakening effect on the winds. That means Western Australia will stay dry and the western parts of Antarctica, stranded outside the winds, will keep melting.
Part of East Antarctica is more vulnerable than expected to a thaw that could trigger an unstoppable slide of ice into the ocean and raise world sea levels for thousands of years, a study showed on Sunday.While a century before the worst effects of the Western Antarctic melt make themselves felt seems like a distant prospect, there are two things to keep in mind. 1) It's already happening, and isn't going to stop. 2) None of the events mentioned above are happening in isolation; there are other things going on as well and how they'll interact is not simple - but it's not likely to be good.
The Wilkes Basin in East Antarctica, stretching more than 1,000 km (600 miles) inland, has enough ice to raise sea levels by 3 to 4 meters (10-13 feet) if it were to melt as an effect of global warming, the report said.
The Wilkes is vulnerable because it is held in place by a small rim of ice, resting on bedrock below sea level by the coast of the frozen continent. That "ice plug" might melt away in coming centuries if ocean waters warm up.
While the U.S. dithers, the new Sentinel satellite from the European Space Agency is already sending back information needed to track climate change.
Melting at one of the largest ice caps on Earth has produced a big jump in its flow speed, satellite imagery suggests. Jonathan Amos and the BBC have the details.
Austfonna on Norway's Svalbard archipelago covers just over 8,000 sq km and had been relatively stable for many years.In sharp contrast to the anti-science, penny-pinching mindset dominating American politics, Europe is making a serious investment in the kind of tools we need to understand what we are doing to the planet. The ambitious Copernicus Program promises to obtain data in quantities that are unprecedented.
But the latest space data reveals a marked acceleration of the ice in its main outlet glacier to the Barents Sea.
The research was presented in Brussels on Thursday to mark the launch of the EU's new Sentinel-1a radar spacecraft.
This satellite has been in orbit barely a month but is already being tasked with a range of science observations and other duties.
European Commission officials are keen to showcase the platform's capabilities before it goes into full service, including what it can do at high latitudes.
It's not like we haven't had plenty of warning. The NY Times article notes:
The new finding appears to be the fulfillment of a prediction made in 1978 by an eminent glaciologist, John H. Mercer of the Ohio State University. He outlined the uniquely vulnerable nature of the West Antarctic ice sheet and warned that the rapid human release of greenhouse gases posed “a threat of disaster.” He was assailed at the time, but in recent years scientists have been watching with growing concern as events have unfolded in much the way Dr. Mercer predicted. (He died in 1987.)The John Oliver story Meteor Blades wrote up seems even more to the point.
UPDATE: The BBC has a more detailed story on the West Antarctic ice sheet.
The new study includes radar observations that map the underlying rock in the region, and this finds no ridge or significant elevation in topography that could act as a barrier to the glaciers' reverse.
"In our new study, we present additional data that the junction of the glaciers with the ocean - the grounding line - has been retreating at record speeds unmatched anywhere in the Antarctic," said Prof Rignot.
"We also present new evidence that there is no large hill at the back of these glaciers that could create a barrier and hold the retreat back. This is why we conclude that the disappearance of ice in this sector is unstoppable."
The researcher, who is also affiliated to the University of California, Irvine, attributed the underlying driver of these changes to global warming.