The state of the Antarctic ice shelves continues to deteriorate. Following the end of the 2008-2009 Southern Hemispheric melt season, a bridge holding the Wilkins Ice Shelf to an island off the coast of Antarctica has finally collapsed. I wrote about the worsening conditions that the Wilkins Ice Shelf was facing here and here (this second post was written just about one year ago, actually). The Wilkins Ice Shelf will now be able to calve (break up and float away in ocean currents) allowing continental ice to flow to the ocean more quickly.
The National Snow and Ice Data Center in Boulder, CO has the following two pictures – the first from two months ago (Feb 3) and the second two weeks thereafter (Feb 17):
Since the 2nd picture was taken, the ice bridge collapsed. It was providing stability to the Wilkins Ice Shelf behind it. In the 1990s, the Wilkins Ice Shelf measured about 5,000 square miles in area. In 2008 alone, nearly 14% of the ice mass (~700 square miles) melted. The Western Antarctic area has seen the largest amount of warming of all of Antarctica. Similar, though much smaller shelves have broken off in recent years as warming air temperatures and warming sea temperatures attack them from two sides. This BBC article describes the situation:
Many of its ice shelves have retreated in that time and six of them have collapsed completely (Prince Gustav Channel, Larsen Inlet, Larsen A, Larsen B, Wordie, Muller and the Jones Ice Shelf).
When Wilkins calves, it is expected to be the largest calving event seen by modern people. Once that happens, ice sheets on continental Antarctica nearby this shelf won’t have thousands of square miles of ice holding them back from the ocean. This acceleration phenomenon and its effects were not included by IPCC) when it made its latest projections on likely future sea level rise. Its 2007 assessment acknowledged that ice dynamics were poorly understood. More recent studies recognize that warmer polar conditions will also lead to 30% less ice coverage in the Arctic, due in no small part to the very thin ice volume left after recent melt seasons.
These events are occurring many years ahead of recent projections. The state of the climate system is worse than many assume. We are running out of time to act and actions like Democratic Senate “moderates” forcing 60 votes to pass meaningful climate legislation clearly are not taking into account the following:
* Staggeringly high temperature rise, especially over land — some 15°F over much of the United States
* Sea level rise of 5 feet, rising some 6 to 12 inches (or more) each decade thereafter
* Widespread desertification — as much as one-third of the land
These impacts and more will be the results we witness by 2100 if we don’t act to stop them today, as I think the Obama administration believes. Read this quote from Sec. of State Clinton at a two-week conference of parties to the 50-year-old Antarctic Treaty:
“With the collapse of an ice bridge that holds in place the Wilkins Ice Shelf, we are reminded that global warming has already had enormous effects on our planet, and we have no time to lose in tackling this crisis,” she told the first-ever joint meeting of Antarctic Treaty parties and the Arctic Council at the State Department.
I certainly can’t imagine any Bush “administration” officials saying such a thing. In this sense, change has come to Washington. Will Sens. Udall and Bennet agree when the time comes to make the hard votes? Forcing 60 votes to maintain tradition and come across as “bipartisan” sounds really good. 5 feet of sea level rise, desertification of U.S. land and 15°F warmer temperatures do not sound really good. When the time comes to make those hard votes, not only do I expect Sens. Udall and Bennet to vote to do something concrete, I also expect them to bring more than enough Republican votes over to the same side. That’s the frame they wanted to work from. They upped the bid and I’m seeing them.
Cross-posted at SquareState.