Global Warming Threat to Antarctica
Catching Scientists by Surprise - Collapse of Wilkins Ice Shelf
In early July 2008 the Wilkins Ice Shelf was deemed to be, "hanging by its last thread." According to images from the Satellite Envisat, of the European Space Agency (ESA), only a narrow bridge of ice (2.7km wide) still connected the ice shelf to Charcot Island. An official ESA statement claimed that, "since the connection to the island helps stabilise the ice shelf, it is likely the break-up of the bridge will put the remainder of the ice shelf at risk."
Other Activity in the Region
This is not the only global-warming related activity in the region in recent years. Wilkins Ice Shelf, situated in the Antarctic Peninsula (about 1600km south of South America), first started to appear unstable in March 2008, when the bridge attaching it to Charcot Island was reduced to 6km. In 2002 the Larson B ice shelf also collapsed while in 1995 the Larsen A ice shelf experienced the disintegration of almost 2000 square kilometres of ice. Other parts of the peninsula have experienced melting and this is expected to worsen in the future.
Warming Around the Antarctic Peninsula
A 2008 article in Issue 14 of the Australian Antarctic Magazine titled, "Rapid Disintegration of Another Ice Shelf on the Antarctic Peninsula", stated that the Antarctic Peninsula has experienced a regional temperature rise of almost 3 degrees over the past 50 years - nearly six times greater than the global average. According to Hamish Pritchard of the British Antarctic Survey, 87 percent of the Antarctic peninsula's glaciers have been melting during this same period.
Phil McKenna, in his May 16, 2007 article "Climate myths: Antarctica is getting cooler, not warmer, disproving global warming" claims this temperature rise is due to circular winds on the Antarctic continent which cause greater warming in some areas compared to others. In fact, some areas in Antarctica have actually dropped in temperature. According to McKenna, "changes in wind patterns and ocean currents can change the distribution of heat, leading to some parts warming much faster than average, while others cool at first." This suggests a delayed warming in central Antarctica. Despite this, Larsen A, Larsen B and Wilkins have shown us that global warming is indeed threatening the Antarctic Peninsula.
In fact, the Wilkins Ice Shelf is collapsing much faster than expected, claims Professor Vaughan, member of a British Antarctic Survey team, in a Times Magazine article of March 23, 2008, titled "Vast iceberg breaks off Wilkins Ice Shelf in Antarctic".
Vaughan’s team predicted in 1993 that the Wilkins ice-shelf could collapse within 30 years if the pace of global warming continued. In March 2008, however, he admitted, “Wilkins is the largest ice shelf on the Antarctic Peninsula yet to be threatened... I didn’t expect to see things happen this quickly. We predicted it would happen, but it’s happened twice as fast as we predicted.”
Consequences of Collapsing Ice Shelves
The collapse of ice shelves could have large ramifications. Altogether Antarctica's ice sheets contain enough water to raise the sea level by a devastating 61 metres. Of course, not all of the ice sheets are threatened as yet, but as highlighted by Professor Vaughan, warming related damage in Antarctica is happening faster than even scientists have predicted.
