For the first time, scientists have found direct evidence linking global warming to melting ice shelves. British and Belgian scientists, writing in the Journal of Climate, have discovered that global warming and a thinning of the ozone layer over Antarctica, caused by human chemicals, has strengthened winds blowing clockwise around the Antarctic peninsula. This area of Antarctica has averaged about 2.2 Celsius over the past 40 years, but stronger summer winds have risen the temperature to 5.5 and even 10 Celsius in recent years.

These warming winds over the Antarctic peninsula contributed to the break-up of the Larsen B ice shelf in 2002. The area of the shelf that collapsed was 3,250 square kilometers, bigger than Luxembourg or Rhode Island, but not too big for the Bush administration to completely ignore. Gareth Marshall, lead author of the study at the British Antarctic Survey said, “This is the first time that anyone has been able to demonstrate a physical process directly linking the break-up of the Larsen Ice Shelf to human activity.� Previous to 2002, the Larsen ice shelf had been in place for 5,000 years.

Luckily, the collapse of Larsen B did not raise world sea levels because the ice was floating. However, if warming trends continue, scientists expect to see an increase in temperature amongst regions further south, breaking up more ice shelves. As floating ice disappears and warm temperatures migrate southward, land-based glaciers will also melt. In fact, Dr Chris Rapley, director of the British Antarctic Survey, has revealed that two major glaciers in eastern Antarctica are already starting to discharge into the sea.

source