Antartica Facing Major Threat

By Larry Wheeler
Florida Today
The beautiful landscape of Antarctica is under threat
A large chunk of an ice shelf in Antarctica is melting at such a rate that in two years a 12,000 sq km area will have disappeared, British scientists have warned.
The area, which sits across the South Atlantic Ocean from the tip of Tierra del Fuego, is the size of a metropolis such as Sao Paulo, or Los Angeles and its suburbs.
Temperatures around Antarctica have risen five times faster than the global average over the past 50 years, going up by around 2.5C since the 1940s.
The threat from changes in global temperature to the frozen Antarctic mass is not new.
At the start of 1995, a storm battered the northern tip of the Antarctic peninsula, known as the Larsen Ice Shelf. When it had ended, a 2,000 sq km area had been shattered into small icebergs.
At the same time, a large iceberg called Larsen A separated from the ice shelf's southern front.
Although the dramatic split attracted most media attention at the time, the disintegration of the northern part was considered less normal and consequently more worrying by scientists who study the area.
Global warming is also being blamed for the new threat to what is being called Larsen B.
Four times larger than the original Larsen A block, scientists from the British Antarctic Survey say it has begun to show the same characteristics.
Other ice shelves in the Antarctic peninsula have shrunk or disappeared in the past three decades.
Sir John Houghton, of the Intergovernmental Panel on Climate Change, says Larsen B covers a greater than the all the previously lost icebergs in 50 years.
The impact would be felt around the world, he said.
"The atmosphere in the ocean is all very connected so even something that happens in Antarctica is important to us because we're all connected by air circulations and water circulations," said Sir John.
In addition, melting ice shelves provide an indication of what may be coming elsewhere.
"It's a sort of symptom of what's happening globally, it's exactly what we expect to occur with global warming," he said. "We expect to see warming of the polar regions perhaps earlier than elsewhere."
But other observers say changes in the weather have occurred throughout the world's history and the icecaps are particularly susceptible to these fluctuations.
In a period of 10,000 years, a number of cycles of growth and decay can be traced in the Antarctic peninsula.
David Vaughan of the British Antarctic Survey says the world will only be sure it has serious problem if the present trend continues.
"Temperature is rising quite rapidly on the Antarctic peninsula and these ice shelves are only going to retreat if that temperature continues to rise. At present we really don't know if that is going to happen, or that it's going to continue at the present rate."

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