From ABC Science Online, News in Science, 23 August 2012:
The rapid warming of the Antarctic Peninsula may partly be due to a long-term trend that began long before the Industrial Revolution, according to a team of Australian, British and French researchers.
But, they say, warming in the past 100 years has been unusual and, if it continues, more ice shelves on the peninsula could collapse.
The researchers, led by Robert Mulvaney from the British Antarctic Survey extracted the first long-term ice-core climate records from the Antarctic Peninsula.
Their findings appear this week in Nature.
The ice cores, taken from James Ross Island, show that the Antarctic Peninsula experienced a warm period during the early Holocene, followed by stable temperatures from about 9,200 to 2,500 years ago, that were similar to modern-day levels.
This was followed by a cooling until about 600 years ago, after which temperatures have been gradually increasing.
One major peninsula ice-shelf — the Larsen B ice shelf — has already collapsed and there are concerns that ice shelves further south on the peninsula, and even on the Antarctic mainland, are now weakening in the warming temperatures.
“If warming continues in this region … then temperatures will soon exceed the stable conditions that persisted in the eastern Antarctic Peninsula for most of the Holocene,” Mulvaney and colleagues write.
The researchers say the ice cores show that natural warming over a number of centuries on the eastern Antarctic Peninsula left ice shelves in this area vulnerable to collapse and further warming could cause ice shelf instability to encroach further southwards along the peninsula. Read more here.
Bianca Nogrady 