Oslo, September 28: Dismayed by ice and storms, British explorer Captain James Cook had no regrets when he abandoned a voyage searching for a fabled southern continent in 1773.
Finding only icebergs after he was the first to cross the Antarctic Circle, he wrote ruefully that if anyone ventured further and found a “land doomed by nature…to lie for ever buried under everlasting ice and snow”:
“I shall not envy him the honor of discovery, but I will be bold to say that the world will not be benefited by it.”
Things may be worse than he thought.
Climate change is turning Antarctica’s ice into one of the biggest risks for coming centuries. Even a tiny melt could drive up sea levels, affecting cities from New York to Beijing, or nations from Bangladesh to the Cook Islands — named after the mariner — in the Pacific.
Scientists are now trying to design ever more high tech experiments — with satellite radars, lasers, robot submarines, or even deep drilling through perhaps 3 kilometers of ice — to plug huge gaps in understanding the risks.
“If you’re going to have even a few metres it will change the geography of the planet,” Rajendra Pachauri, head of the U.N.’s Intergovernmental Panel on Climate Change (IPCC), said of the more extreme scenarios of fast ocean rise.
“Greenland and Antarctica are two huge bodies of ice sitting on land that could really have very serious implications for the levels of the seas,” Pachauri told Reuters.
Eventually discovered in 1820, Antarctica locks up enough water to raise sea levels by 57 metres (187 ft). Greenland stores the equivalent of 7 metres.
Worries about sea level rise are among the drivers of 190-nation talks on a new U.N. deal to combat climate change, mainly by a shift away from fossil fuels, due to be agreed in Copenhagen in December.
COLLAPSE
Scientists are concentrating on the fringes, where the ice meets a warming Southern Ocean. “It’s the underside of the ice sheets that’s crucial,” said David Carlson, a scientist who headed the International Polar Year from 2007-08.
Warmer seas may be thawing ice sheets around the edges, he said, and allow ice to slide off the land into the sea more quickly, adding water to sea levels. But it is hard to be sure because of a lack of long-term observations.
“The same things that defeated Cook — ice and bad weather — are still problems,” Carlson said.
About 10 ice shelves, extensions of ice sheets that float on the ocean and can be hundreds of metres thick, have collapsed on the Antarctic Peninsula in the past 50 years. Part of the Wilkins Ice Shelf snapped in April.
—Agencies