Arctic ice melting at alarming rate
Changes scientists didn't expect for another 50 years are happening now, research suggests
Ed Struzik
Canwest News Service
Tuesday, April 22, 2008
CREDIT: Ed Struzik, Canwest News Service
By the middle of last September, scientists recorded a decline of almost 50 per cent of normal ice cover in the Arctic.
CREDIT: Ed Struzik, Canwest News Service
During the summer melt in the southern Arctic, ice in the Far North -- now feeling the effects of warming -- has been an important refuge for polar bears.
Ice was the last thing David Barber was worried about when he and an international team of scientists made plans last year to have their research icebreaker frozen into the Beaufort Sea for the winter.
But when the Amundsen sailed into the western Arctic in November, the ice that normally begins to take hold in October hadn't even begun to gel.
"Even by mid-December, the southern Beaufort Sea was still wide open," said Barber, a University of Manitoba sea ice physicist and chief scientist aboard the Amundsen. "That's over a month longer than the time freeze-up normally occurs."
Barber and his colleagues got an even bigger surprise when they sailed north into M'Clure Strait, the main channel connecting the Northwest Passage to the western Arctic. The strait is legendary as a gateway for thick, rock-hard, multi-year ice that piles in from the Beaufort Sea, but Barber and his colleagues found nothing but clear sailing.
"It was surreal," he said. "The weeks spent on the ship were some of the most remarkable of my career. The multi-year pack ice had migrated about 150 miles (240 kilometres) north from where it has traditionally been located. So the ice-associated, high-pressure system that traditionally forms over the southern Beaufort at this time of year was displaced.
"All that cyclonic activity that was drawn in by the warm, open water not only made for some rough sailing, it also put more heat into the air, keeping the local climate warmer than usual."
Barber isn't alone in wondering whether this winter signals the climatic tipping point that many scientists have been anticipating. That's the moment in time when sea ice in the Arctic becomes so thin and vulnerable that the ice produced each winter can no longer keep up with the spring and summer melts.
Many scientists now believe that when this happens, the world will enter a new era of global change -- one that no one really understands, but that will likely have an enormous impact on the climate of the rest of the world.
Up until last summer, most scientists didn't expect that to occur for another 50 or 60 years. Even the most daring weren't willing to wager that it would happen in 15 years.
But this winter's unexpected developments in the Beaufort Sea suggest that all bets are off. Waters that used to lose 10,000 square kilometres a year in ice cover, according to scientists, currently lose at least eight times that amount. Now, some scientists are speculating that the Arctic could be seasonally ice-free in less than a decade.
"The ice is no longer growing or getting old," says John Falkingham, chief forecaster for the Canadian Ice Service, the Environment Canada agency that helps ships find a way through the Northwest Passage and other parts of the Arctic.
Cold as it was this winter in the Arctic and most parts of Canada, it wasn't enough to temper the heat that warmed the ocean and melted so much ice last summer. By the middle of last September, scientists recorded a decline of almost 50 per cent of the normal ice cover. By way of comparison, the area of sea ice lost was equivalent to 10 United Kingdoms.
What made last year's meltdown even more eye-popping was the loss of ice in places where historically it has never retreated. M'Clintock Channel, the so-called mortuary for old, multi-year ice, was almost completely open. And Viscount Melville Sound, the place where new ice is born, was down to half its summer ice cover. That appears to be why this winter's deep freeze wasn't enough to prevent the dramatic events that unfolded in the Beaufort Sea later in the winter.
Because so much ice melted last summer, there wasn't enough old ice left to put the brakes on the multi-year ice that was driven so far north, towards Siberia, in December and January. So the sheer force of that migration left a huge fracture in the pack ice that was bigger than anything anyone has seen.
"I think this summer really will tell the story," Barber says. "If we get yet another huge meltdown, as I suspect we might, then we could see more of these fractures occurring in the future. That kind of breakup only serves to accelerate the meltdowns we are already seeing.
"Theoretically, we could see an Arctic that is ice-free in summer months a lot sooner than most people previously thought. Some people think that it could happen in five or six years."
Putting that into perspective, Barber notes that the Arctic hasn't been seasonally ice-free for at least the past 1.1 million years.
"Let that sink in for a moment," he suggests. "The medieval warm period occurred about 1,000 years ago; the Egyptian civilization peaked about 4,000 years ago; the last ice age was 18,000 years ago; heck, there have been several ice ages within this 1.1-million-year period, and we have always had sea ice in the northern hemisphere in summer."
As fast as it has been unfolding, none of this happened overnight. The Arctic plumbing system that connects the Pacific to the Atlantic is so big and so complex that cause-and-effect scenarios can take up to a decade to unfold.
Scientists with Canada's Institute of Ocean Sciences (IOS) detected the first significant sign of change in this plumbing system that has kept the Arctic cool for so long sometime around 1989, when atmospheric low pressure began to nudge out the massive highs that traditionally dominate winters in the western Arctic.
Fiona McLaughlin was one of those IOS scientists who tracked a stream of relatively cold freshwater from the Beaufort migrating all the way to the Labrador Sea.
This was right around the time the cod fishery was collapsing. Whether it was climate change or simple physics that precipitated that event, she isn't sure. Cold Pacific water and warm Atlantic flows are constantly streaming through the archipelago.
But there is little doubt in her mind that everything that has happened since then has brought us very close to the tipping point that so many scientists are talking about.
"Each year we go up, there is less ice for the ship to break up," McLaughlin says. "The area we normally covered in five weeks in the 1990s, we now cover in three weeks."
Many of the changes that McLaughlin and other Arctic oceanographers have been seeing are subtle -- slight changes in water temperature and marginal shifts in salinity.
Others, however, are breathtaking in scope.
In the summer of 2006, for example, the Louis St. Laurent, Canada's flagship icebreaker, broke down in the Beaufort Sea, with McLaughlin's scientific crew on board.
In the four days they were left without power, the multi-year ice that surrounded them literally disintegrated before their eyes.
In Victoria at the time, McLaughlin could visualize it all unfolding from satellite imagery and from the reports she was getting from her colleagues.
"For everyone, it was astonishing to see so much ice disappear so fast in an area where it almost never goes away."
No one knows what this change in temperature, chemistry and Arctic Ocean ice cover will do to marine life. Some suggest it could help a fishery that is currently inhibited by the cold and ice. Most others fear it will have a devastating impact on those creatures -- certain types of plankton, Arctic cod, beluga whales and narwhal -- whose well-being are very much dependent on the presence of ice.
Only those in serious denial believe the changes won't decimate the polar bear populations.
University of Alberta scientist Andrew Derocher believes the fracturing of the permanent polar pack this winter could be foreshadowing very big changes for the two Beaufort Sea polar bear populations that typically range across the frozen sea from northern Canada and Alaska.
"The multi-year ice west of Banks Island is a summer refuge for many of these polar bears," says Derocher, who chairs the International Union for the Conservation of Nature (IUCN) Polar Bear Specialist Group. "They head north towards this ice after annual ice melts in summer. But what will happen to the bears once this refuge disappears?"
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