ARCTIC ICE - Not melting after all

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canoe.ca CNews

Arctic sea ice not melting: new research

By BOB WEBER-- The Canadian Press

IQALUIT, Nunavut (CP) -- A Canadian scientist is pouring cold, unfrozen water on the notion that global warming is melting arctic sea ice like a Popsicle at the beach.

Greg Holloway galvanized an international meeting of arctic scientists Tuesday by saying there is little evidence of a rapid decline of the volume of ice in the northern oceans.

Despite breathless media reports and speculation of an ice-free Northwest Passage, he suggests that it's far more likely that the ice has just been moved around in the cycles of Arctic winds.

"It's more complicated than we thought," said Holloway, a scientist with the Institute of Ocean Science in Victoria.

The original theory was based on declassified records from the trips of U.S. submarines under the ice.

Satellite pictures have clearly shown that the surface area of the ice has decreased about three per cent a year for the last 20 years.

But the question was, How thick was it?

The submarine data generated headlines and cover stories from the New York Times to Time Magazine when it seemed to indicate that ice volume had decreased by 43 per cent between 1958 and 1997.

The evidence seemed good. There were only eight different voyages, but they had generated 29 different locations across the central Arctic where there were enough readings to make comparisons.

Holloway, however, couldn't make that conclusion jibe with any of his computer models.

"We couldn't understand how the reduction could be so rapid," he said.

"My first thought was, What is it we don't understand?"

Holloway knew that there was a regular pattern of sea ice being blown into the North Atlantic. He decided to examine if the wind patterns across the circumpolar North could have had something to do with the missing ice.

Wind patterns blow across the Arctic in a 50-year cycle.

At different points in the cycle, ice tends to cluster in the centre of the Arctic. At other points, the ice is blown out to the margins along the Canadian shorelines, where the subs were not allowed to go because of sovereignty concerns.

When Holloway lined up the submarine visits with what he knew about the wind cycles, the explanation for the missing ice became clear: "The submarine sampled ice during a time of oscillation of ice toward the centre of the Arctic. They went back during a time when ice was oscillating to the Canadian side."

Holloway had found the missing ice.

"I believe it is most probably explained with the shifting ice within the Arctic locations," he said to applause from scientific delegates from Norway to China.

If the submarines had made their first visit one year earlier and their return one year later, Holloway says they would have found no change in the thickness of the sea ice at all.

Holloway cautions that his research doesn't force a total re-evaluation of the theory of global warming. Temperatures on average are rising around the world, he says.

It does, however, deflate excitement about the possibility of an ice-free Northwest Passage.

The chance of a year-round northern shipping route has thrilled commercial shippers, worried environmentalists, and concerned those worried about Canada's ability to enforce sovereignty in those waters.

"At this time, we do not have the basis to predict an open Northwest Passage," said Holloway.

It also calls into question some of the findings and recommendations of the International Panel on Climate Change, which accepted the 43 per cent hypothesis in its report to various governments.

More data is coming in as further reports from American and British submarines are released. But the furore over the first results contains a lesson for both scientists and the public, Holloway says.

"It's a very small amount of time and a very limited number of places those submarines could go," he said.

"The cautionary tale to all this is the undersimplifying of a big and complex system."

"Who know what's going on out there?"

-- Anonymous, April 24, 2001


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