TUKTOYAKTUK, N.W.T. (CP) - The Northwest Passage isn't likely ever to become a northern version of the Panama Canal, suggests the latest research on climate change and the northern ice pack.

While some types of shipping are likely to increase, fears of regular commercial traffic through Canada's Arctic waters are probably overblown, said Ross MacDonald, a scientist at Transport Canada.

"You have a lot of concerns about an issue that has yet to develop," MacDonald said at a conference on Canada's Arctic coastline in Tuktoyaktuk, N.W.T., earlier this month.

"Transit shipping would seem to be many years off."

As climate change reduces the amount of ice in northern waters around the globe, many have suggested the Northwest Passage could finally open to commercial shipping between North American and Asian ports. But MacDonald - as well as mariners such as Duke Snider, a longtime Arctic ice pilot who now directs the Coast Guard's Pacific operations - say that ice in the Canadian Arctic is as unpredictable and dangerous as it ever was and is likely to remain so.

"We still have the same variability," said Snider, who was aboard the HMCS Montreal during recently completed naval exercises in the passage.

"There's every indication that variability will continue for a number of decades to come."

Some areas of the Arctic, notably the sea off Russia's northern coast, are seeing less ice. But in Canadian waters, ice continues to drift down from the polar ocean to be driven against the western shores of the High Arctic islands by a combination of winds and currents called the Beaufort Gyre.

While eastern stretches of the passage such as Lancaster Sound may be increasingly ice-free, the west is not.

Although even the west has occasional open years, they aren't consistent enough for commercial shippers trying to guarantee deliveries. As well, even the threat of ice is enough to make the expense of ice-capable vessels and the cost of insurance prohibitive in comparison with other international routes.

Canadian waters have the highest proportion of hard, dangerous, multi-year ice in the Arctic, said Humphrey Melling, an ice scientist with the Department of Fisheries and Oceans. He is spending the summer studying ice and meltwater flows in the High Arctic.

"As long as we have this reservoir of multi-year ice up here, we are still going to have shipping problems in the Northwest Passage," he said.

Still, the passage is likely to see increased shipping from tourism and vessels serving resource development, said MacDonald.

At least six cruise ships now regularly ply those waters. Three were in the neighbourhood last week alone.

The development of countries such as China and India has driven commodity prices to the point where remote Arctic mines can now be economically viable.

One company is currently considering a billion-dollar iron mine on northern Baffin Island, complete with port to remove the ore concentrate. And there is increasing talk of a return to offshore oil and natural gas development in the Beaufort Sea and other High Arctic waters.

New technology has made ice-capable tankers more available, at the same time as climate change has reduced the ice road season that many mines rely on for resupply.

That increased traffic will force Canada to manage both environmental risks and social disruptions. Spills and contamination can have a lasting effect in the fragile Arctic, and the Inuit may not be able to cross the sea ice to reach hunting grounds if it is continually traversed by icebreakers.

"It's a responsibility to make sure shipping is managed in a way that respects their life," MacDonald said. "People call these waters home and they don't distinguish between ice and land."

He said that's one reason why it's important to establish sovereignty over Arctic waters.

But regular shipping of international commercial cargo through the Northwest Passage is unlikely, he said.

"We're a long way from that."