They are the frozen arteries of Canada's northernmost lands, a network of roads built on icy rivers, lakes and muskeg that bring supplies to mines and towns across the country. Every year, provinces, territories and companies build some 5,400 kilometres of ice roads in Canada, providing a way in for critical items such as diesel, gas and groceries.
But new research is raising troubling questions about the future of those ice roads, suggesting that a warming climate could melt away the winter lifelines. A trio of geographers at the University of California, Los Angeles, report in the journal Nature that, by the middle of this century, Canada is likely to lose nearly 400,000 square kilometres of land accessible by winter road - an area the size of Newfoundland and Labrador.
"This is a transportation system that is going to be profoundly affected by a warming climate in an adverse direction," said Scott Stephenson, a physical geographer and PhD student who is the study's lead author.
The researchers - Mr. Stephenson, Laurence C. Smith and John A. Agnew - based their work on a sophisticated climate model developed by the National Center for Atmospheric Research in Boulder, Colo. The model suggests the Arctic will see warming that far outstrips the rest of the world. Where the planet is expected to see a two to four degree Celsius gain in temperature by the end of the century, projections show the Arctic temperature increasing by two to nine degrees - and as much as 11 degrees in winter.
That has profound implications for transportation in the highest latitudes, and the researchers set out to find out exactly how much.
What they found was striking. By midcentury, a window of years from 2045-2059, they project that three major Arctic shipping corridors will be completely open to moderately ice-reinforced vessels from July to September. Those are the Northern Sea Route, a route across the top of Russia also known as the North East Passage; the North Pole route, which would allow vessels to sail directly over the top of the globe; and the Arctic Bridge, a route that connects Churchill, Man., with the Russian port of Murmansk via the east coast of Greenland.
In fact, the Arctic Bridge is already fully open to marine traffic today, the researchers found.
But the research suggests Canada may have more to lose than gain when it comes to transportation in a part of the country where the quest for resources is immensely dependent on its connections to the outside world.
The Northwest Passage, despite dramatic Arctic melt, is unlikely to open to shipping any time soon, the researchers suggest. They conclude that the complicated network of channels in the Canadian Arctic Archipelago will leave that route only 82 per cent accessible by midcentury to ships with modest ice-strengthening, during late summer months. That's up from 63 per cent today.
However, if ice roads prove difficult to build, will governments instead finance the construction of all-season roads that cost at least $1-million a kilometre?
When it comes to developing high-latitude resources, the effects of warming may be muted by industry's efforts to reduce reliance on winter roads.
New mining proposals - including a huge Baffin Island iron mine, as well as gold and uranium projects on the Nunavut mainland - are increasingly planning permanent road and rail connections to tidewater. In fact, increased maritime access could in some cases counteract warming tundra, since in the Northwest Territories, for example, supplies could be brought south on ice roads from the Arctic Coast, rather than up from Yellowknife. That could allow winter roads to be built in areas that are farther north and, therefore, more likely to be sufficiently cold.
Even on existing ice road routes, "I don't see a real major problem for some time to come," because planners can compensate for shorter seasons by concentrating traffic during those times, said John Zigarlick, chairman of Nuna Logistics, which builds the 600 km diamond mine road that is featured on the television series Ice Road Truckers.
And use of improved water access could help to offset winter road declines, he said.
There is little doubt that the prospect of Arctic shipping is already stirring significant global interest. South Korea recently built an icebreaker. Chinese researchers now regularly work alongside Canadian scientists in the North. The minds behind Winnipeg's CentrePort Canada logistics hub envision a future where goods from China travel not to Vancouver but by rail to Murmansk, by ship to Churchill, and by rail to the rest of North America - a route that, they believe, can trim current transit times.
Scientists, however, say one thing is clear: The ice is melting so rapidly that even the UCLA forecast may be conservative. Fifteen years ago, 80 per cent of the Arctic basin was covered in concrete-like multiyear ice that poses a major shipping hazard. Today, that has decreased to 16-18 per cent, said David Barber, a professor at the University of Manitoba and Canada Research Chair in Arctic Systems Science.
"At the trajectory we're on, we're going to be out of multiyear ice very quickly in the northern hemisphere," he said. "People argue right now the North East Passage is already open. I would say you'll be able to use the over-the-pole route very soon as well."