Some time around late January or early February the first trucks will roll off the end of the Ingraham Trail north of Yellowknife and onto the fabled Tibbitt to Contwoyto Winter Road.
The 600-kilometre ice corridor is a vital supply line for both operating diamond mines and NWT and Nunavut exploration projects. In 2012, drivers hauled more than 6,500 loads totaling 210,000 tonnes up the road, and with De Beers Canada moving 600 tanker truck loads of early construction material to its Gahcho Kue diamond project, the tally will likely be higher this year.
Meanwhile, climate change is already creating numerous headaches for public officials and civil engineers as they try to divine where, when and how melting permafrost and changes in weather will impact the North’s infrastructure. One estimate, published in Nature Climate Change in 2012, warned the winter road could face a season that’s 17 per cent shorter in 2020 than it is now. The season generally runs from late January or early February to late March to early April.
But fears that a warming climate could wreak havoc on the NWT’s winter roads may be premature, according to climate scientists speaking at the NWT Geoscience Forum in Yellowknife.
Tim Patterson, a geology professor at Carleton University in Ottawa, studied NWT climate cycles dating back 3,500 years and predicts two major patterns will help hold down winter temperatures for the next few decades. One is that we’re entering a period of decreased sunspot activity, which causes cooler temperatures on Earth. The other is a weather pattern called the Pacific decadal oscillation, which switches between 20- to 30-year warm and cool phases.
Even with climate change driven by greenhouse gas emissions, Patterson says winter temperatures will remain sufficient to maintain the ice road’s two-month operating window “for a considerable time in the future.”
Greame Swindles, another geologist from the University of Leeds, mostly concurs with Patterson, but adds a qualifier: the NWT can expect a jump of around 4C between 2050 and 2096.
Robert Douglas, a geotechnical engineer with Golder Associates, says winter temperatures in the NWT are rising by about 0.5C per decade. But while winters are warmer, springtime is cooler and the seasons are arriving later, meaning that so far, it appears the winter road season isn’t shrinking, it’s just moving on the calendar.
Part of that is because ice road operators are increasingly adept at finding ways to lengthen the ice road season. Keeping the road plowed helps it freeze thicker (because snow insulates the ice beneath it), ground penetrating radar allows drivers to know exactly when the road is safe to drive on, and travelling only at night at the end of the season reduces wear and tear on the road. Douglas says operators are also “applying backyard ice rink technology” and flooding roads to make them thicker.
“They’re not just sitting still and taking it,” Douglas says. “They’re adapting and their adaptation is coming faster than the climate is changing.”