FEATURE-In Canada's far north, warm weather threatens vital ice road
By Susan Taylor
YELLOWKNIFE, Northwest Territories Dec 24 (Reuters) - Each winter, in the far reaches of Canada's north, a highway of ice built atop frozen lakes and tundra acts as a supply lifeline to remote diamond mines, bustling with traffic for a couple of months before melting away in the spring.
This year, the world's busiest ice road is running late. Unseasonably warm weather has set back ice formation on the Tibbitt to Contwoyto Winter Road, named after the first and last of hundreds of lakes on the route.
The road is still expected to open on schedule in late January, but if current weather patterns continue that could mean more work for crews trying to build the ice or cut the road's already short period of operation.
Since its first season in 1982, the road has been vital to a handful of mines scattered across Canada's Northwest Territories (NWT), cut off by a maze of water and spongy tundra, otherwise only reachable by air. Running 400 kilometers (248 miles), it links to three diamond mines, stretching as far as 600 km when it supplied a now-shuttered gold mine.
A shorter season could mean extra costs and inconvenience for moving what amounted last year to 9,000 truckloads of diesel, machines and mining supplies from the NWT's capital city, Yellowknife.
To climate scientists, this year's late freeze could be a harbinger of winters to come. It also raises the alarming prospect of thawing permafrost - the frozen layer of soil covering nearly half of Canada's landmass - which traps methane, a greenhouse gas, which would only hasten warming.
This year's warmer temperatures may be connected to the El Nino climate phenomenon, a periodic warming of Pacific Ocean waters that has far-reaching effects.
It is Yellowknife's second warmest December on record, said David Phillips, a senior climatologist at Environment Canada, Canada's national weather service. So far, the average temperature for this December is just above -15 Celsius, marginally cooler than the -13 Celsius for December 2005, but well above the mean of around -22 Celsius. Continued...