Scientists to Canada: clean your dirty snow

TORONTO (Reuters) - Even Canada's thinly populated Arctic regions can play a role in curbing global warming, by reducing soot from dirty, old cooking stoves which are blackening snow and making it melt faster.

It's one problem on a list of many outlined by researchers at the universities of California and Colorado. They urged Canadians to filter smoke stacks, reduce ship traffic and burn fuels out in their entirety to minimize dirty waste.

In a study examining the impact of burning fossil fuel in snow-covered northern climes, the scientists said grubby snow contributes to global warming because it absorbs more heat from the sun, and melts faster.

"Canada is special because it's so far north and when you look at climate change prediction, the global mean temperature changes," said Charlie Zender, one of the authors of the report, published in the Journal of Geophysical Research.

Zender said average Arctic temperatures have risen by 1.6 degrees Celsius (2.9 degrees Fahrenheit) since the late 1700s, with filthy snow accounting for a degree of that alone.

"For the next 20 years, it's crucial for the Northern polar regions," he said. "The key to averting massive climate change ... is to preserve the summer pack and sea ice."

Once the ice starts to recede and the water is exposed to the sun, the polar ice cap melts more quickly, he said.

That could mean new shipping lanes, but trade opportunities won't be the only things washing up onshore.

"Those are going to produce sources of some of the dirtiest soot because of their diesel engines ... it's going to push an already vulnerable region past its tipping point."