The chances of seeing at least two centimetres of snow on the ground on Dec. 25 have been decreasing steadily over the past several decades as the effects of global warming take hold in cities from coast to coast, the agency said.
Senior climatologist David Phillips tabulated the numbers after hearing anecdotal grumbling about the lack of snow come Christmas Day.
By compiling snowfall figures across the country from 1964 to 2009 and tracking averages, he began to see a picture that verified the informal accounts he'd been dismissing for years.
"The one season that truly is not what it used to be is winter," Phillips said in an interview.
"I had this argument with old-timers years ago. They'd say, 'We don't think the winters are what they used to be," and I'd say, 'Nonsense.' But they've been right."
In Edmonton, Saskatoon and Quebec City, where a white Christmas was all but a certainty between 1964 and 1982, the probability of a snowbound holiday has fallen sharply between 1991 and 2009.
Quebec City's chances have slipped to 95 per cent, Saskatoon's to 89 per cent and Edmonton to 79 per cent. The steepest drop, however, was in Sarnia, Ont., where the odds of a white Christmas, once three in four, are now less than one in three.
WINTER SO FAR (Story Continues Under The Slideshow)
Canadian winters are one of the best places to observe the impact of global warming, said Phillips, noting that average temperatures have increased nearly three degrees over the last 64 years. That's what's to blame for the diminished snowfall.
P.J. Partington, climate-change policy analyst with the Pembina Institute, a think tank focused on environmental issues, said the numbers represent a serious problem.
Canada's cultural traditions, which are largely grounded in winter symbols and sports, would be threatened by a long-term reduction in snowfall � to say nothing of the impact on the tourism industry, Partington said.
"There's also a big risk to agriculture and municipal water supply," he said. "For some areas that rely on snow pack for their water, less precipitation in winter means more water stress in summer."
Also Monday, Environment Minister Peter Kent confirmed what had long been suspected: Canada is pulling out of the Kyoto Protocol, the binding climate treaty forged in the late 1990s to which the country was a signatory.
Kent made the announcement one day after marathon climate talks wrapped up in the South African port city of Durban, where nearly 200 countries took key steps towards a new climate treaty by 2015 to replace Kyoto, which expires at the end of next year.
The impact of global warming will likely be more dramatic in the coming years as temperatures continue to rise, and the face of Christmas may be changed for good, Phillips warned.
"We're going to have to dream a little harder, I think, to see the kind of things our parents and our parents absolutely took for granted," he said.
"Maybe we'll all be asking Santa Claus for a white Christmas now."By Michelle McQuigge, The Canadian Press