The country’s greenhouse-gas emissions are almost a third higher than 1990 levels, and it has a 6 percent CO2 reduction target for the end of 2012. If it couldn’t meet its goal, Canada would have to buy carbon credits, under the rules of the legally binding treaty.

Canada, which has the world’s third-largest proven oil reserves, would be the first of 191 signatories to the Kyoto Protocol to annul its emission-reduction obligations. While Environment Minister Peter Kent declined to confirm Nov. 28 that Canada is preparing to pull out of Kyoto, which may ease the burden for oil-sands producers and coal-burning utilities, he said the government wouldn’t make further commitments to it.

“Canada is the only country in the world saying it won’t honor Kyoto,” said Keith Stewart, an energy and climate policy analyst for Greenpeace in Toronto. Under a previous Liberal government, Canada was one of the first countries to sign Kyoto in 1998. The current Conservative government made a non-binding commitment at 2009 United Nations talks in Copenhagen to reduce emissions by 17 percent by 2020 from 2005 levels, in line with a pledge by the U.S., its biggest trading partner.