Canada will formally withdraw from the Kyoto Protocol on climate change, the minister of the environment has said.
Peter Kent said the protocol "does not represent a way forward for Canada" and the country would face crippling fines for failing to meet its targets.
The move, which is legal and was expected, makes it the first nation to pull out of the global treaty.
The protocol, initially adopted in Kyoto, Japan, in 1997, is aimed at fighting global warming.
"Kyoto, for Canada, is in the past, and as such we are invoking our legal right to withdraw from Kyoto," Mr Kent said in Toronto.
He said he would be formally advising the United Nations of his country's intention to pull out.
He said meeting Canada's obligations under Kyoto would cost $13.6bn (10.3bn euros; £8.7bn): "That's $1,600 from every Canadian family - that's the Kyoto cost to Canadians, that was the legacy of an incompetent Liberal government".
He said that despite this cost, greenhouse emissions would continue to rise as two of the world's largest polluters - the US and China - were not covered by the Kyoto agreement.
"We believe that a new agreement that will allow us to generate jobs and economic growth represents the way forward," he said.
Beijing criticised Canada's decision. Chinese foreign ministry spokesman Liu Weimin said it went "against the efforts of the international community and is regrettable".
Mr Kent's announcement came just hours after a last-minute deal on climate change was agreed in Durban.
Talks on a new legal deal covering all countries will begin next year and end by 2015, coming into effect by 2020, the UN climate conference decided.
"The Kyoto Protocol is a dated document, it is actually considered by many as an impediment to the move forward but there was good will demonstrated in Durban, the agreement that we ended up with provides the basis for an agreement by 2015."
He said that though the text of the Durban agreement "provides a loophole for China and India", it represents "the way forward".
Canada's previous Liberal government signed the accord but Prime Minister Stephen Harper's Conservative government never embraced it.
Canada declared four years ago that it did not intend to meet its existing Kyoto Protocol commitments and its annual emissions have risen by about a third since 1990.