Canada's Environment Minister Peter Kent said his country is invoking the legal right to withdraw from the Kyoto Protocol on climate change.
"The Kyoto protocol as you know originally covered countries generating less than 30 per cent of global emissions. Now it covers less than 13 per cent and that number is only shrinking," Kent said.
"The Kyoto protocol does not cover the world's two largest emitters -- China and the U.S. and therefore cannot work. It is now clear that Kyoto is not the path forward for a global solution to climate change. If anything, it's an impediment."
Canada becomes the first nation to renounce the protocol, concluded amid much hope in 1997.
Canada had said it would not accept new Kyoto commitments.
Analysts say Prime Minister Stephen Harper's Conservative government is reluctant to hurt Canada's booming oil sands sector.
Canada's decision comes a day after marathon climate talks wrapped up in the South African port city of Durban.
Negotiators from nearly 200 countries agreed on a deal that sets the world on a path to sign a new climate treaty by 2015 to replace the first Kyoto Protocol, which expires at the end of next year.
The UN's climate change chief, Christiana Figueres, said she regrets Canada's decision to withdraw from the Kyoto Protocol, and called on developed countries to meet the commitments they made at the conference in Durban.
compiled from agency reports