Canadian Prime Minister Stephen Harper's Conservative government has defeated a climate change bill calling for cuts in CO2 emissions.
Conservatives killed the motion backed by opposition parties 13 days before a UN climate change summit is held in Cancun.
The bill called for a reduction of greenhouse gases in the country by 25% from 1990 levels.
Canada's House of Commons originally passed the legislation last year.
It was then reintroduced in May and passed again, before being struck down by the Conservative-led Senate late on Tuesday.
"This is a very sad day for Canada, for the environment, and for the role of Canada in the international stage on dealing with the crisis of climate change," said New Democratic Party leader Jack Layton, adding that he was appalled by the Senate's decision.
The Conservative government has said it hopes to reduce greenhouse gases in the country by 20% from 2006 levels by 2020.
Canada's efforts are less dramatic when compared to other countries and political structures, like the European Union, which plans to cut emissions by 2020 by up to 30% from 1990 levels.