The Conservative government's proposal immediately drew the ire of environmentalists and the Liberal opposition.

The proposed reduction is based on emissions from 2003. The bill introduced Thursday in the House of Commons would also apply intensity-based targets until 2020, allowing emissions to continue to rise until then.

"Our greenhouse gases have skyrocketed ... It's time for us to contribute both to reducing air pollution and reducing greenhouse gases, and this is a step in the right direction," Environment Minister Rona Ambrose said.

But environmental activists greeted her comments with skepticism while opposition members of Parliament outright ridiculed the plan.

Canada agreed under the Kyoto Protocol to reduce greenhouse gas emissions to six percent below 1990 levels by 2012.

In 2004, the emissions were 26.6 percent above 1990 levels, despite 6.3 billion Canadian dollars (5.7 billion US dollars) spent by the previous Liberal administration on climate change measures since 1997.

Smog alerts have also increased dramatically in major Canadian cities in recent decades with the rise in air pollution.

Canada's Conservative government has repeatedly said it could not meet its Kyoto targets.

Prime Minister Stephen Harper said last week the new regulatory framework "will take time to put in place," as it requires further consultations with industry stakeholders.

Opposition leader Bill Graham said Thursday in the House of Commons the proposed bill is "nothing less than a national embarrassment."

"They've killed Kyoto," he said. "While the Conservatives are consulting, our planet is dying ... There's not one single new action in this decade to stop climate change or reduce air pollution for the citizens in this country."

Liberal environment critic John Godfrey added the plan takes "the most leisurely approach" to dealing with a global warming crisis, comments echoed by environmentalists who earlier had accused Harper of stalling.

"It will take forever for any regulations to be actually put in place," said Beatrice Olivastri, chief executive of Friends of the Earth. "They've set us back by years in terms of clean air."

As well, the proposed act "will weaken what we have in place at the moment," she lamented.

In a letter, 50 environmental groups had asked Harper to embrace the Kyoto Protocol despite his opposition to the international accord; to build on Canada's existing air quality law; to force industries responsible for half of Canada's emissions to curb their output; and to implement firm targets.

The draft law proposes applying intensity-based targets that reduce emissions incrementally as industrial output increases until 2020, instead of firm targets that would force cuts to total emissions.

It would also harmonize air pollution standards for vehicles and fuels with US Environmental Protection Agency standards, according to government documents, which environmentalists say are outdated.

Canada's car manufacturers, based in Ontario province, agreed previously to a voluntary reduction of 5.3 mega tonnes of greenhouse gas emissions through better fuel efficiency by 2010.

New mandatory regulations for vehicles would only take effect for 2011 car and truck models.

As well, Canada's oil and gas, forestry and other heavy industries -- responsible for 52 percent of air pollution and 47 percent of greenhouse gas emissions -- would be forced to cut air pollution under the legislation.

But industry targets will not be announced until consultations with various sectors conclude in 2008, according to documents.

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