Environment Minister Rona Ambrose defended the government's environmental plan Wednesday as critics warned against setting "intensity-based" emissions targets.

"Cleaning up the air is a priority for the prime minister and our government," Ambrose told CBC Newsworld on Wednesday, a day after Prime Minister Stephen Harper said that his government would introduce the Clean Air Act in Parliament next week.

She spoke from Yellowknife, where provincial and territorial environment ministers are meeting with their federal counterparts.

The proposed act will impose restrictions — developed over the next year with industry and the provinces — on both greenhouse gas emissions and air pollutants.

Speaking to reporters during Tuesday's outdoor announcement in Vancouver, Harper said for the first time that his government plans to set intensity-based environmental emissions targets.

"We will produce intensity-based targets over the short range and the long term and they will cover a range of emissions," said the prime minister.

Intensity-based targets means environmental emissions would be relative to the economic output of various industries. That means even though individual emission limits for each barrel of oil or piece of coal could be lowered, if production increases, the overall amount of greenhouse gas emissions and air pollutants could grow.

Many environmentalists believe capping greenhouse gas emissions is key to tackling climate change. Critics of intensity-based targets say the approach allows heavily polluting industries, such as Alberta's oilsands, to continue to grow and pollute, while remaining under government-imposed limitations.

More details next week: Ambrose

When asked Wednesday whether the Conservative plan promotes a conflict between economic growth and environmental action, Ambrose would only say that more details about the Clean Air Act would be released when the legislation is tabled next week.

"Next week, you'll get a chance to see our discussion about targets and how targets are set depending on the industry sector," Ambrose told CBC Newsworld.

Ambrose, who appeared at the prime minister's news conference Tuesday along with the ministers of Natural Resources, Health and Transportation, said Harper considers the environment in an "unacceptable" state. Harper was the sole speaker during Tuesday's appearance.

The targets spelled out in the proposed act will be set according to what is healthy for Canadians, she said.

"The health of Canadians is what will guide how we implement our regulatory framework," said Ambrose.

Ambrose said that as she meets with provincial and territorial environment ministers in Yellowknife, she will give them "more details about what will unfold next week."
 
She addressed critics who say Canada's Environmental Protection Act already gives the federal government the authority it needs to beef up regulations surrounding greenhouse gas emissions and smog.

"Canada's Clean Air Act will give us enhanced powers," said Ambrose, adding the proposed legislation will mark the first time the federal government has regulated both greenhouse gas emissions and air pollution.

Plan is 'hot air,' say critics

Critics were quick to express their disappointment with the government's plan for intensity-based targets.

''By [Alberta's] own numbers, its greenhouse gas emissions would rise by 39 per cent over two decades,'' Dale Marshall, an analyst with the David Suzuki Foundation, told a news conference following the announcement.

''That's what intensity-based targets means. The absolute emissions continue to go up even though the emissions, based on a per economic activity, continue to go down."

The foundation's Morag Carter, who was was turned away from attending Tuesday's journalists-only announcement, said solid timelines and real targets are absent from Ottawa's plan.

Stephen Hazell, with the Sierra Club of Canada, was blunt.

"The Clean Air Act is a hot air act," he said. "We have all the legislation we need to bring in the regulations that are necessary."

With files from the Canadian Press