Canada could lag behind the U.S. when it comes to cutting emissions from coal-fired power plants, despite claims by Prime Minister Stephen Harper that Canada is way ahead of its closest neighbour when it comes to cleaning up coal. 

A study by the International Institute for Sustainable Development says Canada's new rules to control carbon pollution from coal plants will have a "negligible effect" on greenhouse gas emissions for at least the next 15 years. New regulations in the U.S. could push that country much further along much faster.

"While both countries have introduced regulations, the U.S. regulations have a much deeper cut in providing real meaningful, substantial reductions in greenhouse gases compared to Canada," said Scott Vaughan, the institute's president and the former federal commissioner for the environment and sustainable development.

The report contradicts claims by the prime minister that when it comes to coal regulations "we're acting sooner and we're acting bigger."

Harper made these comments on June 2, the day the Obama administration introduced new emission limits on coal-fired plants. The American goal is to move the U.S. away from coal and toward cleaner natural gas.

Canadian rules apply only to new plants

Canada's new rules for coal plants will phase in starting next year, but only apply to new coal plants built after 2015.

Existing plants built in the last 50 years are grandfathered, meaning they would have up to 2030 to close or introduce carbon capture and storage technology to reduce emissions.

The report concludes the U.S. policy delivers a bigger bang for the buck because it deals with both existing and future plants. 

"The U.S. policy is much more impactful in terms of its contribution to total national emission mitigation because of its targeting of both new and existing plants," concludes the report, "and because of the intensive use of coal in the U.S. electricity sector compared to Canada's greater relative reliance on hydroelectric sources."

Canada has also given the coal-fired power plants more time adjust to the rules.

"They've been basically given a carve-out," said Vaughan in an interview with CBC News. "They have much more time to meet this, so between now and the next decade this will have negligible effects, which is unfortunate."

But a spokesperson for Environment Minister Leona Aqlukkaq said that any reductions to the U.S. coal sector will have a bigger impact because their industry is so much larger.

"We are happy the United States has proposed steps to regulate greenhouse gas emissions from their coal-fired electricity energy generation sector, which produces twice the greenhouse gas emissions of the entire Canadian economy," said Ted Laking in an email to CBC News.

"Only one-third of the electricity supply in the United States is from non-emitting sources. In contrast, Canada's is a world leader in clean energy as 77 per cent of our electricity supply emits no greenhouse gasses," he said.

Laking also pointed out that Canada's is further along the path because it regulations are now law.

"The proposed American regulations are not in effect and are still only under consultation, whereas our government took action on this sector two years ago."

Marginal reduction in Canada's emissions

Federal ministers, including Environment Minister Leona Aglukkaq, regularly defend Canada's action on greenhouse gas emissions, pointing out that the new coal regulations are helping to move Canada toward the international target with the U.S. by cutting emissions by 17 per cent below their 2005 levels.

But the report concludes that's overstating the case, at least for now.

It found that Canada's new coal regulations could reduce greenhouse gas pollution by the end of this decade by about 0.4 per cent, based on 2011 levels. 

In contrast, the proposed U.S. regulations could reduce that country's emissions by up to 6.6 per cent by 2020.

"Comparing the two, the U.S. will have significantly more cuts in emissions and therefore will be significantly more important in moving the U.S. towards their 2020 target than Canada," said Vaughan.

The regulations won't really have much of an effect in Canada until 2030, when the older plants start to close. 

And the report concludes that that while the new rules for coal are a good start, they are really just a drop in the bucket when it comes to dealing with industrial emissions in both countries.

"Overall, despite these impacts, neither country’s policies puts it significantly on track to meeting 2020 mitigation pledges given current emissions trajectories, and a very large gap is expected to remain for Canada."