Clean-air agreements signed by California Governor Arnold Schwarzenegger and two Canadian provinces could dramatically slow oil production in the Alberta tarsands.

Ontario and British Columbia have agreed to adhere to California's low-carbon fuel standards, which means the provinces will have to curb oil production sources that create high amounts of global-warming emissions.

The agreements require a 10-per-cent reduction of greenhouse gas output from gasoline and diesel fuels by 2020.

Nine other U.S. northeastern states plus Illinois, Quebec and Manitoba are all expected to sign on to California's low-carbon fuel standard, which will shrink the market for Alberta's oil industry.

The authors of California's new standard say oil companies must adapt or risk losing business.

At the same time, one of the most influential environmental groups in the U.S. is training its sights on Alberta's oilsands in an attempt to convince Americans to stop increasing their dependence on "bottom of the barrel" energy.

A report by the Natural Resources Defence Council, to be released this week at a symposium in Washington, D.C., was obtained by The Canadian Press.

The report potentially damages the market for oilsands oil by encouraging U.S. regulations against fuels that generate high volumes of greenhouse gases in their use and manufacture.

"In a horrible way, the tarsands have put Alberta on the map for people in the U.S.," said Susan Casey-Lefkowitz, one of the report's authors.

The paper summarizes environmental objections to the oilsands that are already familiar to Albertans but not necessarily to U.S. consumers of the energy produced from the sticky deposits in northern Alberta.

It repeats arguments that oilsands expansion is strip-mining vast tracts of boreal forest and draining and polluting watersheds.

It also points out that one barrel of oilsands oil creates three times as much greenhouse gas as one barrel of conventional oil because it is more difficult to extract and refine.

Nearly two-thirds of Canadian oil production, including oilsands production, heads directly south. American energy multinationals such as Conoco Phillips, Chevron Texaco and Exxon all have major investments in the oilsands.

The report advocates low-carbon fuel standards, such as those adopted by California, which would take into account carbon emissions produced over a fuel's entire life cycle.

"There are certainly ways for the American public to have a voice in how much of this tarsands oil we're taking," said Casey-Lefkowitz.

"You have a choice about what the future looks like for fuel and that really is what this is about."

Alberta's oilsands are also under attack in Europe, where the World Wildlife Fund in the United Kingdom recently released a report blaming oilsands expansion for Canada's failure to live up to its Kyoto commitments.

But Alberta industry observers and government representatives are skeptical about the impact of international criticism.

"You've got consumers who want to be green, but don't want to put their money where their mouth is," said analyst George Eynon of the Calgary-based Canadian Energy Research Institute.

Eynon points out California continues to buy electricity generated by coal-fired plants outside its borders.

"It won't make a blind bit of difference - the demand for oil is going to increase," he said. "It really becomes a political PR problem."

Alberta Energy spokesman Jason Chance said the province meets regularly with U.S. government officials. "They have recognized that the province is a sustainable and well-managed source of energy," he said.

Environmentalists should credit the province and its energy industry with advances made in reducing energy and water use, Chance suggested. "Image and perception is one thing, but we're taking real, tangible steps."

Still, Dan Woynillowicz of the Alberta-based Pembina Institute, which contributed to the report, said there are numerous examples of public pressure scuttling industrial plans, including the defeat of proposals to drill in Alaska's National Wildlife Refuge.

Another public campaign forced lingerie company Victoria's Secret to stop printing catalogues made from old-growth boreal forest. As well, Quebec's Great Whale hydro project was shelved in the mid-'90s after American power customers backed out over environmental concerns.

"I would expect that other major American (environmental) groups will follow suit," said Woynillowicz. "As people's awareness increases on this issue, they'll exert pressure economically but they'll also exert it politically."

-with files from The Associated Press