An often-heard complaint about the Canadian oil sands is that they are climate disaster. But a new study suggests that their emissions can be controlled and perhaps can even help the climate.

How?

The Canadian oil sands are likely to be developed regardless of U.S. oil import policy, and sent to Asia, asserted Robert Curl, a Nobel Prize winner in chemistry and co-author of the paper from the Baker Institute of Public Policy at Rice University. Globally, that means that the climate impact will be the same regardless of whether the oil heads to the United States via projects such as the proposed Keystone XL pipeline, he said.

"We believe concern about additional carbon dioxide from Canadian oil sands production is misplaced," states the paper, which was co-authored by Dagobert Brito, a political economy professor at Rice University.

Furthermore, a lack of Canadian crude imports into the United States could give a boost to even worse fuels for the climate, such as coal-to-liquids, that release four times as much carbon dioxide per gallon of fuel than Canadian fuels, he said.

So, instead of blocking Canadian oil into the United States, the study says it would be wiser to control the resulting emissions from increased oil sands production by "offsetting" their greenhouse gases with a greater "coal to gas" shift in the electricity sector.

Because coal is such a dominant part of the U.S. electricity mix and gas burns roughly 50 percent cleaner than coal in a power plant, any greenhouse gas blip from increased oil sands production could be easily mitigated with wider use of natural gas, according to the analysis.

Natural gas use makes up the difference

"We will show that shifting some electricity generation from coal to natural gas could easily compensate for all additional carbon dioxide emissions from Canadian oil sands," the report says.

The report adds to a swirling debate about the true carbon impact of the Canadian oil sands. Yesterday, environmentalists criticized the findings as misleading.

It is not the case that Canadian oil sands will be automatically developed via new pipelines to Asia or elsewhere, considering strong opposition from green groups in Canada to those projects, they said. There are two main proposed projects in Canada to move oil sands crude to Asia via Canada's West Coast, and both are currently facing protests in British Columbia.

Additionally, Canadian Natural Resources Minister Joe Oliver has said that the Canadian oil sands are in danger of being "landlocked in bitumen" before the end of the decade.

It is also not necessarily true that "clean" alternatives to the oil sands have to be fuels like coal-to-liquids, the environmental analysts said.

"One thing that the study seems to disregard is the ability to reduce our fossil fuel use through efficiency and advanced vehicles and other technologies," said Anthony Swift, an analyst at the Natural Resources Defense Council. He pointed to an analysis from his organization that outlines how the United States can become more fuel independent without greater reliance on the oil sands or other fossil fuels.

Additionally, the study is relying on the premise that additional carbon regulations will be put in place on power plants to switch them from coal to gas, a prospect that is not likely in today's political environment, another critic said.

Switching power plants

The study says that 19 percent of the present fleet of coal-fired power plants would need to be switched to gas to offset the carbon dioxide emissions of 5 million additional barrels of oil sands crude. Last year, Canadian oil sands production stood at 1.6 million barrels per day. That number could rise to 3 million barrels per day by 2020, according to an analysis this month from the Canadian Association of Petroleum Producers.

Under Energy Information Administration statistics looking out to 2025, coal's share of the electricity mix is expected to drop around 6 percent under existing policies.

But Curl said that movement of the Canadian oil sands to U.S. Gulf refineries not only makes climate sense, but economic sense. He said importing oil from Canada rather than from other countries would be less detrimental to the U.S. trade balance, by helping generate a two-way street of goods.

"Income to Canada from whatever source is going to result in higher exports from the United States to Canada," he said.

Considering that new finds of unconventional gas are showing a 90-year supply for the United States, it makes financial sense to shift more coal plants to gas, even if gas prices rise significantly, he said.

According to the Rice analysis, the additional cost of shifting electricity generation from coal to gas is less than $11 per barrel of oil. While it is true that the gas switch called for in the study will not be accomplished without additional carbon regulations in the United States, the switch would not require a massive economywide program like a carbon tax, said Curl.

"The switch to gas levels we're talking about could be accomplished by additional EPA regulations on carbon from coal-fired power plants," he said. "That will give enough offsetting [of emissions]."

He said the possibility that import of Canadian oil sands would replace energy-intensive coal-to-liquids in some regions of the United States is also compelling. Curl and Brito calculated that the development of coal-to-liquids in the United States would be a "very real possibility" if oil prices stabilized above $100 a barrel. The researchers said that if coal-to-liquid production -- which involves liquefying coal -- ever reached 1 million barrels a day, it would result in release of 300 million to 335 million tons of carbon dioxide annually.

A wild card for the findings is the greenhouse gas footprint of natural gas, Curl explained. There is an ongoing debate about how much methane -- a powerful greenhouse gas -- escapes during the natural gas production process.