WASHINGTON—Allowing a Canadian company to construct a third oil sands pipeline through the nation's heartland could eventually eliminate U.S. dependence on Middle Eastern oil, while having little impact on global emissions of heat-trapping gases.

That's how oil pipeline giant TransCanada interprets a new report focused on its controversial Keystone XL pipeline project.

Economists and environmental advocates reviewing the same report beg to differ with those sweeping conclusions.

At issue is a recently released U.S. Department of Energy study called "Keystone XL Assessment," which has sparked further debate over the long-running pipeline controversy, as Canada's prime minister visits the White House today and protesters take up positions outside.

DOE's Office of Policy and International Affairs hired the consulting firm EnSys Energy to write the report. EnSys was tasked with evaluating what impact TransCanada's Keystone XL project would have on refining, trade and oil markets. The authors present multiple scenarios in their 124-page study.

Energy Department officials commissioned the analysis for the State Department as part of a wide-reaching environmental review of the $7 billion-pipeline proposed by Calgary, Alberta-based TransCanada. The State Department is in the midst of updating its draft environmental impact statement.

"This study supports what we have been saying for some time," TransCanada president and chief executive officer Russ Girling said via a news release. "Keystone XL will improve U.S. energy security and reduce dependence on foreign oil from the Middle East and Venezuela."

Due to the international nature of Keystone XL, Secretary of State Hillary Clinton's team at the State Department is tasked with granting a thumbs up or down to TransCanada's request for a presidential permit to build and operate the 1,959-mile pipeline.  The infrastructure could carry up to 510,000 barrels of heavy crude oil from tar sands mines in the province of Alberta and across six states to refineries in the Gulf of Mexico.

A decision on the proposal is expected within the next weeks or months. The Canadian National Energy Board approved the project in March 2010.

Despite the involvement of several federal agencies, the State Department appears to be calling the shots over the pipeline, and was responsible for releasing the DOE report.

Liz Barratt-Brown, a senior attorney with the Natural Resources Defense Council, pointed out to Solve Climate News in an interview the curious timing of the study's release. The study is dated Dec. 23, 2010, but it was only made public earlier this week, just ahead of Canadian Prime Minister Stephen Harper's meeting today with President Obama at the White House.

The two leaders are likely to discuss the Alberta oil sands and the new pipeline, as well as bilateral efforts on climate change, trade and security, according to news reports about the visit.

Greenhouse Gas Emissions

Last July, the Environmental Protection Agency gave the draft environmental impact statement that the State Department issued concerning Keystone XL its lowest possible ranking.

EPA officials said they found the document "inadequate" because of a lack of safety and spill-response planning, inattentiveness to the potential impact on Canada's indigenous communities and concerns about greenhouse gas emissions affiliated with the pipeline.

The Ensys analysis hypothesizes that construction of Keystone XL would not significantly alter either the carbon footprint of refineries on a global basis or the total lifecycle of greenhouse gas emissions.

However, NRDC experts argued that framing the emissions impact in a global transportation emissions context — instead of a U.S. context — can dwarf any impact.

The greenhouse gas savings from not constructing Keystone XL would be 26 million tons of carbon dioxide by 2030. That's the equivalent of emissions reductions from doubling California's low carbon fuel standards, according to numbers crunched by NRDC low carbon specialist Simon Mui.

EPA spokespeople contacted this week by SolveClimate News about the DOE report did not respond to requests for comment.

When asked to comment about the emissions impact of Keystone XL, TransCanada spokesman Terry Cunha stated that "it's important to recognize that the oil sands will be produced regardless of whether Keystone XL is built as there are a few options to bring Canadian crude to international markets."

"Therefore, the pipeline's existence is independent of the emissions associated with the oil production," he said.

Cunha also pointed out that the Gulf Coast is a large refining center with many choices of crude oil available.