Extracting and refining Canadian oil sands crude oil produces 20 percent more climate-warming greenhouse gas emissions than the same processes for conventional American crude, according to a peer-reviewed study funded by the U.S. Department of Energy. The finding adds more evidence to the argument that the Keystone XL pipeline will exacerbate the U.S.'s emissions. President Barack Obama has said he will not allow the Keystone XL pipeline to be built unless it "does not significantly exacerbate the problem of carbon pollution."
The study, published this month in Environmental Science & Technology, is the largest of its kind to look at wheel-to-wheel emissions from oil sands, meaning the emissions involved in the full life cycle of the oil: extracting, transporting, refining and ultimately burning the fuel for use in vehicles. The authors note that Canada's oil sands production is expected to more than double over the next 15 years, from 1.95 million barrels per day in 2013 to 4.81 million barrels per day by 2030.
Right now, only about 9 percent of the mix of crude oil that passes through U.S. refineries comes from Canadian oil sands. But as Canadian production of oil sands continues to grow, the researchers note much more of it will flow into U.S. refineries and contribute to total American emissions. How much more depends partly on the fate of pending pipeline projects. Keystone XL isn't the only major pipeline project planned to move Canadian oil sands over the U.S. border: Enbridge, another Canadian company, is currently working to significantly increase the capacity of its Alberta Clipper pipeline to push 800,000 barrels of tar sands crude per day over the North Dakota border.
The research team, composed of scientists from DOE's Argonne National Laboratory, Stanford University, and the University of California Davis, analyzed the monthly emissions data from 27 oil sands operations in Alberta, beginning in 2008. "No one has generated a data set as comprehensive as this," Adam Brandt, a co-author of the report and an assistant professor at Stanford's Department of Energy Resources Engineering, told The Wall Street Journal.
They found that oil sands ultimately made into gasoline emit 18 percent more total greenhouse gases over their life cycle than gasoline derived from conventional U.S. crude does, and oil sands-derived deisel fuel produces 21 percent more greenhouse gases than conventionally-derived deisel.
"Without significant reduction in the energy intensity of extraction, separation, and upgrading of oil sands…higher emissions for gasoline and diesel production in the U.S. are expected when oil sands products become a larger fraction of the U.S. fuel mix," the authors conclude.
