Gasoline and diesel refined from Canadian oil sands have a significantly larger carbon footprint and climate impact than
fuels from conventional crude sources, according to an analysis by the U.S. Department of Energy’s Argonne National Laboratory. Oil sands-derived fuels will release on average 20 percent more carbon into the atmosphere over their lifetime — and possibly up to 24 percent more — depending on how they are extracted and refined, the study says. Methane emissions from tailing ponds and carbon emissions from land disturbance and field operations also contribute to the higher carbon footprint. “This is important information about the greenhouse gas impact of this oil source, and this is the first time it has been made available at this level of fidelity,” said Hao Cai, the Argonne researcher who led the study. Roughly 9 percent of the total crude processed in U.S. refineries in 2013 came from the Canadian oil sands, and that percentage is projected to rise to 14 percent by 2020.