It’s thick and sticky like peanut butter and there’s lots of it. Please don’t call it “dirty oil” (crude is never clean), but fuels derived from Canada’s tar sands do produce more greenhouse gas than conventional forms of gasoline and heating oil. Called “oil sands” by petroleum executives and “bitumen” by geologists, it’s the stuff that would flow through the Keystone XL pipeline on its way from Alberta to Gulf Coast refineries. An angry debate over its environmental impact has played a big role in the dispute over whether President Barack Obama should approve the Keystone project.
Alberta’s copious bitumen deposits let Canada claim the world’s third-largest recoverable reserve of crude oil. More tar sands crude enters the world’s oil mix every year, but the proportion is still small, about 2.3 percent. Canadian tar sands account for 0.1 percent of the world’s greenhouse-gas emissions and have a smaller potential to warm the planet than coal, natural gas and conventional oil. A gallon of fuel produced from tar sands bitumen releases 8 to 37 percent more carbon than conventionally produced fuel, according to a study by the Pembina Institute. The industry and the Alberta government say oil sands producers release 6 percent more greenhouse gases into the atmosphere. That’s partly because it takes more energy to extract and refine it compared with lighter forms of crude.
Governments are restricting the production and use of fuels that release carbon dioxide into the atmosphere to slow global warming. California in 2007 enacted the world’s first low-carbon fuel standard, which aims to reduce the carbon intensity of the state’s transportation fuels by 10 percent by 2020. The European Union is considering rules that would penalize carbon-intensive fuels including the Canadian tar sands. Alberta, which produces a third of Canada’s greenhouse gas emissions, is failing to meet its own carbon reduction targets as production soars.
As the tar sands industry focuses on reducing emissions, environmental groups point out that more bitumen production will lock in further dependency on oil for decades to come and delay a transition to renewable energy. Both sides also quarrel over the appropriate carbon comparison for the tar sands: Oil producers say coal plants pump much more carbon dioxide into the atmosphere, while environmentalists say the best apples-to-apples comparison is conventional oil because most crude is used as transportation fuel. Stopping Keystone XL will slow tar sands development, they say, while proponents argue the bitumen will be produced and shipped either by other pipelines or rail — with consequences.
The Reference Shelf
- The Pembina Institute provides insight into the debate around oil sands development
- The Canadian Association of Petroleum Producers provides its explanation of carbon emissions from the oil sands
- A peer-reviewed assessment of greenhouse gas emissions from the oil sands in the journal Environmental Science & Technology
- The Congressional Research Service’s March 2013 report on the life-cycle assessment of Canadian oil sands greenhouse gas emissions
- Paul Chastko, a historian at the University of Calgary, explores the development of Alberta’s bitumen resources in his book “Developing Alberta’s Oil Sands”