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Tuesday, March 26, 2013

Canadian Oil Sands: Life-Cycle Assessments of Greenhouse Gas Emissions

Richard K. Lattanzio
Analyst in Environmental Policy

Canadian Oil Sands and Climate Change 

Recent congressional interest in U.S. energy policy has focused in part on ways through which the United States could secure more economical and reliable petroleum resources both domestically and internationally. Many forecasters identify petroleum products refined from Canadian oil sands as one possible solution. Increased production from Canadian oil sands, however, is not without controversy, as many have expressed concern over the potential environmental impacts. These impacts include emissions of greenhouse gases (GHG) during resource extraction and processing. A number of key studies in recent literature have expressed findings that GHG emissions per unit of energy produced from Canadian oil sands crudes are higher than those of other crudes imported, refined, and consumed in the United States. The studies identify two main reasons for the difference: (1) oil sands are heavier and more viscous than lighter crude oil types on average, and thus require more energy- and resource-intensive activities to extract; and (2) oil sands are chemically deficient in hydrogen, and have a higher carbon, sulfur, and heavy metal content than lighter crude oil types on average, and thus require more processing to yield consumable fuels by U.S. standards. 

Selected Findings from the Primary Published Studies 

CRS surveyed the published literature, including the U.S. Department of State-commissioned studies for the Keystone XL pipeline project in both the August 2011 Final Environmental Impact Statement (EIS) and the March 2013 Draft Supplementary EIS. The primary literature reveals the following:

  • Canadian oil sands crudes are on average somewhat more GHG emissionintensive than the crudes they may displace in U.S. refineries, as Well-to-Wheel GHG emissions are, on average, 14%-20% higher for Canadian oil sands crudes than for the weighted average of transportation fuels sold or distributed in the United States; 
  • discounting the final consumption phase of the life-cycle assessment (which can contribute up to 70%-80% of Well-to-Wheel emissions), Well-to-Tank (i.e., “production”) GHG emissions are, on average, 70%-110% higher for Canadian oil sands crudes than for the weighted average of transportation fuels sold or distributed in the United States; 
  • compared to selected imports, Canadian oil sands crudes range from 9% to 19% more emission-intensive than Middle Eastern Sour, 5% to 13% more emissionintensive than Mexican Maya, and 2% to 18% more emission-intensive than various Venezuelan crudes, on a Well-to-Wheel basis; 
  • compared to selected energy- and resource-intensive crudes, Well-to-Wheel GHG emissions for Canadian oil sands crudes are within range of heavier crudes such as Venezuelan Bachaquero and Californian Kern River, as well as lighter crudes that are produced from operations that flare associated gas (e.g., Nigerian Bonny Light); 
  • the estimated effect of the proposed Keystone XL pipeline on the U.S. GHG footprint would be an increase of 3.7 million to 20.7 million metric tons of GHG emissions annually (equal to the annual GHG emissions from the combustion of fuels in approximately 770,800 to 4,312,500 passenger vehicles); and 
  • the estimated effect of the Keystone XL pipeline on global GHG emissions remains uncertain, as some speculate that its construction would encourage an expansion of oil sands investment and development, while others suggest that the project would not substantially influence either the rate or magnitude of oil extraction activities in Canada or the overall volume of crude oil transported to and refined in the United States. 

Scope and Purpose of This Report 

This report discusses the basic methodology of life-cycle assessments and compares several of the publicly available studies of GHG emissions data for Canadian oil sands crudes against each other and against those of other global reference crudes. As congressional concern over the environmental impacts of Canadian oil sands production may encompass both a broad understanding of the resource as well as a specific assessment of the proposed Keystone XL pipeline, the report surveys both the general scientific literature as well as the individual findings in the State Department’s 2011 Final EIS and 2013 Draft Supplementary EIS for the Keystone XL Project.

Date of Report: March 15, 2013
Number of Pages: 35
Order Number: R42537
Price: $29.95

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