May 24: The Congressional Research Service (CRS), has prepared a report entitled, Canadian Oil Sands: Life-Cycle Assessments of Greenhouse Gas Emissions, and it has been released via the OpenCRS project. The report is dated May 15, 2012. According to the report, 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 crude oil resources both domestically and internationally. Many forecasters identify petroleum refined from Canadian oil sands as one possible solution.
The report says, "Increased petroleum production from Canadian oil sands, however, is not without controversy, as many have expressed concern over the potential environmental impacts. These impacts may include increased water and natural gas use, disturbance of mined land, effects on wildlife and water quality, trans-boundary air pollution, and emissions of greenhouse gases (GHG) during extraction and processing. A number of key studies in recent literature have expressed findings that GHG emissions from the production of Canadian oil sands crudes may be higher than those of other crudes imported, refined, and consumed in the United States. The studies identify two main reasons for the increase: (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 compositionally 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."
CRS indicates that it surveyed the available literature, including the U.S. Department of State-commissioned study in the Environmental Impact Statement for the Keystone XL pipeline project. The report that the literature reveals the following:
- despite differences in the design and input assumptions of the various studies, Canadian oil sands crudes are on average somewhat more GHG emission-intensive than the crudes they would displace in the U.S. refineries, with a range of increase from 14%-20% over the average Well-to-Wheel emissions of other imported crudes;
- 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) emissions from Canadian oil sands crudes have a range of increase from 72%-111% over the average Well-to-Tank emissions of other imported crudes;
- Canadian oil sands crudes, on a Well-to-Wheel basis, range from 9%-19% more emission-intensive than Middle Eastern Sour, 5%-13% more emission-intensive than Mexican Maya, and 2%-18% more emission-intensive than various Venezuelan crudes;
- the estimated effect of the proposed Keystone XL pipeline on the U.S. GHG footprint would be an increase of 3 million to 21 million metric tons of GHG emissions annually (equal to the annual GHG emissions from the combustion of fuels in approximately 588,000 to 4,061,000 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 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.
CRS notes regarding the "Scope and Purpose of This Report" that, "After discussing the basic methodology of life-cycle assessments [LCAs] and examining the choice of boundaries, design features, and input assumptions, this report compares several of the publicly available assessments of life-cycle emissions data for Canadian oil sands crudes against each other and against those of other global reference crudes. Further, as congressional concern over the environmental impacts of Canadian oil sands production may encompass both a broad understanding of the global 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 of the State Department's Keystone XL Project Environmental Impact Statement. Finally, as life-cycle assessments have become an influential -- albeit developing -- methodology for collecting, analyzing, and comparing GHG emissions, the report concludes with a discussion of some tools for policymakers who are interested in using these assessments to investigate the potential impacts of U.S. energy policy choices on the environment."
In a concluding comment for further consideration, CRS indicates, ". . .because of the complex life cycle of hydrocarbon fuels and the large number of analytical design features that are needed to model their emissions, LCAs retain many variables and uncertainties. These uncertainties often make comparing results across resources or production methods problematic. Hence, the usefulness of LCA as an analytical tool for policymakers may lie less in its capacity to generate comparative rankings, or 'scores,' between one source and another, and more in its ability to highlight 'areas of concern,' or 'hot spots,' in the production of a given hydrocarbon fuel. In this way, LCA can serve to direct policymakers' attention to those areas in resource development that present the greatest challenges to GHG emissions control, and hence, the biggest potential benefits if adequately managed."
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