Quantifying land use of oil sands production: a life cycle perspective

Methods for the inclusion of land use in life cycle assessment are not well established. Here, we describe an approach that compares land disturbance between spatially compact and diffuse activities that contribute to the life cycle of a single product, in this case synthetic crude from Alberta's oil sands. We compare production using surface mining and in situ extraction technologies. In situ technologies disturb less land per unit of production than surface mining, but the spatial footprint of in situ production is more dispersed-increasing landscape fragmentation-and in situ production requires more natural gas which increases land use due to gas production. We examine both direct and peripheral land use of oil sands development by quantifying land disturbance using a parameterized measure of fragmentation that relies on 'edge effects' with an adjustable buffer zone. Using a life cycle perspective, we show that the land area influenced by in situ technology is comparable to land disturbed by surface mining when fragmentation and upstream natural gas production are considered. The results suggest that land disturbance due to natural gas production can be relatively large per unit energy. This method could be applied to other energy developments, for example, a comparison between coal mining and natural gas production when both fuels are used to generate electricity.