Effectiveness of regionalized lifecycle impact assessment: A study on the arctic region of Nunavik, Canada

Regionalized life cycle impact assessment (LCIA) enables users to differentiate between the results for individual sites/areas, generally at a country or subcontinental scale. Previous studies that conducted life cycle assessments (LCAs) in the Arctic regions did not use regionalized LCIA, despite the regional environmental specificities. The goal of this study is to assess the importance of LCIA regionalization on the variability of the results and to bring recommendations regarding LCIA regionalization for Arctic regions. Characterization factors (CFs) are determined for the 11 regionalized midpoint impact categories (ICs) of Impact World + methodology at a consistent resolution for the Nunavik region, located in the Arctic region of Québec, Canada. These CFs, together with the global average CFs and country/sub-continental resolution CFs, are then applied to two case studies, on electricity and heat production, to assess the impacts of using Arctic-region-specific CFs on LCIA results. Results indicate that for hotspot analyses, country/subcontinental resolution is appropriate; the impact scores and the main contributors at the country/subcontinental resolution are consistent with those at the Nunavik resolution. However, for comparative analysis, region-specific resolution must be used as the results of the comparisons vary significantly due to differences between the life cycle inventories (LCIs) of the systems being compared. When comparing energy systems using different fuels, the differences shown vary significantly between resolutions, to an extent leading to inversions as to which system has the best environmental performance. This research suggests that the regionalization of the impact assessment should be conducted after collecting and modeling the inventory. Notably, this study can be used to optimize LCIAs for the context of Arctic regions. • Country-specific values should be preferred over generic values in Arctic regions. • Low population is a driving factor for models that consider human intervention. • Some models are not mature enough for Arctic regions. • Arctic-specific resolution brings significant differences and can change conclusions. • An analysis of the inventory should guide the decision to regionalize the LCIA.