Dynamic greenhouse gas life cycle inventory and impact profiles of wood used in Canadian buildings

Wood is increasingly promoted due to its reported low climate change impacts; however, the literature reports provides high variability of climate change impact scores, making comparisons with non-wood materials difficult. The objective of this study is to calculate a database of life cycle inventories (LCI) and dynamic climate change impacts (DCCI) of wood building products, for different use contexts across Canada. Temporally differentiated gate-to-gate LCIs were developed, to which dynamic life cycle assessment (DLCA) was applied, yielding a modular database of cradle-to-grave LCIs and DCCIs of wood products. Four wood product case studies were chosen to demonstrate the use of the modular LCI and DCCI database of wood product use in buildings. The results show that most wood building products provide overall net negative climate change impact scores, though for some wood product specifications results show net positive climate change impacts. Results are sensitive to a few factors, including ecosystem carbon cost (ECC), wood carbon content, building lifespan and end-of-life. This research develops a gate-to-gate LCI and DCCI database for each life cycle stage of wood building products, allowing life cycle assessment (LCA) practitioners to calculate DCCI results with respect to a chosen time horizon relevant for decision-making. This modular database would be particularly useful to those practitioners wishing to account for biogenic carbon in wood product life cycle assessment, which is currently quite difficult due to a lack of data. It could also be readily implemented into LCA tools to support building designers in sustainable building material selection.