Substitution benefits of British Columbia’s mitigation strategies in the bioeconomy

Abstract

Globally, efforts to increase land sector contributions to net-zero emissions are pursued. Harvested wood products may retain carbon, and substitute emission-intensive products. The emission reductions achieved through substitution, or substitution benefits, can inform the design of climate-effective wood-use strategies. Mitigation analyses of a wood-based bioeconomy therefore need to include substitution to evaluate the mitigation outcomes across sectors. Substitution benefits can be estimated using displacement factors, which quantify the emissions avoided per unit of wood use. Here, we calculated the displacement factors of timber constructions and wood-derived biofuels to be around 1.03 and 0.45 tCO2e/tCO2e, respectively. Assuming substitution was achieved when changes in human behavior increased the share of wood use relative to the reference market share, we added the substitution benefits to a previous analysis that focused on biogenic emissions in British Columbia, Canada. At projected declining harvest rates, the theoretical maximum reduction that forest products can contribute over the period 2016 to 2050 is 66 MtCO2e·year−1 with an uncertainty range of 45–79 MtCO2e·year−1, relative to the baseline, by focusing on long-lived, high-displacement construction applications. However, because construction uses of wood in foreign markets are not guaranteed, and constrained by market access, the practical strategy that combines construction and biofuel uses can achieve 17.4 MtCO2e·year−1, equivalent to 30% of British Columbia’s 2050 target. Although a transformation of the bioeconomy may help achieve both climate and socio-economic benefits, potential conflict exists between maximizing regional and global benefits. How and where wood will be used can influence the desired mitigation outcomes.