Biodiversity impact of the consumption of peat and wood-fired district heating

Abstract

A shift from fossil fuels to biofuels is becoming an increasingly important part of national and corporate climate strategies, but the biodiversity impacts of biofuels are often ignored and remain poorly understood. Here we developed a novel eight-step general framework for the assessment of consumption-based biodiversity impacts of biofuels and applied the framework to assess the biodiversity impacts of peat and wood-fired district heating in Finland. We utilize the habitat hectare approach for which information about the ecosystem condition before and after the impact is needed. The habitat hectare approach has not yet been used on assessments of consumption-based biodiversity impacts. Of the different fuel types used in peat and wood-fired district heating in Finland, peat had the highest biodiversity impact per unit area, followed by chips from roundwood and logging residue chips. By-products from sawmill industry are argued to have no additional biodiversity impacts. Interestingly, however, when we consider the biodiversity impacts per unit energy, chips from roundwood had the highest and peat the lowest biodiversity impact. Our results suggest there is a truly substantial trade-off between the climate and biodiversity impacts of wood and peat firing. We conclude that the habitat hectare approach combined with the presented general assessment framework is a promising approach to be used in the assessment of consumption-based biodiversity impacts in different land use contexts, such as biodiversity offsetting, around the globe. This protocol should be further developed and refined in different systems and with different bio-based materials and land use contexts.