Climate Impacts of Bioenergy Produced from Willow Grown in Sweden

Short rotation coppice willow (SRCW) is a fast-growing and potentially high-yielding energy crop. Replacing fossil fuel with bioenergy has been identified as one strategy to mitigate climate change and decrease the dependency on fossil energy in Sweden. By using life cycle assessment (LCA) methodology, the climate impact of SRCW systems was assessed and compared. The purpose was to evaluate which key factors that influence climate mitigation potential of SRCW grown on historically tilled soils in Sweden. Carbon fluxes between soil, biomass and atmosphere were modelled by using a carbon balance model. The results indicated that SRCW can increase the soil organic carbon content and thereby lead to a climate mitigating effect. The magnitude of this mitigating effect was shown to be dependent on willow yield, where a high yield gave the highest climatic benefits. Opposite, a low yield gave the lowest mitigating effect of the studied scenarios, nevertheless it was still better than the two reference systems, district heating produced from coal or natural gas.