Does renewable mean good for climate? Biogenic carbon in climate impact assessments of biomass utilization

Using biomass to substitute fossil resources is seen as one of the sustainable ways to tackle climate change. Yet not all biomass projects can be a priori declared beneficial. A climate impact assessment, such as life cycle assessment or carbon footprint, is crucial for a science-based policy recommendation. However, those assessments can often be incomplete, especially since many of those adopt an assumption that biogenic CO2 emissions cause no harm to the climate and do not need to be accounted. Such a simplistic neutrality assumption can lead to inaccurate results and thus to undesired consequences. This article synthesizes and further develops the diverse argumentation against the neutrality assumption, especially regarding the complexity of biomass production, differences in the timing of emission, allocation procedure, and climate change characterization methodology. Thus, the article draws a broader picture of the complex issue of biomass projects and argues for more comprehensive assessments.

Automated summary

Using biomass as a substitute for fossil resources is considered a sustainable approach to addressing climate change. However, comprehensive climate impact assessments are necessary to make science-based policy recommendations. Currently, there is a tendency to adopt a simplistic neutrality assumption in these assessments, which can lead to inaccurate results and undesired consequences. This article argues for more comprehensive evaluations of biomass projects, taking into account the complexity of production, timing of emissions, allocation procedures, and climate change characterization methodology.