Diverting residual biomass to energy use: Quantifying the global warming potential of biogenic CO 2 ( GWP bCO2 )

• Published in: Global change biology. Bioenergy 2023-05, Vol.15 (5), p.697-709
• Main Authors: Adetona, Adekunbi B., Layzell, David B.
• Format: Article
• Language: English
• ISSN: 1757-1693; 1757-1707
• DOI: 10.1111/gcbb.13048

To calculate the global warming potential of biogenic carbon dioxide emissions (GWP bCO2 ) associated with diverting residual biomass to bioenergy use, the decay of annual biogenic carbon pulses into the atmosphere over 100 years was compared between biomass use for energy and its business‐as‐usual decomposition in agricultural, forestry, or landfill sites. Bioenergy use increased atmospheric CO 2 load in all cases, resulting in a 100 GWP bCO2 (units of g CO 2 e/g biomass CO 2 released) of 0.003 for the fast‐decomposing agricultural residues to 0.029 for the slow, 0.084–0.625 for forest residues, and 0.368–0.975 for landfill lignocellulosic biomass. In comparison, carbon emissions from fossil fuels have a 100 GWP of 1.0 g (CO 2 e/g fossil CO 2 ). The fast decomposition rate and the corresponding low 100 GWP bCO2 values of agricultural residues make them a more climate‐friendly feedstock for bioenergy production relative to forest residues and landfill lignocellulosic biomass. This study shows that CO 2 released from the combustion of bioenergy or biofuels made from residual biomass has a greenhouse gas footprint that should be considered in assessing climate impacts.