The climate change mitigation potential of bioenergy with carbon capture and storage

Bioenergy with carbon capture and storage (BECCS) can act as a negative emission technology and is considered crucial in many climate change mitigation pathways that limit global warming to 1.5–2 °C; however, the negative emission potential of BECCS has not been rigorously assessed. Here we perform a global spatially explicit analysis of life-cycle GHG emissions for lignocellulosic crop-based BECCS. We show that negative emissions greatly depend on biomass cultivation location, treatment of original vegetation, the final energy carrier produced and the evaluation period considered. We find a global potential of 28 EJ per year for electricity with negative emissions, sequestering 2.5 GtCO₂ per year when accounting emissions over 30 years, which increases to 220 EJ per year and 40 GtCO₂ per year over 80 years. We show that BECCS sequestration projected in IPCC SR1.5 °C pathways can be approached biophysically; however, considering its potentially very large land requirements, we suggest substantially limited and earlier deployment.