Decades of increased emissions from forest-fuelled BECCS

Should climate policies encourage bioenergy with carbon capture and storage (BECCS) using wood from existing forests? Although mitigation pathways in integrated assessment models often rely on BECCS fuelled by energy crops, European governments are moving to financially support BECCS sourced instead from existing forests. To estimate its emissions and financial costs, we develop a model that transparently tracks carbon flows from forest to end use and allows policymakers to easily alter assumptions. Modelling multiple wood-sourcing scenarios, we found that BECCS is unlikely to generate negative emissions within 150 years, is likely to produce higher emissions for decades than using natural gas without carbon capture and is likely to increase electricity costs by ~3.5-fold. Only limited improvements occur even if half of the wood comes from residues and half from fast-growing plantations. These results reflect the fact that most emissions occur before the power plant and therefore cannot be captured, and that wood has twice the carbon intensity of natural gas and generates electricity less efficiently. These results counsel against emerging BECCS policies, and our easy-to-use model allows policymakers to evaluate results and different scenarios themselves.