2016年1月12日，荷兰环境署（PBL）受国际可再生能源机构（International Renewable Energy Agency，IREA）的委托，发布题为《生物能源路径的温室气体影响》（Greenhouse Gas Impact of Bioenergy Pathways）的技术报告，评估了不同生物能源技术路径的温室气体排放收益与影响。
Wide ranges in emissions
Supply-chain emissions – i.e. emissions from the cultivation, production and transport of bioenergy – could range from around 20 grams of CO2-equivalent per megajoule (gCO2eq/MJ) for advanced biofuels to close to 60 gCO2eq/MJ for ethanol from wheat. The carbon impact for wood pellets ranges from 8 to 30 gCO2eq/MJ.
Major areas of uncertainty are nitrous-oxide (N2O) field emissions and the assumed yields of woody crops. Studies using general or partial equilibrium models show land-use-change emissions from various types of conventional bioethanol ranging from 3 to 61 gCO2eq/MJ; those of conventional biodiesel range from 7 to 94 gCO2eq/MJ. For biodiesel, the use of peatland plays an important role in the greenhouse gas effects.
Costs, benefits and policies
Bioenergy options can deliver net cost benefits, compared to fossil fuel alternatives, and even more so if greenhouse gas emission reductions are valued in monetary terms. However, costs and benefits largely depend on climate policies, rules and regulations in the countries or sectors involved in the biofuel supply chain. Negative impacts of ambitious bioenergy schemes on natural ecosystems can be reduced significantly through the simultaneous introduction of measures to keep land conversion in check. In particular, schemes to protect forest areas can be instrumental to limit land-use change, leading to beneficial effects for nature protection and biodiversity conservation in highly valued forest areas.
