Climate-change mitigation potential of biochar
Biochar is a multi-faceted strategy to mitigate climate change. The bio-oil produced during pyrolysis could replace fossil fuels and therefore avoid supplementary GHG emissions. The pyrolysis gas would represent additional GHG emission reduction potential if fossil fuels were displaced to provide heat, electricity or transport fuels in processes occurring outside the biochar system. The successful adoption of biochar-making stoves could reduce biomass consumption for cooking, and therefore reduce the rate of deforestation and CO2 emissions. The carbon stabilisation potential of biochar is important and the application of biochar into soils could diminish CH4 and N2O emissions in agriculture. An increasing amount of Life Cycle Assessment (LCA) studies have been conducted for biochar systems around the world. The results suggest that, under certain conditions, the production and application of biochar into soils can be the best use of biomass for climate-change mitigation. Since biomass is a local resource, the best use of biomass depends on the specific local conditions of the baseline and project scenarios. To evaluate the climate-change mitigation potential of a biochar system it is recommended to assess and compare the life cycle climate impacts of using the biomass for biochar production and application to soil with those of using the biomass as per common local practices.