The term 𝐹 is the C-sink loss due to the CO 2 expenditure from provision and handling of the biomass and from the pyrolysis process itself. As the biomass consisted of wood from landscape conservation and gardening, it can be considered carbon neutral according to . Further, as the waste biomass was used, no emissions from cultivation of the biomass (e.g. due to fertilizers) need to be accounted for. Only the emissions due to the use of fossil fuels during collection and processing of the biomass were included, corresponding to carbon expenditure of 0.7% of the mass of biochar according to the example presented in . Emissions resulting from the pyrolysis process originate mainly from preheating of the reactors with fossil fuels, emissions of methane and electricity to operate the plant; they were assumed after as corresponding to the carbon content loss of 2.4% by mass of biochar. A further 10% of the safety margin was accounted for due to the socalled indirect emissions that fall outside those estimated as provision of biochar and pyrolysis , finally yielding 𝐹 1.1 • 0.007 0.024 0.034.