The mass of biomass material injected for geologic storage — or used as an input for another storage process — can be measured directly as a metered output from the biomass transformation system (e.g. a pyrolyzer) and as a metered input to the storage system. This quantity can also be checked for consistency against the measured mass of biomass feedstock and operational data from the biomass transformation system. The carbon content of the biomass material can be directly measured and converted to CO₂e using a default factor.