While nearly all biomass carbon eventually makes its way back to the atmosphere, the effective drawdown from more durably storing biomass carbon occurs when the biomass feedstock would otherwise have released CO₂ into the atmosphere. If the counterfactual fate of the biomass feedstock would have resulted in little to no carbon storage — for example, burning or rapid decomposition — any durable storage achieved represents additional carbon removal. If, however, the counterfactual fate of the biomass feedstock would have resulted in medium-to-long term carbon storage — for example in soils, slow-degradation environments like some landfills, or living ecosystems — the mass of stored carbon in the counterfactual should not count as additional carbon removal unless and until counterfactual emissions would have occurred. This component may not apply in cases where carbon is purpose grown.