Calyx Global assesses the greenhouse gas (GHG) claims of energy-efficient and fuel-switch cookstoves, alongside domestic biodigester projects. A key parameter in calculating emission reductions for projects that aim to reduce the consumption of unsustainable biomass for thermal energy is the fraction of non-renewable biomass (fNRB), which represents the proportion of wood harvested that exceeds the regeneration rate of a given area. As such, fNRB is a core component for determining baseline emissions, and associated emission reduction claims, for projects involving the dissemination of cookstoves and/or household biodigesters.