Greenhouse-gas emission mitigation has been estimated for the use of existing and mature biomass technologies. A general methodology has been:developed to determine potential; amounts of residues that can be made available for energy Purposes and the resulting fossil-fuel replacement from utilization-of these residues. The consequent reductions in CO2, CH4 and N2O emissions in CO2 equivalents for a time horizon of 20 years, as well as costs of abatements, were calculated, Both traditional and improved-energy uses are considered.