Organics: Yard Trimmings and Food Scraps

This chapter describes the methodology used in EPA's Waste Reduction Model (WARM) to estimate streamlined life-cycle greenhouse gas (GHG) emission factors for yard trimmings and food scraps beginning at the point of waste generation. The WARM GHG emission factors are used to compare the net emissions associated with these two organic material types in the following three materials management options: composting, landfilling, and combustion. Exhibit 1 shows the general outline of materials management pathways for these materials in WARM. For background information on the general purpose and function of WARM emission factors, see the Introduction & Overview chapter. For more information on Composting, Landfilling, and Combustion, see the chapters devoted to those processes. WARM also allows users to calculate results in terms of energy, rather than GHGs. The energy results are calculated using the same methodology described here but with slight adjustments, as explained in the Energy Impacts chapter.