Case Study Type:
Apply WARM emissions factors against waste composition data to estimate the lifecycle GHG impacts of disposed materials; include these in the inventory
- Description of tool/’patch’ (action statement): Use waste composition study and waste flow/disposal records to estimate the quantities of individual materials disposed of. Multiply these tonnages by materials-specific "life cycle" emissions factors (from WARM or other sources) to account for the GHG impacts of producing and disposing of materials. Include these in the inventory so that future reductions in disposal count as reductions in inventoried emissions.
- Tips/best practices for applying the tool: TBD.
- Issues/obstacles: May need more thought as to which life cycle emissions to include. For example, Ft. Collins uses the "source reduction" emissions factors to estimate the impacts of producing materials. If these materials are subsequently recycled, that doesn't mean that they aren't produced in the first place . . . only that there are some resulting reductions in GHG emissions over the life of the first product and the next product that uses these recycled wastes as feedstocks. Another concern is whether or not to include forest carbon sequestration factors. EPA's WARM model includes estimates of carbon sequestered as a result of changes in land use when wood-based materials are source reduced or recycled. These estimates are based on analyses of marginal changes in land use practices, which is different from the emissions factors associated with energy savings (which are based on average conditions).
- Resources/citations (justification for use of this particular tool/patch): Ft. Collins Colorado has used this approach, limited to specific materials (cardboard, aluminum, carpet, etc.) targeted for recovery in the City's Climate Action Plan.