Report: GHG emission and energy factors used in the waste reduction model (WARM)
U.S. Environmental Protection Agency Office of Resource Conservation and Recovery - Management Practices Chapters Revised March 2018
Prepared by ICF International For the U.S. Environmental Protection Agency Office of Resource Conservation and Recovery
This chapter describes the development of material-specific emission factors for source reduction in EPA’s Waste Reduction Model (WARM). Source reduction, or waste prevention, refers to practices that reduce the amount of materials entering the waste stream, including changes in the design, manufacture, purchase or use of materials. This document provides examples of source reduction and a summary of how EPA estimates the GHG benefits from source reduction of materials.
Types of source reduction
Source reduction can result from any activity that reduces the amount of a material or agricultural input needed and therefore used to make products or food.1 Some specific examples of source reduction practices are:
- Redesigning products to use fewer materials (e.g., lightweighting, material substitution).
- Reusing products and materials (e.g., a refillable water bottle).
- Extending the useful lifespan of products.
- Avoiding using materials in the first place (e.g., reducing junk mail, reducing demand for uneaten food).
In addition to the activities above, there are limited circumstances where the emission factors can be used to estimate GHG benefits of substituting one material or product for another material or product. Section 1.3.2 presents considerations for estimating the GHG effects of material substitution.