WARM (Waste Reduction Model)
EPA's model of the greenhouse gas effects of managing waste materials different ways.
WARM is EPA's Waste Reduction Model. It estimates the greenhouse gas emissions and energy effects of source reduction, recycling, composting, combustion and landfilling for dozens of materials, and is used to compare scenarios: what changes if this material is reused instead of landfilled?
WARM's factors are life-cycle factors. They include credits that a corporate inventory leaves out, such as carbon stored in landfills, forest carbon left standing when material is reused, and electricity displaced by energy recovery. That makes them suited to avoided-emissions estimates, not to scope 3 inventories.
This site uses WARM version 16, published December 2023, chapter 12 (Wood Products). Each factor in the Pallet Fate Report is shown with its exhibit number, and we check for a new version each January.
Sources
- Documentation for Greenhouse Gas Emission and Energy Factors Used in WARM, Version 16: Construction Materials Chapters, ch. 12 Wood Products (EPA-530-R-23-020) U.S. EPA. Accessed October 27, 2026. Exhibits 12-3 (p. 12-3), 12-9, 12-13, 12-15 and 12-16 (p. 12-10).