Biogenic CO2
Carbon dioxide released from burning or decomposing biomass such as wood.
Biogenic CO2 comes from biological carbon, such as wood, rather than from fossil fuels. When pallets are burned, most of the CO2 released is biogenic.
EPA's WARM model excludes biogenic CO2 from combustion of wood products from its net emissions, on the basis that it was absorbed from the atmosphere as the tree grew. That's why WARM's combustion factor for dimensional lumber is negative (−0.58 MTCO2E per short ton): the credit for electricity displaced outweighs the transport and nitrous oxide emissions counted.
The GHG Protocol's Scope 3 Standard asks companies to report biogenic CO2 from their value chain separately from the scopes rather than ignore it. If you burn pallet wood on site, check how your inventory treats it. See biomass fuel.
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).
- Corporate Value Chain (Scope 3) Accounting and Reporting Standard GHG Protocol (WRI/WBCSD). Accessed October 27, 2026. Box 5.6 and section 9.5 on avoided emissions; section 5.5 category descriptions.