Life-cycle assessment of hardwood lumber production in the southeastern United States
| Authors: | M. Davoud Heidari, James Salazar, Richard Bergman, Steven S. Hubbard, Scott A. Bowe |
| Year: | 2023 |
| Type: | Research Paper |
| Station: | Forest Products Laboratory |
| DOI: | https://doi.org/10.2737/FPL-RP-716 |
| Source: | FPL-RP-716 |
Abstract
Because of environmental awareness and regulations and the advent of environmental preferential purchasing, documenting the environmental profiles of building products using life-cycle assessment (LCA) has become a widespread emergent global trend. This study conducted a cradle-to-gate LCA of hardwood lumber production in the southeastern United States. System boundaries in this study included the following production stage information modules: raw material extraction (A1), resource and material transportation (A2), and hardwood lumber manufacturing (A3). Module A1 included forest management activities. The declared unit was 1 m3 of hardwood lumber packaged and ready for shipment. Surveys were used to collect primary hardwood lumber production data. This LCA study followed the standards of the International Organization for Standardization and the wood products product category rules. The tool for the reduction and assessment of chemical and other environmental impacts (TRACI), CML baseline, and cumulative energy demand were used to conduct a life-cycle impact assessment. The weighted average oven-dried density of southeastern hardwood lumber was 576 kg/m3. Results showed that about 209 kg CO2eq were released in the production of 1 m3 of hardwood lumber (all information modules combined), with the A3 module accounting for 71%, followed by A1 (15%) and then A2 (14%). Raw material extraction (A1), resource and material transportation (A2), and hardwood lumber manufacturing (A3) consumed about 9%, 7%, and 84%, respectively, of total cradle-to-gate primary energy. About 59% of the total primary energy used in the production of hardwood lumber (A1–A3) came from nonrenewable, mostly fossil, resources. One cubic meter of southeastern hardwood lumber stores 1,055 kg CO2eq, which is about four times more than the embodied carbon released from all three modules of the production of this lumber (209 kg CO2eq).