The Cradle-to-Gate Life Cycle Assessment on Hardwood Lumber Production in New Brunswick, Canada

This case study conducted a cradle-to-gate life cycle assessment (LCA) on the production of hardwood lumber in New Brunswick, Canada, evaluating the environmental impacts from raw material extraction to the point where lumber exited the mill as rough green lumber, the primary input for manufacturing pallets and railway ties. Data on annual production, material flow, and energy use for harvesting and sawmilling were gathered through survey questionnaires and on-site visits. The life cycle inventory (LCI) was developed in SimaPro software, the life cycle impact assessment (LCIA) was conducted using the North American TRACI method to quantify impact categories, and the cumulative energy demand (CED) method was employed to analyze the total energy consumption. It was found that rough green hardwood lumber production emitted approximately 41 kg CO2−eq/m3 (excluding biogenic carbon storage), with manufacturing accounting for 42% of total emissions and consuming 736 MJ/m3 of total energy, 98% of which came from non-renewable sources. The carbon stored in lumber was 975 CO2 eq/m3, 24 times greater than its cradle-to-gate emissions, highlighting its significant environmental benefit. Future research will aim to conduct a cradle-to-grave LCA on hardwood production by including drying and planing and increase the number of sawmill samples.