Carbon footprint of forest harvesting operations in New Zealand

Authors: Dougal Shepherd, Simon Smith, Rien Visser
Publication: New Zealand Journal of Forestry, Volume N.Z.J.For. 2023, Issue N.Z.J.For. 68(2) 2023, pp 19 - 26, Aug 2023
Publisher: New Zealand Institute of Forestry

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Abstract: As the world transitions to a low-carbon economy, companies that are at the forefront of this change will be in a position to offer benefits and competitive advantages. The forest industry is currently experiencing the early stages of pressure to measure and report greenhouse gas (GHG) emissions. Currently there is little research on the emissions produced by harvesting operations or options for crews to reduce emissions in New Zealand. The scope of this study was set to include only direct GHG emissions for harvesting crews. For forestry operations this is primarily the fuel used from the harvesting operation itself, but also includes the travel of the crew to and from the site. Fuel use data, as well as system description, was collected from 55 unique operations from participating forest managers and crews. They included 30 ground-based, 13 swing yarder and 12 tower yarder crews, and they operated on average 4.8, 8.1 and 7.4 machines, respectively. Carbon footprint is typically reported in tonnes of CO₂ equivalent (tCO₂e) and published fuel to CO₂e conversion factors are used. Fuel use ranged from 1.2–11.2 L/m³ (average of 3.67) for ground-based, 2.8–9.1 L/m³ (4.3) for swing yarder and 2.0–11.3 L/m³ (5.0) for tower yarder crews. The tower yarder (‘hauler’) crews had the highest average carbon footprint both per annum and per m³ harvested, with an average of 935 tCO₂e/annum and 14.7 kgCO₂e/m³, respectively. Swing yarder crews averaged the next highest (782 tCO₂e/annum and 12.6 kgCO₂e/m³) with ground-based resulting in the least (693 tCO₂e/annum and 10.7 kgCO₂e/m³). The results provide an initial benchmark for the carbon footprint of New Zealand harvesting operations. By cross-referencing with previous fuel use values, this paper suggests that fuel consumption, and therefore emissions, has increased significantly through the higher levels of mechanisation adopted in the last decade. The paper demonstrates a simplified methodology for emissions reporting and also provides a reference for future emissions reductions techniques, technology and innovations.

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