Net greenhouse-gas emissions and reduction opportunities in the Western Australian beef industry

Abstract

Context The Western Australian (WA) Government has set ambitious emission reduction targets and is developing strategies to reduce emissions across the state economy, including agriculture. Aims This study determined the product carbon footprint (CF) and total emissions of the WA beef industry, to establish a baseline for emission reduction planning. Methods A cradle-to-gate attributional life-cycle assessment with a reconciled livestock inventory of herd numbers and turnoff, was used. Emission reduction strategies were examined and included herd management, enteric-methane mitigation, and removals via carbon sequestration in vegetation and soils. Key results Modelled livestock numbers were found to be 36% higher than reported in the Australian Bureau of Statistics (ABS), resulting in an emission profile of 4.7 million tonnes (Mt) of carbon dioxide equivalent (CO2-e) (excluding land use (LU) and direct LU change (dLUC)). This profile was 26% higher than emissions reported in state inventories. LU and dLUC were estimated to be a greenhouse-gas removal of −2.6 Mt CO2-e, although with high uncertainty. The mean CF for WA was 15.3 kg CO2-e per kg liveweight (LW) (excluding LU and dLUC). State-wide removals from LU and dLUC were estimated to be −8.5 kg CO2-e/kg LW. The CF was 11.7, 19.2 and 18.2 kg CO2-e/kg LW for the Agricultural, Kimberley and Arid regions respectively. The implementation of herd-management strategies and anti-methanogenic supplements resulted in a maximum 25% reduction. Conclusions Herd productivity and market specifications were key drivers of regional differences in CF. Opportunities exist to reduce the CF in northern herds through diverting cattle to Australian backgrounding and feedlot supply chains to reach slaughter weight at a younger age. Adoption of anti-methanogenic feed supplements were important; however, achieving major reductions in the next decade will rely on removals via carbon sequestration in soil and vegetation. Implications Considering the magnitude of removals and elevated uncertainty in this result, further research and new datasets are needed to refine this analysis. New datasets are required to accurately report livestock numbers and track and reduce future GHG emissions from this higher baseline. Technical, cost and adoption barriers will need to be addressed by developing actionable pathways to achieve emission reduction in the mid- to long term.