Trends in the environmental impacts of the Australian pork industry

Context Over the past four decades, major changes have occurred in Australia’s pork industry, affecting productivity and environmental performance. Aims This study determined long-term changes in greenhouse gas and key resource use efficiency indicators. Methods Life cycle assessment was used to determine impacts at decadal intervals between 1980 and 2010, and are presented alongside results for 2020 and 2022. Key results Over 42 years since 1980, greenhouse gas emissions, excluding land use and direct land use change (dLUC), fell by 74% from 11.7 to 3.0 kg CO2-e/kg liveweight. Land use and dLUC emissions declined by 92%. Fossil energy use decreased from 35 to 13 MJ/kg liveweight between 1980 and 2022. Freshwater consumption and water stress fell from 506 L and 671 L H2O-e in 1980 to 52 L and 43 L H2O-e/kg liveweight in 2022, respectively. Land occupation decreased by 42% from 22 m2/kg liveweight in 1980 to 13 m2/kg liveweight in 2022. Over the analysis period, emissions per kilogram of liveweight fell by an average of 1.8% per year, land use and dLUC emissions by 2.2%, greenhouse gas including land use and dLUC emissions by 1.9%, fossil energy use by 1.5%, and freshwater consumption, stress, and land occupation by 2.1%, 2.2%, and 1%, respectively. Between 2010 and 2020, uptake of covered anaerobic ponds resulted in an annual rate of improvement in emissions (excl. land use and dLUC) of 2.9%, however, the rate of improvement fell to 1.4% between 2020 and 2022. Conclusions Long-term improvements were principally driven by improved herd productivity and feed production systems, and changes in housing and manure management. Herd and system efficiencies led to better feed conversion ratio, resulting in lower feed requirements, reduced manure production and lower feed wastage, which reduced manure greenhouse gas emissions. Concurrently, reduced tillage, higher yields, and a decrease in the proportion of irrigation water used for grain production resulted in lower impacts of feed grains. Implications Ongoing changes and improvements in production efficiency have resulted in large gains in environmental performance in the Australian pork industry but new strategies will also be needed to maintain these trends into the future.