Regionalised greenhouse gas emissions from food production in South-Eastern Australia

Agriculture is a significant source of greenhouse gases (GHG). Agriculture GHG emissions are often quantified at national or state level, with local-scale emissions not available to inform the state's regional policies and local government and community action to mitigate climate change. We present spatial inventories of GHG from food production for the state of New South Wales in Australia for methane (CH4), nitrous oxide (N2O) and the sum of the two GHG in carbon dioxide equivalent (CO2-e). We used a top-down approach to disaggregate emissions from state level reported in the State and Territory Greenhouse Gas Inventories to emissions at local government area level using publicly available agricultural census data. Our estimates showed that regional local government areas accounted for 18,522,010 t of CO2−e, 572,707 t of CH4 and 10,785 t of N2O emissions for food production, while metropolitan local government areas (Greater Sydney) accounted for 104,057 t of CO2−e, 2313 t of CH4 and 151 t of N2O emissions for food production. Livestock emissions dominated most regional local government areas, contributing on average (median) 14 times more emission than cropping emissions. Our study applies an approach for a transparent estimate of local-scale emissions consistent with the Australian National Inventory Reporting. To supplement the food production emissions inventory, a spatial food consumption-based inventory using emission factors derived by Hendrie et al. (2016) is presented to illustrate the importance of engaging cities when addressing GHG emissions from food systems. Sources and spatial trends in food production-based and consumption-based emissions in New South Wales are addressed to guide policymakers and communities on opportunities to mitigate associated emissions to address climate goals.