NEXUS project: pathways for greenhouse gas mitigation and climate change adaptation of Australian livestock industries

Australian sheep and beef production systems face the dual challenges of reducing net greenhouse gas emissions and adapting to a warmer climate with changing rainfall patterns. The ‘Nexus project’ is exploring pathways for livestock production systems to meet these challenges using farm systems modelling approaches. The objective of this component of the project was to estimate the GHG emissions intensity (GHG EI) from sheep and beef farms. Seven case study farms in eastern Australia were investigated across a diverse range of agroecological zones from the high rainfall, cool-temperate climate in Tasmania through to the arid, tropical region of northern Queensland. The production systems were one sheep-only farm (Midlands, Tasmania), three beef-only farms (north-west Tasmania, central Queensland and northern Queensland) and three mixed sheep and beef farms (Gippsland Victoria, northern Victoria and central New South Wales). Data on current farm management and production was collected through interviews with farm managers and used to estimate GHG EI using the Australian National Greenhouse Gas Inventory Report methodology. For sheep production, emissions were partitioned between meat and wool using the protein allocation method. Results were expressed as tonnes carbon dioxide equivalents (CO2e) per tonne of production sold (liveweight for beef and sheep meat, and greasy wool). GHG EI of beef production ranged from 9.8-15 t CO2e/t liveweight sold, with the lowest value on the farm in north-west Tasmania and the highest value in the central Queensland. For sheep production, the GHG EI of meat production ranged from 5.3-8.7 t CO2e/t liveweight sold and wool production from 19.7-31.0 t CO2e/t greasy wool sold. In general sheep and beef production GHG EI’s were lower where the reproduction rates were higher. Further research will investigate options to reduce both total GHG and GHG EI using combinations of mitigation and sequestration opportunities on-farm.