Australia's livestock industry produces approximately 10 per cent of Australia's total greenhouse gas emissions.
Most of these emissions are in the form of methane, a greenhouse gas produced by the natural digestion process of cattle and sheep. Methane is approximately 25 times more potent than carbon dioxide as a thermal warming gas.
Cattle and sheep production also produces indirect emissions, with sources including:
- Application of nitrogen fertilisers to pastures and to grow grain
- Nitrous oxide from manure in feedlots
- Upstream inputs such as chemicals and diesel
- Clearing of trees to promote grass growth
- Loss of soil carbon if pastures are overgrazed
- Savannah burning conducted to manage woody weeds and promote pasture quality also generates emissions
The Australian beef and lamb industry recognises the impact of the sector on Australia’s total emissions profile and in partnership with the Australian federal government has invested significantly over the past 6 years to understand:
- How much methane is produced by cattle and sheep
- If some animals produce less methane and if we can breed for lower methane producing animals
- What forages and feed additives can reduce methane production
- The relationship between methane emission and animal productivity
- How to convert manure at feedlots and processors into energy
Science in this area is still relatively new, but progress is being made and Australia is leading the world in developments.
Research is being undertaken to reduce emissions at each stage of the beef and lamb supply chain.
- On-farm the cattle and sheep industry and the Australian Government are investing in the National Livestock Methane Program (NLMP), made up of 16 distinct research projects to find ways to reduce methane emissions from cattle and sheep.
- At feedlots research is focussed on improving productivity through high quality feed to reduce emissions. Feedlots are also investigating the potential of re-using methane as a renewable energy source, and recycling manure to reduce emissions and create a resource from a waste product.
- At processors beef and lamb processing plants generate large quantities of wastewater that is rich in organic compounds and produces methane that if not captured, is released into the atmosphere. Research into new wastewater treatment systems, better handling of waste as well as using captured methane as a source of renewable energy help reduce greenhouse gas emissions from meat processing.
Peer-reviewed research, published in Agricultural Systems, has quantified the environmental impacts of Australian beef production, using Life Cycle Assessment. The research identifed that the Australian beef industry has reduced emission intensity (per kg of liveweight) by 14% since 1981, and that emissions due to land use change have fallen by 42% - you can read more about that here.
Key developments that have reduced the environmental impact and improved the productivity of Australian beef farmers include:
- improved genetic selection of animals
- heavier finishing weights
- increased survival rates
- an increase in lot feeding since the early 1990s
Some of the most notable results include:
- 14% reduction in Green House Gas (GHG) emissions intensity, from 15.3 to 13.1 kg CO2-e / kg Live Weight
- 42% reduction in emissions associated with land use change, mainly due to vegetation protection and tree planting.
Research released in 2011 by the CSIRO found also the amount of methane emitted from cattle fed on tropical grasses in northern Australia is up to 30 per cent less than the figures currently used to calculate the northern cattle industry's contribution to Australia's greenhouse gas accounts. If this research is endorsed by the National Greenhouse Gas Inventory it will mean a reduction in emissions across the whole industry. The National Greenhouse Gas Inventory does not currently fully account for the capacity of trees, grass and soil to store carbon as part of the carbon cycle. If it did the industry’s overall contribution would be reduced.