Climate change mitigation is becoming increasingly urgent as climate impacts are appearing earlier and are more severe than expected. The world faces multiple unavoidable climate hazards over the next two decades with global warming of 1.5ºC and accelerated action is required to avoid mortality and loss of biodiversity and infrastructure.
The Western Australian State Government has set a goal of becoming carbon neutral by 2050 and WA is taking action in reducing Green House Gas (GHG) emissions, both at an industry and government level. Reducing our emissions and contributing to the critical goals of the Paris Agreement will safeguard Western Australia’s environment, community, and long-term prosperity.
The State Government is developing sectoral emissions reduction strategies in consultation with business, industry research institutions and the community to transition our economy to net zero emissions.
The document Shaping Western Australia’s low-carbon future sets out the high-level process, objectives and timeline for delivering SERS.
Emissions reduction in the agricultural sector
DPIRD is one of the lead agencies contributing to the SERS by leading the development of emissions reduction solutions for the agriculture sector (AgSERS) through close engagement with key industry and stakeholder groups.
DPIRD has consulted with stakeholders across agriculture sub sectors, including livestock, grains, horticulture, rangelands and intensive industries from early 2022. Working directly with industry to undertake detailed analysis and scenario modelling, DPIRD is developing practical and effective abatement options, including shared transition pathways.
Four key reports will form the basis of the SERS for Agriculture:
- 2020 Emissions Baseline Report for the Agriculture Sector in Western Australia, June 2022 - available
- Greenhouse Gas Emissions Reduction Options for Western Australian Agriculture - Consultation and Feedback document to inform the Sectoral Emission Reduction Strategies - available Mid February 2023
- 2023 Emissions Projection Modelling report - available in March 2023
- 2023 Report on agriculture for the Sectoral Emission Reduction Strategies - available in October 2023
2020 Emissions Baseline Report for the Agriculture Sector in Western Australia, June 2022
In order to track changes in emissions, a baseline is required to serve as a reference point. It also plays an important part in designing mitigation pathways. The 2020 Emissions Baseline Report for the Agriculture Sector in Western Australia provides that baseline for the agriculture sector and estimates of each industry within the sector. The full report is available for download in the side bar.
Emissions can be calculated several ways. The state and national inventories are based on a set of rules outlined by the Intergovernmental Panel on Climate Change (IPCC) and it is how we report Australia’s emissions to the world on a country basis.
The report is broken into two parts:
1. Emissions from the national greenhouse gas inventory (NGHGI) method
2. Industry level analyses (life cycle analyses and farm carbon accounts)
to generate a baseline of GHG emissions for the WA agriculture sector and for each industry represented within the sector. Detailed analysis and scenario modelling to develop practical and effective abatement options, including shared transition pathways was undertaken in writing the report.
The NGHGI method estimates state and national GHG emissions using a set of rules outlined by the IPCC. These NGHGI emissions are used to report our emissions to the world and compare global emissions on a country-by-country basis. NGHGI reports gather emissions data from five sectors across the economy:
- Industrial Processes
- Land Use, Land Use Change; Forestry (LULUCF)
Collectively, the emissions from these sectors make up Australia’s state and national emissions reported through the NGHGI.
Life cycle analysis (LCA) and carbon accounts are used to gather more detailed information about the sources and intensity of emissions along agricultural supply chains. These methods are used to drill down to a farm, enterprise or product level to generate emissions profiles for agricultural businesses and their inputs and products. This more detailed emissions information can be used to guide production efficiencies and carbon mitigation strategies along supply chains.
Establishing a baseline of agricultural emissions is needed to monitor changes in industry emissions over time. The emissions baseline will also play an important role in designing mitigation pathways.
Western Australian emissions
WA is the only Australian state where overall emissions are increasing, with the increase driven mainly by rapid expansion of the energy sector. When carbon sequestration from the LULUCF sector is excluded, the energy sector is responsible for 83% of total emissions and agriculture for 10%.
WA Agricultural sector emissions
Emissions from the WA agriculture sector have been largely stable since 2012 at just under 10,000Gg CO2e. This stable period was preceded by a period of significant decline (24%) in emissions (from about 11,500Gg in 2004 to 8,750Gg in 2011), which resulted mainly from a 43% decline in the WA sheep flock over the same period.
WA Agriculture sector emissions are dominated by emissions from the extensive livestock industry with sheep, cattle and associated pasture emissions accounting for just over 80% of total emissions in 2020 (Figure 3).
Broadacre cropping accounts for the next largest proportion of total Agriculture sector emissions (about 15%) followed by intensive livestock industries (pigs and poultry) at about 3% and horticulture at about 0.4%.
In 2020, WA agricultural emissions were reported in the NGHGI as 9758.56Gg CO2e (Figure 4) with this total comprising:
- 57% from enteric fermentation
- 23% from agricultural soils
- 9% from manure management
- 7% from liming
- 4% from urea application
- 0.4% from field burning of agricultural residues
Methane (CH4) production via enteric fermentation is the dominant contributor to WA agricultural emissions, generating about 57% of total emissions in 2020. Nitrous oxide (N2O) production from nitrogen mineralisation and nitrification processes in agricultural soils is the second largest contributor to WA agricultural emissions – generating about 23% of total GHG emissions in 2020 (Figure 1b and Figure 4).
Total emissions from the WA Agriculture sector have dropped by 15% since 2005 (Figure 3 and Table 1) with most of this due to a 30% reduction in enteric methane emissions from the livestock industry. However, over the same period, emissions from lime and urea application have increased by about 60% (Table 1).
WA’s agricultural industries differ in the amount and type of greenhouse gas emissions they produce (Table 2). The sheep and cattle industries produce predominantly methane through enteric fermentation, with a smaller amount produced via manure breakdown. By contrast, emissions from the intensive livestock industries (pigs and poultry) consist predominantly of methane generated through manure breakdown. Grain industry emissions are driven by nitrous oxide (N2O) production from the microbial breakdown of organic matter and fertilisers in the soil. Horticultural emissions are dominated by CO2 production from the application of lime and urea (Table 2).
Relationship between Agriculture and LULUCF sectors
The Land Use, Land-Use Change & Forestry sector (LULUCF) of the NGHGI is used to calculate changes in carbon stocks and net emissions from WA land. The LULUCF sector represents a significant sink for WA emissions. Since 2011, grassland, cropland and forestland have been net GHG sinks for WA (Figure 5) and in 2020 they represented -14,120.90 Gg CO2e (about 35% of Australia’s carbon sink) (Figure 5).
In 2020 the ‘forest land’ LULUCF category made up most of the carbon sink in WA with -10,255 Gg CO2-e stored in carbon stock in existing forests and increases in area of plantations and regenerated bushland (often on land managed by agricultural businesses – see Table 3).
The 'cropland remaining cropland’ and ‘grassland remaining grassland’ categories were also significant carbon sinks (Figure 5 & Table 3). These categories are mainly based on land managed for agriculture (excluding rangelands under crown control) and capture changes in soil carbon and carbon stored in plants brought about through management practices of agricultural producers (Table 3).
When the 2020 emissions from the WA Agriculture sector are balanced against the 2020 carbon sequestration that occurred on agricultural land (as part of the LULUCF sector), a net positive balance of 225 Gg CO2-e is calculated for emissions from the Agriculture sector (Table 3). This means that nearly all (97.5%) emissions from agricultural activities in WA in 2020 were balanced by carbon sequestration activities occurring on land managed primarily for agricultural enterprises.
The emissions profiles generated by agricultural products and industries are driven largely by the intensity of the production system (Table 4).
Life cycle analysis (LCA) and carbon accounts provide valuable insight into the emissions profiles associated with producing meat, wool, grain, fruit and vegetables along the entire supply chain or up to the farmgate. Both methods estimate the emission intensity of a product and capture emissions across NGHGI sectors with relevance to the Agriculture sector (e.g., Energy, Industrial Processes, LULUCF).
LCA and farm account reports include emissions associated with the manufacture and transport of agricultural inputs such as electricity, fuel, fertilisers, pesticides and herbicides. Because of this, they provide a more complete picture of the emissions generated to produce agricultural products and can be used to indicate the environmental impact of a particular commodity or product. Farm carbon accounts provide the total emissions from a business at a point in time, and can be used to monitor movement of the business towards carbon neutrality.
While it is difficult to get definitive measures of emission intensity for WA products (due to variable production environments and scales of production), publicly available LCAs and carbon accounts enable an estimate of likely emissions per product (Table 5).
WA emissions reduction goals
Some sectors will be more easily able to reduce emissions in the short term while others may be constrained by technical limitations, existing infrastructure or stock turnover. Not all sectors will be required to decarbonise at the same pace, however the WA State Government goal of becoming carbon neutral by 2050 will require all sectors to reduce emissions.