Emissions from agriculture comprise a third of Irish greenhouse gas (GHG) emitted, and a new report from Teagasc projects that they could increase by 9 per cent over 2005 levels by 2030 if mitigation measures are not applied. The report, An/ Analysis of Abatement Potential of Greenhouse Gas Emissions in Irish Agriculture 2021-2030, also identifies 28 abatement measures that could be used to reduce these emissions.
Ireland has made a commitment to the European Union to reduce overall GHG emissions by 20 per cent by 2020, and by 30 per cent by 2030, relative to the 2005 level and faces the prospect of substantial fines if these targets are not met.
Agricultural GHG emissions principally comprise methane, from enteric fermentation and manure management, and nitrous oxide (N2O) from fertiliser and animal excreta deposition on soils. Grasslands and forests soak up carbon dioxide (CO2) from the atmosphere, offsetting some of these emissions.
The report finds that without action to address agricultural emissions the baseline level of GHG emissions in CO2 equivalent terms could reach almost 20.5 million tonnes per annum by 2030.
The report also highlights the potential for GHG abatement based on current scientific knowledge to limit the emissions from the sector. The 28 measures identified would either reduce emissions of methane and N2O from agriculture or increase the level of carbon sequestration through additional forestry and bio-energy production.
Efficiency
Farm practices that improve efficiency and thereby reduce methane and N2O emissions are emphasised. The principal mitigation measures include further improvements in dairy and beef genetics, improved efficiency in the use of nitrogen, altering the fertiliser type applied, increased afforestation, improved sequestration in agricultural soil and enhanced production of biomass and biogas.
These measures were analysed under four headings: agricultural emissions, land use, land use change and energy. This reflects Teagasc’s four-point approach to reducing GHG emissions: to stabilise methane emissions through increased efficiency; to decouple N2O emissions from production via nitrogen use efficiency and the use of low-emission fertilisers and spreading techniques; to absorb CO2 via carbon sequestration in forests and soil while also reducing CO2 emissions from organic soil hotspots; and fossil fuel displacement to offset fossil fuel emissions either by energy-saving measures or substitution with bioenergy.
The total abatement potential arising from cost-beneficial, cost-neutral and cost-positive mitigation measures for agricultural emissions (methane and N2O) was 1.85 million tonnes of CO2 equivalents (CO2-e) per annum between 2021 and 2030, compared with the baseline scenario. The maximum projected annual abatement in 2030 is 3.07 million tonnes of CO2-e.
In land use mitigation, the enhancement of CO2 removals could potentially remove another 2.97 million tonnes of CO2-e annually on average from 2021 until 2030. The maximum projected removal in 2030 is 3.89 million tonnes of CO2-e. However, under current arrangements sequestration would be capped at 2.68 million tonnes annually.
Emissions inventory
The cultivation of biofuel and bioenergy crops, along with the adoption of anaerobic digestion and biomethane and on-farm energy saving, has the potential to account for a further reduction of 1.37 million tonnes of CO2-e per annum from 2021 until 2030, mainly associated with the displacement of fossil fuel usage. The maximum projected annual abatement in 2030 is 2.03 million tonnes of CO2-e. However, in the national emissions inventory these reductions would largely be attributed to the fuel-consuming sectors such as transport and power generation.
Over the period to 2030 the CO2-e mitigation identified in the report could average 6.19 million tonnes annually. This comprises 1.85 million tonnes from agriculture, 2.97 million tonnes from land-use change and 1.37 million tonnes from energy-saving and fossil fuel displacement. Most of the measures analysed could be delivered at a cost of less than €50 per tonne of CO2-e.
"With agricultural production likely to increase further, the sector faces significant challenges in meeting its emissions obligations. Teagasc has now provided a menu of cost-effective mitigation options for reducing agricultural emissions that will go a long way towards overcoming these challenges," said Teagasc director Prof Gerry Boyle.
“Our report highlights, in particular, the need for enhanced knowledge transfer, as the rate at which mitigation measures are adopted by Irish farmers is of critical importance if the maximum amount of mitigation is to be achieved. Furthermore, this study provides a useful framework for the complex discussions surrounding agricultural GHG mitigation that we can expect over the next few years.”