The Road Map for Agriculture
Teagasc has set out opportunities to reduce GHG emissions in three phases (Figure 1). In Phase I, initial implementation of the technical measures in the current Marginal Abatement Cost Curve (MACC) for Agriculture, 2019 can bring the sector about one third of the way to the 2030 target, almost-ready technologies (Phase II) and early stage technologies (Phase III) are required for the remaining two thirds.
While the pathway shown below is linear, it is unlikely that this will be the case in reality as, for example, not all of the Phase I measures will be implemented on farm at an early stage, while some of the Phase II and Phase III measures may emerge more quickly or slowly than currently anticipated.
The updated Teagasc GHG MACC, to be published in 2023, will give a more accurate assessment of the scale and timeline of the mitigation options available to Irish agriculture. The National Climate Action Plan 2023 will provide clarity of policy actions that will support the decarbonisation of Irish agriculture, and it will be informed by the reports of the Food Vision Dairy and Food Vision Beef and Sheep Groups.
In addition, the science behind how methane contributes to global warming is constantly evolving. For example, changing the metric for assessing its contribution from the current GWP100 to GWP* would be very significant in the assessment of the impact of methane. GWP100, accounts for methane emissions evenly across a 100 year time-horizon, while GWP* reflects methane existence as a short-lived gas that causes warming for about a 12 year period. This means that using GWP* in a herd with stable methane emissions will show a much lower warming effect coming from livestock. While the concept of GWP* is discussed in the IPCC’s AR6, it is not yet used in the international accounting system for greenhouse gas emissions.