Assessment of measures for ammonia mitigation in Irish agriculture using marginal abatement cost curve analysis

Agriculture accounts for over 99% of ammonia emissions in Ireland. Furthermore, the country has not met its emissions reduction commitments agreed upon with the European Union (EU) for several years. This research explores the cost-effectiveness of a suite of ammonia mitigation measures relevant to animal-based agriculture that pre-dominate across Ireland, modelled under three economic activity scenarios (i.e., business as usual scenario, lower activity and higher activity levels) and three technology adoption rates (i.e., lower, moderate and higher) over the 2022 to 2033 period. Findings show the significant influence of assumptions about future agricultural activity and adoption rates on emissions projections, emphasising the importance of considering these uncertainties when assessing the ability to achieve ammonia emission reduction commitments. From the 13 mitigation measures examined for bovine, pig and poultry farms, the potential ammonia mitigation ranged from 0.03 for covered slurry storage tanks to 5.22 kt/yr for low-emission slurry spreading on bovine farms. The use of urea stabilised with a urease inhibitor, clover establishment on intensive dairy farms, liming and reduction of crude protein in bovine and pig diets were found to be cost-negative in all three adoption rates and economic activity scenarios. Finally, moderate and higher technology adoption rates assumed in this study will allow Ireland to abate enough ammonia to comply with the EU emission reduction commitments under the business as usual and lower economic activity scenarios. The higher technology adoption rates assumed in this study are required to achieve the ammonia emission reduction commitment for a higher economic activity scenario.