Cost-effective strategies for the abatement of ammonia emissions from European agriculture

Anthropogenic emissions of ammonia, primarily from agriculture, have been recognised as a significant contributor to overall nitrogen deposition in Europe and are being incorporated within the development of a new international protocol on total nitrogen emissions aimed at protecting natural ecosystems from acidification and eutrophication. In response, the MARACCAS model has been developed to assess the cost-effectiveness of potential abatement measures, mainly relating to the management of livestock wastes, and to assist in the design of efficient abatement strategies. Results indicate that although maximum feasible reductions in emissions are fairly limited, most of the possible abatement can be achieved at relatively low cost. By analysis of the measures which consistently produce cost-effective emissions reductions, a set of guideline measures has been identified which could provide significant reductions at costs competitive with those for NOx abatement measures. Greater inherent uncertainties in the estimation of ammonia emissions and abatement potential as compared to NOx, and practical obstacles to ensuring compliance suggest that a more flexible ‘soft’ protocol may be more appropriate in tackling ammonia.