Emission trends of ammonia NH3
Assessment made on 01 Dec 2005
ClassificationAir pollution (Primary theme)
- APE 3a
Policy issue: Are we reaching emission targets for acidifying and eutrophicating substances?
- EEA-32 emissions have declined by 20% between the years 1990 and 2005. Agriculture was responsible for 93% of NH3 emissions in 2005.
- The reduction in emissions within the agricultural sector is primarily due to a reduction in livestock numbers (especially cattle) since 1990, changes in the handling and management of organic manures and from the decreased use of nitrogenous fertilisers. The reductions achieved in the agricultural sector have been marginally offset by the increased emissions which have occurred during this period in sectors such as transport and to a lesser extent the energy industry and other (non-energy) sectors.
- In general, Member States have made excellent progress in reducing emissions below the level of their respective emission ceilings set in the National Emission Ceilings Directive (NECD). Twenty of the EU-27 Member States have already achieved their ceilings. Only Denmark, Finland and Spain still need to make significant further reductions in order to meet their respective ceilings under the NECD.
- Environmental context: NH3 contributes to acid deposition and eutrophication. The subsequent impacts of acid deposition can be significant, including adverse effects on aquatic ecosystems in rivers and lakes and damage to forests, crops and other vegetation. Eutrophication can lead to severe reductions in water quality with subsequent impacts including decreased biodiversity, changes in species composition and dominance, and toxicity effects. NH3 also contributes to the formation of secondary particulate aerosols, an important air pollutant due to its adverse impacts on human health.
EEA-32 ammonia emissions have decreased by 20% between 1990 and 2005. The agricultural sector remains the major source of ammonia emissions (93% of total 2005 emissions).
These emissions derive mainly from the decomposition of urea in animal wastes and uric acid in poultry wastes. Emissions depend on the animal species, age, weight, diet, housing systems, waste management and storage techniques. The majority of the reduction in emissions is due to the combination of reduced livestock numbers across Europe (especially cattle), and the lower use of nitrogenous fertilisers. Emissions from road transport, although relatively small have been rising as a result of the increasing use of three-way catalytic converters in the vehicle fleet (this is due to an unwanted reaction involving hydrogen which reduces NO to NH3.
However, emissions are projected to fall in the future as the second generation of catalysts (which emit lower levels of NH3 than the first generation catalysts) penetrate the vehicle fleet.
NH3 emissions have also declined in countries outside the European Union (EFTA-4 and CC-3) between 1990 and 2005. Again this is primarily due to reductions which have occurred in the agricultural sector as a result of decreasing animal numbers.
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Emission trends of ammonia NH3