General notes: Ammonia (NH3) emissions are strongly related with animal farms and are associated, as a driving force, with acidification and eutrophication. Agriculture is the main source of ammonia emissions, with shares ranging on average between 80% and 99%. Ammonia with sulphur dioxide (SO2) and nitrogen oxides (NOx) contribute to acidification of soil and water when it combines with water in the atmosphere or after deposition. Deposition of ammonia can also raise nitrogen levels in soil and water, which may contribute to eutrophication in receiving aquatic ecosystems. Deposited ammonia can also contribute to the emissions of nitrous oxide, which is a GHG. Ammonia in the atmosphere can also combine with industrial and transport pollution generating secondary particulate pollution. Indicator: Ammonia (NH3) emissions from agriculture as a % of total NH3 emissions. Methodology: Share Ammonia from agriculture/total Ammonia emissions (%): (Total Ammonia emissions from agriculture)/(Total Ammonia emissions) * 100. Data sources: Total Ammonia emissions from agriculture (Gg) from European Monitoring and Evaluation Programme (EMEP). Total Ammonia emissions (Gg) from European Monitoring and Evaluation Programme (EMEP). Link: European Monitoring and Evaluation Programme (EMEP). The indicator in EUROSTAT and OECD frameworks: Eurostat: AEI n.18, OECD: AEI n.2. Definition in the original frameworks: EUROSTAT: Main indicator:: Ammonia emissions from agriculture (ktonnes/yr); Supporting indicator: Share of agriculture in total ammonia emissions. OECD: Share of agricultural ammonia emissions in national total ammonia (NH3) emissions. Data used in the original frameworks: EU: Data provided annually for the NECD (National Emissions Ceiling Directive). OECD: UNECE/EMEP. References: EUROSTAT: IRENA indicator factsheet; DireDate Task 1 Report.