This indicator tracks trends since 2005 in anthropogenic emissions of the five main air pollutants — NOX, NH3, SOX, NMVOCs and PM2.5. All of these pollutants, directly or indirectly, have negative effects on human health, vegetation or ecosystems.
Methodology for indicator calculation
This indicator is based on national total emissions officially reported to the EEA and the UNECE ‘Co-operative programme for monitoring and evaluation of the long-range transmissions of air pollutants in Europe’ (EMEP) LRTAP Convention. For the 27 EU Member States, the data used are consistent with the emission data reported by the EU in its annual submission to the LRTAP Convention .
Recommended methodologies for emission inventory estimation are compiled in the EMEP/EEA air pollutant emission inventory guidebook. Base data are available from the EEA Data Serviceand the EMEP website. Where necessary, gaps in reported data are filled by the European Topic Centre on Air and Climate Change using simple interpolation techniques (see below). The final gap-filled data used in this indicator are available from the EEA’s LRTAP data viewer.
Methodology for gap filling
An improved gap-filling methodology was implemented in 2010 that enables a complete time series trend for the main air pollutants (e.g. NOX, SOX, NMVOCs, NH3and PM2.5 to be compiled. In cases in which countries did not report emissions for any year, gap filling could not be performed. For these pollutants, therefore, the aggregated data are not yet complete and are likely to underestimate true emissions. Further methodological details of the gap-filling procedure are provided in the European Union emission inventory report 1990-2018 under the UNECE Convention on Long-range Transboundary Air Pollution (LRTAP).
Anthropogenic emissions of these air pollutants contribute to air quality problems in Europe. The consequences are adverse health effects caused particularly by PM, and NO2. PM can be emitted directly into the air (primary PM) or it can be formed in the atmosphere (secondary PM) from airborne precursor substances (NOX, NH3, SOX). Ground-level ozone (O3) is created from precursor substances (NO2, NMVOCs, CH4 and CO) in the atmosphere via photo-chemical reactions and contributes to the formation of secondary PM. Ground-level ozone has negative effects not only on human health, but also on crops and natural ecosystems. In addition, excess deposition of sulphur and nitrogen compounds also lead to disturbances in the functioning and structure of ecosystems, i.e. by causing acidification of soils and waters, and, in the case of nitrogen, eutrophication in nutrient-poor ecosystems such as grasslands.
More detailed summaries of the effects of air pollution on human health and ecosystems are included in the EEA’s indicators ‘Exceedance of air quality limit values in Europe’ and ‘Exposure of ecosystems to ozone’.
This indicator supports the assessment of progress towards meeting the national emission ceilings under Directive 2016/2284/EU and the Gothenburg Protocol under the 1979 LRTAP Convention. The 1999 Gothenburg Protocol was amended in 2012.
Environment action programmes (EAP) have led the development of EU environment policy since the early 1970s. A new strategy, the clean air programme for Europe, was proposed by the European Commission at the end of 2013. Current EU air pollution policy is underpinned by the objectives and long-term goals of, for example, the Seventh Environment Action Programme (7th EAP), which ran until 2020. To achieve the objectives of the 7th EAP, EU air pollution legislation has followed a twin-track approach, of implementing both emission mitigation controls and air quality standards. In 2020, the Commission adopted a proposal for a decision on a general EU Environment Action Programme to 2030, to continue from the seventh EAP. As part of the European Green Deal, the EU is revising the Ambient Air Quality Directive, to align air quality standards more closely with the recommendations of the World Health Organization.
Internationally, the 1979 UNECE LRTAP Conventionwas the first step towards addressing the impacts of air pollution on health and the environment. A centrepiece of this convention is the 1999 Gothenburg Protocol to Abate Acidification, Eutrophication and Ground-level Ozone, amended in 2012. The amended protocol set emission ceilings (limits) for the year 2010 and national emission reduction commitments for the emission of the main air pollutants, namely SOX, NOX, NH3 and NMVOCs. It also included reduction commitments for PM2.5 emissions for 2020. Under the protocol, the critical loads concept was established as a tool for informing political discussions related to damage to sensitive ecosystems. Critical ozone levels (concentrations) for vegetation were also defined under the LRTAP Convention.
The 1999 Gothenburg Protocol was followed in 2001 by the EU’s NECD, which was repealed by the revised NECD in 2016. The original directive introduced legally binding national emission limits for four main air pollutants: SOX, NOX, NH3and NMVOCs. The directive required that EU Member States had met emission ceilings by 2010 or in the years thereafter, up to the end of 2019, and established emission reduction commitments for 2020-2029 and 2030 onwards for the five main pollutants. The goal of this legislation was to enable the EU to comply with the amended Gothenburg Protocol by 2020, followed by enabling more ambitious emission reductions from 2030 onwards. The human health and environmental objectives defined in the NECD, the Gothenburg Protocol and the EU’s Air Quality Directiveare addressed by other EEA indicators.
The EU directives currently regulating the ambient air concentrations of the main pollutants are designed to avoid, prevent or reduce the harmful effects of air pollutants on human health and the environment by implementing limit or target values for ambient concentrations of air pollutants. They are:
- Directive 2008/50/EC on ambient air quality and cleaner air for Europe, which regulates ambient air concentrations of SO2, NO2 and other nitrogen oxides, coarse particulate matter (PM10) and PM2.5, lead, benzene (C6H6), carbon monoxide (CO) and ozone;
- Directive 2004/107/EC relating to arsenic, cadmium, mercury, nickel and polycyclic aromatic hydrocarbons in ambient air.
In the case of non-compliance with the air quality limit and target values stipulated in EU legislation, air quality management plans must be developed by Member States and implemented in the areas in which exceedances occur. These plans should aim to bring concentrations of air pollutants to levels below the limit and target values. To ensure overall coherence, and consistency between different policies, air quality plans should be consistent (if feasible) and integrated with plans and programmes in line with the directives regulating air pollutant emissions.
Source-specific EU legislation focuses on industrial emissions, road and off-road vehicle emissions, fuel quality standards, etc., by setting emission standards, requiring the use of best-available technology or setting requirements on fuel composition. In addition, several legal instruments are used to reduce environmental impacts from different activities or to promote environmentally friendly behaviour, and these also contribute indirectly to reducing air pollution, as summarised below.
End-of-pipe control in industrial installations:
- Directive 2001/80/EC on the limitation of emissions of certain pollutants into the air from large combustion plants (the LCP Directive): the overall aim of the LCP Directive is to reduce emissions of acidifying pollutants, PM and ozone precursors; it also addresses emissions from large combustion plants, i.e. those with a rated thermal input equal to or greater than 50 MW.
- Directive 2010/75/EU on industrial emissions (integrated pollution prevention and control): this directive targets certain industrial, agricultural and waste treatment installations.
Emission standards for cars:
- The Euro regulations set standards for road vehicle emissions, with the Euro 5 and 6 standards being defined in Regulations (EC) No 692/2008and No 595/2009. The Communication CARS 2020sets out a timetable for implementation of the Euro 6 vehicle standards in real-world driving conditions, and for the revision of the non-road mobile machinery legislation.
Handling and storage:
- Directive 94/63/EC on the control of volatile organic compound (VOC) emissions resulting from the storage of petrol and its distribution from terminals to service stations and Directive 2009/126/EC on Stage II petrol vapour recovery during refuelling of motor vehicles at service stations;
- Directive 1999/13/EC on the limitation of emissions of volatile organic compounds (VOCs) due to the use of organic solvents in certain activities and installations.
Fuel quality:
- Directive 2012/33/EU amending Directive 1999/32/EC as regards the sulphur content of marine fuels, Directive 1999/32/EC on the reduction of the sulphur content of certain liquid fuels and Directive 2003/17/EC (amending Directive 98/70/EC) relating to the quality of petrol and diesel fuels regulate fuel quality.
International shipping:
- The International Convention for the Prevention of Pollution from Ships (Marpol) of the International Maritime Organization (IMO) is the main international convention on preventing ships from polluting as a result of operational or accidental causes. Annex VI sets limits on emissions of SOX, NOX, VOCs and PM in ship exhausts, and prohibits deliberate emissions of ozone-depleting substances.
- For international shipping, tighter shipping fuel standards and emission standards at IMO/Marpol level resulted in the recent revision of the Sulphur Content of Fuel Directive.
In addition to the policy instruments outlined above, there are several EU directives that also contribute indirectly to efforts to minimise air pollution. These directives are intended to reduce environmental impacts, including on climate change, and/or to promote environmentally friendly behaviour. Some examples are outlined below.
Agriculture:
- The Nitrates Directive, i.e. Directive 91/676/EEC concerning the protection of waters against pollution caused by nitrates from agricultural sources, particularly through the implementation of agricultural practices that limit fertiliser application and prevent nitrate losses, aims to reduce agricultural emissions of nitrogen compounds to air.
Energy taxation:
- The Energy Taxation Directive, i.e. Directive 2003/96/EC restructuring the Community framework for the taxation of energy products and electricity, establishes minimum taxes for motor fuels, heating fuels and electricity, depending on the energy content of the product and the amount of CO2 it emits. This directive aims to promote energy efficiency and less-polluting energy products.
Ecodesign:
- The Ecodesign Directive, i.e. Directive 2009/125/EC establishing a framework for the setting of ecodesign requirements for energy-related products, provides consistent EU-wide rules for improving the environmental performance of energy-related products through ecodesign, which should benefit both businesses and consumers by enhancing product quality, achieving energy savings and thereby increasing environmental protection. Energy-related products (the use of which impacts energy consumption) include products that use, generate, transfer or measure energy (electricity, gas and fossil fuel). These include boilers, computers, televisions, transformers, industrial fans and industrial furnaces. Some energy-related products do not use energy, but do have an impact on energy use, and can therefore contribute to related savings, such as windows, insulation material, shower heads and taps.
- The Ecodesign Directive is complemented and supported by the Energy Labelling Directiveand Directive 2006/32/EC on energy end-use efficiency and energy.
Targets
National Emission Ceilings Directive (2001/81/EC; amended by (EU) 2016/2284)
The original NECDset pollutant-specific and legally binding emission ceilings for NOX, NMVOCs, SOX and NH3 for each EU Member State. The directive requires Member States to have met the ceilings and interim environmental objectives by 2010 and in the years thereafter. The directive sets specific environmental objectives that address the impacts of acidification and eutrophication on ecosystems, and the harmful effects of ozone on vegetation and human health.
The NECD was reviewed as part of the clean air policy package (COM/2013). In December 2016, the Council adopted the new directive (Directive (EU) 2016/2284), and reporting under this directive started in February 2017. The new directive repealed and replaced the existing EU regime on the annual capping of national emissions of air pollutants, as defined in Directive 2001/81/EC. By doing so, it ensures that the national emission ceilings set in the original NECD for 2010 onwards for SOX, NOX, NMVOCs and NH3 are applied until 2020, and it establishes new national emission ‘reduction commitments’, which are applicable from 2020 and from 2030, for SOX, NOX, NMVOCs, NH3 and PM2.5. The reduction commitments are binding for the period from 2020 to 2029 and from 2030 onwards. In principle, the commitments are indicative for 2025 by a linear emission reduction trajectory. A non-linear reduction trajectory is permissible if it is economically and technically more efficient, and provided that, from 2025, it progressively converges with the linear reduction trajectory.
UNECE Convention on Long-range Transboundary Air Pollution’s Gothenburg Protocol (1999; amended in 2012)
The amended Gothenburg Protocol sets national ceilings (limits) for the emission of the main air pollutants, namely SOX, NOX, NH3, NMVOCs and PM2.5 . The EU as a whole has ratified the protocol, and reports emissions to the UNECE.
The target under the amended protocol is to ensure that — in the long term and using a stepwise approach that takes into account advances in scientific knowledge — atmospheric depositions or concentrations do not exceed critical loads for the nutrient nitrogen. Critical levels of ozone for the protection of crops and for the protection of forests have also been defined under the LRTAP Convention, and the critical level for crops is consistent with the EU long-term objective for vegetation.
The 2010 targets under the NECD and Gothenburg Protocol are included in the EEA’s NECD data viewer and LRTAP data viewer.
Related policy documents
No related policy documents have been specified.
Methodology uncertainty
The use of a gap-filling methodology for countries that have not reported emissions for 1 or more years can potentially lead to artificial trends, but it is considered unavoidable for obtaining a comprehensive and comparable set of emissions data for European countries for policy analysis purposes.
Data sets uncertainty
NOX emission estimates in Europe are thought to have an uncertainty of about ± 20%, as NOX is emitted from both fuel burnt and the combustion of air, so emissions cannot be estimated accurately from fuel nitrogen alone. However, because of the need for interpolation to account for missing data, the complete data set used will have a higher degree of uncertainty. The overall trend is likely to be more accurate than individual absolute annual values — the annual values are not independent of each other.
Overall scoring — 1-3; 1 = no major problems, 3 = major reservations:
- relevancy: 1
- accuracy: 2
- comparability over time: 2
- comparability over space: 2.
SOX emission estimates in Europe are thought to have an uncertainty of about ± 10%, as the sulphur comes from only the fuel burnt; therefore, emissions of SOXcan be more accurately estimated than emissions of NOX. However, because of the need for interpolation to account for missing data, the complete data set used will have a higher degree of uncertainty. The EMEP has compared modelled and measured concentrations throughout Europe. From these studies, differences in the annual averages have been estimated to be ± 30%, which is consistent with an inventory uncertainty of ± 10% (there are also uncertainties in the measurements and especially in the modelling). The trend is likely to be much more accurate than individual absolute values.
Overall scoring — 1-3; 1 = no major problems, 3 = major reservations:
- relevancy: 1
- accuracy: 2
- comparability over time: 2
- comparability over space: 2.
NH3 emission estimates in Europe are more uncertain than those for NOX, SOX and NMVOCs, largely because of the diverse nature of major agricultural sources. It is estimated that they have an uncertainty of around ± 30%. The overall trend is likely to be more accurate than the individual absolute annual values — the annual values are not independent of each other.
Overall scoring — 1-3; 1 = no major problems, 3 = major reservations:
- relevancy: 1
- accuracy: 2
- comparability over time: 2
- comparability over space: 2.
Rationale uncertainty
This indicator is regularly updated by the EEA and is used in state of the environment assessments. The uncertainties related to methodology and data sets are therefore important.
