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Transport emissions of air pollutants

Indicator Assessmentexpired Created 23 Nov 2012 Published 04 Feb 2013 Last modified 11 Sep 2015, 12:46 PM
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This content has been archived on 12 Dec 2014, reason: Other (New version data-and-maps/indicators/transport-emissions-of-air-pollutants-8/transport-emissions-of-air-pollutants-2 was published)
Indicator codes: TERM 003

Key messages

Between 2009 and 2010, all air pollutant emissions from transport, except NOx, decreased (ranging between 2.5 % and 10 %). During the period 1990 to 2010, the main pollutants that contribute to acidification and particulate and ozone formation have shown a decreasing trend in emissions in the EEA‑32 (with fluctuations in some years). The largest percentage decreases over this period have been for CO (76 %) and non-methane volatile organic compound (NMVOC) (75 %). However, increases in shipping activity since 1990 have offset some of the reductions elsewhere, in particular for SOx, but also for NOx and PM. International shipping currently contributes to nearly 87 % of all transport SOx emissions. The rise of road freight transport explaines most of the increase in NOx in 2010.

Are emissions of acidifying substances, particulates and ozone precursors from transport decreasing?

Trend in emissions of air pollutants from transport in EEA-32

Note: Transport emissions of PM2.5, CO, SOx, NMVOC, NOx in EEA member countries.

Data source:
Downloads and more info

The contribution of the transport sector to total emissions of the main air pollutants in 2009 (EEA-32)

Note: The graphs report the percentage contribution of transport and not transport sector to total emission of air pollutants in EEA32. Transport sector includes road transport, shipping, aviation and railways.

Data source:
Downloads and more info

Transport is one of the main sources of air pollution in Europe, particularly in cities and urban areas such as towns, airports and sea ports. Key air pollutants emitted from combustion engines in all modes of transport include NOx, PM, CO, and VOCs. However, non-exhaust emissions of PM are also released due to the mechanical wear of brakes, tyres and road surfaces, and are not currently regulated. Emissions of VOCs also come from gasoline evaporation during refuelling and from vehicle and fuel storage tanks.

The Figure shows the trend in emissions of most pollutants from transport in EEA‑32 member countries since 1990. Emissions of different pollutants have been falling but at different rates. The decline has occurred in spite of a growth in transport activities reflected by various indicators such as energy consumption and passenger and freight transport volumes since 1990. The downward trend for most pollutants has followed the progressive introduction of tighter Euro emission standards on new road vehicles supplemented by improvements in fuel quality driven by EU Fuel Quality Directives. Tighter regulations in emissions from new diesel engines for railway locomotives and the sulphur content of marine fuels have also contributed to this downward trend in emissions in more recent years. The trends in emissions of key pollutants NOx and PM2.5 have been tempered by the increased market penetration of diesel vehicles since 1990. Diesel vehicles generally emit more of these pollutants per kilometre than their gasoline equivalents, particularly black carbon which has impacts on health and the climate but also NO2.

Indicator specification and metadata

Indicator definition

The indicator is based on the emission trend assessment of CO, NOx, NMVOCs, SOx and primary particulates. 


Emissions are expressed as percentage over the 1990 levels.

Policy context and targets

Context description

Directive 2008/50/EC (EC, 2008) sets LVs for the atmospheric concentrations of main pollutants, including sulphur dioxide (SO2), nitrogen dioxide (NO2), airborne particulate matter (PM10, PM2.5), lead, carbon monoxide (CO), benzene, and ozone (O3) for EU Member States. These limits are related to transport implicitly, but the introduction of progressively stricter Euro emission standards and fuel quality standards has led to substantial reductions in air pollutant emissions. Policies aimed at reducing fuel consumption in the transport sector to cut greenhouse gas emissions may also help further reduce air pollutant emissions.
Iceland, Liechtenstein, Norway, Switzerland and Turkey are not members of the European Union and hence have no emission ceilings set under the National Emission Ceilings Directive (NECD) 2001/81/EC. As well as most of the EU Member States, Norway and Switzerland have ratified the 1999 United Nations Economic Commission for Europe Convention on Long-range Transboundary Air Pollution (UNECE Trend in emissions of air pollutants from transport in EEA-33 LRTAP) Gothenburg Protocol, which required them to reduce their emissions to the agreed ceiling specified in the protocol by 2010. Liechtenstein has also signed, but has not ratified the protocol.


Both the NECD and Gothenburg protocol set reductions targets for sulphur dioxide, nitrogen oxides and non-methane volatile organic compounds and ammonia for the 33 EEA member countries. There are substantial differences in emission ceilings, and hence emission reduction percentages for different countries, due to the different sensitivities of the affected ecosystems and technical feasibility for reductions.

Related policy documents

  • 1999 Protocol to Abate Acidification, Eutrophication and Ground-level Ozone
    Convention on Long-range Transboundary Air Pollution 1999 Protocol to Abate Acidification, Eutrophication and Ground-level Ozone, amended on 4 May 2012.
  • Council Directive 96/61/EC (IPPC)
    Council Directive 96/61/EC of 24 September 1996 concerning Integrated Pollution Prevention and Control (IPPC). Official Journal L 257.
  • Directive 98/70/EC, quality of petrol and diesel fuels
    Directive 98/70/EC of the European Parliament and of the Council of 13 October 1998 relating to the quality of petrol and diesel fuels and amending Directive 93/12/EEC
  • Directive 2001/80/EC, large combustion plants
    Directive 2001/80/EC of the European Parliament and of the Council of 23 October 2001 on the limitation of emissions of certain pollutants into the air from large combustion plants
  • Directive 2001/81/EC, national emission ceilings
    Directive 2001/81/EC, on nation al emissions ceilings (NECD) for certain atmospheric pollutants. Emission reduction targets for the new EU10 Member States have been specified in the Treaty of Accession to the European Union 2003  [The Treaty of Accession 2003 of the Czech Republic, Estonia, Cyprus, Latvia, Lithuania, Hungary, Malta, Poland, Slovenia and Slovakia. AA2003/ACT/Annex II/en 2072] in order that they can comply with the NECD.


Methodology for indicator calculation

For air pollutants officially reported data to EMEP/LRTAP has been used. Please refer to indicators CSI002 and CSI003

Methodology for gap filling

Where a complete time series of emissions data has not been reported, data has been gap-filled according to EEA ETC/ACC methodologies. Details of the gap-filling procedure for the air pollutant data set are described in the European Union emission inventory report 1990–2008 under the UNECE Convention on Long-range Transboundary Air Pollution (LRTAP) (EEA Technical Report No 7/2010).

Methodology references

No methodology references available.


Methodology uncertainty

Interpolation/extrapolation procedures are used for gap-filling of the underlying emissions dataset.

Data sets uncertainty

A quantification of uncertainty in the European Union LRTAP emission inventory requires the provision of detailed underpinning information on emission uncertainties from Member States.

Rationale uncertainty

No uncertainty has been specified

Data sources

Generic metadata


Transport Transport (Primary topic)

Air pollution Air pollution

air pollutant emissions | ghg emissions | transport indicators | transport | air pollution
DPSIR: Pressure
Typology: Descriptive indicator (Type A - What is happening to the environment and to humans?)
Indicator codes
  • TERM 003
Temporal coverage:
Geographic coverage:
Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, United Kingdom

Contacts and ownership

EEA Contact Info

Cinzia Pastorello


EEA Management Plan

2012 2.9.2 (note: EEA internal system)


Frequency of updates

Updates are scheduled once per year
European Environment Agency (EEA)
Kongens Nytorv 6
1050 Copenhagen K
Phone: +45 3336 7100