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EEA-32 Sulphur dioxide SO2 emissions

Indicator Specification Created 15 Sep 2009 Published 15 Feb 2010 Last modified 04 Sep 2015, 06:59 PM
Note: new version is available!
Indicator codes: APE 001

Assessment versions

Published (reviewed and quality assured)
  • No published assessments


Justification for indicator selection

Sulphur dioxide (SO2) is emitted when fuels containing sulphur are combusted. Sulphur dioxide is a pollutant which contributes to acid deposition, which in turn can lead to potential changes occurring in soil and water quality. 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. In many cases, the deposition of acidifying substances still exceeds the critical loads of the ecosystems (see EEA indicator CSI 005 'Exposure of ecosystems to acidification, eutrophication and ozone'). Acidification can also damage buildings and cultural monuments. Further details concerning emissions of acidifying pollutants are provided in EEA's Core Set Indicator CSI 001 'Emissions of acidifying substances'.

As a secondary particulate matter precursor, SO2 also contributes to the formation of particulate aerosols in the atmosphere. Particulate matter is an important air pollutant due to its adverse impacts on human health, and SO2 is therefore also indirectly linked to effects on human health (see EEA's Core Set Indicator CSI 003 'Emissions of primary particles and secondary particulate precursors ' for further details concerning emissions of particulate matter.

Scientific references

  • No rationale references available

Indicator definition

  • The indicator tracks trends since 1990 in anthropogenic emissions of Sulphur Dioxide .
  • The indicator also provides information on emissions by sectors: Energy industries; road and other transport; industry (processes and energy); other (energy); fugitive emissions; waste; agriculture and other (non energy).
  • Geographical coverage: EEA-32. The EEA-32 country grouping includes countries of the EU-27 (Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, and the United Kingdom) EFTA-4 (Iceland, Liechtenstein, Switzerland and Norway) and Turkey.
  • Temporal coverage: 1990-2007


ktonnes (1000 tonnes)

Policy context and targets

Context description

A number of policies have been implemented within Europe that either directly or indirectly act to reduce emissions of SO2. These include:

  • The National Emission Ceilings Directive 2001/81/EC (NECD) which entered into force in the European Community in 2001. The NECD sets emission ceilings for four important air pollutants (SO2, nitrogen oxides (NOx), ammonia (NH3) and non-methane volatile organic compounds (NMVOCs)) to be achieved from 2010 onwards for each Member State. The ceilings are designed to improve the protection in the Community of the environment and human health against risks of adverse effects arising from acidification, eutrophication and ground level ozone. The NECD is presently under review, the European Commission may adopt a proposal for a revised Directive during 2010.
  • The Gothenburg Protocol (1999) to the United Nations Economic Commission for Europe's (UNECE) Convention on Long-Range Transboundary Air Pollution (LRTAP Convention) to abate acidification, eutrophication and ground-level ozone. A key objective of the protocol is to regulate emissions on a regional basis within Europe and to protect eco-systems from transboundary pollution by setting emission reduction ceilings to be reached by 2010 for the same 4 pollutants as addressed in the NECD (i.e. SO2, NOx, NH3 and NMVOCs). Overall for the EU Member States, the ceilings set within the Gothenburg protocol are generally either slightly less strict or the same as the emission ceilings specified in the NECD.
  • The Directive for the Sulphur content of Certain Fuels (93/12/EC). This requires Member States to cease the use of heavy fuel oil with a sulphur content greater than 1% by mass from 2001, and the use of gas oil with a sulphur content greater than 0.2% from 2001 and greater than 0.1% from 2008.
  • The Large Combustion Plant Directive 2001/80/EC (LCPD) is important in reducing emissions of SO2, NOx and dust from combustion plants having a thermal input capacity equal to or greater than 50 MW. Installations within the scope of this Directive include power stations, petroleum refineries, steelworks and other industrial processes running on solid, liquid and gaseous fuels. "New" plant must meet the emission limit values (ELVs) given in the LCPD. However Member States can choose to meet obligations for existing plant (i.e. those in operation per-1987) by either complying with the ELVs or they can operate within a national emission reduction plan (NERP) that sets a ceiling for each pollutant. The interaction of the LCPD and the IPPC Directive (see below) is currently being examined as part of a review of the IPPC Directive. 
  • The Directive on Integrated Pollution Prevention and Control (96/61/EC) entered into force in 1999.  It aims to prevent or minimise pollution to air, water or land from various industrial sources throughout the European Union. Those installations covered by Annex I of the IPPC Directive are required to obtain authorisation from the authorities to operate. New installations and existing installations, which are subject to 'substantial changes' have been required to meet the requirements of the IPPC Directive since 30th October 1999. Other existing installations must have been brought into compliance by the 30th October 2007. The emission limit values outlined in the permit conditions must be based on best available techniques (BAT). The Commission has been undertaking a review of the IPPC Directive and related legislation on industrial emissions and on the 21st December 2007 adopted a proposal for a Directive on industrial emissions. The proposal recasts seven existing Directives relating to industrial emissions (including IPPC and the LCPD) into a single legislative instrument.
  • The aim of the Directive 96/62/EC on ambient air quality assessment and management (the 'Air Quality Framework Directive') is to maintain and improve air quality within the European Community by establishing objectives for ambient air, drawing up common methods and criteria for assessing air quality and obtaining and disseminating information. The "Daughter" Directive 99/30/EC of the Air Quality Framework Directive entered into force in 1999 and sets limit values for concentrations of several pollutants including sulphur dioxide.
  • The European Sulphur Content of Marine Fuels Directive (SCMFD) (2005/33/EC) requires "Member States to ensure that marine gas oils are not placed on the market in their territory if the sulphur content exceeds 0.1% by mass" amongst other requirements.
  • The Marpol Convention covers the prevention of pollution of the marine environment by ships from operational or accidental causes. It is a combination of two treaties adopted in 1973 and 1978 and updated by amendments over the years since. Annex VI covers the prevention of air pollution from ships and it sets limits on sulphur dioxide emissions from ship exhausts. This came into force in May 2005.
  • Current market grade petrol and diesel fuels do not have a sulphur level exceeding 50 ppm.  This is the maximum level of sulphur permitted for road fuels in EU Member States from 2005 under the fuel quality Directive 98/70/EC.  The introduction of "sulphur-free fuels", with sulphur levels <10 ppm, is required by 1st January 2009 under Directive 2003/17/EC. 


Emissions of SO2 are covered by the EU National Emission Ceilings Directive (NECD) (2001/81/EC) and the Gothenburg protocol under the United Nations Convention on Long-Range Transboundary Air Pollution (LRTAP Convention) (UNECE 1999). The NECD generally involves slightly stricter emission reduction targets than the Gothenburg Protocol for EU-15 countries for the period 1990-2010. The Gothenburg Protocol entered into force on 17 May 2005, after ratification by 16 countries early in 2005.


Table: Percentage reduction (#) required by 2010 from 1990 levels by country, for emissions of SO2



1990 - 2010: NECD ceiling (%)

1990 - 2010: CLRTAP Gothenburg Protocol ceiling (%)













Czech Republic
























Iceland *

























































United Kingdom




# The actual 2010 emission ceilings specified in the NECD and Gothenburg Protocol are expressed as absolute emissions of SO2, NOx, NH3 and NMVOC (in ktonnes). For the purposes of this indicator 1990 is considered as a 'base year' and the percentage change to emissions to meet the ceilings is calculated. Reported emissions for past years may change reflecting e.g. updated and revised emission inventory guidance, and so the % reduction required to meet the CLRTAP and NECD targets as shown here may change slightly in the future.

 * Emissions data not available for Iceland.


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.
  • 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

Indicator is based on officially reported national total and sectoral emissions to UNECE/EMEP (United Nations Economic Commission for Europe/Co-operative programme for monitoring and evaluation of the long-range transmission of air pollutants in Europe) Convention on Long-range Transboundary Air Pollution (LRTAP Convention), submission 2009. Recommended methodologies for emission inventory estimation are compiled in the EMEP/CORINAIR Atmospheric Emission Inventory guidebook, EEA Copenhagen (EEA, 2009). Base data are available from the EEA Data Service ( and the EMEP web site ( Where necessary, gaps in reported data are filled by ETC/ACC using simple interpolation techniques (see below). The final gap-filled data used in this indicator is available from the EEA Data Service (

This base data, reported in SNAP, draft NFR or NFR are aggregated into the following EEA sector codes to obtain a common reporting format across all countries and pollutants:

  • 'Energy industries': emissions from public heat and electricity generation, oil refining and production of solid fuels;
  • 'Fugitive emissions': Emissions from extraction and distribution of solid fossil fuels and geothermal energy;
  • 'Industry (Energy)': emissions from combustion processes used in the manufacturing industry including boilers, gas turbines and stationary engines;
  • 'Industry (Processes)': emissions derived from non-combustion related processes such as the production of minerals, chemicals and metal production;
  • 'Road transport': light and heavy duty vehicles, passenger cars and motorcycles;
  • 'Off-road transport': railways, domestic shipping, certain aircraft movements, and non-road mobile machinery used in agriculture & forestry;
  • 'Other (energy-related)' emissions principally occurring from fuel combustion in the services and household sectors;
  • 'Other (Non Energy)': non-combustion related emissions mainly in the services and households sectors including activities such as paint application, dry-cleaning and other use of solvents;
  • 'Agriculture': manure management, fertiliser application, field-burning of agricultural wastes
  • 'Waste': incineration, waste-water management;
  • 'Unallocated': The difference between the reported national total and the sum of the sectors reported by a country.

The 'unallocated' sector corresponds to the difference between the reported national total and the sum of the reported sectors for a given pollutant / country / year combination. It can be either negative or positive. Inclusion of this additional sector means that the officially reported national totals do not require adjustment to ensure that they are consistent with the sum of the individual sectors reported by countries.

The following table shows the conversion of Nomenclature for Reporting (NFR) sector codes used for reporting by countries into EEA sector codes:

EEA classification

NFR Emission Source Category

0 National totals

National total

1 Energy Industries


3 Industry (energy)


2 Fugitive emissions


7 Road transport


8 Other transport (non-road mobile machinery)

1A3 (exl 1A3b)

9 Industry processes


4 Agriculture

4 + 5B

5 Waste


6 Other (energy)

1A4a, 1A4b, 1A4b(i), 1A4c(i), 1A5a

10 Other (non-energy)

3 + 7

12 Energy industries (power and heat production)


14 Unallocated

Difference between national total and sum of sectors (1 - 10)


Methodology for gap filling

Methodology of data manipulation: EEA/ETC-ACC gap-filling methodology. To allow trend analysis where countries have not reported data for one or several years, data has been interpolated to derive annual emissions. If the reported data is missing either at the beginning or at the end of the time series period, the emission value has been considered to equal the first (or last) reported emission value. It is recognised that the use of gap-filling can potentially lead to artificial trends, but it is considered unavoidable if a comprehensive and comparable set of emissions data for European countries is required for policy analysis purposes.

Methodology references

No methodology references available.

Data specifications

EEA data references

Data sources in latest figures


Methodology uncertainty

The use of gap-filling for when countries have not reported emissions for one of more years can potentially lead to artificial trends, but it is considered unavoidable if a comprehensive and comparable set of emissions data for European countries is required for policy analysis purposes.

Data sets uncertainty

SO2 emission estimates in Europe are thought to have an uncertainty of about +/-10% as the sulphur comes from the fuel burnt and therefore can be accurately estimated. However, because of the need for interpolation to account for missing data, the complete dataset used will have higher uncertainty. EMEP has compared modelled and measured concentrations throughout Europe (EMEP 1998).  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 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

Rationale uncertainty

This indicator on emissions of Sulphur Dioxide is produced annually by EEA and is used regularly in its State of the Environment reporting. The uncertainties related to methodology and data sets are therefore of importance. Any uncertainties involved in the calculation and in the data sets need to be accurately communicated in the assessment, to prevent erroneous messages influencing policy actions or processes.

Further work

Short term work

Work specified here requires to be completed within 1 year from now.

Long term work

Work specified here will require more than 1 year (from now) to be completed.

General metadata

Responsibility and ownership

EEA Contact Info

Martin Adams


European Environment Agency (EEA)


Indicator code
APE 001
Version id: 1
Primary theme: Air pollution Air pollution


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DPSIR: Pressure
Typology: Performance indicator (Type B - Does it matter?)

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