Indicator Assessment

Sulphur dioxide (SO2) emissions

Indicator Assessment
Prod-ID: IND-169-en
  Also known as: APE 001
Published 20 Dec 2012 Last modified 11 May 2021
21 min read
This page was archived on 31 Jul 2015 with reason: No more updates will be done
    • EEA-32 emissions of sulphur oxides (SOX) have decreased by 75% between 1990 and 2010. In 2010, the most significant sectoral source of SOX emissions was 'Energy production and distribution' (57% of total emissions), followed by emissions occurring from 'Energy use in industry' (21%) and in the 'Commercial, institutional and households' (14%) sector.
    • The reduction in emissions since 1990 has been achieved as a result of a combination of measures, including fuel-switching in energy-related sectors away from high-sulphur solid and liquid fuels to low-sulphur fuels such as natural gas, the fitting of flue gas desulphurisation abatement technology in industrial facilities and the impact of European Union directives relating to the sulphur content of certain liquid fuels.
    • All of the EU-27 Member States have reduced their national SOX emissions below the level of the 2010 emission ceilings set in the National Emission Ceilings Directive (NECD)[1]. Emissions in 2010 for the three non-EU countries having emission ceilings set under the UNECE/CLRTAP Gothenburg protocol (Liechtenstein, Norway and Switzerland) were also below the level of their respective 2010 ceilings.
    • Environmental context: Sulphur dioxide is emitted when fuels containing sulphur are combusted. It is a pollutant which contributes to acid deposition which in turn can lead to 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. SO2 emissions also aggravate asthma conditions and can reduce lung function and inflame the respiratory tract, and contribute as a secondary particulate pollutant to formation of particulate matter in the atmosphere, an important air pollutant in terms of its adverse impact on human health. Further, the formation of sulphate particles in the atmosphere after its release results in reflection of solar radiation, which leads to net cooling of the atmosphere.

[1] Emissions data reported by EU member states under NECD is used for comparison with NECD ceilings, and data reported under CLRTAP is used for all other calculations unless otherwise stated.

This indicator is discontinued. No more assessments will be produced.

Change in emissions of sulphur oxides compared with the 2010 NECD and Gothenburg protocol targets (EEA member countries)

Note: The reported change in sulphur oxide emissions (SOx) for each country, 1990-2010, in comparison with the 2010 NECD and Gothenburg protocol targets.

Distance-to-target for EEA member countries

Note: The distance-to-target indicator shows how current NMVOC emissions compare to a linear emission reduction 'target-path' between 2010 emission levels and the 2020 emission ceiling for each country. Negative percentage values indicate the current emissions in a country are below the linear target path; positive values show that current emission lie above a linear target path to 2020.

Significant progress in reducing SOX emissions has been made by many countries; EEA-32 emissions of SOX have decreased by 75% between 1990 and 2010. Within the EEA-32 group of countries, all have reported lower emissions in 2010 compared to 1990 except Iceland (3.6 times greater), Hungary (3.4 times greater) and Turkey (2.0 times greater). The large apparent magnitudes of these increases in Turkey and Hungary are due to the inclusion in 2010 reports of emissions from sectors which were not reported in 1990; for example, only 'Industrial processes' emissions are reported in CRF data from Hungary in 1990, whilst in 2010 LRTAP submissions emissions are reported in the majority of sectors.

The large increase in SOX emissions in Iceland, from 20 kt in 1990 to 72 kt in 2010, is due chiefly to the reported emissions from the 'Energy production and distribution' sector rising by 45 kt since 1990. This sector alone now contributes 14% of Iceland's total emissions in 2010. These emissions are mostly comprised of emissions from activities related to fugitive emissions from the 'other energy extraction' sector, which includes geothermal energy production, many of these would occur naturally but are included in Iceland's emission total due to their use in energy generation.

All of the EU-27 Member States have reduced their national SOX emissions below the level of the 2010 emission ceilings set in the National Emission Ceilings Directive (NECD).

Iceland, Lichtenstein, Norway, Switzerland and Turkey are not members of the European Union and hence have no emission ceilings set under the NECD. However, Norway and Switzerland have ratified the UNECE LRTAP Convention's Gothenburg Protocol, requiring them to reduce their emissions to the agreed ceiling specified in the protocol by 2010. Liechtenstein has also signed, but not ratified the protocol. All three countries have reported that emissions in 2010 were lower than their respective 2010 Gothenburg Protocol ceilings.

The NECD protocol is currently being reviewed, as part of the implementation of the Thematic Strategy on Air Pollution, but a proposal for a revised directive is presently on hold until 2013. A revision of the Gothenburg protocol was published in June 2012, and proposed percentage emission reductions from 2005 levels to be met by 2020 for the four already regulated substances (NOX, NMVOC, SO2 and NH3) and in addition for primary emissions of PM2.5. Existing emission ceilings for 2010 have been extended to 2020 such that all countries have additional obligations to maintain emission levels below their 2010 ceilings, or to further reduce emissions if they have not yet met these ceilings.

Eight of the EU-27 Member States have already met the 2020 targets proposed under the Gothenburg protocol, and all of the remaining countries except four (Lithuania, Finland, Estonia and Sweden) are on track to reduce emissions to their ceiling by or before 2020.

Of the five non-EU countries within the EEA-32, only Norway and Switzerland have 2020 targets proposed under the Gothenburg protocol. Both of these countries reported emissions in 2010 which were lower than their 2020 emission ceilings.

Sector share of sulphur oxides emissions - 2010 (EEA member countries)

Note: The contribution made by different sectors to emissions of sulphur dioxide

Change in sulphur oxides emissions for each sector between 1990 and 2010 (EEA member countries)

Note: Percentage change in sulphur oxides (SOx) emissions for each sector between 1990 and 2010.

Contribution to total change in sulphur oxides (SOx) emissions for each sector between 1990 and 2010 (EEA member countries)

Note: The contribution made by each sector to the total change in sulphur oxides (SOx) emissions between 1990 and 2010.

Substantial SOX emission reductions have been made across a number of sectors including: 'Road transport' (a 99% reduction between 1990 and 2010), 'Waste' (81%), 'Energy production and distribution' (75%) and 'Energy use in industry' (66%).

The 'Energy production and distribution' sector (encompassing activities such as power and heat generation) is responsible for the largest reduction in absolute terms of emissions, contributing 57% of the total reduction in SOX emissions reported by countries. Nevertheless, despite this significant reduction, this single sector remains the most significant source of SOX in the EEA-32 region, contributing over half of total SOX emissions. Across Europe there is also an increasing awareness of the contribution made to SOX emissions by national and international ship traffic, and especially the health effects of such emissions whilst at berth (a more detailed discussion of this issue is contained in the TERM indicator fact sheet TERM03 - Transport emissions of air pollutants). From 1st January 2010 all ships using fuel at berth in EU ports for significant periods were required to use exclusively low-sulphur fuel (0.1%), and from 1st July 2010, within SECAs (Sulphur Emission Control Areas) defined in the North Sea, English Channel and Baltic Sea, all ships were required to use fuel with sulphur content not exceeding 1.0%. EEA32 countries have reported a reduction in emissions from national navigation (shipping) of 9.5% between 2009 and 2010, and further reductions in later years may be expected as additional legislation comes into force.

A combination of measures has led to the reductions in SOX emissions. This includes fuel-switching from high-sulphur solid (e.g. coal) and liquid (e.g. heavy fuel oil) fuels to low sulphur fuels (such as natural gas) for power and heat production purposes within the energy, industry and domestic sectors, improvements in energy efficiency, and the installation of flue gas desulphurisation equipment in new and existing industrial facilities. The implementation of several directives within the EU limiting the sulphur content of fuel has also contributed to the decrease.

The newer Member States of the European Union have in a number of cases also undergone significant economic structural changes since the early 1990s which have led to a general decline in certain activities which previously contributed significantly to high levels of sulphur emissions (e.g. heavy industry) and the closure of older inefficient power plants.

Supporting information

Indicator definition

  • The indicator tracks trends since 1990 in anthropogenic emissions of sulphur dioxide.
  • The indicator also provides information on emissions by sector: energy production and distribution; energy use in industry;, industrial processes; road transport; non-road transport; commercial, institutional and households; solvent and product use; agriculture; waste; other.
  • 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: 1990-2010


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 of the environment and human health in the Community 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 four pollutants as addressed in the NECD (i.e. SO2, NOx, NH3 and NMVOCs). Overall, for 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): This is important in reducing emissions of SO2, NOx and dust from combustion plants with 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" plants must meet the emission limit values (ELVs) given in the LCPD. However Member States can choose to meet obligations for existing plants (i.e. those in operation pre-1987) by either complying with the ELVs or by operating 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), which entered into force in 1999: This Directive 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 obliged to meet the requirements of the IPPC Directive since 30 October 1999. Other existing installations must have been brought into compliance by the 30 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 21 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): This 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: This 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 sets limits on sulphur dioxide emissions from ship exhausts. This came into force in May 2005.
  • Fuel quality Directive 98/70/EC and sulphur-free fuels Directive 2003/17/EC: Current market grade petrol and diesel fuels do not have a sulphur level exceeding 50 parts per million (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 less than 10 ppm, is required by 1 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 Member States for the period 1990-2010. The Gothenburg Protocol entered into force on 17 May 2005, after ratification by 16 countries early in 2005. The 2012 revision to the Gothenburg protocol proposed emission reduction targets for 2020 relative to 2005 reported emissions for all EU-27 Member States and some EEA-32 non-EU member states.

Table: 2010 SO2 ceilings under the NEC Directive and the Gothenburg Protocol (kt)


2010 NECD

2010 CLRTAP Gothenburg Protocol ceilings

2020 CLRTAP Gothenburg Protocol ceilings

Austria 39 39 62
Belgium 99 106 70
Bulgaria 836 856 58
Cyprus 39 N/A 5
Czech Republic 265 283 76
Denmark 55 55 63
Estonia 100 N/A 10
Finland 110 116 31
France 375 400 635
Germany 520 550 544
Greece 523 546 63
Hungary 500 550 72
Iceland* N/A N/A N/A
Ireland 42 42 108
Italy 475 500 395
Latvia 101 107 16
Liechtenstein N/A 0.11 N/A
Lithuania 145 145 35
Luxembourg 4 4 5
Malta 9 N/A 2
Netherlands 50 50 123
Norway N/A 22 21
Poland 1397 1397 267
Portugal 160 170 47
Romania 918 918 173
Slovakia 110 110 25
Slovenia 27 27 18
Spain 746 774 354
Switzerland N/A 26 59
Sweden 67 67 47
Turkey* N/A N/A N/A
United Kingdom 585 625 282

* Iceland and Turkey do not have a ceiling under either the NEC Directive or the Gothenburg protocol.

Related policy documents



Methodology for indicator calculation

This indicator is based on officially reported national total and sectoral emissions to the EEA and 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 2011. For the EU-27 Member States, the data used is consistent with the emissions 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, (EMEP/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 European Topic Centre/EEA using simple interpolation techniques (see below). The final gap-filled data used in this indicator is available from the EEA Data Service (

Base data, reported in the UNECE/EMEP Nomenclature for Reporting (NFR) sector format are aggregated into the following EEA sector codes to obtain a consistent reporting format across all countries and pollutants:

  • Energy production and distribution: emissions from public heat and electricity generation, oil refining, production of solid fuels, extraction and distribution of solid fossil fuels and geothermal energy;
  • Energy use in industry: emissions from combustion processes used in the manufacturing industry including boilers, gas turbines and stationary engines;
  • Industrial 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;
  • Non-road transport: railways, domestic shipping, certain aircraft movements, and non-road mobile machinery used in agriculture and forestry;
  • Commercial, institutional and households: emissions principally occurring from fuel combustion in the services and household sectors;
  • Solvent and product use: 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;
  • Other: emissions included in national total for entire territory not allocated to any other sector.


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

EEA classification

Non-GHGs (NFR)


National totals

National total


Energy production and distribution

1A1, 1A3e, 1B


Energy use in industry



Road Transport



Non-road transport (non-road mobile machinery)

1A3 (excl. 1A3b)


Industrial processes



Solvent and product use









Commercial, institutional and households

1A4ai, 1A4aii, 1A4bi, 1A4bii, 1A4ci, 1A4cii, 1A5a, 1A5b





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 (eg NOX, SOX, NMVOC, NH3 and CO) to be compiled. In cases where countries did not report emissions for any year, it meant that gap-filling could not be applied. For these pollutants, therefore, the aggregated data is not yet complete and is likely to underestimate true emissions. Further methodological details of the gap-filling procedure are provided in section 1.4.2 'Data gaps and gap-filling' of the European Union emission inventory report 1990–2009 under the UNECE Convention on Long-range Transboundary Air Pollution (LRTAP).

Methodology references



Methodology uncertainty

The use of gap-filling when countries have not reported emissions for one or 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 2010). 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 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 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.

Data sources

Other info

DPSIR: Pressure
Typology: Performance indicator (Type B - Does it matter?)
Indicator codes
  • APE 001
Frequency of updates
This indicator is discontinued. No more assessments will be produced.
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