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Emissions of acidifying substances (version 2) (CSI 001) - Assessment published Jan 2010

Indicator Assessment Created 13 Aug 2009 Published 26 Jan 2010 Last modified 04 Mar 2015, 11:50 AM
 
Contents
 

Indicator definition

The indicator tracks trends since 1990 in anthropogenic emissions of the acidifying pollutants nitrogen oxides (NOx) , ammonia (NH3), and sulphur dioxide (SO2), each weighted by their respective acidifying potential factor.

The indicator also provides information on the sources of emissions from a number of sectors: Energy industries; road and other transport; industry (processes and energy); other (energy); fugitive emissions; waste; agriculture and other (non energy).

Units

ktonnes (acidifying equivalent)


Key policy question: What progress is being made in reducing emissions of acidifying pollutants across Europe?

Key messages

  • Aggregated emissions of acidifying pollutants (nitrogen oxides (NOx), sulphur dioxide (SO2) and ammonia (NH3) have decreased significantly in most of the EEA member countries between 1990 and 2007. This decrease has been achieved despite the increased rates of economic activity that have occurred during this period.
  • Across the EEA-32 region, emissions of acidifying pollutants decreased from 1 545 kt to 775 kt between 1990 and 2007 - a 50% reduction.
  • The EU-27 as a whole is on track to meet its target to reduce emissions from acidifying pollutants based on an aggregation of its NEC Directive ceilings for the three individual pollutants. However, a number of individual Member States anticipate missing their emission ceilings for one or more of the individual acidifying pollutants.

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

Note: Gothenburg protocol targets are shown for the non-EU countries (e.g

Data source:

EEA aggregated and gap-filled air emission dataset, based on 2009 officially reported national total and sectoral emissions to UNECE LRTAP Convention, the EU NEC Directive and EU-MM/UNFCCC.

Downloads and more info

Distance-to-target for EEA member countries

Note: Data are for acidifying pollutants. The distance to target results are shown in green (countries need to do more to be on track to meet their ceiling in 2010) and purple (countries are on track to meet their ceiling in 2010)

Data source:

EEA aggregated and gap-filled air emission dataset, based on 2009 officially reported national total and sectoral emissions to UNECE LRTAP Convention, the EU NEC Directive and EU-MM/UNFCCC.

Downloads and more info

Key assessment

In the EEA-32 region, total emissions of acidifying pollutants have decreased by 50% between 1990 and 2007 (Figure 1). Emissions of these pollutants are weighted using a factor that reflects their specific acidification formation potential prior to aggregation - see the CSI 001 indicator specification for further details. Within most countries, emissions of the aggregated acidifying pollutants have also decreased significantly (Figure 2). The largest reductions have occurred in the Czech Republic (-80%), Slovakia (76%) and Latvia (74%). In contrast, the total emissions of acidifying pollutants have increased in three countries between 1990 and 2007 - Greece (10%) and Turkey (43%). 

 

The reduction across the EEA-32 has occurred mainly as a result of decreased SO2 emissions - since 1990 these have decreased by 69% (Figure 5). This reduction of SO2 has contributed 76% of the total emission reduction observed for all acidifying pollutants (Figure 6). Reflecting this, in 1990 SO2 was responsible for 55% of total acidifying emissions, whereas by 2007 the contribution made by SO2 had decreased to 34% (i.e. similar to the contribution made to acidifying emissions by NOx and slightly greater than that made by NH3). Emissions for the other two acidifying pollutants have also decreased since 1990, although not to the same extent as for SO2 - NOx emissions have decreased by 31% and NH3 by 22%.  Key reasons behind the observed reductions in emissions are provided in the 'Specific assessment' section below.

 

The National Emission Ceilings Directive (NECD) sets for each of the EU-27 Member States ceilings (i.e. limits) for NH3, NOx and SOx emissions that must be met by 2010 [1]. The reported data shows that as of 2007, 22 Member States are on track toward meeting their combined target for the acidifying pollutants, as was the EU-27 as a whole (Figure 3). However on an individual pollutant basis, other EEA analysis [2] indicates that many Member States anticipate that, without implementing additional measures to reduce emissions, they will miss one or more of their respective 2010 NECD ceilings. The 2010 emission ceiling for NOx is the most difficult of the four ceilings for many Member States to meet. Twelve Member States have reported that they anticipate missing their NOx ceiling (Austria, Belgium, France, Germany, Ireland, Luxemburg, the Netherlands, Poland, Slovenia, Spain, Sweden and the United Kingdom). For NH3 two Member States (Germany and Spain) anticipate missing their ceiling, and one Member State (the Netherlands) - its SO2 ceiling.

 

Several of the non-EU countries also have 2010 emissions ceilings defined under the Gothenburg protocol of the UNECE Convention on Long-range Transboundary Air Pollution. Of these countries, Norway alone has reported emissions that lie above a linear target path to its aggregated ceiling for 2010 - in contrast Switzerland appears on track to meet its respective aggregated Gothenburg ceiling [3].

 

Further details concerning emissions of the individual acidifying pollutants may be found in the following indicator fact sheets (updated versions of these fact sheets will be available in the near future): 

Emission trends of ammonia (NH3)

Emission trends of nitrogen oxides (NOx)

Emission trends of sulphur dioxide (SO2)

 

[1] The NECD and Gothenburg protocol also set an emission ceiling for non-methane volatile organic compounds (NMVOCs), which contribute to ground-level ozone formation.

[2] NEC Directive Status report (EEA Technical report No 11/2009).

[3] Lichtenstein did not report any data.

 

Specific policy question: How do different sectors and processes contribute to emissions of acidifying pollutants?

Sector split of emissions of acidifying pollutants (EEA member countries; EU-15; New EU-12; Other EEA countries (EFTA-4 and CC3)

Note: Due to numerical rounding, values may not add exactly to 100%

Data source:

EEA aggregated and gap-filled air emission dataset, based on 2009 officially reported national total and sectoral emissions to UNECE LRTAP Convention, the EU NEC Directive and EU-MM/UNFCCC.

Downloads and more info

Change in acidifying pollutants emissions for each sector and pollutant between 1990 and 2007 (EEA member countries)

Note: No emissions data are available for Liechtenstein.

Data source:

EEA aggregated and gap-filled air emission dataset, based on 2009 officially reported national total and sectoral emissions to UNECE LRTAP Convention, the EU NEC Directive and EU-MM/UNFCCC.

Downloads and more info

Contribution to total change in acidifying pollutants emissions for each sector and pollutant (EEA member countries)

Note: Contribution to change plots show the contribution to the total emission change between 1990-2007 made by a specified sector/pollutant

Data source:

EEA aggregated and gap-filled air emission dataset, based on 2009 officially reported national total and sectoral emissions to UNECE LRTAP Convention, the EU NEC Directive and EU-MM/UNFCCC.

Downloads and more info

Specific assessment

In 2007 the most significant emission sources of acidifying emissions in the EEA-32 region were the 'energy industries' (29% of total emissions), 'agriculture' (27% of total emissions) and 'road transport' sectors (19% of total emissions) (Figure 4). Since 1990, acidifying emissions from the 'energy industries' and 'industry (energy)' sectors have in particular reduced significantly, contributing 44% and 15% respectively of the total reduction of acidifying emissions (Figure 6). Factors that have contributed to the reduction in these sectors include:

  • 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 industries', industry and domestic sectors;
  • the impact of European Community directives relating to the sulphur content of certain liquid fuels;
  • the introduction of flue-gas abatement techniques (e.g. flue gas desulphurisation, NOx scrubbers and selective (SCR) and selective non-catalytic (SNCR) reduction) and introduction of combustion modification technologies (such as use of low NOx burners).

 

Data sources

Policy context and targets

Context description

Within the European Union, the National Emission Ceilings Directive (NEC Directive) imposes emission ceilings (or limits) for emissions of the acidifying pollutants nitrogen oxides, sulphur dioxide and ammonia that harm human health and the environment (the NEC Directive also sets emissions ceilings for a fourth pollutant - non-methane volatile organic compounds). The European Commission is expected to propose a revised NEC Directive in 2010.

 

Other key EU legislation is targeted at reducing emissions of air pollutants from specific sources, for example:

  • transport;
  • industrial facilities and other stationary sources.

 

Internationally, the issue of air pollution emissions is also being addressed by the UNECE Convention on Long-range Transboundary Air Pollution (the LRTAP Convention) and its protocols. The Gothenburg 'multi-pollutant' protocol under the LRTAP Convention also contains national emission ceilings for the acidifying pollutants that are either equal to or slightly less ambitious than those in the EU NEC Directive. 

 

References

Directive 2001/81/EC, on national emissions ceilings (NECD) for certain atmospheric pollutants. http://ec.europa.eu/environment/air/pdf/necd_consolidated.pdf

UNECE (1999). Protocol to the 1979 Convention on Long-Range Transboundary air pollution (LRTAP Convention) to abate acidification, eutrophication and ground-level ozone. http://www.unece.org/env/lrtap/multi_h1.htm 

Targets

 

Emissions of NOx, SOx and NH3 are covered by the NECD and the Gothenburg Protocol to the UNECE LRTAP Convention. Both instruments contain emission ceilings (limits) that countries must meet by 2010.

Table 1. Percentage reduction required by 2010 compared to 1990 levels by country, for aggregated emissions of the acidifying pollutants NOx, SOx and NH3 (individual pollutant emission ceilings weighted by acidifying potential factors prior to aggregation).

 

Table 1. Percentage reduction required by 2010 from 1990 levels by country, for emissions of ozone precursors NOx and NMVOCs (emission targets weighted by ozone formation potential).

Country

NECD Targets 1990 - 2010

LRTAP Convention Gothenburg Protocol Targets 1990 - 2010

Austria

-31%

-31%

Belgium

-58%

-57%

Denmark

-54%

-54%

Finland

-48%

-46%

France

-42%

-41%

Germany

-74%

-73%

Greece

7%

9%

Ireland

-36%

-36%

Italy

-52%

-51%

Luxembourg

-45%

-45%

Netherlands

-54%

-54%

Portugal

-12%

-3%

Spain

-45%

-45%

Sweden

-33%

-33%

United Kingdom

-69%

-68%

Bulgaria

-38%

-36%

Cyprus

29%

-

Czech Republic

-77%

-75%

Estonia

-47%

-

Hungary

-43%

-39%

Latvia

-4%

5%

Lithuania

-19%

-19%

Malta

-22%

-

Poland

-43%

-43%

Romania

-2%

-2%

Slovakia

-66%

-66%

Slovenia

-67%

-67%

EU27

-52%

-52%

Liechtenstein

-

-

Norway

-

-26%

Switzerland

-

-29%

Iceland

-

-

Turkey

-

-

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

Methodology for indicator calculation

This indicator factsheet uses emissions data from the EEA dataservice dataset 'EEA aggregated and gap-filled air emission data'. The 2010 projection estimates reported by the EU-27 Member States under the requirements of the NEC Directive are also included in the analysis http://www.eea.europa.eu/themes/air/datasets).

 

The dataset 'EEA aggregated and gap-filled air emission data' is consistent with the annual 'European Community LRTAP Convention emission inventory' compiled by EEA. This inventory is based on the officially reported emissions data from countries submitted to the UNECE LRTAP Convention and supplemented with additional data reported under the NEC Directive and the EU GHG Monitoring Mechanism/UNFCCC.   

 

Air pollutant emissions data are reported by countries using the Nomenclature For Reporting (NFR) sectroal classification system developed by UNECE/EMEP.  For the purposes of the 'EEA aggregated and gap-filled air emission dataset', the numerous NFR sectors reported by countries are combined into the following EEA aggregated sectors to allow a simpler analysis: 

  • 'Energy industries': emissions from public heat and electricity generation
  • '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 from production processes
  • 'Road transport': emissions from light and heavy duty vehicles, passenger cars and motorcycles;
  • 'Off-road transport': emissions from railways, domestic shipping, certain aircraft movements, and non-road mobile machinery used in agriculture, forestry;
  • 'Agriculture': emissions from manure management, fertiliser application, field-burning of agricultural wastes
  • 'Waste': emissions from incineration of waste, waste-water management.
  • 'Other (energy-related)': emissions from energy use principally in the services and household sectors
  • 'Other (Non Energy)': emissions from solvent and other product use.

 

The following table shows how the NFR categories used by countries to report their emissions are aggregated into the EEA aggregated sectors listed above:

 EEA Code

EEA classification

NFR Emission Source Categories

0

National totals

National Total

1

Energy industries

1A1

3

Industry (Energy)

1A2

2

Fugitive emissions

1B

7

Road transport

1A3b

8

Other transport (non-road mobile machinery)

1A3 (excl 1A3b) + sectors mapped to 8 in table below

9

Industry (Processes)

2

4

Agriculture

4 + 5B

5

Waste

6

6

Other (Energy)

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

10

Other (non-energy)

3 + 7

14

Unallocated

Difference between NT and sum of sectors (1-10)

12

Energy Industries (Power Production 1A1a)

1A1a

The 'unallocated' sector (14) 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 they are consistent with the sum of the individual sectors reported by countries.

 

Where reported data from countries is incomplete, simple gap-filling techniques are used in the 'EEA aggregated and gap-filled air emission dataset' in order to obtain a consistent time-series (see following section).

 

To obtain an aggregated estimate of the total acidifying substances emissions, the emission values of the individual acidifying pollutants are multiplied by an acidifying potential factor (de Leeuw, 2002) prior to aggregation. The factors are NOx 0.02174, SO2 0.03125 and NH3 0.05882. Results are expressed in terms of 'acidification equivalents' (ktonnes).

 

In addition to historic emissions, Figure 1 of the indicator factsheet also shows the latest 2010 projection estimates reported by the EU-27 Member States under the requirements of the NEC Directive. The "with measures" (WM) projections reported by Member States take into account currently implemented and adopted policies and measures. Where countries have instead reported "business as usual" or "current legislation" projections, it is assumed for comparison purposes that these are equivalent to a WM projection. The "with additional measures" projections reported by Member States take into account additional future planned policies and measures but which are not yet implemented.

Methodology for gap filling

To allow trend analysis, where countries have not reported data for one or more years, data in the 'EEA aggregated and gap-filled air emission dataset' has been interpolated to derive the emissions for the missing year or years. If the reported data is missing either at the beginning or at the end of the period, the emission value is assumed to equal the first or last reported value. The use of gap-filling may lead to artificial trends, but it is considered necessary if a comprehensive and comparable set of emissions data for European countries is to be obtained. A spreadsheet containing a record of the gap-filled data is available from EEA's European Topic Centre on Air and Climate Change (ETC/ACC) (http://air-climate.eionet.europa.eu/)

Methodology references

No methodology references available.

Uncertainties

Methodology uncertainty

The use of interpolation/extrapolation procedures to gap-fill the underlying emissions dataset and the application of acidifying potential factors both lead to uncertainties. With respect to the acidifying potential factors, these are assumed to be representative for Europe as a whole; on the local scale different factors might be estimated. An extensive discussion on the uncertainties in these factors is available in de Leeuw (2002).

Data sets uncertainty

The NOx, SO2 and NH3 emissions data officially submitted by EU Member States and other EEA member countries follow common calculation (EMEP/EEA 2009) and reporting guidelines (UNECE 2003).

Sulphur dioxide emission estimates in Europe are thought to have an uncertainty of about 10% as the sulphur emitted comes from the fuel burnt and therefore can be more accurately estimated.  However, because of the need for interpolation to account for missing data the complete dataset used here will have higher uncertainty. EMEP has compared modelled (using emission inventory data) and measured concentrations throughout Europe (EMEP, 1998). From these studies differences in the annual averages have been estimated in the order of 30% consistent with an inventory uncertainty of 10% (there are also uncertainties in the measurements and especially the modelling).

Nitrogen oxide emission estimates in Europe are thought to have an uncertainty of about ±20% (EMEP, 2009), as the NOx emitted comes both from the fuel burnt and the combustion air and so cannot be estimated accurately from fuel nitrogen alone.  However, because of the need for interpolation to account for missing data, the complete dataset used will have higher uncertainty. The trend is likely to be more accurate than the individual absolute annual values - the annual values are not independent of each other.

Ammonia emissions are also relatively uncertain. NH3 emission estimates in Europe are more uncertain than those for NOx or SO2 due largely to the diverse nature of agricultural sources - which account for the vast majority of NH3 emissions. It is estimated that they are around ±30% (EMEP, 2007). The trend is likely to be more accurate than the individual absolute annual values - the annual values are not independent of each other.

References

Rationale uncertainty

This indicator on emissions of acidifying pollutants is updated annually by EEA and is used regularly in our reports on the state of the environment. It is therefore important to note the uncertainties related to methodology and data sets.

More information about this indicator

See this indicator specification for more details.

Generic metadata

Topics:

Air pollution Air pollution (Primary topic)

Agriculture Agriculture

Industry Industry

Tags:
acidification | csi | air quality | air emissions | pollution
DPSIR: Pressure
Typology: Performance indicator (Type B - Does it matter?)
Indicator codes
  • CSI 001
Dynamic
Temporal coverage:
2007, 2010
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

Martin Adams

Ownership

EEA Management Plan

2010 (note: EEA internal system)

Dates

European Environment Agency (EEA)
Kongens Nytorv 6
1050 Copenhagen K
Denmark
Phone: +45 3336 7100