Air pollution by industries and households
From Statistics Explained
Data from March 2014. Most recent data: Further Eurostat information, Main tables and Database
This article analyses the emissions of five acidifying gases and ozone precursors in the European Union (EU) in a breakdown by industries and households that are responsible for their generation. It briefly explains the differences between data on emissions of air pollutants reported under the Regulation (EU) Nr 691/2011 on European environmental economic accounts, and the data reported under the Convention on Long-Range Transboundary Air Pollution (CLRTAP).
The emissions of acidifying gases (sulphur dioxide (SO2), nitrogen oxides (NOx) and ammonia (NH3)) decreased by 32 % between 2000 and 2011. This represents a reduction of SO2, NOx and NH3 of 9.4 million tonnes of SO2 equivalents. In 2011, emissions of nitrogen oxides accounted for the highest share of the acidifying potential (39 %) followed by ammonia (35 %) and sulphur dioxide (26 %).
The emissions of ozone precursors (including nitrogen oxides (NOx), methane (CH4), carbon monoxide (CO) and non-methane volatile organic compounds (NMVOC)) fell by 32 % between 2000 and 2011. The main pollutants contributing to the tropospheric ozone formation potential in 2011 were NOx and NMVOC with 57 % and 31 % respectively.
- 1 Main statistical findings
- 2 Data sources and availability
- 3 Context
- 4 See also
- 5 Further Eurostat information
- 6 External links
Main statistical findings
Several air pollutants contribute to the acidification of the environment. The most important ones are discussed in this article and comprise sulphur dioxide (SO2), nitrogen oxides (NOx) and ammonia (NH3). The impact of SO2, NOx and NH3 can be observed in the progressive degradation of soils, water and forests. They also contribute to the formation of fine particles in the air that cause respiratory diseases. The acidifying potential of SO2, NOx and NH3 is commonly measured in SO2 equivalents. The conversion factors are shown in Table 2.
In 2011, emissions of nitrogen oxides accounted for the highest share of the acidifying potential (39 % or 7.8 million tonnes of SO2 equivalents) followed by ammonia (35 % or 6.9 million tonnes of SO2 equivalents) and sulphur dioxide (26 % or 5.1 million tonnes of SO2 equivalents). The emission of acidifying gases decreased by 32 % between 2000 and 2011. This represents a reduction of 9.4 million tonnes of SO2 equivalents, two thirds of which are due to the reduction of SO2 emissions. Emissions of nitrogen oxides fell by 22 %, ammonia by 11 % and sulphur dioxide by 55 % (Figure 1).
Acidifying gas emissions by economic activity
Agriculture, forestry and fishing account for the largest share of all industries: In 2011, they emitted 36 % of total acidifying potential, compared to 28 % in 2000. Although it has decreased between 2000 and 2011 by 12 %, mainly due to the reduction in livestock numbers, changes in the management of organic manures and the decreased use of nitrogenous fertilisers, it has decreased less than most of the other economic activities discussed in this chapter. Ammonia is the largest contributor to the acidifying emissions from agriculture, forestry and fishing with 6.3 million tonnes of SO2 equivalents.
The second largest contributor to acidifying emissions in 2011 was the transport industry with a share of 18 % or 3.5 million tonnes of SO2 equivalents, closely followed by the electricity, gas, steam and air conditioning supply industry (17 % or 3.4 million tonnes of SO2 equivalents). While in the transport industry the largest share of emissions came from NOx, in the electricity, gas, steam and air conditioning supply industry SO2 emissions were predominant (Figure 2 and 3).
All activities recorded significant drops in acidifying emissions. The most significant decrease was observed for the electricity, gas, steam and air conditioning supply industry, which dropped from 7.9 to 3.4 million tonnes of SO2 equivalents (-57 %) between 2000 and 2011. The more systematic use of end-of-pipe pollution filters and the use of more efficient combustion technologies in the electricity and heat production are the main contributors to this development.
Intensity of acidifying gas emissions
The ratio of acidifying emissions in tonnes of SO2 equivalents per million euros of gross value added (GVA) measures the intensity of acidifying gas emissions of industries (Figure 4). In 2011, with 39 grammes per euro, a predominance of agriculture, forestry and fishing over other industries can be seen. This is due to the fact that the agriculture, forestry and fishing industry has large emissions of ammonia and contributes a comparatively low GVA to the economy. Compared to 2011 the intensity of acidifying gas emissions decreased in all main industries. The biggest decrease was recorded for the electricity, gas, steam and air conditioning industry (-60 %).
Tropospheric ozone occurs when non-methane volatile organic compounds (NMVOC), nitrogen oxides (NOx), carbon monoxide (CO) and methane (CH4) react in the atmosphere in the presence of sunlight. High ozone levels occur during the warmer summer months as the sun makes e.g. exhaust fumes from vehicles react in the atmosphere. The emissions are known to damage tissue and are a health risk, especially for people with respiratory problems. Through the National Emissions Ceilings Directive (NECD) and the Gothenburg Protocol under UNECE-CLRTAP, the EU focuses on the emissions of NOx and NMVOC as they are the most relevant of the four pollutants.
Similarly to the emissions of acidifying gases, the emissions of ozone precursors in the EU fell between 2000 and 2011 for all pollutants. The total change in emissions of NMVOC, NOx, CO and CH4 was a decrease of 32 % or 11 million tonnes of NMVOC equivalents. The main pollutants contributing to the tropospheric ozone formation are NOx and NMVOC with 57 % and 31 % respectively. Between 2000 and 2011, the emissions of NOx fell by 22.5 % or 4 million tonnes of NMVOC equivalents, and NMVOC by 42 % or 5.3 million tonnes (Figure 5).
Ozone precursor emissions by economic activity
The highest contributors to ozone precursor emissions in 2011 were households with 26 % and the transport industry with 22 % of total EU ozone precursor emissions. The manufacturing industry is the third largest emitter (20 % of total ozone precursor emissions).
Between 2000 and 2011, the biggest absolute drop occurred in households (4.3 million tonnes of NMVOC equivalents or -41 %), while the biggest relative drop was recorded in the mining and quarrying industry (288 thousand tonnes or -46 %) (Figure 6 and 7).
Ozone precursor emission intensities
Ozone precursor emission intensity is the ratio of ozone precursor emissions in tonnes of NMVOC equivalents per million euros of gross value added (GVA). Figure 8 shows that in 2011 transport (17.4 grammes NMVOC equivalents per euro) was, relative to GVA, the most important contributor to ozone precursor emissions in the EU, followed by electricity, gas, steam and air conditioning supply and by agriculture, forestry and fishing. Compared to year 2000 the intensity decreased in all main industries. The biggest decrease was observed in agriculture, forestry and fishing (-44 %).
Data sources and availability
Emission accounts versus emission inventories
In the reporting of air pollutants (as well as greenhouse gases) two different approaches are internationally established – air emission accounts and national air emission inventories (for example for reporting obligations under the Convention on Long-Range Transboundary Air Pollution). The main differences are explained in Table 1.
Analysis by economic activity
In air emissions accounts, the emissions data are organised by economic activity, using NACE, the same statistical classification of economic activities as used in national accounts which makes it possible to have an integrated environmental-economic analysis to supplement traditional economic data. Economic activities encompass all businesses resident in a country, including those operating ships, aircraft and other transportation equipment in other countries.
Air emissions accounts also include households as consumers. Their emissions are accounted for whenever household consumption is directly responsible for environmental pressures. For example, emissions from a privately owned car are counted under households, whereas cars owned by transport businesses (such as taxis) are counted under transport.
Air emissions data for 2000 are classified using NACE Rev. 1.1, whereas data for 2011 relate to NACE Rev. 2. In order to ensure comparability over time the activities are grouped accordingly. The following activity groupings are used in this article:
- agriculture, forestry and fishing — NACE Rev. 2 section A (NACE Rev. 1.1 sections A and B);
- mining and quarrying — NACE Rev. 2 section B (NACE Rev. 1.1 section C);
- manufacturing — NACE Rev. 2 section C (NACE Rev. 1.1 section D);
- electricity, gas, steam and air conditioning supply — NACE Rev. 2 section D (NACE Rev. 1.1 division 40);
- transport — NACE Rev. 2 divisions 49, 50 and 51 (NACE Rev. 1.1 divisions 60, 61 and 62);
- other services, water supply and construction — all remaining economic activities as defined in NACE Rev. 2 or NACE Rev. 1.1;
- households — households as consumers.
SO2 equivalent and NMVOC equivalent
Emissions of individual acidifying gases and ozone precursor are converted and aggregated to provide information for the environmental pressures 'acidifying potential' and 'tropospheric ozone formation potential'. They use common units (SO2 equivalent and NMVOC equivalent) to allow comparison and combination of the relative effect of different gases – for example, a single kilogram of ammonia has 1.9 times the acidic effect of a kilogram of sulphur dioxide (see Table 2 for more details on the conversion factors employed).
The source for Eurostat's air emissions accounts is annual data transmitted by the 28 EU Member States, as well as some of the European Free Trade Association (EFTA) countries and candidate countries. Regulation (EU) 691/2011 on European environmental economic accounts stipulates the data requirements of air emissions accounts.
There are two possible approaches for compiling air emissions accounts:
- The inventory-first-approach starts from existing national emission inventories and re-arranges those data to a format compatible with national accounts. There is a correspondence to NACE and households for each inventory source code: the Common Reporting Framework - CRF (used in greenhouse gas emissions inventories reported under the United Nations Framework Convention on Climate Change (UNFCCC)), the Nomenclature For Reporting - NFR (used in reporting emissions under the Convention on Long-range Transboundary Air Pollution (CLRTAP)) and the Selected Nomenclature for sources of Air Pollution - SNAP (coding establshed before introducing the two mentioned nomenclatures). However, the correspondence is not always a one to one relationship and certain models and transformations are required.
- The energy-first-approach starts from energy statistics/balances which are rearranged to form energy accounts from which air emissions are calculated using emission factors. Each country applies its individual methodological steps depending on the primary statistical sources available.
The need to supplement information on the economy with environmental indicators has been recognised in a European Commission Communication titled 'GDP and beyond'COM(2009) 433). Furthermore, similar recommendations have been made within the Report by the Commission on the Measurement of Economic Performance and Social Progress,the so-called Stiglitz report. The recommendations support the expansion of the statistical understanding of human well-being by supplementing economic indicators such as GDP with additional information, including physical indicators related to the environment.
Air emissions accounts are a statistical means of measuring the interplay between the economy and the environment with respect to air emissions, in order to see whether current production and consumption activities are on a sustainable path of development. Measuring sustainable development is a complex undertaking as it has to incorporate economic, social and environmental indicators. The data obtained from air emissions accounts may subsequently feed into political decision-making, underpinning policies that target both continued economic growth and sustainable development, for example, initiatives such as the Europe 2020 strategy, which aims to achieve a resource-efficient, low-carbon economy for the EU by 2020.
- Air pollution statistics
- Environmental accounts - establishing the links between the environment and the economy
- Greenhouse gas emissions by industries and households
- NACE background
- National accounts – GDP
Further Eurostat information
- Environment (env), see:
- Emissions of greenhouse gases and air pollutants (env_air)
- Air emissions accounts (env_air_aa)
Methodology / Metadata
- Air emissions accounts by industry and households (NACE Rev. 2) (ESMS metadata file - env_ac_ainah_r2)
- Air emissions accounts totals in NACE Rev. 2 bridging to emission inventory totals (ESMS metadata file - env_ac_aibrid_r2)
- System of Environmental - Economic Accounting 2012 - Central Framework
Source data for tables and figures (MS Excel)
- Convention on Long-Range Transboundary Air Pollution
- E-PRTR - Releases from Diffuse Sources to Air (maps)
- Gothenburg Protocol
- United Nations Framework Convention on Climate Change (UNFCCC)