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No. 183: Annual Danish Informative Inventory Report to UNECE

Nielsen, O.-K., Plejdrup, M.S., Winther, M., Mikkelsen, M.H., Nielsen, M., Gyldenkærne, S., Fauser, P., Albrektsen, R., Hjelgaard, K., Bruun, H.G. & Thomsen, M. 2016. Annual Danish Informative Inventory Report to UNECE. Emission inventories from the base year of the protocols to year 2014. Aarhus University, DCE – Danish Centre for Environment and Energy, 491 pp. Scientific Report from DCE – Danish Centre for Environment and Energy No. 183 http://dce2.au.dk/pub/SR183.pdf




I Background information on emission inventories

Annual report

This report is Denmark’s Annual Informative Inventory Report (IIR) due March 15, 2016 to the UNECE-Convention on Long-Range Transboundary Air Pollution (LRTAP). The report contains information on Denmark’s inventories for all years from the base years of the protocols to 2014.

The air pollutants reported under the LRTAP Convention are SO2, NOX, NMVOC, CO, NH3, TSP, PM10, PM2.5, As, Cd, Cr, Cu, Hg, Ni, Pb, Se, Zn, dioxins/furans, HCB, PCBs and PAHs,.

The annual emission inventory for Denmark is reported in the Nomenclature for Reporting (NFR) 2014 format.

The issues addressed in this report are: trends in emissions, description of each NFR category, uncertainty estimates, recalculations, planned improvements and procedures for quality assurance and control. The structure of the report follows to the extent possible the proposed outline.

Information contained in this report is available to the public on the Danish Centre for Environment and Energy (DCE), Aarhus University’s homepage:


This report and the NFR tables are available on the Eionet central data repository:


Responsible institute

DCE-Danish Centre for Environment and Energy, Aarhus University, is on behalf of the Danish Ministry of the Environment responsible for the annual preparation and submission to the UNECE-LRTAP Convention of the Annual Danish Emissions Report and the inventories in the NFR format. DCE participates in meetings under the UNECE Task Force on Emission Inventories and Projections and the related expert panels, where parties to the convention prepare the guidelines and methodologies on inventories.

II Trends in emissions

Acidifying gases

In 1990, the relative contribution in acid equivalents was almost equal for the three gases SO2, NOx and NH3. In 2014, the most important acidification factor in Denmark is ammonia nitrogen and the relative contributions for SO2, NOX and NH3 were 5 %, 35 % and 60 %, respectively. However, with regard to long-range transport of air pollution, SO2 and NOX are still the most important pollutants.

Sulphur dioxide (SO2)

The main part of the SO2 emission originates from combustion of fossil fuels, i.e. mainly coal and oil, in public power and district heating plants. From 1990 to 2014, the total emission decreased by 94 %. The large reduction is mainly due to installation of desulphurisation plants in public power and district heating plants and use of fuels with lower content of sulphur. Despite the large reduction of the SO2 emissions, these plants make up 24 % of the total emission. Also emissions from industrial combustion plants, non-industrial combustion plants, other mobile sources and production of bricks and tiles are important. National sea traffic (navigation and fishing) contributes with about 13 % of the total SO2 emission in 2014. This is due to the use of residual oil with high sulphur content.

Nitrogen oxide (NOx)

The largest sources of emissions of NOX are road transport followed by other mobile sources and combustion in energy industries (mainly public power and district heating plants). The transport sector is the sector contributing the most to the emission of NOX and, in 2014, 44 % of the Danish emissions of NOX stems from road transport, national navigation, railways and civil aviation. Also emissions from national fishing and off-road vehicles contribute significantly to the NOX emission. For non-industrial combustion plants, the main sources are combustion of gas oil, natural gas and wood in residential plants. The emissions from energy industries have decreased by 82 % from 1990 to 2014. In the same period, the total emission decreased by 62 %. The reduction is due to the increasing use of catalyst cars and installation of low-NOX burners and denitrifying units in power plants and district heating plants.

Ammonia (NH3)

The majority of emissions of NH3 result from agricultural activities. Only a minor part originates from stationary combustion (2 %), road transport (2 %), industrial processes (<1 %) and waste (1 %). The share for road transport increased during the 1990’ties and early 2000’s due to growing use of catalyst cars. In more recent years the share is again decreasing due to more advanced catalysts being implemented.

The major part of the emission from agriculture stems from livestock manure (49 %) and the largest losses of ammonia occur during the handling of the manure in animal housing systems. The second largest agricultural source is agricultural soils contributing 46 % in 2014; this is mainly emissions from application of mineral fertiliser, application of animal manure and emissions from crowing crops.

The total ammonia emission decreased by 43 % from 1985 to 2014. Due to the action plans for the aquatic environment and the Ammonia Action Plan, a series of measures to prevent loss of nitrogen in agricultural production has been initiated. The measures have included demands for improved utilisation of nitrogen in livestock manure, a ban against field application of livestock manure in winter, prohibition of broad spreading of manure, requirements for establishment of catch crops, regulation of the number of livestock per hectare and a ceiling for the supply of nitrogen to crops. As a result, despite an increase in the production of pigs and poultry, the ammonia emission has been reduced considerably.

Other air pollutants

Non-methane volatile organic compounds (NMVOC)

The emissions of NMVOC originate from many different sources and can be divided into two main groups: incomplete combustion and evaporation. Road vehicles and other mobile sources such as national navigation vessels and off-road machinery are the main sources of NMVOC emissions from incomplete combustion processes. Road transportation vehicles are still the main contributors, even though the emissions have declined since the introduction of catalyst cars in 1990. The evaporative emissions mainly originate from the agricultural sector, use of solvents and the extraction, handling and storage of oil and natural gas. The total anthropogenic emissions have decreased by 50 % from 1990 to 2014, largely due to the increased use of catalyst cars and reduced emissions from use of solvents.

Carbon monoxide (CO)

Non-industrial combustion plants are the main source to the total CO emission. For the non-industrial sector, emissions from commercial/institutional sources have increased and emissions from agriculture/forestry/fishing sources have decreased from 1990 to 2014, while emissions from the residential sector have been fluctuating, but around the same level in 1990 and 2014.

Transport is the second largest contributor to the total CO emission in 2014, showing a decrease of 83 % from 1990 to 2014. The major transport source is passenger cars, which make up 58 % in 1990, but has decreased to 19 % in 2014. The main driver is the increase of catalyst cars.

In 1990 a law forbidding the burning of agricultural crop residues on fields was implemented, which caused a significant reduction in CO emission.

The total CO emission decreased further by 58 % from 1990 to 2014, largely because of decreasing emissions from road transportation.

Particulate Matter (PM)

The particulate matter (PM) emission inventory has been reported for the years 2000 onwards. The inventory includes the total emission of particles Total Suspended Particles (TSP), emission of particles smaller than 10 µm (PM10) and emission of particles smaller than 2.5 µm (PM2.5).

The largest PM2.5 emission sources are residential plants (59 %), road transport (10 %) and other mobile sources (9 %). Emissions from residential plants have increased by 84 % from 2000 to 2007, followed by a decrease of 48 % from 2007 to 2014. For other mobile sources, the most important sources are off-road vehicles and machinery in the industrial sector and in the agricultural/forestry sector (35 % and 33 %, respectively). For the road transport sector, exhaust emissions account for the major part (52 %) of the emissions. The PM2.5 emission decreased by 24 % from 2000 to 2014 as the increasing wood consumption in the residential sector has been counterbalanced by decreasing emissions for the remaining sectors, the most important being the transport sector.

The largest TSP emission sources are agriculture and non-industrial combustion (72 % and 14 % of total TSP emission in 2014, respectively). Residential plants is the largest source in the non-industrial combustion sector, making up 13 % of the national total TSP emission in 2014.The TSP emissions from transport are also important and include both exhaust emissions and the non-exhaust emissions from brake and tyre wear and road abrasion. The non-exhaust emissions account for 72 % of the TSP emission from road transport in 2014.

Black carbon (BC)

The black carbon (BC) emission inventory is reported for the years 2000 onwards. The main sources are residential plants and road transport contributing 39 % and 21 % in 2014, respectively. From 2000 to 2014 the total BC emission decreases by 33 %. BC emissions from non-industrial plants have increased by 42 % from 2000 to 2007, followed by a decrease of 40 % from 2007 to 2014. The trend for non-industrial combustion is mainly controlled by the trend for the wood consumption in the residential sector. BC emissions from the transport sector decrease by 54 % from 2000 to 2014, mainly due to implementing of new EURO norms and improved technology. An important factor is the use of particle filters for heavy duty vehicles and personal cars, which reduce the BC emission effectively. BC emissions from fugitive emissions from fuels, which are mainly due to storage of coal, decrease by 29 % from 2000 to 2014, in accordance with the decrease of the coal consumption in electricity and heat production.

Heavy metals

In general, the most important sources of heavy metal emissions are combustion of fossil fuels and waste. The heavy metal emissions have decreased substantially in recent years, except for Cu. The reductions span from 19 % to 91 % for Zn and Pb, respectively. The reason for the reduced emissions is mainly increased use of gas cleaning devices at power and district heating plants (including waste incineration plants). The large reduction in the Pb emission is due to a gradual shift towards unleaded gasoline, the latter being essential for catalyst cars. The major source of Cu is automobile tyre and break wear (94 % in 2014) and the 29 % increase from 1990 to 2014 owe to increasing mileage.

Cadmium (Cd)

The main sources of emissions of cadmium (Cd) to air are mainly combustion of wood, wood waste and municipal waste. Non-industrial combustion contributes 72 % in 2014, of which 97 % comes from residential plants. Emissions from residential plants have increased by 215 % from 1990 to 2014 due to increasing wood consumption. Emissions from energy industries, manufacturing industries and construction, and industrial processes have decreased by 89 % from 1990 to 2014. The decreasing emission from energy industries are related to the decreasing combustion of coal. In the transport sector emissions from passenger cars is the main source contributing with 57 % of the sectoral emission in 2014.

Mercury (Hg)

The largest sources of mercury (Hg) emissions to air are waste incineration and coal combustion in energy industries. Due to improved flue gas cleaning and decreasing coal combustion the emissions from Energy industries decreased by 76 % from 1990-2000. The trend has continued in the following years and the corresponding decrease from 1990-2014 is 92 %. Non-industrial combustion is dominated by wood combustion in residential plants while the main contributions to emissions from manufacturing industries and construction are food processing, beverages and tobacco, and non-metallic minerals. The variations in emissions from industrial processes owe to shut down in 2002 followed by re-opening and a second shut down in 2005 of the only Danish electro-steelwork.

Lead (Pb)

The main lead (Pb) emission sources are transport, waste, non-industrial combustion and industrial processes. In earlier years combustion of leaded gasoline was the major contributor to Pb emissions to air but the shift toward use of unleaded gasoline for transport have decreased the Pb emission from transport by 94 % from 1990-2014. The trend in the Pb emission from non-industrial combustion from 1990 to 2014 is almost constant. In the non-industrial combustion sector the dominant source is wood combustion in residential plants, which has been increasing from 1990 to 2014, but counterbalanced by decreasing emissions from stationary combustion in commercial/institutional and in agriculture/forestry/fishing. The decreasing emission from Energy industries (97 % from 1990 to 2014) is caused by the deceasing coal combustion and more efficient particle abatement.

Polycyclic aromatic hydrocarbons (PAHs)

The present emission inventory for polycyclic aromatic hydrocarbons (PAH) includes four PAHs: benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene and indeno(1,2,3-cd)pyrene. Benzo(b)fluoranthene and Benzo(a)pyrene contribute the major PAH emission by 35 % and 31 %, respectively in 2014. The most important source of PAHs emissions is combustion of wood in the residential sector making up 68 % of the total emission in 2014. The increasing emission trend is due to increasing combustion of wood in the residential sector. The PAH emission from combustion in residential plants has increased by 22 % from 1990 to 2014.

Dioxins and furans

The major part of the dioxin emission owes to wood combustion in the residential sector, mainly in wood stoves and ovens without flue gas cleaning. Wood combustion in residential plants accounts for 48 % of the national dioxin emission in 2014. The contribution to the total dioxin emission from the waste sector (35 % in 2014) owes to accidental fires, especially building fires. The emissions of dioxins from energy industries mainly owe to the combustion of biomass as wood, wood waste and to a less extend agricultural waste

Hexachlorobenzene (HCB)

Stationary combustion accounts for 48 % of the estimated national hexachlorobenzene (HCB) emission in 2014. This owes mainly to combustion of municipal solid waste in heating and power plants. Transport is an important source, too, and has increased by 62 % since 1990 due to increasing diesel consumption. The HCB emission from stationary plants has decreased 74 % since 1990 mainly due to improved flue gas cleaning in MSW incineration plants. The emission from agriculture was very high in the early 1990’ties due to the use of pesticides containing impurities of HCB. The HCB emission from agriculture decreased by 94 % from 1990 to 1994 and by 99 % from 1990 to 2014, causing the share of HCB emission from agriculture to drop from 67 % in 1990 to 6 % in 2014.

Polychlorinated biphenyls (PCBs)

Transport accounts for 63 % of the estimated national polychlorinated biphenyls (PCBs) emission in 2013. This owes mainly to combustion of diesel in road transport. The emission from transport has decreased by 69 % since 1990 due to the phase out of leaded gasoline, which has a high PCBs emission factor. This has led to diesel fuel use being the most important source of PCBs emissions from transport in later years. The emission from manufacturing industries and non-industrial combustion is dominated by diesel fuel used in non-road machinery.

III Recalculations and Improvements

In general, considerable work is being carried out to improve the inventories. Investigations and research carried out in Denmark and abroad produce new results and findings which are given consideration and, to the extent which is possible, are included as the basis for emission estimates and as data in the inventory databases. Furthermore, the updates of the EMEP/EEA Guidebook, and the work of the Task Force on Emission Inventories and its expert panels are followed closely in order to be able to incorporate the best scientific information as the basis for the inventories.

The implementation of new results in inventories is made in a way so that improvements, as far as possible, better reflect Danish conditions and circumstances. This is in accordance with good practice. Furthermore, efforts are made to involve as many experts as possible in the reasoning, justification and feasibility of implementation of improvements.

In improving the inventories, care is taken to consider implementation of improvements for the whole time series of inventories to make it consistent. Such efforts lead to recalculation of previously submitted inventories. This submission includes recalculated inventories for the whole time series. A description of the recalculations is provided in Chapter 9 and more detail can be found in the sectoral chapters of this report. For sector specific planned improvements please also refer to the relevant sectoral chapters.