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No. 437: Denmark's National Inventory Report 2021. Emission Inventories 1990-2019

Nielsen, O.-K., Plejdrup, M.S., Winther, M., Nielsen, M., Gyldenkærne, S., Mikkelsen, M.H., Albrektsen, R., Thomsen, M., Hjelgaard, K., Fauser, P., Bruun, H.G., Johannsen, V.K., Nord-Larsen, T., Vesterdal, L., Stupak, I., Scott-Bentsen, N., Rasmussen, E., Petersen, S.B., Olsen, T. M. & Hansen, M.G. 2021. Denmark's National Inventory Report 2021. Emission Inventories 1990-2019 - Submitted under the United Nations Framework Convention on Climate Change and the Kyoto Protocol. Aarhus University, DCE – Danish Centre for Environment and Energy, 944 pp. Scientific Report No. 437 http://dce2.au.dk/pub/SR437.pdf 


ES.1 Background information on greenhouse gas inventories and climate change

ES.1.1 Reporting

This report is Denmark’s National Inventory Report (NIR) 2021 for submission to the United Nations Framework Convention on Climate Change due April 15, 2021. The report contains detailed information about Denmark’s inventories for all years from 1990 to 2019. The structure of the report is in accordance with the UNFCCC reporting guidelines (UNFCCC, 2013). The main difference between Denmark’s NIR 2020 report to the European Commission, due March 15, 2021, and this report to UNFCCC is reporting of territories. The NIR 2021 to the EU Commission was for Denmark, while this NIR 2021 to the UNFCCC is for Denmark, Greenland and the Faroe Islands. The report includes detailed and complete information on the inventories for all years from year 1990 to the year 2019, in order to ensure transparency.

The annual emission inventories for the years from 1990 to 2019 are reported in the Common Reporting Format (CRF). Within this submission separate CRF’s are available for Denmark (EU and KP – CP2), Greenland, the Faroe Islands, for Denmark and Greenland (KP – CP1) as well as for Denmark, Greenland and the Faroe Islands (UNFCCC). The CRF spreadsheets contain data on emissions, activity data and implied emission factors for each year. Emission trends are given for each greenhouse gas and for total greenhouse gas emissions in CO2 equivalents.

The issues addressed in this report are: Trends in greenhouse gas emissions, description of each emission category of the CRF, uncertainty estimates, explanations on recalculations, planned improvements and procedure for quality assurance and control. The information presented in Chapters 2-9 and Chapter 11 refers to Denmark (EU and KP – CP2) only. Specific information regarding the submission of Greenland and the Faroe Islands is included in Chapter 16 and Annex 8, respectively. Chapter 17 contains information on the aggregated submission of Denmark and Greenland under the Kyoto Protocol (e.g. on trends, uncertainties and key category analysis).

This report itself does not contain the full set of CRF tables. The full set of CRF tables is available at the EIONET, Central Data Repository, kept by the European Environmental Agency:   

In the report English notation is used: “.” (full stop) for decimal sign and mostly space for division of thousands. The English notation for division of thousand as “,” (comma) is not used due to the risk of being misinterpreted by Danish readers.

ES.1.2 Institutions responsible

On behalf of the Ministry of the Environment and Food and the Ministry of Energy, Utilities and Climate, the Danish Centre for Environment and Energy (DCE), Aarhus University, is responsible for the calculation and reporting of the Danish national emission inventory to EU, the UNFCCC (United Nations Framework Convention on Climate Change) and the UNECE LRTAP (Long Range Transboundary Air Pollution) conventions. Hence, DCE prepares and publishes the annual submission for Denmark to the EU and UNFCCC of the National Inventory Report and the greenhouse gas (GHG) inventories in the Common Reporting Format, in accordance with the UNFCCC guidelines. Further, DCE is responsible for reporting the national inventory for the Kingdom of Denmark to the UNFCCC. DCE is also the body designated with overall responsibility for the national inventory under the Kyoto Protocol for Greenland and Denmark. Furthermore, DCE participates when reporting issues are discussed in the regime of UNFCCC and EU (Monitoring Mechanism).

The work concerning the annual greenhouse gas emission inventory is carried out in cooperation with Danish ministries, research institutes, organisations and companies. The Government of Greenland is responsible for finalising and transferring the inventory for Greenland to DCE. The Faroe Islands Environmental Agency is responsible for finalising and transferring the inventory for the Faroe Islands to DCE.

ES.1.3 Greenhouse gases

The greenhouse gases reported are those under the UN Climate Convention:

  • Carbon dioxide                               CO2
  • Methane                                        CH4
  • Nitrous oxide                                   N2O
  • Hydrofluorocarbons                         HFCs
  • Perfluorocarbons                             PFCs
  • Sulphur hexafluoride                       SF6
  • Nitrogen trifluoride                          NF3 

The global warming potential (GWP) for various greenhouse gases has been defined as the warming effect over a given time frame of a given weight of a specific substance relative to the same weight of CO2. The purpose of this measure is to be able to compare and integrate the effects of the individual greenhouse gases on the global climate. Typical lifetimes in the atmosphere of greenhouse gases are very different, e.g. approximately 9 and 130 years for CH4 and N2O, respectively. So the time perspective clearly plays a decisive role. The life frame chosen is typically 100 years. The effect of the various greenhouse gases can then be converted into the equivalent quantity of CO2, i.e. the quantity of CO2 giving the same effect in absorbing solar radiation. According to the IPCC and their Fourth Assessment Report, which UNFCCC has decided to use as reference, the global warming potentials for a 100-year time horizon are:

  • Carbon dioxide (CO2):                      1
  • Methane (CH4):                              25
  • Nitrous oxide (N2O):                     298 

Based on weight and a 100-year period, CH4 is thus 25 times more powerful a greenhouse gas than CO2 and N2O is 298 times more powerful than CO2. Some of the other greenhouse gases (hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride) have considerably higher global warming potentials. For example, sulphur hexafluoride has a global warming potential of 22 800. The values for global warming potential used in this report are those prescribed by UNFCCC. The indirect greenhouse gases reported are nitrogen oxides (NOx), carbon monoxide (CO), non-methane volatile organic compounds (NMVOC) and sulphur dioxide (SO2).

ES.2 Summary of national emission and removal trends

Summary ES.2-4 refers to the inventory for Denmark only. The inventories for Greenland, Denmark and Greenland and the Faroe islands are described in Chapter 16 and 17 and Annex 8, respectively. The emissions from Greenland and the Faroe Islands are minor compared to the emissions from Denmark and shows limited fluctuations.

ES.2.1 Greenhouse gas emissions inventory

The greenhouse gas emissions are estimated according to the IPCC guidelines and are aggregated into six main sectors. The greenhouse gases include CO2, CH4, N2O, HFCs, PFCs, SF6 and NF3, although NF3 is not occurring in Denmark. Figure ES.1 shows the estimated total greenhouse gas emissions in CO2 equivalents from 1990 to 2019. The emissions are not corrected for electricity trade or temperature variations.

CO2 is the most important greenhouse gas contributing in 2019 to the national total in CO2 equivalents excluding LULUCF (Land Use and Land Use Change and Forestry) with 70.3 %, followed by CH4 with 16.3 %, N2O with 12.5 %, and f-gases (HFCs, PFCs, SF6 and NF3) with 0.9 %. The energy sector and agriculture represent the largest sources, followed by industrial processes and product use and waste, see Figure 2.1. The net GHG emission by LULUCF in 2019 is 5.5 % of the total emission in CO2 equivalents excl. LULUCF. The total national greenhouse gas emission in CO2 equivalents excluding LULUCF and including indirect CO2 has decreased by 37.6 % from 1990 to 2019, if excluding indirect CO2 the emissions have decreased by 36.9 %. The decrease is mainly caused by decreasing emissions from the energy sector due to increasing production of wind power and other renewable energy. Comments on the overall trends etc. seen in Figure ES.1 are given Chapter 2.

ES.2.2 KP-LULUCF activities

Table ES.1 contains information on emissions/removals of greenhouse gases in 2019.

ES.3 Overview of source and sink category emission estimates and trends

ES.3.1 Greenhouse gas emissions inventory


The emission from the energy sector in 2019 covers 68.2 % of the total emission in CO2 equivalents (excl. LULUCF and indirect CO2). The emission of CO2 equivalents from energy industries (CRF 1A1) has decreased by 67.0 % from 1990 to 2019. The relatively large fluctuation in the emission through the time-series 1990-2019 is due to inter-country electricity trade. Thus, the high emissions in 1991, 1996, 2003 and 2006 reflect a large electricity export and the low emission in 1990, 2005, 2008, 2011 and 2012 is due to import of electricity. In general, CO2 emissions are decreasing due to a lower consumption of fossil fuels and a higher electricity production based on renewable energy, mainly wind power.

The increasing emission of CH4 is due to the increasing use of gas engines in decentralised cogeneration plants. However, in later years the CH4 emission has decreased due to less use of natural gas in gas engines. The CH4 emission from residential combustion (mainly wood) has increased as a result of increased use of wood. However, the wood consumption has decreased substantially over the last years, so that emission is decreasing. The emission of CO2 equivalents from the transport sector (CRF 1A3) increased by 22.0 % from 1990 to 2019, mainly due to increasing road traffic.

Industrial processes and product use

The emissions from industrial processes and product use, i.e. emissions from processes other than fuel combustion, amount in 2019 to 4.2 % of the total emission in CO2 equivalents (excl. LULUCF and indirect CO2). The main sources are cement production and f-gases used in refrigeration and air conditioning.

The largest source is CO2 emission from cement production, which in 2019 contributes with 1129.2 kt CO2, i.e. 2.4 % of the national greenhouse gas emissions. The CO2 emission from cement production has increased by 28.0 % since 1990. The second largest source is the emission from consumption of HFCs mainly from refrigeration and air condition equipment. This source contributes with 335.8 kt CO2 eq, i.e. 0.7 % of the national total. Historically (1990-2004), the emission of N2O from the production of nitric acid has been the second largest source (after cement), with up to 1002.5 kt CO2 equivalents (1990). However, the production of nitric acid ceased in 2004, which reduced the N2O emission from industrial processes drastically.


The agricultural sector contributes in 2019 with 24.8 % of the total emission in CO2 equivalents (excl. LULUCF) and the major part is related to the livestock production. Since 1990, the agricultural emission has decreased 16.7 % mainly due to a decrease in the N2O emission.

In 2019, the agricultural activities accounts for 81.4 % of the total CH4 emission (excl. LULUCF). Since 1990, the emission of CH4 from enteric fermentation has decreased by 7.9 %, which is mainly due to the decrease in the number of dairy cattle. However, the emission from manure management has in the same period increased 14.3 %, which is mainly driven by a change from traditional housing systems towards slurry-based housing systems. In total, the CH4 emission from the agriculture sector 1990 – 2019 has decreased 1.0 %.

In 2019, the agricultural activities accounts for 88.7 % of the total N2O emission (excl. LULUCF). Since 1990, the N2O emission has decreased 25.9 %. A string of measures have been introduced by action plans to prevent the loss of nitro-gen from agriculture to the aquatic environment. These actions have brought a decrease in animal nitrogen excretion, improvement in use of nitrogen in manure and a fall in the use of inorganic N fertiliser, which all have consequences for a reduce of the N2O emission.

Land Use and Land Use Change and Forestry (LULUCF)

The total sector has been estimated to be a net source of 3.4 % of the total Danish emission incl. LULUCF (average 2013-2019). The average emission in 2013-2019 has been estimated to 1738 kt CO2-eq. with an emission of 2412 kt CO2-eq. in 2019. Emissions/removals from the sector fluctuate based on specific conditions in the given year. In general, the forest sector has been a net sink, while Cropland and Grassland have been net sources. The latter due to a large area with drained organic soils. Emissions from drained organic agricultural soils accounts for approximately for 6-7 % of the total Danish emission incl. LULUCF in the latter years. In years where the total sector accounts to approximately zero, the forest and/or the agricultural mineral soils are net sinks. Since 2013, Forest has been estimated to be an accumulated net sink of 22 094 kt CO2 equivalents. In 2019, Cropland has been estimated to be a net source of 6.2 % of the total Danish emission incl. LULUCF. This is mainly due to a large area with cultivated organic soils. Grassland is a net source contributing to 4.8 % of the total Danish emission. This is also due to a large area with drained organic soils. Emissions from Cropland have shown a continuous decrease since 1990 with 42 % and the emission from Grassland has decreased with 4 %. However, large variations occur between years, e.g. in 2018 the emissions are very high due to the unusual high temperatures during the summer accelerating the emissions.


The waste sector contributes in 2019 to 2.8 % of the total emission in CO2 equivalents (excl. LULUCF and indirect CO2). The emission from the sector has decreased by 34.7 % since 1990. The most important activity in the sector is solid waste disposal on land with CH4 emissions contributing in 2019 to 53.6 % of the sectoral total GHG emission.

The CH4 emission from solid waste disposal has been decreasing since 1990 by 65.2 % due to banning of deposing organic waste and an overall decrease in waste deposited because waste has increasingly been used for power and heat production and/or recycled.

Biological treatment of solid waste (5.B) is the second largest contributor to the sectoral total GHG emission in 2019. It contributes to the sectoral total in CO2 equivalents in 2019 with 38.9 %. The emissions from biological treatment of solid waste have increased by 1161 % for CH4 and 234 % for N2O since 1990, due to an increase in the number of biogas plants and the amount of bio-waste composted in Denmark.

Wastewater handling contributes to the sectoral total in CO2 equivalents in 2019 with 15.8 %. The CH4 emissions from wastewater handling have increased by 27.3 % from 1990 to 2019 while the N2O emission has decreased by 40.0 %.

Since all incinerated waste (municipal, industrial, hazardous) is used for power and heat production, the emissions are included in the 1A1a category. Emissions from composting and biogas production have been increasing through the time series due to an increase in the amount of waste being composted and anaerobic digested.

ES.3.2 KP-LULUCF activities

A more detailed description is given in Chapter 10.

ES.4 Other information

ES.4.1 Quality assurance and quality control

A plan for Quality Assurance (QA) and Quality Control (QC) in greenhouse gas emission inventories is included in the report. The plan is in accordance with the guidelines provided by the UNFCCC (Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories and Guidelines for National Systems). ISO 9000 standards are also used as an important input for the plan.

The plan comprises a framework for documenting and reporting emissions in a way that emphasize transparency, consistency, comparability, completeness and accuracy. To fulfil these high criteria, the data structure describes the pathway, from the collection of raw data to data compilation and modelling and finally reporting.

As part of the Quality Assurance (QA) activities, emission inventory sector reports are being prepared and sent for review to national experts not involved in the inventory development. To date, the reviews have been completed for the stationary combustion plants sector, the fugitive emissions from fuels sector, the transport sector, the solvents and other product use sector and the agricultural sector. In order to evaluate the Danish emission inventories, a project where emission levels and emission factors are compared with those in other countries has been conducted.

ES.4.2 Completeness

The Danish greenhouse gas emission inventories include all sources identified by the revised IPPC guidelines.

Please see Annex 5 for more information.

ES.4.3 Recalculations and improvements

Recalculations and improvements are continuously made to the inventory. The sector-specific recalculations and improvements are documented in the sectoral chapters of this report (Chapter 3-7) and a general overview is provided in Chapter 9.