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No. 632: Denmark's National Inventory Report 2007. Emission Inventories - Submitted under the United Nations Framework Convention on Climate Change, 1990-2005

Illerup, J.B., Lyck, E., Nielsen, O.-K., Mikkelsen, M.H., Hoffmann, L., Gyldenkærne, S., Nielsen, M., Winther, M., Fauser, P., Thomsen, M., Sørensen, P.B., & Vesterdal, L. 2007. NERI Technical Report No. 632, 642 p.

 

Summary

 

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

 

Annual report

 

This report is <st1:country-region w:st="on"><st1:place w:st="on">Denmark</st1:place></st1:country-region> ’s National Inventory Report (NIR), for submission to the United Nations Framework Convention on Climate Change (UNFCCC), for 15 April 2007. The report contains information on <st1:country-region w:st="on"><st1:place w:st="on">Denmark</st1:place></st1:country-region> ’s inventories for all years from 1990 to 2005. The structure of the report is in accordance with the UNFCCC guidelines on reporting and review. The report includes detailed information on the inventories for all years, from the base year to the year of the current annual inventory submission, in order to ensure transparency.

 

The annual emission inventory for <st1:country-region w:st="on"><st1:place w:st="on">Denmark</st1:place></st1:country-region> from 1990 to 2005 is reported in the Common Reporting Format (CRF). 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 NIR is available to the public on the National Environmental Research Institute’s homepage (please see link at the bottom of this page) and the CRF tables are available at the Eionet web site.

 

This report does not contain the full set of CRF Tables. Only the trend tables, Tables 10.1-5 of the CRF format, are included in Annex 9.

 

Concerning figures, please note that figures in the CRF tables (and Annex 9) are in the Danish notation which is “,” (comma) for decimal sign and “.” (Full stop) to divide thousands. In the report (except where tables are taken from the CRF as “pictures” as Annex 9) 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 use due to the risk to be misinterpreted in Danish.

 

Institute responsible

 

The National Environmental Research Institute (NERI), <st1:place w:st="on"><st1:PlaceType w:st="on">University</st1:PlaceType> of <st1:PlaceName w:st="on">Aarhus</st1:PlaceName></st1:place> , is responsible for the annual preparation and submission to the UNFCCC and the EU of the National Inventory Report and the GHG inventories in the Common Reporting Format, in accordance with the UNFCCC guidelines. NERI is also the body designated with overall responsibility for the national inventory under the Kyoto Protocol. The work concerning the annual greenhouse emissions inventory is carried out in cooperation with Danish ministries, research institutes, organisations and companies.

 

Greenhouse gases

 

The greenhouse gases reported under the Climate Convention are:

  • Carbon dioxide            CO2
  • Methane                      CH4
  • Nitrous Oxide              N2O
  • Hydrofluorocarbons     HFCs
  • Perfluorocarbons         PFCs
  • Sulphur hexafluoride    SF6

 

The global warming potential (GWP) for various gases has been defined as the warming effect over a given time 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 individual substances on the global climate. Typical lifetimes in the atmosphere of substances are very different, e.g. approximately for CH4 and N2O, 12 and 120 years respectively. So the time perspective clearly plays a decisive role. The lifetime 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 Second Assessment Report, which UNFCCC has decided to use as reference, the global warming potentials for a 100-year time horizon are:

  • CO2:                            1
  • Methane (CH4):           21
  • Nitrous oxide (N2O):   310

 

Based on weight and a 100-year period, methane is thus 21 times more powerful a greenhouse gas than CO2, and N2O is 310 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 23,900. The values for global warming potential used in this report are those prescribed by UNFCCC.

 

ES.2. Summary of national emission and removal trends

 


Greenhouse Gas Emissions

 

The greenhouse gas emissions are estimated according to the IPCC guidelines and are aggregated into seven main sectors. The greenhouse gases include CO2, CH4, N2O, HFCs, PFCs and SF6. Figure ES.1 shows the estimated total greenhouse gas emissions in CO2 equivalents from 1990 to 2005. The emissions are not corrected for electricity trade or temperature variations. CO2 is the most important greenhouse gas, followed by N2O and CH4 in relative importance. The contribution to national totals from HFCs, PFCs and SF6 is approximately 1%. Stationary combustion plants, transport and agriculture represent the largest sources. The net CO2 removal by forestry and soil (Land Use and Land Use Change and Forestry (LULUCF)) is in the region of 2 % of the total emission in CO2 equivalents in 2005. The national total greenhouse gas emission in CO2 equivalents without LUCF has decreased by 7 % from 1990 to 2005 and by 10 % with LULUCF.

 

 

Figure ES.1     Greenhouse gas emissions in CO2 equivalents distributed on main sectors for 2005 and time-series for 1990 to 2005.

 

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

 


Energy

 

The largest source of the emission of CO2 is the energy sector, which includes the combustion of fossil fuels such as oil, coal and natural gas. Public power and district heating plants contribute with 44 % of the emissions. Approximately 26 % come from the transport sector. The CO2 emission decreased by approximately 7 % from 2004 to 2005. A relatively large fluctuation in the emission time-series from 1990 to 2005 is due to inter-country electricity trade. Thus, high emissions in 1991, 1996 and 2003 reflect electricity export and the low emissions in 1990 and 2005 were due to import of electricity in these years. The increasing emission of CH4 is due to increasing use of gas engines in the decentralised cogeneration plants. The CO2 emission from the transport sector has increased by 26 % since 1990, mainly due to increasing road traffic.

 

Agriculture

 

The agricultural sector contributes with 16 % of the total greenhouse gas emission in CO2-equivalents and is one of the most important sectors regarding the emissions of N2O and CH4. In 2005, the contributions to the total emissions of N2O and CH4 were 89 % and 65 %, respectively. The main reason for a fall of approximately 31% in the emission of N2O from 1990 to 2005 is legislative demand for an improved utilisation of nitrogen in manure. This result in less nitrogen excreted per livestock unit produced and a considerable reduction in the use of fertilisers. From 1990, the emission of CH4 from enteric fermentation has decreased due to decreasing numbers of cattle. However, the emission from manure management has increased due to changes in stable management systems towards an increase in slurry-based systems. Altogether, the emission of CH4 for the agricultural sector has decreased by 9 % from 1990 to 2005.

 

Industrial processes

 

The emissions from industrial processes – i.e. emissions from processes other than fuel combustion, amount to 4 % of total emissions in CO2-equivalents. The main sources are cement production, refrigeration, foam blowing and calcination of limestone. The CO2 emission from cement production – which is the largest source contributing with about 3 % of the national total – increased by 65 % from 1990 to 2005. The second largest source has been N2O from the production of nitric acid. However, the production of nitric acid/fertiliser creased in 2004 and therefore the emission of N2O also creased.

 

The emission of HFCs, PFCs and SF6 has, since 1995 until 2005, increased by 158 %, largely due to the increasing emission of HFCs. The use of HFCs, and especially HFC-134a, has increased several fold, so HFCs have become dominant F-gases, contributing 67% to the F-gas total in 1995, rising to 96% in 2005. HFC-134a is mainly used as a refrigerant. However, the use of HFC-134a is now stable. This is due to Danish legislation, which, in 2007, forbids new HFC-based refrigerant stationary systems. Running counter to this trend, however, is the increasing use of air conditioning systems among mobile systems.

 

Land Use and Land Use Change and Forestry (LULUCF)

 

The LULUCF sector is generally a net sink. In 2005 it has been estimated to be a net sink equivalent to 2% of the total emission. This is lower to previous years due to stormfelling in the forests in 2005 reducing the net sink in forests from normally 3500 Gg CO2/yr to 1852 Gg CO2/yr. In cropland a net sink has been estimated of 308 Gg CO2 with the organic soils as source and the mineral cropland as net sink. The emission estimate from cropland is calculated with a dynamic model taking into account harvest yields and actual temperatures and thus may therefore fluctuate between years. 2005 was an average year and the emission from cropland is therefore an average estimate. Only a small area with permanent grassland is occurring in <st1:country-region w:st="on"><st1:place w:st="on">Denmark</st1:place></st1:country-region> and has only little influence on the overall emission trend.

 

Waste

 

Waste disposal is the third largest source of the CH4 emission. The emission has decreased by 21 % from 1990 to 2005, at which point the contribution from waste was 19 % of the total CH4 emission. This decrease is due to the increasing use of waste for power and heat production. Since all incinerated waste is used for power and heat production, the emissions are included in the 1A1a IPCC category. The CH4 emission from wastewater handling amounts to around 5 % of the total CH4 emission.

 

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 emphasises 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 final reporting.

 

As part of the Quality Assurance (QA) activities, emission inventory sector reports have been prepared and sent to national experts, not involved in the inventory development, for review. To date, the reviews have been completed for the stationary combustion plants sector, the transport sector and the agriculture 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 performed.

 

ES.4.2. Completeness

 

The Danish greenhouse gas emission inventory, which was due 15 April 2007, includes all sources identified by the revised IPPC guidelines except the following:

 

Agriculture: The methane conversion factor in relation to the enteric fermentation for poultry and fur farming is not estimated. There is no default value recommended by the IPCC. However, this emission is seen as non-significant compared with the total emission from enteric fermentation.

 

ES.4.3. Recalculations and improvements

 

The main improvements of the inventories are:

 

Energy

 

Stationary Combustion

 

For stationary combustion plants the emission estimates have been updated according to latest energy statistics published by the Danish Energy Authority. The update includes the years 1990-2004. This is the main reason for the changes in this sector. However changed fuel type aggregation also caused imperceptible changes.

 

The distribution of emissions from the industrial sector, 1A2 was updated based on new information from Statistics Denmark and the Danish Energy Authority. The total emission from category 1A2 was not affected only the distribution between the sub-sectors 1A2a-1A2f.

 

Harmonisation of the GHG inventory and the information compiled for the European Emission Trading System (ETS) is on-going.

 

Mobile sources

 

The biggest changes for CO2 are seen for off-road vehicles in the agriculture sector, where updated stock information for tractors and harvesters (2001-2004) have resulted in increasing estimated fuel consumption and emissions.

 

Minor changes are:

  1. The estimated consumotion of fuel oil from the fishery sector in the national energy statistics has been moved to the national sea transport category, resulting in emission changes for 1990-2004.
  2. A minor amount of diesel oil fuel use has been subtracted from the fishery sector, in order to correct an error in last year’s submission for 1990-2004.

 

Industry

 

No methodological changes have been introduced in the 2005 GHG inventory. Harmonisation of the GHG inventory and the information compiled for the ETS is on-going.

 

Solvent

 

A survey based on new methodologies results in new NMVOC emission estimates. Revisions have been made regarding use of pentane and styrene in the plastic industry, use and emission factors of glycolethers, use and emission factor of tertrachloroethylene and reassignment of some product groups from degreasing to paints.

 

Agriculture

 

Small changes in the emission estimates for the agricultural sector have taken place. These changes reflect increased emissions from years 1990-2004 by less than 1 %. There is no change in the calculation methodology. Based on the expert review team request, the feed consumption for dairy cattle 1990 – 1994 has been interpolated, in order to remove the time-series inconsistency. Another change is due to updated normdata for nitrogen excretion in 2003 and new data for export of living poultry from 1994.

 

Waste

 

The methodology for CH4-emissions from solid waste disposal sites has been slightly changed following a suggestion by the review team. The point was in the decay model to change the use of the oxidation factor, so that the subtraction of CH4 due to oxidation was done after the subtraction due to recovered CH4. The change has resulted in an increase in yearly CH4 emission from solid waste disposals for the time-series up to maximum of 2 %.

 

Land Use and Land Use Change and Forestry (LULUCF)

 

Cropland, grassland and wetlands

 

A small recalculation has been made for the area converted from cropland and grassland to wetlands. The total area affected by this is less than 0.02 % of the Danish agricultural area. The influence on the emission estimate is almost zero.

 

The new report from UNFCCC has made it possible to include CH4 emissions from wetlands, which was not possible earlier. Drainage of wetlands with the aim of peat extraction reduces the emissions from these areas. The total area with peat extraction is 887 ha. For all years are included a reduced CH4 emission due to the drainage. A standard emission factor of 20 kg/CH4/ha/yr is used. The effect of this on the total LULUCF sector is < 0.1 %.

 

Total changes

 

For the National Total CO2 Equivalent Emissions without Land-Use, Land-Use Change and Forestry (LULUCF), the general impact of the improvements and recalculations performed is small and the changes for the whole time-series are between -0.02 % and +0.18 %. Therefore, the implications of the recalculations on the level and on the trend, 1990-2004, of this national total are small.

 

For the National Total CO2 Equivalent Emissions with Land-Use, Land-Use Change and Forestry (LULUCF), the general impact of the recalculations is rather small, although the impact is larger than without LULUCF due to recalculations in the LULUCF sector for 2003 and 2004. The differences vary between –1.01 % and +0.14 %. These differences refer to recalculated estimates, with major changes in the LULUCF for those years.

 

Full report  in pdf format (9,686 kB)