Authors: Ole-Kenneth Nielsen 1), Erik Lyck 1), Mette Hjorth Mikkelsen 1), Leif Hoffmann 1), Steen Gyldenkærne 1), Morten Winther 1), Malene Nielsen 1), Patrik Fauser 1), Marianne Thomsen 1), Marlene S. Plejdrup 1), Jytte Boll Illerup 1), Peter Borgen Sørensen 2), Lars Vesterdal 3)
Departments: 1) Department of Policy Analysis, National Environmental Research Institute, University of Aarhus.
Note: Jytte Boll Illerup (Affiliation since February 1, 2008: Department Chemistry and Biochemical Engeering, Technical University of Denmark
2) Department of Terrestrial Ecology, National Environmental Institute, University of Aarhus
3) Department of Forestry and Landscape, Faculty of Life Sciences, University of Copenhagen
Denmark’s National Inventory Report 2008 Subtitle: Emission Inventories 1990-2006 - Submitted under the United Nations Framework Convention on Climate Change. National Environmental Research Institute, University of Aarhus. 701 pp. – NERI Technical Report no. 667.
Executive summary
ES.1. Background information on greenhouse gas inventories and climate change
Reporting
This report is Denmark’s National Inventory Report (NIR) 2008, for submission to the United Nations Framework Convention on Climate change, due April 15, 2008. The report contains detailed information about Denmark’s inventories for all years from 1990 to 2006. The structure of the report is in accordance with the UNFCCC guidelines on reporting and review. The difference between Denmark’s NIR 2008 report to the European Commission, due March 15, 2008, and this report to UNFCCC is reporting of territories. The NIR 2008 to the EU Commission was for Denmark, while this NIR 2008 to UNFCCC is for Denmark, Greenland and the Faroe Islands. The annual emission inventory report for Denmark for the years from 1990 to 2006 is unchanged compared with the NIR 2008 to the EU Commission. Since the inventories for Greenland and Faroe Islands are included and described in this report in Annex 6 only, the sector chapters and the summary below are also basically unchanged since the EU reporting, March 15, 2008. The reporting format is 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.
This report is available to the public on the National Environmental Research Institutes homepage
http://www.dmu.dk/International/Publications/ (search for “National Inventory Report 2008”)
This report it self does not contain the full set of CRF Tables. Only the trend tables, Tables 10.1-5 of the CRF format, are included, refer to Annex 9. The full set of CRF tables is available at the EIONET, Central Data Repository, kept by the European Environmental Agency:
http://cdr.eionet.europa.eu/dk/Air_Emission_Inventories/Submission_UNFCCC/envrtkpa
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 in 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 (mostly) not used due to the risk of being misinterpreted in Danish.
Institute responsible
The National Environmental Research Institute (NERI), University of Aarhus, is responsible for the annual preparation and submission to the EU and UNFCCC 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 gas emission inventory is carried out in cooperation with Danish ministries, research institutes, organisations and companies.
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
The global warming potential (GWP) for various greenhouse 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 the individual greenhouse gases on the global climate. Typical lifetimes in the atmosphere of greenhouse gases 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:
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 guidance and are aggregated into seven main sectors. According to decisions made under the UNFCCC and the Kyoto protocol the greenhouse gas emissions are estimated according to IPCC 1996 guidelines and IPCC 2000 good practice guidance. 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 2006. The emissions are not corrected for electricity trade or temperature variations. CO2 is the most important greenhouse gas contributing in 2006 to national total emission in CO2 equiv. excluding LULUCF (Land Use and Land Use Change and Forestry with 81.7 %, followed by N2O with 9.2 %, CH4 7.8 % and F-gases (HFCs, PFCs and SF6) with 1.3 %. Seen over the time span from 1990 to 2006 these percentages have been increasing for CO2 and F-gases, almost constant for CH4 and falling for N2O. Stationary combustion plants, transport and agriculture represent the largest emission categories, followed by Industrial processes, Waste and Solvents, see figure ES.1. The net CO2 removal by forestry and soil is in 2006 2.6 % of the total emission in CO2 equivalents in 2006. The National total greenhouse gas emission in CO2 equivalents excluding LULUCF has increased by 2.1 % from 1990 to 2006 and decreased 1.3 % including LULUCF. Comments on the overall trends etc seen in Figure ES.1 are given in the sections below on the individual greenhouse gases.
Figure ES.1 Greenhouse gas emissions in CO2 equivalents distributed on main sectors for 2006 and time-series for 1990 to 2006.
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 in 2006 with 51 % of the national total CO2 emissions. Approximately 23 % come from the transport sector. The CO2 emission from the energy sector increased by approximately 15 % from 2005 to 2006. A relatively large fluctuation in the emission time-series from 1990 to 2006 is due to inter-country electricity trade. Thus, high emissions in 1991, 1996, 2003 and 2006 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 27 % since 1990, mainly due to increasing road traffic.
Agriculture
The agricultural sector contributes with 13.6 % of the total greenhouse gas emission in CO2-equivalents (excl LULUCF) and is one of the most important sectors regarding the emissions of N2O and CH4. In 2006 the contributions to the total emissions of N2O and CH4 were 91 % and 66 %, respectively. The main reason for the fall at approximately 34 % in the emission of N2O from 1990 to 2006, 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 to 2006, 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 2006.
Industrial processes
The emissions from industrial processes – i.e. emissions from processes other than fuel combustion, amount to 3.5 % of total emissions in CO2-equivalents. The main categories are cement production, refrigeration, foam blowing and calcination of limestone. The CO2 emission from cement production – which is the largest source contributing with about 2 % of the national total – increased by 58 % from 1990 to 2006. The second largest source has been N2O from the production of nitric acid. However, the production of nitric acid/fertiliser ceased in 2004 and therefore the emission of N2O also ceased.
The emission of HFCs, PFCs and SF6 has, since 1995 until 2006, increased by 172 %, 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 94% in 2006. 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 in mobile systems.
Land Use and Land Use Change and Forestry (LULUCF)
The LULUCF sector is generally a net sink. In 2006 it has been estimated to be a net sink equivalent to 2.6% of the total emission. This is slightly higher compared with 2005 due to stormfelling in the forests in 2005 reducing the net sink in forests from normally 3 000-3 500 Gg CO2/yr to 2757 Gg CO2/yr. In cropland a net emission has been estimated to 708 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 may therefore fluctuate between years. The winter 2005/2006 was very mild and therefore the mineral soil was a large emitter in 2006. In Denmark there are small areas with permanent grassland so emission/removal from these areas has only a limited influence on the overall emission trend.
Waste
The waste sector contributes in 2006 with 1.9 % of the national total. The trend of emission from 1990 to 2006 is decreasing by 14.3 %. The sector is dominated by CH4 emission from solid waste disposal contributing 77.5 % to the sector total in 2006 This emission has decreased by 23.0 % from 1990 to 2006, at which point the contribution from waste was 18.6 % of the total CH4 emission. This decrease is due to the increasing incineration 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 and N2O emissions from wastewater handling contribute to the sectoral total with 18.7 and 3.8% respectively. For the wastewater handling emissions the CH4 has an increasing trend while N2O decreases.
Solvents
The use of solvents in industries and households contribute 0.2 % of the total greenhouse gas emissions in CO2-equivalents. There is a 27 % decrease in total VOC emissions from 1995 to 2006. This year’s inventory comprises N2O for the first time. N2O comprises in 2006 26 % of the total CO2-equivalent emissions for solvent use.
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 emphasis transparency, consistency, comparability, completeness and accuracy. To fulfill 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 transport 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 performed.
ES.4.2. Completeness
The Danish greenhouse gas emission inventories include 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
Update of fuel rates according to the latest energy statistics. The update included the years 1990-2005.
For natural gas fired gas engines emission factors for CH4, NMVOC, CO and NOx were updated in connection with a research project including a higher emission factor during start-up/shut-down in the total emission factor.
Data from the ETS has been utilised for the first time in the inventory for 2006. It was mainly coal and residual oil fuelled power plants where detailed information was available.
Based on the in-country review in April 2007 several improvements have been made to the NIR:
Mobile sources
The biggest changes for CO2 are noted for national sea transport and fisheries. Based on new research findings, the fuel consumption of heavy oil and gas oil for national sea transport is now calculated directly by NERI. Fuel adjustments are made in the fishery sector (gas oil) and stationary industry sources (heavy fuel oil) in order to maintain the Grand National energy balance. The fuel consumption changes for national sea transport cause the CO2, CH4 and N2O emissions to change from 1990 to 2005, and the emission changes are followed by the opposite emission changes in fisheries of approximately the same absolute values.
Minor changes are:
1. For road transport, an error occurring for the years 1990-2005 in the distribution of the total mileage between passenger cars and vans has been corrected, and this change in input data has given small emission changes. Also changes have been made to the gasoline fuel consumption input data for the NERI model, throughout the 1990-2005 time series, due to a reduced gasoline consumption calculated for non road working machinery in the same years.
2. For road transport, the emission factors of CH4 and N2O have been updated due to new emission data provided by the COPERT IV model developers.
The changes described in 1) and 2) cause the CO2, CH4 and N2O emissions from road transport to change for the years from 1990 to 2005.
3. For military, the emission factors derived from the new road transport simulations have caused minor emission changes of CH4 and N2O for the years from 1990 to 2005.
4. For residential, the CO2, CH4 and N2O emissions decrease somewhat for the years 1990 to 2005 due to a smaller amount of fuel used by gasoline fuelled working machinery.
5. For agriculture, updated stock information for ATV's (All Terrain Vehicles) from 2002 to 2005, has given a small fuel use and CO2, CH4 and N2O emissions increase for these years.
Industry
No major methodological changes have been introduced in the 2006 GHG inventory. However, the calculations have been changed for calcination of lime to handle lime and hydrated lime separately. For cement industry and sugar refining EU-ETS data has been implemented for 2006.
Solvents
The mean volume of spraying cans is reduced according to information from e.g. trade associations, which reduces the propane and butane emissions in households for the years 1990-2005. Propylalcohol used as windscreen washing agent is reallocated from autopaint and repair to household use and the emission factor is changed, this affects the years 1990-2005. N2O emission is introduced in the solvents emission inventory from 2005.
Agriculture
Small changes in the emission estimates for the agricultural sector 1994-2005 have taken place and influence the total emission from agriculture by less than 1 %. Based on updated data for 2005 from Statistics Denmark a change in livestock production and cultivated area has been made. Another change is due to updated data concerning the N-fixing crops and amount of biogas treated slurry (2002-2005). There is no change in the calculation methodology
Waste
The methodology for CH4-emissions from solid waste disposal sites is unchanged; a very small change from this category occurs due to update of data for biogas recovery for 2005. For waste water handling and the years 2003-2005 an error in the model formulation has been corrected resulting in a minor increase in CH4 emissions.
Land Use and Land Use Change and Forestry (LULUCF)
Forestry, cropland, grassland and wetlands
A small error for forestry in 2005 as well as a rounding error for lime consumption in 1990 has been corrected. Recalculations have been made for mineral soils in 2003, 2004 and 2005 due to errors in the export of data from the the spreadsheets to the CRF-Reporter. Furthermore a recalculation is made due to the chosen methodology where a five-year average is used. The recalculation has the largest impact on the emission estimate for 2004, which has turned from a net sink of 836 Gg CO2 to a large emitter of 1422 Gg CO2.
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 -0.61 % (2005) and +0.26 % (1994). Therefore, the implications of the recalculations on the level and on the trend, 1990-2005, of this national total emission 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 small, although the impact is larger than without LULUCF. The differences vary between –0.44 % (2001) and +2.90 % (2004). These differences refer to recalculated estimates, with major changes in the LULUCF for those years.
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