Aarhus Universitets segl

No. 48: Projection of greenhouse gases 2011-2035

Nielsen, O-K., Plejdrup, M.S., Winther, M., Hjelgaard, K., Nielsen, M., Hoffmann, L., Fauser, P., Mikkelsen, M.H., Albrektsen, R., Gyldenkærne, S. & Thomsen, M. 2013. Projection of greenhouse gases 2011-2035. Aarhus University, DCE – Danish Centre for Environment and Energy, 179 pp. Scientific Report from DCE – Danish Centre for Environment and Energy No. 48 http://www.dmu.dk/Pub/SR48.pdf


This report contains a description of the models, background data and projections of the greenhouse gases (GHG) carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6) for Denmark. The emissions are projected to 2035 using a scenario, which includes the estimated effects of policies and measures implemented by September 2012 on Denmark’s GHG emissions (‘with existing measures’ projections). The official Danish forecasts, e.g. the latest official forecast from the Danish Energy Agency (DEA), are used to provide activity rates in the models for those sectors for which these forecasts are available. The emission factors refer to international guidelines or are country-specific and refer to Danish legislation, Danish research reports or calculations based on emission data from a considerable number of industrial plants in Denmark. The projection models are widely based on the same structure and methodology as the Danish emission inventories in order to ensure consistency.

The main sectors in the years 2008-2012 (‘2010’) are expected to be Energy Industries (38 %), Transport (23 %), Agriculture (16 %) and Other Sectors (10 %). For the latter sector the most important sources are fuel combustion in the residential sector. GHG emissions show a decreasing trend in the projection period from 2010 to 2035, with decreasing emissions from 2010 to 2025 and slightly increasing emissions from 2025 to 2035. In general, the emission share for the Energy Industries sector can be seen to be decreasing while the emission share for the Transport sector is increasing. The total emissions in ‘2010’ are estimated to be 59 255 ktonnes CO2 equivalents and 45 731 ktonnes in 2035, corresponding to a decrease of 23 %. From 1990 to ‘2010’ the emissions are estimated to decrease 14 %.

Stationary combustion

Stationary combustion includes Energy industries, Manufacturing industries and construction and Other sectors. Other sectors include combustion in commercial/institutional, residential and agricultural plants. The GHG emissions in ‘2010’ from the main source, which is public power production (64 %), are estimated to decrease significantly in the period from 2011 to 2024 due to a partial shift in fuel type from coal to wood and municipal waste. From 2025 to 2035 the emission is projected to be almost constant. Also, for residential combustion plants and combustion in manufacturing plants a significant decrease in emissions is projected; the emissions decrease by 46 % and 48 % from 2011 to 2035 respectively. The emissions from the other sectors remain almost constant over the period except for energy use in the offshore industry (oil and gas extraction), where the emissions are increasing by 274 % from 1990 to ‘2010’ and projected to increase by 145 % from ‘2010’ to 2035.

Fugitive emissions from fuels

The greenhouse gas emissions from the sector "Fugitive emissions from fuels" increased in the years 1990-2000, when the emission reached its maximum. Emissions are estimated to decrease in the projection period 2011-2035. The decrease mainly owe to expected decrease of offshore flaring in the oil and natural gas extraction. Further, technical improvements at the crude oil terminal leads to decreasing emissions from storage of crude oil in tanks at the terminal and to a lesser extent from onshore loading of ships in the harbor. Emissions from extraction of oil and natural gas are estimated to decline over the period 2011-2035 due to the expectation of a decrease of extracted amounts of oil and natural gas. Emissions of greenhouse gases from other sources are estimated to be constant or nearly constant over the projection period.

Industrial processes

The GHG emission from industrial processes increased during the nineties, reaching a maximum in 2000. Closure of a nitric acid/fertiliser plant in 2004 has resulted in a considerable decrease in the GHG emission. The most significant source of the process-related GHG emission in ‘2010’ is cement production, which contributes by more than 83 %. Consumption of limestone and the emission of CO2 from flue gas cleaning are assumed to follow the consumption of coal and waste for generation of heat and power. The GHG emission from this sector will continue to be strongly dependent on the cement production at Denmark’s one cement plant.

Solvents and other product use

In 2010 solvent and other product use accounted for 0.2 % of the total GHG emission. The major sources of GHG emissions are N2O from the use of anaesthesia and indirect CO2 emissions from other use of solvents, which covers e.g. use of solvents in households. The CO2 emission from use of solvents is expected to decrease in the projection timeframe.

Transport and other mobile sources

Road transport is the main source of GHG emissions in ’2010’ and emissions from this sector are expected to increase by 47 % from 1990 to 2035 due to a forecasted growth in traffic. The emission shares for the remaining mobile sources (e.g. domestic aviation, national navigation, railways and non-road machinery in industry, households and agriculture) are small compared with road transport. For industry, the emissions decrease from 1990-2035. For this sector there was a significant emission growth from 1990-2009 (due to increased activity), followed by a decline in the level of GHG emissions from 2010 onwards, due to use of gradually more fuel efficient machinery. For agriculture/fishing and navigation the projected emission in 2030 is almost the same as the 1990 emission.

Fluorinated gases

In the timeframe of this project, the total F-gas emission has a maximum in 2008-2009 and hereafter it decreases due to legislative requirements. HFCs are the dominant F-gases, which in 2010 are expected to contribute with 91 % of the F-gas emission.


From 1990 to 2010, the emission of GHGs in the agricultural sector decreased from 12 462 ktonnes CO2 equivalents to 9 520 ktonnes CO2 equivalents, which corresponds to a 24 % reduction. This development is expected to continue and the emission by 2035 is expected to decrease further to 8 859 ktonnes CO2 equivalents. The reduction both in the historical data and the projection can mainly be explained by improved utilisation of nitrogen in manure, a significant reduction in the use of fertiliser and a reduced emission from N-leaching. These are consequences of an active environmental policy in this area. Measures in the form of technologies to reduce ammonia emissions in stables and expansion of biogas production are considered in the projections.


The total historical GHG emission from the waste sector has been decreasing since 1990. The level predicted for 2011 and onwards is decreasing compared with the latest historic year. In ‘2010’, CH4 emission from landfill sites is predicted to contribute 70 % of the emission from the sector as a whole. From 2010 a further decrease in the CH4 emission from landfill is foreseen due to less waste deposition on landfills. An almost constant level for both the CH4 and N2O emission from wastewater in the period considered is foreseen. Emissions from wastewater handling in ‘2010’ contribute with 16 %. The categories waste incineration & other waste contributes 14 % of the total GHG emission from the waste sector in ‘2010’. The emission is expected to increase due to increasing use of composting as a mean of waste disposal.


The overall picture of the LULUCF sector is a net source of 4 423 Gg CO2 eqv. in 1990. In 2010 it was turned into a net sink of 2 176 Gg CO2 eqv. In the future it is expected that the whole LULUCF sector will be a net source of 3 204 Gg CO2 eqv. in 2015. Until 2035 it is assumed that this will remain relatively constant. The major reason for this increase is that calculation of emissions from agricultural soils uses a temperature dependent model, which takes into account the expected increased global warming. Afforestation is expected to continue to take place in Denmark with an estimated rate of 1 745 hectare per year. Together with a very small deforestation rate, the carbon stock in the Danish forest is expected to increase in the future. Cultivation of organic soils is a major steady source of emissions. Possible future regulations will reduce the area with cultivated agricultural organic soils further in the future, but there will continue to be a large net emission from these soils.