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No. 129: Projection of greenhouse gases 2013-2035:

Nielsen, O.-K., Plejdrup, M.S., Winther, M., Hjelgaard, K., Nielsen, M., Fauser, P., Mikkelsen, M.H., Albrektsen, R., Gyldenkærne, S. & Thomsen, M. 2014. Projection of greenhouse gases 2013-2035. Aarhus University, DCE – Danish Centre for Environment and Energy, 139 pp. Scientific Report from DCE – Danish Centre for Environment and Energy No. 129 http://dce2.au.dk/pub/SR129.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 2014 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 (2013-2025) in the models for those sectors for which these forecasts are available. For the years 2026-2035 the emissions are projected by DCE based on the best available knowledge, but is not based on an official energy projection. The estimates for these years are therefore not part of the official projection by the Danish Energy Agency. 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 generally based on the same structure and methodology as the Danish emission inventories in order to ensure consistency. Emissions are not corrected for electricity trade, and it should be pointed out that there is a substantial uncertainty regarding the projection of electricity import/export, which may have a significant effect on the projected emissions.

The main sectors in 2013 are Energy Industries (34 %), Transport (23 %), Agriculture (19 %) 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 2013 to 2035, with decreasing emissions from 2013 to 2025 and almost constant emissions from 2025 to 2035. In general, the emission share for the Energy Industries sector can be seen to be decreasing for the years 2013-2027 followed by an increase in the years 2028-2035, the emission share for the Agriculture is increasing, while emissions from the remaining sectors show a decreasing trend over the projection period. The total emissions in 2013 are estimated to be 53.4 million tonnes CO2 equivalents and 39.8 million tonnes in 2035, corresponding to a decrease of 25 %. From 1990 to 2013 the emissions are estimated to decrease 22 %.

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 2013 from the main source, which is public power and heat production (63 %), are estimated to decrease significantly in the period from 2013 to 2028 (67 %) due to a partial shift in fuel type from coal to wood and municipal waste. From 2029 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 45 % and 30 % from 2013 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 164 % from 1990 to 2012 and projected to increase by 54 % from 2013 to 2035.

Fugitive emissions from fuels

The greenhouse gas emissions from the sector "Fugitive emissions from fuels" show large fluctuations in the historical years 1990-2012, due to emissions from exploration, which occur only in some years with varying amounts of oil and gas flared. Emissions from exploration are not included in the projection, as no projected activity data are available. Emissions are estimated to decrease in the projection period 2013-2035 by 27 %. The decrease mainly owe to expected decrease of offshore flaring in the oil and natural gas extraction. 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 natural gas. Emissions of greenhouse gases from other sources are estimated to be constant or nearly constant over the projection period.

Industrial processes and product use

The GHG emission from industrial processes and product use 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 sources of GHG emission in 2013 is cement production (49 %) and use of substitutes (f-gases) for ozone depleting substances (ODS) (35 %). The corresponding shares in 2035 are expected to be 80 % and 4 %, respectively. 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.

Transport and other mobile sources

Road transport is the main source of GHG emissions in 2013 (67 %) and emissions from this source are expected to decrease by 13 % from 2013 to 2035 due to a forecasted reduction 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. Non-road machinery in industry contributes with 16 % of the GHG emission in 2013 and this share is expected to stay at 16 % in 2035.


The main sources in 2013 are enteric fermentation (36 %), agricultural soils (36 %) and manure management (26 %). The corresponding shares in 2035 are expected to be 41 %, 33 % and 24 %, respectively. From 1990 to 2012, the emission of GHGs in the agricultural sector decreased by 15 %. In the projection years 2013 to 2035 the emissions are expected to increase by 7 %. The reduction in the historical years 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, but emissions are estimated to increase due to an expected increase of the number of animals.


The total GHG emission from the waste sector has been decreasing in the years 1990 to 2013 by 35 %. The decreasing trend is expected to continue with a decrease of 24 % from 2013 to 2035. In 2013, GHG emission from solid waste disposal is predicted to contribute 66 % of the emission from the sector as a whole. A decrease of 55 % is expected for this source in the years 2013 to 2035, due to less waste deposition on landfills. An almost constant level for emissions from wastewater is expected for the period considered. GHG emissions from wastewater handling in 2013 contribute with 13 %. Emissions from biological treatment of solid waste contribute 19 % in 2013 and 41 % in 2035.


For all land categories except Forest Land is assumed an overall emission of around 4 500 Gg CO2 eqv. per year in 2013, decreasing to 4 100 Gg CO2 eqv. per year in 2035. The main drivers for this decrease is a reduction in the area with organic soil in agricultural crop production and an expected decrease in the emission from agricultural mineral soils as they are expected to approach an equilibrium state with the annual organic matter input to and the annual degradation of the organic matter in the mineral soils.

Major changes have been made in the emission inventory for the LULUCF (Land Use, Land Use Change and Forestry) sector. The emission factors have been updated and new sources such as N2O from mineral soils in cropland, CH4 sources in Forests, Grassland and Wetlands, movement of liming from LULUCF to Agriculture etc. has been introduced. All these changes have changed the overall emission from the LULUCF sector from being a net sink of 851 Gg CO2 eqv. to a net source of 491 Gg CO2-eqv. (excl. liming) compared to the reported emission for 2012 in the annual 2014 submission to UNCCC. The largest changes are found in the emission factors for organic soils which have increased. In total the expected emission from Cropland is expected to increase with 22 % and from Grassland with 83 % compared with 2012.

It has not been possible to get updated forest data and the projection does therefore not include living biomass, dead organic matter and the organic soils in the forest. It does however include emissions from the expected land use conversions of mineral soils and loss of living biomass in the converted area. Based on the evidence from historical data this has little influence on the overall carbon stock changes in forest.