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No. 244: Projection of greenhouse gases 2016-2035

Nielsen, O.-K., Plejdrup, M.S., Winther, M., Hjelgaard, K., Nielsen, M., Mikkelsen, M.H., Albrektsen, R., Gyldenkærne, S. & Thomsen, M. 2017. Projection of greenhouse gases 2016-2035. Aarhus University, DCE – Danish Centre for Environment and Energy, 126 pp. Scientific Report from DCE – Danish Centre for Environment and Energy No. 244. http://dce2.au.dk/pub/SR244.pdf  

Summary

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 latest historic year that has formed the basis of the projection is 2015. The emissions are projected to 2035 using a scenario, which includes the estimated effects of policies and measures implemented by the end of December 2016 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 (2016-2030) in the models for those sectors for which these forecasts are available. From 2031 to 2035, the projection is not part of the official energy projection and is an estimate made by DCE. 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.

The main emitting sectors in 2016 are Energy Industries (31 %), Transport (24 %), Agriculture (21 %) and Other Sectors (10 %). For the latter sector, the most important sources are fuel combustion in the residential sector. GHG emissions show a table trend in the projection period from 2016 to 2035. The total emissions in 2016 are estimated to be 50.8 million tonnes CO2 equivalents and 49.3 million tonnes in 2035. From 1990 to 2016 the emissions decreased by 27 %. 

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 2016 from the main source, which is public power and heat production (61 %), are estimated to decrease in the period from 2016 to 2035 (2 %) due to an decrease in the fossil fuel consumption for electricity production in the later part of the time-series. For residential combustion plants, a significant decrease in emissions is projected; the emissions decrease by 52 % and from 2016 to 2035, due to a lower consumption of fossil fuels. Emissions from manufacturing industries on the other hand increases by 21 %, due to an increase in fossil fuel combustion. The emissions from the other major subsectors remain almost constant over the period.

Fugitive emissions from fuels

The greenhouse gas emissions from the sector "Fugitive emissions from fuels" show large fluctuations in the historical years 1990-2015, 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 2016-2035 by 38 %. 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 projection period 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 2016 are mineral industry (mainly cement production) with 55 % and use of substitutes (f-gases) for ozone depleting substances (ODS) (30 %). The corresponding shares in 2035 are expected to be 82 % and 6 %, 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 only cement plant.

Transport and other mobile sources

Road transport is the main source of GHG emissions from transport and other mobile sources in 2015 (76 %) and emissions from this source are expected to decrease slightly in the projection period 2016 to 2035. 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 agriculture, forestry and fishing contributes 11 % of the sectoral GHG emission in 2016 and this share is expected to increase to 12 % in 2035.

Agriculture

The main sources in 2016 are agricultural soils (38 %), enteric fermentation (35 %) and manure management (24 %). The corresponding shares in 2035 are expected to be 40 %, 38 % and 20 %, respectively. From 1990 to 2015, the emission of GHGs in the agricultural sector decreased by 18 %. In the projection years 2016 to 2035, the emissions are expected to increase by 2 %. 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. 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 in the number of animals.

Waste

The total GHG emission from the waste sector has been decreasing in the years 1990 to 2015 by 35 %. The decreasing trend is expected to continue with a decrease of 7 % from 2016 to 2035. In 2016, GHG emission from solid waste disposal is predicted to contribute 55 % of the emission from the sector as a whole. A decrease of 47 % is expected for this source in the years 2016 to 2035, due to less waste deposition on landfills. An almost constant level for emissions from wastewater is expected for the projection period. GHG emissions from wastewater handling in 2016 contribute with 15 %. Emissions from biological treatment of solid waste contribute 28 % in 2015 and 49 % in 2035.

LULUCF

The LULUCF sector includes emissions from Afforestation, Deforestation, Forestland remaining Forestland, Cropland, Grassland, Wetlands, Settlement and Other Land. The LULUCF sector is generally a source in Denmark due to a large area of cultivated organic soils, which emit CO2 into the atmosphere. The forest are generally in an equilibrium state although afforestation will increase the standing amount of living biomass. In 2016, the Danish farmers were allowed to increase the fertilization of the agricultural crop and hereby increase the crop yield. This will lead to an increased carbons sequestration in the agricultural soils which therefore in the coming years will turn into a net sink. The large area of cultivated organic soils is expected to be a large source also in the future. Danish initiatives for rewetting the organic soils and return them to Wetlands are incorporated in the projection. The LULUCF sector has reported a decrease the emission from 4902 kt CO2 eqv in 1990 to 4153 kt CO2 eqv in 2015. Until 2035 the emission is expected to decrease further to around 1 000 kt CO2 eqv per year.

The Department of Geosciences and Natural Resource Management, Copenhagen University, carry out projections of emissions/removals from forestry.