Mikkelsen, M.H., Gyldenkærne, S., Poulsen, H.D., Olesen, J.E. & Sommer, S.G. Report from NERI no. 231.
By regulations given in international conventions Denmark is obliged to work out an annual emission inventory and document the methodology used in the inventory. The National Environmental Research Institute (NERI) in Denmark is responsible for preparing the emission inventory. The first section of this report contains a description of the emission from the agricultural sector from 1985 to 2002. The second part of the report includes a detailed description of methods and data used to calculate the emissions.
The emission from the agricultural sector includes emission of ammonia (NH3) and the greenhouse gases methane (CH4) and nitrous oxide (N2 O).
The emission inventory in this report differs from previous emission inventories. The calculated emission is based on an integrated model with an improved methodology. The model covers all aspects of the agricultural inputs and estimates both the emissions of ammonia and greenhouse gases. The input data related to the livestock population and land use is based on data from Statistics Denmark, Danish standards for livestock production and fodder consumption from the Danish Institute of Agricultural Science, nitrogen content in crops from animal feed Figures and the amount of nitrogen runoff and leaching from estimations developed in preparing for the Danish Water Action Plan III. The emission inventory is adjusted to reflect the Danish agricultural production. In cases where no Danish data is available default values recommended by the Climate Panel (IPCC) are used.
The ammonia emission from 1985 to 2002 has decreased from 138.400 tonnes of NH3 to 98.300 tonnes NH3 , corresponding an approximately 30% reduction. The main part of the ammonia emission is related to the livestock manure. In 2002 the emission from swine and cattle contributed to the total ammonia emission with 53% and 33% respectively.
The emission of greenhouse gases in 2002 is estimated to 10.15 M tonnes CO2-equivalents. From 1985 the emission has decreased from 13.79 M tonnes CO2 -equivalents, which corresponds to a 26% reduction. From 1990, which is the base year of the Kyoto protocol, the emission from the agricultural sector has decreased by 21%.
The emission of methane is primarily related to the cattle and swine production, which contribute to the total GHG emission with 70% and 26% respectively. The methane emission in 2002 is estimated to 180.3 Gigagram (Gg) or given in CO2 - equivalents 3.79 M tonnes.
The emission of nitrous oxide originates from the nitrogen turnover in the agricultural fields. The main sources are related to the use of livestock manure, synthetic fertiliser and the nitrogen run-off and leaching.
The emission of N2O in 2002 is estimated to 20.53 Gg N2O corresponding to 6.36 M tonnes CO2 - equivalents.
Biogas plants using animal slurry reduce the emission of
methane and nitrous oxide. The methods to estimate the reduced emission are not yet described in the IPCC guidelines. The calculation is based on the amount of treated slurry and the content of volatile solid and nitrogen. In 2002 the emission reduction due to biogas production is estimated to 0.03 M tonnes CO2 - equivalents.
Improvements in utilisation of nitrogen in livestock manure and the following lower consumption of synthetic fertiliser are the most important reasons for the reduction of both the ammonia and greenhouse gas emission. From 1990 there are almost no changes in the emission of methane. A decrease in the cattle production caused a decrease in the emission. But, on the other hand, the emission has increased due to changes in stabling systems towards more slurry. By coincidence the decrease and the increase balance so the emission trend is about zero.
The CO2 emission from land use, land use changes and liming of agricultural soils are not included in the emissions inventory from the agricultural sector. According to the IPCC guidelines this emission should be included in the LULUCF sector (Land-Use, Land-Use Change and Forestry). This CO2 emission is included in the inventories from year 2005 (submission 2003) under the LULUCF sector reported to Climate Convention. The emissions are based on results from a project worked out in co-operation between NERI, the Danish Institute of Agricultural Science and the Danish Centre for Forest, Landscape and Planning (Gyldenkærne et al., 2005).
Full report in pdf-format (1,120 kB).
Link to the summary in AR204.
