Aarhus Universitets segl

No. 501: Comparison of climate effects

Mikkelsen, M.H., Albrektsen, R., Gyldenkærne, S. 2022. Sammenligning af klimaeffekter - Emissionsopgørelse, emissionsfremskrivning og Klimaeffekttabet. Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, 166 s. - Videnskabelig rapport nr. 501. http://dce2.au.dk/pub/SR501.pdf

Summary

The Climate Impact Table (Petersen, 2020) includes 56 measures and for each of these measures, a short description is given as well as a review of the background data used for calculation of the climate impact, which is based on information and data given in Eriksen et al. (2020) and Olesen et al. (2018). The original setting of CO2-eqv is based on Global Warming Potential (GWP) given in AR4 (IPCC, 2007). Furthermore, the climate effect for each of the 56 measures is described based on the methodology used to calculate the emissions for the national emission inventory.

In this report there are not estimated which Tier level the emission calculations should be at, to include the measures in The Climate Impact Table. This will be included in the updating of The Climate Impact Table ultimo 2022 in the project ”Klimatabel m. tilhørende katalog”.

The comparison of the calculated climate impact is completed for the emission related to the agricultural sector and the LULUCF sector (Land Use, Land-Use Change and Forestry). Emissions related to energy consumption are included in the energy sector, where emission calculation is based on Energy Statistics, and thus, the changes in fuel consumption will be reflected directly in the emissions inventory and the projection. Therefore, comparison of climate impact due to energy consumption is not included.

For most of the measures, the calculation of climate impact is based on the latest historical data by the national emissions inventory, which  refer to emission inventory reported in 2020 (Nielsen et al., 2020). For some of the measures, changes in data has taken place since 2020, and for these situations a description and update based on the 2022 reporting (Nielsen et al., 2022) is provided.

For many of the measures, the calculation of climate impact is based on the same methodology for both the national emission inventory and the projection. For cases where the methodology differ, this will be mentioned.

The Climate Impact Table includes indirect nitrous oxide (N2O) from atmospheric deposition, which covers atmospheric deposition and nitrogen leaching to groundwater and run-off to water streams and the sea. The Indirect N2O from atmospheric deposition occurs when ammonia (NH3) and NOX are transformed in animal housing, manure storage and during the nitrogen application to agricultural soils. The emission inventories and projections emission of indirect N2O from atmospheric deposition is based on emission of both NH3 and NOX, but in the calculations made for the Climate Impact Table only N2O in connection with NH3 transformation is taken into account and therefor are the comparisons only made for NH3. Furthermore, the NOx emission is very limited and thus have a small impact on the N2O emission.

N2O from leaching are in the national inventory based on the national monitoring programme NOVANA, where department of Ecoscience is responsible for the calculations of N-leaching to groundwater, rivers, and estuaries. For measures with effect on N-leaching are expected to be reflected in data from NOVANA over time.