|
|
|
The report at hand provides supplementary documentation to the National Inventory Report (NIR) on German green house gas emissions and the [Informative Inventory Report (IIR)](https://iir.umweltbundesamt.de/2023/) on German emissions of air pollutants (especially ammonia). The report documents the calculation methods used in the German agricultural inventory model Py-GAS-EM as well as input data, emission results and uncertainties of the emission reporting submission 2023 for the years 1990 - 2021. More detailed and specific data than available from inventory submissions to [UNFCCC](https://unfccc.int/) are provided as supplementary data ([NIR and CRF tables](https://unfccc.int/ghg-inventories-annex-i-parties/2023)).
|
|
|
|
|
|
|
|
In this context the sector Agriculture comprises the emissions from animal husbandry, the use of agricultural soils and anaerobic digestion of energy crops. As required by the [guidelines](https://unfccc.int/process-and-meetings/transparency-and-reporting/reporting-and-review-under-the-convention/greenhouse-gas-inventories-annex-i-parties/reporting-requirements), emissions of production resources (such as fertlizers) and equipment (such as agricultural machinery), from the use of energy and from land use change are reported elsewhere in the national inventories.
|
|
|
|
|
|
|
|
Calculation methods are based on and adhering to the international guidelines for emission reporting and have been continuingly improved by the [Thünen Institute's](https://www.thuenen.de/de/) working group on agricultural emission inventories with support from [KTBL](https://www.ktbl.de/international#c4874). In particular, these improvements concern the calculation of energy requirements, feeding and the N balance of the most important animal categories as well as emissions from anaerobic digestion. In addition, technical measures such as air scrubbing (mitigation of ammonia emissions) and digestion of animal manures (mitigation of emissions of methane and nitrous oxide) have been taken into account.
|
|
|
|
|
|
|
|
Total GHG emissions from German agriculture decreased from 72.6 Tg CO<sub>2eq</sub> in 1990 to 56.3 Tg CO<sub>2eq</sub> in 2021 (-22.4 %). This reduction is a consequence of the following emission changes of partial sources (rounded figures):
|
|
|
|
|
|
|
|
- decrease of 11 Tg CO<sub>2eq</sub> (-29.6 %) as CH<sub>4</sub> from enteric fermentation,
|
|
|
|
- decrease of 2.7 Tg CO<sub>2eq</sub> (-22.6 %) as CH<sub>4</sub> and N<sub>2</sub>O from manure management,
|
|
|
|
- increase of 1.7 Tg CO<sub>2eq</sub> as CH<sub>4</sub> and N<sub>2</sub>O from anaerobic digestion of energy crops (digester + storage of digestate; 1990: 0 Tg),
|
|
|
|
- decrease of 3.7 Tg CO<sub>2eq</sub> (-18.3 %) as N<sub>2</sub>O from agricultural soils,
|
|
|
|
- decrease of 0.5 Tg CO<sub>2eq</sub> (-29.3 %) as CO<sub>2</sub> from liming (agriculture and forest),
|
|
|
|
- decrease of 0.08 Tg CO<sub>2eq</sub> (-17 %) as CO<sub>2</sub> from application of urea.
|
|
|
|
|
|
|
|
These changes are largely the result of the decline in animal numbers following reunification (reduction of oversized livestock numbers in Eastern Germany) and from the mid-2000s due to the limiting effect of the milk quota system and other economic conditions. Recently, there were also strong impacts of stricter regulations (i.e., amendments of the fertilizer ordinance), of a severe drought in 2018 and following years, and of outbreaks of African Swine Fever, which all accelerated ongoing structural changes in German agriculture.
|
|
|
|
|
|
|
|
NH<sub>3</sub> emissions from agriculture were 482.3 Gg in 2021, which is 27.9 % less than 1990 and 11.5% less than 2005. They are impacted strongly by changing animal numbers as well. The decrease of animal numbers after the German reunification is the main reason for the considerable drop of the emissions from 1991 to 1992. Mitigation measures like emission-reduced storage and application of manure led to a reduction of emissions in subsequent years. However, opposite trends are caused by increase of animal performance and, for some years, animal numbers. In addition, emissions from application of synthetic fertilizer were higher than in 1990 in the years between 1998 and 2017, even though the amount of synthetic fertilizer applied decreased (in units of nitrogen). The observed increase of emissions was due to the increasing share of urea, as urea has a considerably higher emission factor than other synthetic fertilizers. Since 2020, urea fertilizers must either be incorporated within four hours or be stabilized with a urease inhibitor, which is why the emission factor has been greatly reduced from this year onwards. Sales of urea also declined as a result of the regulation. A major contributor to the increase in NH<sub>3</sub> emissions since the early 2000s has been the increase in anaerobic digestion of energy crops.
|
|
|
|
|
|
|
|
**Key words:** Emission inventory, agriculture, livestock husbandry, agricultural soils, anaerobic digestion, energy crops, renewable primary products, greenhouse gases, air pollutants, methane, laughing gas, ammonia, particulate matter |
|
|
\ No newline at end of file |
