Total greenhouse gas emissions from the Agriculture sector in 2024 were 6'059 kt CO2 equivalent which is a contribution of 15.1 % to the total of Swiss greenhouse gas emissions (excluding LULUCF, Table 2-5, Table 5-1). Main agricultural sources of greenhouse gases were 3A Enteric fermentation, emitting 59 % of all agricultural greenhouse gases, followed by 3D Agricultural soils with 23 % and 3B Manure management with 15 % (Figure 5-1). 3G Liming and 3H Urea application contributed 0.6 % and 0.2 % respectively.
CH4 and N2O emissions generally declined from 1990 until 2004 (Figure 5-2). Subsequently CH4 emissions increased slightly until 2008 and decreased again afterwards. N2O emissions remained more or less on a constant level after 2004 with particularly low emissions in 2022 and 2023. This general development can be explained by the development of the cattle population and the input of mineral fertilisers. Use of mineral fertiliser declined due to the introduction of the “Proof of Ecological Performance (PEP)” in the early 1990s (Agroscope 2019a, Leifeld and Fuhrer 2005). The very low consumptions in the years 2022 and 2023 is probably a consequence of the high fertiliser price in these years. The cattle population was influenced by the market situation, the milk quotation system (suspended in 2009) and the general agricultural policy- and subsidy-system (OECD 2022). Most emission factors did not change significantly over the inventory years. CO2 emissions display high year to year variability due to variability of urea application, which depends among others on the relative price levels of different industrial fertilisers.