The indicator shows the trend in emissions of methane (CH₄), nitrous oxide (N₂O) and carbon dioxide (CO₂) from agriculture over the period 1986–2023. These greenhouse gases increase Earth’s surface temperature and cause global climate change. They affect the natural environment and cause significant damage to the economy, especially to agriculture.

The data are presented in comparison with 1986, which is the base year Slovenia uses to assess progress in reducing emissions under the United Nations Framework Convention on Climate Change. Methane and nitrous oxide are the main greenhouse gases monitored in the Agriculture sector (CRF3 sector). Carbon dioxide, released through liming of agricultural soils and fertilisation with urea and calcium ammonium nitrate, accounts for less than 3% of the total greenhouse gas effect in this sector. Due to differences in greenhouse effect, methane and nitrous oxide emissions are converted into carbon dioxide equivalents. According to the global warming potential method for a 100-year time horizon (GWP₁₀₀), methane is assigned a greenhouse effect 28 times greater than carbon dioxide, and nitrous oxide is assigned a greenhouse effect 265 times greater than carbon dioxide. Methane is a short-lived gas in the atmosphere, and recent research shows that the GWP₁₀₀ method overestimates the global warming effect of methane in Slovenia by several times. Nevertheless, this indicator uses the GWP₁₀₀ method as currently applied. Carbon dioxide from the land use, land use change and forestry (LULUCF) and from use of fossil fuels in agriculture is not included in the Agriculture sector according to the UNFCCC reporting format. Therefore, these emissions are not shown in this indicator.

Agriculture is characterised by large emissions of non-CO₂ greenhouse gases, methane and nitrous oxide. Agriculture is a source of direct and indirect emissions. Direct emissions occur in stables, during the storage of livestock manure and on agricultural land. Indirect emissions occur in the natural environment as a result of the leakage of nitrogen compounds from agriculture.

Methane is produced during the fermentation of feed in the digestive tract of farm animals and during the storage of livestock manure. Due to the relatively large herd and the specificity of digestion, cattle production in Slovenia contributes to over 90% of methane emissions.

Most of the nitrous oxide is produced by fertilizing agricultural crops with livestock manure and mineral fertilizers. A large part of the nitrous oxide is also contributed by indirect emissions resulting from leaching of nitrogen compounds into groundwater and watercourses and ammonia emissions into the air. Storage of livestock manure is also an important source of nitrous oxide.

According to the IPCC (2019) methodology, part of the CO₂ emissions is also reported within the agricultural sector. In Slovenian agriculture, three minor sources of CO₂ are taken into the account, namely the use of urea and calcium ammonium nitrate (KAN) for fertilization and soil liming. They contributed less than 3% to total emissions in Slovenian agriculture in 2023.

From 1986 to 2023, annual methane emissions from agriculture decreased from 53,017 to 41,718 tons, or by 21.3%, and nitrous oxide emissions decreased from 1,932 to 1,597 tons, or by 17.3%. The greenhouse effect of all gasses, expressed in CO₂ equivalents, decreased from 2,053,470 tons to 1,631,979 tons, or by 20.5%, during this period. The rapid decline in emissions was typical of the early years of this period until 2013. From 2013 to 2016, emissions increased. Between 2016 and 2021, they remained at a similar level, but then decreased again. In 2022, Slovenia met the target set by Integrated National Energy and Climate Plan of the Republic of Slovenia until 2030 (decrease by 2,8% compared to 2005). Slovenia is comparable to the countries of Western Europe in terms of GHG emission reduction. However, the decrease was much lower than in most of the Visegrad countries and the countries of South-Eastern Europe, where emissions were reduced by about 50% on average due to problems in the livestock sector.

In absolute terms, pig farming contributed most to the reduction of greenhouse gas emissions, as it significantly reduced methane emissions from enteric fermentation and livestock manure storage. The reduction after 1990 was mainly due to improved manure management, and in the last 15 years to a reduction in animal numbers due to problems in the sector. Methane emissions from enteric fermentation in cattle, particularly dairy cattle, were also significantly reduced. This was mainly due to improvements in production efficiency as similar milk production was achieved with a much smaller dairy herd than previously. Improved fertilization techniques also contributed to the reduction in greenhouse gas emissions. Despite reduced nitrogen inputs from livestock and mineral fertilizers, crop yields increased significantly.

Greenhouse gas emissions from grazing and the keeping of small ruminants increased. The increase in emissions from grazing is not problematic, as emissions from animal houses and manure storage have decreased due to the conversion to grazing.

In general, Slovenian legislation does not address greenhouse gas emissions from agriculture. Exceptions are large pig and poultry farms, which are obliged to operate according to the principle of "best available practice" under the Decree on the types of activities and installations causing industrial emissions (UL RS, 68/22). Indirectly, emissions are reduced by certain regulations for the protection of water and soil, in particular the Regulation for the Protection of Waters against Pollution by Nitrates from Agricultural Sources (UL RS, 113/09, 5/13, 22/15, 12/17, and 44/22). Agri-environmental measures, introduced in 2001 under the Slovenian Agri -environmental Program and later included in Rural Development Programs 2004–2006, 2007–2013, and 2014-2020 also contributed indirectly to the reduction of nitrous oxide emissions. They are also implemented under Common Agricultural Policy Strategic Plan 2023–2027 for Slovenia. Common Agricultural Policy Strategic Plan 2023-2027 includes measures such as optimizing feed rations for farm animals and feeding supplements to reduce enteric methane emissions. Previous rural development programs did not include measures that would make a significant contribution to reducing methane emissions. Professional tasks in animal production and the Public Agricultural Advisory Service, funded by the Ministry of Agriculture, Forestry and Food, are also considered to contribute to the reduction of methane and nitrous oxide emissions.