The indicator shows the trend in emissions of methane (CH₄), nitrous oxide (N₂O) and carbon dioxide (CO₂) from agriculture over the period 1986–2019. These are greenhouse gases that increase air temperature and cause global climate change. They affect the natural environment and cause great damage to the economy, especially agriculture.

The data are presented in relation to the base year 1986, which according to United Nations Framework Convention on Climate Change is the base year for Slovenia to evaluate the effectiveness of emission reductions. Methane and nitrous oxide are the main greenhouse gases reported in relation to agricultural emissions. Carbon dioxide released from liming of agricultural soils and urea fertilisation accounts for less than 2% of the total greenhouse gas effect in agriculture. Because of the differences in greenhouse effect, emissions of methane and nitrous oxide are converted to carbon dioxide equivalents. Methane has a greenhouse effect 25 times greater and nitrous oxide 298 times greater than carbon dioxide. Methane is a short-lived gas in the atmosphere and recent research shows that its importance is overestimated in official emissions inventories. Nevertheless, we treat it in this indicator as it is currently established. According to the IPCC (2006) methodology, carbon dioxide produced by fossil fuel use in agriculture is not reported within the agricultural sector. Therefore, it is not included in this indicator either.

Agriculture is a source of direct (e.g. methane production due to enteric fermentation and during livestock manure storage, formation of nitrous oxide during livestock manure storage, fertilization with animal manure, other organic and mineral fertilizers, grazing, decomposition of crop residues and due to cultivation of histosols) and indirect (e.g. as a result of the leakage of nitrogen compounds from agriculture into water and air and the subsequent release of nitrous oxide from aquatic and terrestrial ecosystems) greenhouse gas emissions.

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 animal 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 (2006) methodology, part of the CO₂ emissions is also reported within the agricultural sector. In Slovenian agriculture, two 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 2% to total emissions in Slovenian agriculture in 2019.

From 1986 to 2019, annual methane emissions from agriculture decreased from 52,256 to 46,985 tons, or by 10.1%, and nitrous oxide emissions decreased from 1,903 to 1,730 tons, or by 9.1%. The greenhouse effect of all gasses, expressed in CO₂ equivalents, decreased from 1,930,579 tons to 1,718,382 tons, or by 11.0%, during this period. After a rapid decrease in the first years of this period, the decrease slowed down. In 2019, Slovenia met the target (increase of CO₂ emissions by 0.3% compared to 2005) set by Operational programme for limiting greenhouse gas emissions until 2020 (increase by a maximum of 5% 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 Ordinance on Activities and Installations Causing Large-Scale Pollution (UL RS, št. 57/15). 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, št. 113/09, 5/13, 22/15 in 12/17). Agri-environmental measures, introduced in 2001 under the Slovenian Agri -environmental Program and later included in Rural Development Programs 2004–2006 and 2007–2013, also contributed indirectly to the reduction of nitrous oxide emissions. They are also implemented under Rural Development Program 2014–2020 (implementation goes beyond 2020). Previous rural development programs did not include measures that would make a significant contribution to reducing methane emissions. Professional tasks in animal husbandry 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.