1. Introduction  

The emissions of ammonia (NH₃), other reactive nitrogen (Nr) species and methane (CH₄) from the agricultural sector have been identified as significant contributors to both air pollution and climate change.

Sutton, Howard, Mason, Brownlie, & Cordovil, 2022

Reactive nitrogen refers to all nitrogen compounds that are chemically active, with the exception of inert nitrogen gas (N₂), which makes up 78 percent of the Earth's atmosphere but is largely unreactive. Agricultural emissions primarily contribute to global warming through the release of nitrous oxide (N₂O) and CH_4,

Naturvårdsverket, 2024

while air pollution is mainly driven by the emission of nitrogen oxides (NO_x) and NH₃.

European Commission, 2024e

CH₄ also contributes to air pollution by the forming of ground-level ozone.

European Commission, 2024a

The emission of pollutants from the agricultural sector is compiled each year by UNFCCC and CLRTAP. Emissions of CH₄, NO_x, NH₃ and N₂O from each Nordic country are shown in table 1.

Environmental issues are complex, ranging from climate change and biodiversity loss to resource depletion and pollution. These issues link to sustainable development; biodiversity; food systems; international environmental cooperation; environmental impact assessment and public participation; implementation, enforcement and monitoring.

European Parliament, 2024

Unsustainable production and consumption patterns drive both climate change and environmental pollution in a negative direction.

EEA, 2024

The policies and measures adopted to mitigate climate change and reduce pollution are inevitably characterised by synergies and trade-offs.

EEA, 2024

This study focusses on co-benefits and trade-offs between mitigation of NH₃, N₂O, CH₄ and NO_x on the basis of effects on both air pollution and climate. Agriculture is a main polluting sector for emissions of NH₃, N₂O, and CH₄, while NO_x emissions are primarily linked to the energy and transportation sectors. However, agricultural practices also contribute to NO_x emissions, although to a lesser extent. It is expected that mitigation of agricultural air pollution would offer the opportunity to improve human and ecosystem health alongside the co-benefits for climate, water quality and the economy.

Leip, et al., 2023

Table 1. Emissions of NH₃, N₂O, CH₄ and NO_x from the agricultural sector 2022 (tones)

UNFCCC & LRTAP

.* Values marked with (*) from the year 2021.

The Nordic countries have committed to reducing their emissions in line with international conventions and agreements. In addition, there are national and international commitments to reduce nitrate (NO₃^-) leaching that effect ground-, fresh- and coastal waters. Figure 1 illustrates the nitrogen cascade and losses of CH₄ from agriculture.

The existing national action strategies predominantly focus on mitigating negative environmental impacts in isolation, without considering the interconnected or holistic effects on several areas. Consequently, mitigation measures being targeted to reduce climate change can have negative effects on air pollution, by increasing emissions and vice versa. Looking at several areas at the same time would bring a greater overall environmental benefit and reduce the risk of implementing measures that solve one problem but worsen another. It is common to describe the complex interactions of nitrogen as the nitrogen cascade

Galloway, et al., 2003

. In brief terms, the nitrogen cascade refers to the series of environmental changes and impacts that occur as reactive nitrogen (from sources like fertilisers and fossil fuel combustion) moves through ecosystems. It begins with nitrogen deposition, leading to soil and water contamination, to shifts in plant communities, and disruptions in biodiversity. As nitrogen compounds cycle through air, land, and water, they contribute to consequences like climate change and eutrophication, ultimately affecting ecosystem health and functioning.

Figure 1. The nitrogen cascade and CH₄ emissions from agriculture. Modified from

Galloway, et al., 2003

.

Developing integrated strategies for climate and air pollution in the agricultural sector focusing on measures reducing NH₃, CH₄, and N₂O and considering NO₃^- leaching and N use efficiency would help the Nordic countries to work for multiple national goals as well as towards their commitments under several international conventions and agreements. An integrated strategy in this context is a comprehensive plan containing a mix of measures designed to simultaneously reduce more pollutants without increasing other environmental problems.

For air pollution, all Nordic countries are Parties to the UNECE Convention on Long Range Transboundary Air Pollution (CLRTAP)

Directive (EU) 2016/2284 of the European Parliament and of the Council of 14 December 2016 on the reduction of national emissions of certain atmospheric pollutants, amending Directive 2003/35/EC and repealing Directive 2001/81/EC 

. The eight protocols in this convention set national binding emission reduction targets on many air pollutants, including the metals mercury, leads, cadmium as well as many Persistent Organic Pollutants (POP).  In the most recent protocol, the so-called Gothenburg Protocol, from 1999, with the objective to abate acidification, eutrophication and ground-level ozone, emission targets, cover the pollutants: sulfur dioxide (SO₂), NOx, volatile organic compounds (NMVOC), NH₃, fine particulate matter (PM_2,5) (including black carbon) are covered. The Gothenburg Protocol was amended in 2012 to include updated national emission reduction commitments set as percentage emission reductions between the base year 2005 and the target year 2020 and beyond. The Gothenburg Protocol has entered a revision phase in 2024, which is anticipated to enhance efforts to further reduce air pollution across Europe and North America.

Decision 2023/5, 2023

The EU directive on National Emissions Ceilings (NEC) (2016/2284/EU) is another key legislation for air pollution and is closely aligned with the Gothenburg Protocol. It sets national Emissions Reduction Commitments (ERCs) for the same air pollutants (NOx, NMVOCs, SO₂, NH₃ and PM_2.5). The ERCs agreed for the year of 2030, are designed to reduce the health impacts of air pollution by half compared with 2005 levels. In addition, air pollutants are also regulated under the Ambient Air Quality Directives (AAQD), which set air quality standards for 12 pollutants including NOx, based on recommendations from the World Health Organisation (WHO). The standards in the AAQD were under revision, and in October 2024 the amended directive was adopted, with updated air quality standards for pollutants to be reached by 2030.

European Council, 2024

Furthermore, there are also several sector specific legislations that covers air pollutants, for example for the energy, industry, transport and agricultural sector.

European Commission, 2024c

The Paris Agreement, adopted in 2015, is an international binding agreement aimed at mitigating climate change. All Nordic countries have committed to the Paris agreement. On an EU level the Effort Sharing Regulation (ESR) sector is designed to manage greenhouse gas emissions from agriculture as well as other sectors not included in the EU Emissions Trading System (EU ETS) or the Land Use, Land Use Change, and Forestry (LULUCF) Regulation. The ESR sector thus includes the agricultural sector as well as domestic transport (excluding aviation), buildings, small industry and waste. Together the ESR sector stand for almost 60 percent of the total domestic EU emissions.

European Commission, 2024d

The ESR sector establishes a national target for each member state for the reduction of greenhouse gas emissions by 2030. EU Member States, have new emission reduction targets ranging from 10 to 50 percent in 2030 compared to 2005 levels. In addition to establishing targets for the reduction of emissions by 2030, the ESR also defines annual emission limits for the years 2021 to 2030. The EU Climate Law also requires the European Commission to make a legislative proposal for a 2040 climate target, which was put forward in the beginning of February 2024. The European Commission recommended a 90 percent cut on 1990 levels by 2040 to complement the existing targets to reduce net emissions with 55 percent by 2030 and 100 percent by 2050. Although agriculture accounts for around 10 percent of the EU’s greenhouse gas emissions, there was no specific target for the agricultural sector to reduce their emissions in the final proposal. It will be up to a new EU Commission and Parliament, formed after the European Parliament elections in June 2024, to pass the final target.

The Global Methane Pledge (GMP) commits members to a collective goal of reducing CH₄ emissions by at least 30 per cent by 2030, compared with 2020 levels. All Nordic countries are participating in the GMP and have submitted an EU Methane Action Plan, and developed national action plans.

Efficient incentives mechanisms will be needed for the agriculture to contribute to the decided goals on air pollution and climate. The Nordic countries use different policy measures today and have somewhat different plans for the way forward. For the counties that are members in the EU, a large common incentive structure is EU’s common agricultural policy (CAP). The current program period is 2023–2027 and the next will start from year 2028.

This project's main goal is to present and evaluate existing mitigation measures of NH₃, other forms of Nr and CH₄ in the agricultural sector for the Nordic countries. The report primarily focuses on emissions affecting air quality and climate; however, other aspects of reactive nitrogen are also considered. The project will identify and propose measures and science-based policies of integrated strategies for emission reductions for the above-mentioned pollutants. By doing so, this project demonstrates how to simultaneously mitigate negative impacts on both climate change and air quality, and what measures can help the Nordic countries to meet targets under international agreements and commitments.

This project addresses the current state of knowledge through literature review on measure effectiveness on CH₄, NH₃ and Nr in the Nordic countries and mainly the European Union. The project has not performed new measurements or analysis on measure effectiveness beyond the literature review. Another restriction is that this report does not address metrics related to dietary change and consumption patterns because there have been numerous studies on this topic and the applicability of those measures are difficult to apply, although they are efficient in theory. 

There have been earlier studies on co-benefits and trade-offs between mitigation measures for air pollution and climate in agriculture, also earlier studies funded by the Nordic Council of Ministers.

Antman, et al., 2015; Hellsten, et al., 2017

The project ‘Nordic agriculture air and climate, Baseline and system analysis report’

Antman, et al., 2015

constituted one of the main outputs of the project “Pathways to a Nordic food system that contributes to reduced emissions of greenhouse gases and air pollutants”.

The Nordic Council and the Nordic Council of Ministers, 2024

The focus of the project was to describe the greenhouse gas emissions N₂O, CH₄ and CO₂, and other pollution sources such as NH₃ from the agricultural sector. The presence of measures in each country was mapped either as commonplace (C), on trial basis (T), non-existent (N) or uncertain (U). The mapping was done for 13 measures to reduce emissions from manure and fertilisers; 9 measures on feeding, 10 measures on land use, 6 measures on energy efficiency, 5 measures on energy production, and 5 measures on production and consumption.

Antman, et al., 2015

A subsequent project on ‘Nordic nitrogen and agriculture, policy, measures and recommendations to reduce environmental impact’

Hellsten, et al., 2017

stressed the importance of exchanging experiences on practices and knowledge between the Nordic countries to provide solutions to reduce harmful environmental impacts from agriculture.

It was concluded that Nr, if not taken up by crops, may contribute to several environmental problems, affecting ecosystems, climate and human health. It was further concluded that the Nordic countries have, during the last 20 years (prior to 2017), introduced efficient measures to reduce N losses to the environment. But still, N losses are relatively high as compared to the policy targets set, despite the regulatory framework applicable to the agricultural sector at EU and national levels. It was further concluded that the Nordic countries are at very different stages regarding N abatement. The project gave no firm conclusions on climate interactions.

The considered environmental effects included:

A later study from the Norwegian Research Institution NIVIO (Rivedal et al., 2019) estimated the potential for NH₃ reduction of measures linked to livestock manure and mineral fertiliser, and the social and private economic costs of introducing the measures.

Reduction of N₂O and CH₄ emissions, as a result of NH₃-reducing measures, was also estimated. It was found that various measures linked to the spreading of livestock manure on meadows have the greatest potential for NH₃ reduction.

The effect of livestock manure measures on emissions of NH₃ and N₂O (N₂O) was estimated using the "nitrogen model for livestock manure" used in the national emissions calculation. Changes in CH₄ emissions as a result of NH₃-reducing measures were estimated using the "Methane Model for Livestock Manure". Although these earlier studies address the issue of co-mitigation, the starting point has been from one side, looking at co-benefits on air or climate.