4. Discussion and policy options

The primary aim of this project was to determine appropriate actions and develop a policy based on science that would reduce emissions of the pollutants through integrated strategies. In doing so, this project sheds light on how to simultaneously mitigate the negative effects of climate change and air quality, as well as what steps the Nordic countries can take to meet their obligations under international agreements. With reference to both mitigation measures and Nordic policy instrument examples, we have examined the political climate and the implementation of policies to reduce emissions from CH_4, NH₃ and other Nr from the agricultural sector in the Nordic countries.

The policies work on different levels to address different social challenges and improve the environment in different ecosystems. Often, the legislation focuses on solving a certain problem, without considering that a measure may affect another pollutant in a negative or positive way.

To have efficient policies that address the pollutants they need to act on different levels, with an overall legislation and then concrete measures on how to fulfil the commitments/​goals in the overall policy. A good example of this is CAP, where an overall goal to reduce pollution from fertilisers is stipulated, with concreate measures on local levels that will lead to reduce pollutions of fertilisers. In many legislations, this connection can be hard to find, and sometimes there are no suggested measures or regulations on how to comply with the legislation. If there are no suggested measures on how to reduce a certain pollutant and at the same time affecting other pollutants positive, the risk of missing the indirect positive or in worst case increase emissions of other pollutants will increase.

Many of the policies that affects Sweden, Finland and Denmark comes from the EU and are implemented in the national laws and regulations. Norway and Iceland are not members of the EU but are members of the EFTA (the European Free Trade Association). Through the EEA agreement, Norway and Iceland are bound to most of the EUs environmental legislation with some exceptions, for example agriculture. This means that all the Nordic countries work towards reaching the same goal set by the EU. The EU is therefore an important actor with big potential to affect the work towards reducing emissions of Nr and CH₄ from agriculture.

Other important actors on the international area that sets goals for a better air quality is for example the United Nations and the UNECE Convention on Long-range transboundary air pollution (CLRTAP). Through international agreements the Nordic countries are bound to work towards goals that will generate a better air quality. The Nordic countries have often committed to the same goals. An example of this is the Gothenburg protocol annex 17, that all Nordic countries except Iceland have committed to.

The study did not find any webpage within each Nordic country with a combined overview of the commitments and goals that the county has agreed to work with or are bound by. It is also difficult to find information on how they perform on different goals. Therefore, it is hard to get an overall overview of which commitments and goals each country has agreed to work with and how they perform in the area, as well as if there are any conflicts between different goals to reduce emissions of NH₃ and CH₄ or other Nr. To get a better understanding of which goals/commitments that the individual country work with, and how they perform in the area, an overview of all goals and commitments as well as how the country preforms would be a good tool to increase the transparency and understanding of a country’s commitments. 

In this project, we have developed a database with over 300 measures to mitigate emissions of NH₃, Nr and CH₄ (appendix 3). The mitigation measures identified, might have a positive effect on air pollution, but a negative impact on climate, or vice versa. Based on the results of this report, we have identified 17 integrated measures that are effective for both air and climate, table 4.

By using published scenario analysis, comparing the technologies expected to be used for emission reductions according to current and planned legislation with technology solutions available in 2040, we have estimated the emission reduction potential for most of these 17 measures. The scenarios are, to a reasonable degree, comparable with the national emission projections for the agricultural sector, with the main deviations for Icelandic CH₄ emissions and Swedish NH₃ and CH₄ emissions. The estimation of future potentials is naturally uncertain, but serves as informative estimates nevertheless, especially for estimating the size of co-benefits between the pollutants considered in this report. It should be remembered, that much of the potential is associated with implementation of several solutions together, since most agricultural activities already, according to current legislation, will have at least one technology implemented. The cascade effect from implementing several solutions is non-additive, so identification of the emission reduction potential of all measures individually would exaggerate the potential emission reduction.

Table 4 indicates that there are big potentials for reducing NH₃ and CH₄ emissions for the Nordic countries, and that the greatest potential for these emissions seems to be to implement developed measures regarding the storage and use of manure. To reduce NOx emissions focus should be on reducing the use of fertilisers. N₂O can be reduced with several measures focusing on the soil quality, such as avoiding soil-compaction as well as increasing land cover with perennial crops and agroforestry. The latter has a high potential in reducing N₂O for all Nordic countries if assuming tree plantations on 15 percent of the area used for crops and cereal.

Table 5 indicates costs associated with the joint implementation of measures to reduce emissions. As expected, increased production of biogas would imply cost savings with the gas prices assumed in the scenarios. For the combined implementation of increased use of covered storage, low N feed, low emission housing, and low NH₃ application, the combined cost for the Nordic countries would be around 6 € per kilogram NH₃ emissions avoided.

According to Andersen et al.

Andersen, et al., 2024

nearly all types of livestock manure can potentially be utilised for biogas production, with some exceptions like cattle manure contaminated with sand. This is far from the current utilisation rate today. Figures from 2021 indicate that only 18 percent of pig manure and 29 percent of cattle manure in Denmark were processed in biogas plants.

Andersen et al.

Andersen, et al., 2024

calculated the potential reduction of CH₄ emissions to 76 kg CO₂e per tonne of pig manure and 54 kg CO₂e per tonne of cattle manure utilised for biogas production

Assuming Danish agriculture conditions, practises and emissions as baseline

. Additionally, the authors indicate that N₂O emissions could be reduced by 9 kg CO₂e per tonne of pig manure and 10 kg CO₂e per tonne of cattle manure by producing biogas. The reduction is compared to the manure not being utilised for biogas production and is processed according to standard agricultural practises in Denmark.

According to Byers et al.

Byers, Rivedal, Budai, & Øygarden, 2024

less than two percent of Norway’s livestock manure in year 2022 was utilised for biogas production. Their calculations suggest that increasing this proportion to 25 percent could result in annual emissions reductions of 78,000–80,000 tonnes CO₂e by 2030, accounting for CH₄, NH₃, and N₂O

Assuming Norwegian agriculture conditions, practises and emissions in year 2022 as baseline

.

However, Berglund & Mjöfors (2024) highlights the need to further specify regional/​national circumstances when assessing effects on CH₄ emissions from biogas production

Berglund & Mjöfors, 2024

. The authors highlight the importance of clarifying manure removal technologies and speed, as well as rest product temperature during storage after biogas production. In other words, the net effect on emissions might be lower in Sweden than what is quantified by models.

Rivedal et al.

Rivedal, Aune, Hansen, & Prestvik, 2019

estimates that by 2030, NH₃ emissions in Norway can annually be reduced with 810 tonnes and N₂O emissions with 68 tonnes by optimising the feed ration for dairy cows. The authors specifically mention lowering the protein content from 17 percent to 15.5 percent, calving age for heifers from 25.5 to 24 months, and feeding time for bulls from 17.9 to 16.5 months.

A N₂O emission reduction of 50 percent can be achieved by adding nitrification inhibitors (NI) to cattle slurries before application

Sutton, Howard, Mason, Brownlie, & Cordovil, 2022; Recio, et al., 2018

. In a field experiment conducted in a maize field, Recio et al.

Recio, et al., 2018

evaluated the effects of two NI: 3,4 dimethylpyrazole succinic acid (DMPSA) and 3,4 dimethilpyrazol phosphate (DMPP). 30 percent less of cumulatively N₂O was lost because of the measure. However, no appreciable NH₃ loss reduction was observed over time. The measures effect on NO_X emissions have not been studied by the authors.

The rate at which ammonium turns into nitrate can be slowed by adding nitrification inhibitors, such as DCD and DMPP, to fertiliser products that are urea- or ammonium-based.

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

As a result, crops have more access to NO₃^-, which raises yield levels and, depending on soil and climate conditions, lowers N₂O emissions by 35 to 70 percent

According to ‘Akiyama, H., Yan, X., Yagi, K. (2010). Evaluation of effectiveness of enhanced-efficiency fertilisers as mitigation options for N2O and NO emissions from agricultural soils: meta-analysis. Global Change Biology, vol. 16, pp. 1837–1846.’ meta-analysis using field experiment data (113 datasets from 35 studies) published in peer-reviewed journals through 2008.

. A recent Swedish report does, however, indicate that more research is needed to estimate effects on NH₃, and that cost effectiveness appears low

AgriFood economic centre, 2022

. Decreases in NO_x and N₂ emissions are also anticipated, but there isn't enough information available to determine the precise impact.

Several international studies reviewed in Andersen et al.report concluded that precision farming can be an effective tool for emission reductions.

Andersen, et al., 2024

According to one of the studies result

Sehy, Ruser, & Munch, 2003

, an increased N application from 150 kg N/ha to 175 kg N/ha reduce N₂O emissions by 34 percent in areas with low yield potential, whereas areas with high yield potential were unaffected.

Andersen, et al., 2024

Overall, the report by Andersen et al. estimated that the measure could potentially reduce N₂O emissions from Danish agriculture with 130 kg CO₂e/ha/year. The measures effect on NH₃ emissions have not been studied by the authors. However, according to a report by the Nordic Council of Ministers

Nordic Council of Ministers, 2015

NH₃ and N₂O emissions will decrease through precision farming, however it has not been studied further.

“Steering assistance: The 2019 report (Korsæth et al., 2019) examined the impact of using visual guidance systems on 189,000 hectares of grassland which accounted for 40% of all fully cultivated grassland in 2019. It found a climate benefit of 1.4 kg CO₂-eq./daa

Dekar/daa is a Norwegian unit used in agricultre, 1 daa equals 0,1 hectares

, or 2,646 tons CO₂-eq. annually. Additionally, the report indicated a potential economic gain of 15 million NOK. If autosteering had been used on the same area, it could have saved 3.7 kg CO₂-eq./daa, or 6,993 tons CO₂-eq. annually (Korsæth et al., 2019, Table 10).

For potatoes, it was assessed that 80% of the potato area was suitable for steering assistance. Steering assistance allows for denser planting of potato rows, increasing both yield and inputs per decare. Therefore, the climate benefit primarily comes from reduced diesel consumption, although this was not calculated. It was further noted that autosteering, the most advanced form of steering assistance, provided an economic gain of 47 million NOK due to denser potato planting.”

Byers, Rivedal, Budai, & Øygarden, 2024

Precision fertilisation technology makes it possible to adapt to plants site-specific needs.

Bechmann, et al., 2023

Studies on the precise effect on different pollutants has been limited in available literature. One report, Korsæth et al.

Korsæth, A., Lindgaard, H. J., Veidal, A., & Asheim, L. J.

, did, however, conclude that NO₃^- leaching could be reduced by 0.33 kg NO₃-N/daa, corresponding to a 3.4 kg CO₂e/daa reduction of greenhouse gas for precision fertilisation in potato fields.

Bechmann, et al., 2023

Korsæth et al.

Korsæth, A., Lindgaard, H. J., Veidal, A., & Asheim, L. J.

estimated the total emission reduction potential to be 8 800 tonnes of CO₂e, if applied on meadows, barley, spring, wheat and potato fields.

According to a report by Potter et al.

Potter, Delin, Engström, Stenberg, & Hansson, 2022

field-specific N fertilisation reduces hectare-based climate impact with about six percent for field N₂O emissions, which corresponds to a two percent reduction of total climate impact. Quantified, the authors reference (200 kg N/ha) N₂O emissions were 432 kg CO₂e/ha and the field-specific N rate was 409 kg CO₂e/ha, resulting in a reduction of N₂O emissions of 23 kg CO₂e/ha.

According to a study by Andersen et al.

Andersen, et al., 2024

a reduction of 1 kg N fertiliser per hectare will reduce N₂O emissions, from Danish agriculture, with 6.69 kg CO₂e per hectare. However, reducing the amount of fertiliser will also reduce the soils carbon storage capacity. This trade-off effect is estimated to be 2 kg CO₂e/kg less N per hectare, resulting in a cumulative reduction of N₂O emissions of 4.7 kg CO₂e/kg less N per hectare.

Andersen, et al., 2024

The total potential reduction of N₂O emission is estimated to 94–298 million CO₂e/year, depending on the reduced amount of fertiliser (5–15 percent less N). The measures effect on NH₃ emissions have not been studied by the authors.

Rivedal et al.

“Reduced fertilization should be seen in conjunction with measures in livestock husbandry, better utilization of the nitrogen in livestock manure and better agronomy.” Rivedal, Aune, Hansen, & Prestvik, 2019

state that it is possible to reduce fertilisation, whilst maintaining yield levels in Norway. Assuming a reduction of 10 percent, total emission from Norwegian agriculture will be reduced with 162 tonnes of NH₃ and 2.1 tonnes of N₂O (if the measure is implemented by year 2030).

“In addition, there will be a reduction in indirect emissions from runoff and NOx and direct nitrous oxide emissions, which together are estimated at ~194 tonnes of N2O” Rivedal, Aune, Hansen, & Prestvik, 2019

The authors of that study concluded that the measure was not effective in mitigating CH₄ emissions.

According to a report from the Nordic Council of Ministers

Nordic Council of Ministers, 2015

the proposed measure to ‘reduce fertiliser dose to below today’s recommended levels’, aligned with the economical optimum, impacts NH₃, N₂O and CH₄ emissions. The effect has however not been studied further. In the report, the authors emphasise the risk associated with the measure, such as reduced fertiliser will lead to reduced yield. This could in turn potentially result in forest clearing for more agriculture land, which would increase carbon emissions. However, the magnitude of these trade-offs has not been studied further.

Several methods of acidifying manure are being tested and some are already in use, according to a report by Rivedal et al.

Rivedal, Aune, Hansen, & Prestvik, 2019

An established widespread practise in Denmark is to use acids such as sulfuric acid (H₂SO₄) to stabilise N in livestock manure.

Bokashi Norge AS/NIBIO, 2020; Bokashi Norge AS/NIBIO, 2020

A report by Rivedal et al.

Rivedal, Aune, Hansen, & Prestvik, 2019

 assessed the effect of adding acid to open basins containing pig manure by increasing the proportion of artificial floating cover from 1 to 34 percent and simultaneously reducing the number of uncovered basins from 33 to 0 percent. This resulted in a reduction of 109 tonnes NH₃ emissions. However, the reduction is limited to 64 tonnes without implementing additional spreading measures. The authors also studied the effect of adding acid to wet manure spread on meadows and concluded a potential annual emission reduction of 4 700 tonnes of NH₃ emissions and 61 tonnes of N₂O emission (if measure is implemented by year 2030).

Assuming Norwegian agriculture conditions, practises and emissions in year 2019 as baseline

Hellsten et al.

Hellsten, et al., 2017

estimated the NH₃ emission reduction potential of acidifying slurry to 80 percent during storage, and 70 percent during spreading.

Hellsten, et al., 2017

The authors Bechmann et al. estimated that the potential reduction of NH₃ emissions could be 70–90 percent using strong acids compared to current practise.

Bechmann, et al., 2023

The authors did also highlight potential negative trade-offs, such as damage to stock and equipment and mentions bio-acidification as a gentler option although its effects are uncertain.

Rivedal et al. did not asses the measures effect on CH₄ emissions, they did however state its likely to result in a reduction.

Rivedal, Aune, Hansen, & Prestvik, 2019

Bechmann et al. estimated that CH₄ emissions can be reduced upwards 60 percent compared to current practise in year 2019 in Norway, although, more studies are needed to determine the effect.

Bechmann, et al., 2023

A report by Naturvårdsverket & Jordbruksverket

Naturvårdsverket & Jordbruksverket, 2022

summarises results from other studies and presents a reduction in CH₄ emissions from manure according to guideline estimates of  25–90 percent, depending on where in the process the acidification occurs.

Reduced contact between the stored manure and the surrounding air reduces both NH₃ and CH₄ emissions.

Nordic Council of Ministers, 2015

A floating crust coverage for slurry, which is often formed naturally or can be induced with straws or LECA balls, is estimated to reduce NH₃ emissions with 40–65 percent.

Assuming agriculture conditions, practises and emissions in Denmark, Finland, Norway and Sweden during year 2015 as baseline

Floating covers, like plastic sheets, can reduce NH₃ emissions by 60–90 percent and solid covers like roofs or lids can reduce NH₃ emissions by 80–90 percent.

Assuming agriculture conditions, practises and emissions in Denmark, Finland, Norway and Sweden during year 2015 as baseline

Hellsten et al.

Hellsten, et al., 2017

estimates the potential reduction of NH₃ emissions to 50–95 percent, depending on the type of cover.

Assuming Swedish agriculture conditions, practises and emissions as baseline

This is in similar range as Bechmann et al.

Bechmann, et al., 2023

Based of EMEP / EEA (2019) data

and Rivedal et al.

Rivedal, Aune, Hansen, & Prestvik, 2019

Assuming Norwegian agriculture conditions, practises and emissions in 2019 as baseline

result of 40–80 percent reduction, depending on cover (dense and solid cover, artificial floating covers in e.g. plastic and natural cover/​crust). According to the report by Bechmann et al.

Bechmann, et al., 2023

, the measure will also reduce CH₄ emissions, although, the effect has not been studied further. Rivedal et al.

Rivedal, Aune, Hansen, & Prestvik, 2019

suggest that this measure could potentially lead to an annual CH₄ emission reduction of over 300 tonnes from Norway's agricultural sector by year 2030. However, the authors caution that this estimate may not be realistic, as CH₄ emissions can only be significantly reduced through the use of porous covers.

“Slurry: JTI measured emissions over one year of storage (on a trial scale) of cattle and pig slurry, where large-scale conditions were simulated in terms of manure temperature, climate, emptying, and filling (Rodhe, Baky, Olsson, & Nordberg, 2012). Measurements were taken on uncovered slurry, slurry with a floating cover, and slurry with a plastic cover. The results showed about twice as much methane emission during the warm part of the year (5 months) compared to the cold part (7 months), expressed in grams of methane per kg of volatile solids (VS). During the warm part of the year, methane emissions were significantly higher from uncovered cattle slurry and slurry with a floating cover than from cattle slurry with a plastic cover. According to JTI's summary of the trial results, there were no other significant differences between the other cover alternatives or time periods (ibid.). One explanation for the lower methane emissions with a plastic cover in the summer was that the cover may have contributed to a higher concentration of gases that inhibit methane formation. The difference could also be due to measurement uncertainties, as gas bubbles collected under the cover and the gas may have escaped too quickly to be recorded in the measurements.

The results from measurements in other countries suggest that covering (floating cover, membrane/​roof) could reduce methane emissions from slurry, but the effect of cover alternatives varies between studies, and the differences in methane emissions between cover types within a study are not always significant (Petersen et al., 2013; Berg, Brunsch, & Pazsiczki, 2006; Rodhe, Baky, Olsson, & Nordberg, 2012; VanderZaag et al., 2010). According to a literature review by Petersen et al. (2013), floating covers or roofs in some cases reduced methane emissions by about 20–40% compared to uncovered slurry, but in some cases also increased methane emissions. However, it is unclear from their review whether the differences are statistically significant.”

Berglund, 2017. Emissionsfaktorer för utvärdering av klimateffekter av vissa insatser i landsbygdsprogrammet. Hushållningssällskapet Halland, uppdrag för Jordbruksverket.

(machine translated to English)

“Solid and deep litter manure: Methane is produced in oxygen-free environments, but oxygen availability is generally better in deep litter and solid manure compared to slurry, resulting in relatively low methane emissions from solid manure types. However, oxygen-free zones can form in solid manure due to compaction or high oxygen consumption during composting. The composting process also increases the temperature in the manure, which can lead to more methane production, as microbial methane formation is highly temperature-dependent. Covering the manure (with a tarp) can reduce methane production because the cover limits oxygen supply, which inhibits composting and thus prevents temperature rise in the pile (Rodhe, Baky, Olsson, & Nordberg, 2012).”

Berglund, 2017

(machine translated to English)

If solid manure is incorporated into the soil within four hours, NH₃ emissions can potentially be reduced by 60–90 percent, whereas the potential emission reduction decreases to 30 percent if it is done within 24 hours.

Figures are applicable in Sweden, Denmark, Finland and Norway

Nordic Council of Ministers, 2015

According to the authors, this effect has no mitigating effect on N₂O emissions.

According to Rivedal et al.

Rivedal, Aune, Hansen, & Prestvik, 2019

11 percent of the manure is decomposed within one hour. However, if the manure is broken down the share of decomposed manure increases to 34 percent. The authors estimate that by 2030, this technique could lead to an annual reduction of 560 tonnes of NH₃ emissions and 7.2 tonnes of N₂O emissions from emissions associated to animal manure in Norway.

Reducing the exposed slurry area by placing slurry in narrow surface slots can reduce NH₃ emissions with 70–90 percent

Bittman, Dedina, Howard, Oenema, & Sutton, 2014)“Average emission reductions agreed to be achievable across the ECE region”

according to Sutton et al.

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

However, the authors state that this measure can lead to an increase of N₂O emissions as well as NO_X and N₂ emissions.

13 percent of livestock manure is decomposed within one hour and 29 percent within 24 hours.

Byers, Rivedal, Budai, & Øygarden, 2024

If instead 25 percent is decomposed within an hour, and 50 percent within four hours, the maximum potential annual reduction of NH₃ emission is 12 000 tonnes CO₂e in year 2035.

Assuming Norwegian agriculture conditions, practises and emissions as baseline

By adapting crude protein in dairy and beef cattle’s diet, N emissions can be mitigated.

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

A 1 percent reduction of crude protein in cattle’s feed can potentially reduce NH₃ emissions with 5–15 percent

Assuming Norwegian agriculture conditions, practises and emissions as baseline

, as well as reducing N₂O and CH₄ emissions and increase N efficiency in livestock production.

Bechmann, et al., 2023

The authors have not done any further study of the measures effect on N₂O and CH₄ emissions.

The measure reduces NH₃ which in turn reduce indirect N₂O emissions.

Andersen, et al., 2024

CH₄ emissions are also reduced since cooling inhibits the slurry’s biological turnover. However, if parts of the slurry contain unreacted organic matter CH₄ emissions can increase during the slurry’s transfer. Andersen et al.

Andersen, et al., 2024

therefore concludes that the optimal effect is achieved if the slurry is degassed in a biogas plant after discharge, as this simultaneously reduces CH₄ emissions and increases bioenergy production. In total the authors calculated the potential reduction of CH₄ to 3 kg CO₂e/tonne manure and N₂O to 2 kg CO₂e/tonne.

Assuming Danish agriculture conditions, practises and emissions as baseline

Similar calculations were not made for NH₃ emissions. However, in one of the authors calculation examples

Assuming Danish agriculture conditions, practises and emissions as baseline

they concluded that NH₃ emissions will potentially decrease with 13.2 percent in barns with pipe discharge if there is a constant cooling effect of 16.8 W/m². If the barn instead has frequent mechanical removals (like line winch) the reduction is closer to 22.2 percent.

Andersen et. al.

Andersen, et al., 2024

states there are examples of cattle barns who have installed cooling hoses in manure channels to recover heat energy as an alternative to geothermal heating. However, the authors state there is a lack of studies effect of NH₃ and other emissions in relation to this in modern barns.

According to the report by Rivedal et al.

Rivedal, Aune, Hansen, & Prestvik, 2019

Norway’s NH₃ emissions from agriculture could potentially be reduced by 3 490 tonnes and N₂O by 45 tonnes by diluting slurry with water to a 1:1 ratio compared to not diluting at all (study from 2019). The authors also state that if wet manure is diluted with acid, NH₃ discharge can be reduced by 50 percent, resulting in a reduction of Norway’s NH₃ emissions from agriculture with 4 700 tonnes and N₂O emissions with 61 tonnes (study from 2019).

Today, 85 percent of all livestock manure spread on fields in Norway are mixed with water according to the Norwegian statistics bureau (SSB’s) manure survey from 2018.

Rivedal, Aune, Hansen, & Prestvik, 2019

The survey states that 75 percent of livestock manure is mixed with less than one part water to one part fertiliser, and the remaining 25 percent is specifically one part water and one part fertiliser.

Agroforestry integrates the cultivation of trees and shrubs with other crops and is sometimes paired with livestock production.

Naturvårdsverket & Jordbruksverket, 2022

Transfer from regular farming to agroforestry can, according to a report cited by Naturvårdsverket & Jordbruksverket, increase levels of organic carbon in soil by 34 percent.

De Stefano & Jacobson, 2017

Other mentioned trade-off benefits are increased biodiversity, more ecosystem services like pollination and improve the soils water retention (which reduces the loss of nutrient).

According to the report by Andersen et al.

Andersen, et al., 2024

N₂O emissions can be reduced by 170 kg CO2e/ha/year if the trees are harvested in a 5- or 10-year interval, where trees make up 15 percent of the entire area.

Assuming current Danish agriculture conditions, practises and emissions in year 2024 as baseline

However, the net climate effect differs depending on the harvest interval, spanning from 781 to 1 056 kg CO₂e/ha/year.

NH₃ emission from commercial fertilisers is assumed by Andersen et al.

Andersen, et al., 2024

to be four percent of the N content in the applied fertiliser. Therefore, NH₃ emissions are expected to decrease by 6.8 kg N/ha/year with the shift to agroforestry in their working example.

Assuming Danish agriculture conditions, practises and emissions as baseline

“A Danish experiment with willow over 6 years (12,000 plants/ha) showed an annual yield of 4.9, 6.6 and 8.0 tonnes of dry matter per ha per year at harvest intervals of 1, 2 and 3 years, i.e. with a reduction of 18 and 38% by reducing the harvest interval from 3 to respectively 2 and 1 year (Larsen et al., 2019)

An older Swedish study in willow showed that optimal yields were obtained at 4–5 year harvest intervals but also with interaction between plant numbers (10,000-40,000 plants/ha) and harvest interval (Willebrand et al., 1993).”

Jensen, Larsen, Strandberg, & Jørgensen, 2024

(machine translated to English)

Perennial crops like willow, poplar and elephant grass can affect the field’s N and C balance, magnitude depending on factors such as length of growing seasons and the size of the root network.

Andersen, et al., 2024

In recent years, interest in growing perennial crops, specifically for energy purposes, has declined in Denmark according to Andersen et al.

Andersen, et al., 2024

The authors state that this is largely due to the ample availability of alternative biomass sources up until 2022, which kept prices low. Additionally, they state that Denmark's cogeneration sector has primarily relied on wood pellets, limiting the role of perennial crops. However, over the past year, prices for biomass, food, and key inputs like fertiliser have shifted, making future developments uncertain. Andersen et al.

Andersen, et al., 2024

quantified the potential reduction of N₂O emissions by having multi-year perennial crops in rotation to 461 kg CO₂e/ha/year, with a net climate effect (accounting for CO₂/LULUCF and CO₂/energy consumption effect on emissions) to 1 340 kg CO₂e/ha/year

Assuming Danish agriculture conditions, practises and emissions in year 2024 as baseline

. The measures effect on NH₃ emissions were not included in those calculations. However, in one of Andersen et al.

Andersen, et al., 2024

worked examples, the authors concluded that cultivating the perennial crop willow instead of standard crop seeds, a fertiliser saving of 51 kg N/h is achieved. Applying an NH₃ evaporation rate of four percent results in a reduction of 2 kg N/ha.

If livestock are outside for more than 18 hours a day, grazing can reduce NH₃ emissions with 30 to 50 percent and if the animals are outside for 12 hours a day the reduction is estimated to 10 percent.

Assuming Norwegian agriculture conditions, practises and emissions as baseline, study from 2019

Rivedal, Aune, Hansen, & Prestvik, 2019

In the report Rivedal et al.

Rivedal, Aune, Hansen, & Prestvik, 2019

estimates that if grazing is increased to 25 percent in 2030, total NH₃ emissions can be reduced with 799 tonnes, N₂O emissions increased with 23 tonnes and CH₄ emission decreased with 467 tonnes. If animal density is high and grazing is extensive, the expected reduction may not be as significant.

Soil compaction could potentially cause damages to the soils structure, resulting in lower yield levels up to 20 percent.

Bechmann, et al., 2023

By avoiding and/​or minimising soil compaction these yield losses can be reduced. According to the report by Bechmann et al.

Bechmann, et al., 2023

this measure will reduce NH₃ and N₂O emissions, however the magnitude of that effect was not studied by the authors. According to a study by Sitaula et al.

Sitaula, Hansen, Sitaula, & Bakken, 2000

N₂O emissions could potentially be lowered 30 to 60 percent by avoiding and/or minimising soil compaction.

Reduction potential calculated based of Norwegian agriculture conditions, practises and emissions in year 2000 as baseline

In crop rotation, fallow refers to leaving a field uncultivated for at least one growing season/​harvest period.

Andersen, et al., 2024

Therefore, less fertiliser is required which reduces greenhouse gas emissions. Farms in Denmark with more than 15 hectares must allocate 4 percent of their cultivated land with non-productive elements, like for example fallow, in order to receive agricultural support.

Andersen, et al., 2024

According to a report by Andersen et al.

Andersen, et al., 2024

fallow in crop rotation results in a reduction of N leaching by 39–55 N/ha.

Reference leaching of 59 kg N/ha. Figures based of Danish agriculture conditions and practises in year 2023

The effect largely depends on whether the set-aside area was a turnover area or part of environmental schemes, permanent grassland, or uncultivated land.

In Andersen et al.

Andersen, et al., 2024

worked examples, they calculated what effect the measure will have on N₂O emissions. Assuming no fertilisation is needed in fallow areas, and 171 kg N/ha is needed in a regular crop rotation, N₂O emissions would be reduced with 930 kg CO₂e/ha/year, and the net climate effect 1 385 kg CO₂e/ha/year (when taking savings of fossil energy into account).

Assuming Danish agriculture conditions, practises and emissions as baseline

The measure would also reduce NH₃ emissions, although the reduction has not been quantified by the authors. They do however state that NH₃ volatilization is abated and/or reduced because of the reduction of N fertiliser usage, compared to the reference case (171 kg N/ha).

Andersen et al.

Andersen, et al., 2024

proposes producing biochar through pyrolysis of the fibre fraction from digested biomass. In the authors working example, its assumed that pyrolysis occurs in temperatures where the ratio between hydrogen and organic carbon is 0.5 and that that pyrolysis preserves 50 percent of the carbon in biochar. In their report the authors quantified the potential reduction of N₂O emissions by producing biochar through pyrolysis of the fibre fraction from digested biomass to 6 kg CO₂e/​tonne manure

20 percent deep litter in the manure, the rest cattle and pig manure.

, with a net climate reduction effect (accounting for CO₂/LULUCF and CO₂/​energy consumption effect on emissions) of 18 kg CO₂e/​tonne manure.

20 percent deep litter in the manure, the rest cattle and pig manure. Assuming Danish agriculture conditions, practises and emissions as baseline

The measure would also reduce NH₃ emissions, it has however not been quantified by the authors.

Although the focus here is on of NH₃, Nr and CH₄, it is in a policy context necessary to acknowledge that the agricultural sector is important for many reasons, e.g. the importance for food security, economy, land use and landscape, culture, rural communities etc. Agriculture also affects health and environment, both through emissions to air, and through leaching of NO₃^- to ground- and surface waters, pollution with pesticides and heavy metals, soil degradation from agricultural practices etc. There can be linkages between overall N use efficiency, and losses of N as NH₄, NO₃, NO_X and other forms of Nr. This is, however, not dealt with in detail in this report. For all these reasons, regulation and control of the agricultural sector is quite complex with measures ranging from legislation over permits and control for individual farms to tax and subsidies promoting or inhibiting certain practices or encouraging special farming practices like organic farming.

Table 7 summarises some of the tasks and policy areas connected to regulation of the agricultural sector and links to ministerial areas and other authorities, as well as to international regulations. For EU member states, there are policies on many areas affecting agricultural regulations, and other international obligations are typical implemented in EU regulations, that can act directly as law for the member states, or be directives, which need to be implemented in national legislation. The Common Agricultural Policy (CAP) is also an important tool in regulating agriculture. For the non-EU countries, there are still international obligations through Conventions and bilateral agreements that need to be implemented in national law.

Table 7. Policy areas, international obligations and authorities.

Ministerial areas changes with governments depending on political focus and priorities. Because of the complex interactions between agriculture and environment, agricultural regulation is normally divided between different ministerial areas. In many cases, the most important split will be between ministries for agriculture/​food and environment, where the division can shift with governments. In some cases, there can be a split for environment between a pollution-oriented area and a ministry/​ministerial area dealing with nature. In this case, the responsibility for agricultural approvals can also be split.

For the substances in question here, the deposition of NH₃ can have a negative effect on sensitive terrestrial nature types and add to the N pollution of marine areas. However, NH₃ is also a precursor of fine particles (PM_2.5) in the air, which is important for health. CH₄ is an important climate gas, but at the same time a precursor for ozone and therefore important for health. This means that these pollutants and their regulation can also be important for ministries of health and climate, which has a boundary to energy. Planning and rural development also have boundaries to agricultural regulation, and with the latest government reshuffle in Denmark, a new ministry for green transition of agriculture was constructed, which will integrate most of the ministerial areas connected to agriculture.

The organisation of different policy areas in different ministries may appear to be of less importance but can be important for the possibilities of developing policies for co-mitigation of different pollutants. Different ministries and agencies have different traditions for getting science-based advice and different traditions for stakeholder involvement. Established cooperation between knowledge institutions and ministries and agencies can be important, both for national regulation and for cooperation with international entities. As an example, NH₃ emissions are reported to UNECE/​TFRN, whereas CH₄ and NO₂ emissions are reported to UNFCCC, often by different groups in the countries.

Finally, the political and administrative level of a certain regulation can be important; both in how international obligations and regulations are incorporated in national regulations, and at which administrative level a given regulation is implemented, be at national/​regional/​municipality level.

The organisation of ministerial areas, where agriculture, environment and climate are rarely under the same ministerial area can be a potential barrier for the implementation of integrated measures.  This does not mean that effective measures cannot be implemented, but it can lead to a suboptimal prioritisation when measures are implemented to address a single problem like water pollution, emissions to air, or climate mitigation, and the co-benefits of measures might not be fully achieved.

A general basis for environment policy and implementation of instruments could follow the principles of precaution, prevention, rectifying pollution at source, and the ‘polluter pays’ principle.

European Parliament, 2024

Policy instrument can be i) information, ii) direct environmental regulation (command-and control) iii) pricing instruments (taxes, emissions trading systems) and iv) financing instruments (public financial support, payments for ecosystem services).

Andersen & Bonnis, 2021

In general, measures aimed at increasing animal productivity and profitability are implemented continuously and do also have a positive side effect for the environment since they reduce climate impact per kilogram produced food.

Government Offices of Sweden, 2022

A large contribution to CH₄ emissions from the agricultural sector is drained organic soils, mainly originating from waterbodies that have been created by excavation (ditches) on forest land and cropland.

Government Offices of Sweden, 2022

Policies aimed at restoring natural hydrology and extensive farming practises on these areas can give some, but limited effect.

It is generally acknowledged that knowledge dissemination and education of farmers can help to improve their understanding of how best to use fertilisers, and that a fertiliser plan and bookkeeping of actual fertiliser use is an important tool for this purpose.

Andersen & Bonnis, 2021

Reporting of this information to the authorities can be a part of control of existing regulation and the development of new measures. A similar accounting and reporting is, however, not in place for climate gasses.

Since 2001, there has been a free advisory service in Sweden for farmers called “Focus on nutrients” (in Swedish: Greppa Näringen), which is financed by the current rural development programme. The initial focus was on advice for higher nutrient efficiency to reduce nutrient leaching but today, the service also provides advice specifically targeting greenhouse gas emission reductions and energy efficiency.

Government Offices of Sweden, 2022

Mineral fertilisers are associated with emissions of CO₂ and N₂O in the production phase as well as in the cultivation phase (including transport). A tax on N surplus at farm level can play a vital role in limiting the excess use of N fertilisers and improving efficiency in the use of manure-N. Levies or taxes on mineral fertilisers can further underpin efforts to reduce N and GHG emissions.

Andersen & Bonnis, 2021

This can be combined with quotas on the use of mineral fertilisers.

Andersen & Bonnis, 2021

This can be combined with limits to the use of total fertiliser (N and/or P) and manure per hectare, potentially differentiated by crop.

Targeted subsidy can be given as direct support as well as tax credits to farmers and used to encourage farmers to adopt best practices for manure management, including appropriate storage containers and spreading machinery and possible win-win practices.

Andersen & Bonnis, 2021

As described earlier, results show that effective integrated measures mainly are related to manure/​fertiliser application to soils, which can have positive impact for emission reduction for at least two of the pollutants. Measures including information, tax, quotas and targeted subsidy can be relevant in this context.

There can be a significant difference in the price and incentives needed for the implementation of measures in new compared with existing production systems. For example, retrofitting slurry cooling in existing pig farms is estimated to be significantly more expensive than in the case of a new establishment. For new barns, the investment and operation costs of slurry cooling are a barrier to expansion, while the need to meet environmental requirements is a significant incentive.

Andersen, et al., 2024

Nature-based solutions in European farming systems and in cities can simultaneously contribute to nature restoration, climate mitigation and adaptation, and reduce nutrient and pesticide pollution.

Agency, 2021

Measures listed by EEA (2021) with potential impact on nutrients include improvement of soil and water management, as well as mixed crop-livestock systems. 

There are many different possible drivers for changes in the agricultural system, that will also affect emissions, including dietary changes. A broader shift towards healthier diets in Europe could yield significant co-benefits in terms of nutrient pollution and GHG emissions.

EEA, 2024

In the report ‘Nitrogen on the Table: The influence of food choices on nitrogen emissions and the European environment’ Leip et al.

Leip, et al., 2023

analysed the consequences of a demitarian approach, halving meat and dairy intake across Europe (with a corresponding increase of other foods). This scenario at the same time estimated a 43 percent reduction in NH₃ emissions, with similar reductions in greenhouse gas emissions, as well as N losses to water and total N losses from the food system.

For conventional animal-based foods, most of the GHG emissions are associated with feed production, manure management and enteric CH₄ emissions from ruminants; while the GHG emissions of future foods are mainly linked to energy-intensive processes such as drying (e.g., microalgae and insects), cell cultivation, steam production and maintenance of fermentation processes. For this reason, a shift towards renewable energies could potentially bring larger GHG emission reductions related to the production of future foods than from conventional animal-based foods.

Leip, et al., 2023

There are potentially many stakeholders in agricultural regulation. In the political agreement, made for a green transition of Danish agriculture this year, both the Ministry of Agriculture and Environment participated along with the Danish Municipalities Organisation, The branch Organisation for Agriculture and Food, and the Danish Nature Conservation NGO, each with different perspectives.

The ministries are getting science-based advice from knowledge institutions, but although this might include feasibility and barriers for the implementation of measures, the knowledge institutions providing the advice are not stakeholders in the policy process and will generally not give political advice. In a report from 2024 providing an overview of the effects, potentials, uncertainties, and barriers of several measures that can contribute to reducing greenhouse gas emissions from Danish agriculture, DCA/​Aarhus University investigated 29 reduction measures from livestock, manure, crop production, and land use. The main barriers reported, for all measures, was lack of data. Although the report also looked at side-effects on environment and biodiversity, these issues were not dealt with in detail.

Andersen, et al., 2024

For the Municipalities Organisation, the main perspective was on administration, and division of work with the agencies, which is also a perspective of the agencies. The ministries will, however, also focus on realising the political goals of the government and on reaching an agreement that does not conflict with other laws and regulations, and which can pass through parliament.

For the Danish Nature Conservation NGO, the original perspective was to ensure that a CO₂e tax in agriculture ‘should be introduced as early as 2025. The fee should be high and uniform, so that it creates the best starting point for the market to drive the green transition and find the best solutions itself.’, and that this ‘will be cheapest for society and create security around the reductions.

Danmarks naturfredningsforening, n.d.

The perspective of the branch Organisation for Agriculture and Food is reflected in a report on climate measures for Danish agriculture from their research institution SEGES Innovation

Henricksen, et al., 2023

. Here it is stated that “taxes that impose a financial burden on farmers when a certain amount of CO₂ is emitted have the consequence that there is a liquidity drain from the individual company which means, that there is a poorer financial opportunity for the individual farmer to invest in CO₂-reducing measures.” In addition, it is stated that the vast majority of possible measures has both an investment cost and an increased cost of production for farmers. It is therefore desired that a financial incentive structure is created, where consumers must pay an additional price for the food products and the food companies will pay more to their suppliers, which can contribute to financing the implementation of measures with the farmers, and investments in CO₂e-reducing measures in the processing stage.

Henricksen, et al., 2023

SEGES points to a voluntary scheme Arla Foods has made with the milk suppliers who implement "green initiatives" on the farms and are rewarded with an additional payment at the expense of the milk producers who do not actively implements the measures. Furthermore, it is stated that consumer driven demand for specialty products and high-value goods is well known to be well-intentioned when asked, but that it is usually the price of the item that ultimately determines the product choice.

Henricksen, et al., 2023

The range between these views is from the green NGO who calls for a high CO₂e tax to ensure reductions at the lowest cost to society, to agriculture who wants voluntary agreements with an incentive structure paid for by the consumers or the state.

The starting point for the negotiations of a green transition of Danish agriculture was an analysis showing that the agricultural agreement from 2021 would not give sufficient reductions for the agricultural sector. The agreement contained several initiatives which reduce the emission of greenhouse gases, including an implementation track with measures, which can already be implemented, as well as a track with additional measures which need development. A carbon tax was suggested at different levels in addition with subsidies for other measures.

At the end, an agreement was reached where improvement for nature and the aquatic environment was included by taking out agricultural land to rewetting and afforestation meaning that the climate target can be reached with a smaller carbon tax. The price of this agreement supported by both agriculture and nature conservationists was the construction of a land fund of 50 billon DKK to buy up agricultural land.

Synergies and trade-offs between NH₃ and CH₄ abatement has been dealt with in the first part of this report. The intension of this section is not to repeat this, but to widen the scope based on literature and international policy recommendations.

There is strong scientific evidence for the existence of several climate-related co-benefits with significant economic value. This could be climate policy co-benefits, such as improved air quality, co-benefits for climate objectives from policymaking in other fields, such as taxation and land use related measures, and co-benefits from policies designed to achieve multiple objectives.

Karlsson, Westling, & Lindgren, 2023

The number of published scientific articles on co-benefits has increased significantly, while co-benefits are seldom recognised in the preparatory stages of policymaking nor reflected in subsequent policies.

Karlsson, Westling, & Lindgren, 2023

It has been mentioned that NO_X emissions contribute to tropospheric O₃ formation, and NO_X and NH₃ emissions contribute to particle formation which both has effects on health. O₃, in addition has a strong, but short-term warming effect, whereas particles have a strong, but short-term cooling effect.

Erisman & Bleeker, 2011

Nitrogen management measures (including pollution mitigation) often affect air pollution, climate change, food production and biodiversity simultaneously. There are several N management measures with synergistic effects on air pollution mitigation and climate change mitigation. N management can therefore provide a contribution to meeting climate targets. The relationships between N management and climate change mitigation are, however, complex and there is still a limited understanding of the interactions between N management, air pollution mitigation and climate change mitigation at regional and global scales.

UNECE/WGSR, 2010

There are significant interactions between NH₃ and CH₄ emissions from agriculture. Overall, measures to reduce these gases go hand-in-hand through links to sector activity, where there is a trade-off between production intensity (e.g. nitrogen use per ha) and efficiency. While some measures offer synergistic benefits, there is an ongoing need to optimise practices in order to minimise trade-offs between the two gases. These interactions highlight the opportunity to further develop synergies when including both NH₃ and CH₄ in the revised EU National Emissions Ceilings Directive (NECD).

UNECE/WGSR, 2010

In Sweden, it is expected that with a continuous, and in accordance with the Swedish food strategy, increased food production, a large part of the greenhouse gas emissions deriving from biological processes will remain. Efficient policy packages are needed to reduce the emissions from the sector as much as possible without causing negative side effects on other environmental or societal goals.

Government Offices of Sweden, 2022

Under the EU Common Agricultural Policy (CAP), farmers can, based on certain requirements, receive support for measures aimed at producing non-profitable services delivered to the wider public such as landscapes, farmland biodiversity and certain climate change mitigation measures. Through the CAP’s second pillar for rural development, member states have access to a wide range of measures to encourage higher environmental performance, including climate mitigation and adaptation.

Government Offices of Sweden, 2022

Measures specifically contributing to climate change mitigation in agriculture include those aimed at: increasing energy efficiency; production and use of renewable energy (including biogas production and establishment of perennial energy crops); conversion from fossil to renewable energy sources; improved manure handling; more efficient use of N; climate and energy advice; measures to prevent the risk of N leakage; restoration and establishment of wetlands; promotion of grass ley and catch crop production in intensive cropping areas; conservation of semi-natural pastures; and other separate projects relating to climate and energy.

Government Offices of Sweden, 2022

The most important measures with synergies and trade-offs for NH₃ and CH₄ are described in the first section of the report. Below is a short overview of a larger range of measures based on UNECE/​TFIAM.

UNECE/TFIAM, 2015

Examples of effective strategies for reducing both CH₄ and NH₃ emissions from animal manure include covering slurry stores (potentially with CH₄ capture), extracting biogas from slurries, and acidifying the slurry. Given the right circumstances and the use of optimal methods, each of these measures contributes to lowering emissions of both gases, though they operate through different mechanisms. Covering slurry stores is a straightforward yet impactful method for controlling emissions. The coverage prevents the release of CH₄ from the slurry’s surface, as it traps the gas and either captures it for energy use or minimises its escape into the atmosphere. Additionally, covering helps to reduce NH₃ volatilization by limiting the exposure of the slurry to air, which in turn decreases the rate at which NH₃ escapes. Acidification of slurry is another effective approach for mitigating emissions. By lowering the pH of the slurry through the addition of acids, like sulfuric acid or formic acid, NH₃ is converted into ammonium, a less volatile form that is retained in the slurry rather than being released into the air. Acidification reduces CH₄ emissions by inhibiting the activity of methanogenic bacteria during anaerobic decomposition. However, this method is only effective for CH₄ emissions when applied early in the manure management chain. The production of biogas from slurries through anaerobic digestion offers significant advantages in reducing both CH₄ and NH₃ emissions. During anaerobic digestion, CH₄ is captured and utilised as a renewable energy source. However, there is still some uncertainty regarding the overall impact of anaerobic digestion, particularly concerning CH₄ emissions during storage of the remaining digestate. Variability in emissions is influenced by factors such as manure type, pH, and storage conditions, leading to uncertainty about the methane emissions during digestate storage. Furthermore, the digestion process stabilises the slurry and can reduce its potential for NH₃ volatilization. However, the remaining digestate, particularly the liquid fraction, can have a high pH, which may increase NH₃ emissions if not managed properly. To address this, it is crucial to use low-emission land-spreading techniques.

For example, measures designed to mitigate NH₃ emissions from N fertiliser applications or manure applications to land generally do not impact CH₄ emissions significantly. This is because N fertilisers and manure applications are not major sources of CH₄ in the agricultural sector. Instead, CH₄ is primarily emitted from enteric fermentation in ruminants and anaerobic decomposition of organic matter in manure storage.

One strategy to reduce NH₃ emissions involve the natural crusting of slurry storage. This method works by forming a layer on the surface of the slurry, which helps to minimise NH₃ volatilization. However, its effectiveness in reducing CH₄ emissions is limited. CH₄ tends to escape through cracks in the crust rather than being effectively trapped. Although some CH₄ may be consumed and converted to carbon dioxide by microbial activity within the crust, this process does not substantially lower overall CH₄ emissions from the slurry.

Similarly, feeding ruminants a lower protein diet can lead to reduced N excretion, as less N is available for conversion into NH₃. However, if the total dry matter and fibre intake remain constant, the effect on enteric CH₄ emissions is minimal. This is because enteric CH₄ production is more closely related to the fermentation process in the rumen, which is influenced by the type and amount of fiber and carbohydrates in the diet, rather than just N content. Finally, certain novel feed additives may selectively reduce CH₄ emissions.

Some animal feeding strategies or dietary supplements aimed at reducing enteric CH₄ emissions can inadvertently lead to increased N excretion. This increase in N excretion can subsequently result in higher NH₃ emissions, as excess N in manure is more readily released into the atmosphere in the form of NH₃. Similarly, while active aeration of stored manure is an effective method for mitigating CH₄ emissions – by accelerating the decomposition of organic matter and capturing CH₄ for use as a renewable energy source – it often leads to increased NH₃ emissions. This occurs because the aeration process promotes the breakdown of N compounds, releasing NH₃ into the air.

These scenarios highlight the complex interplay between different environmental interventions and the potential for unintended consequences. The increase in one type of emission while reducing another underscore the necessity to use integrated strategies to mitigate pollution from the agricultural sector, and to minimise the trade-offs and enhance the environmental benefits.

The main new development on the policy side in the Nordic countries is the Danish agreement on a green transition for agriculture and the subsequent forming of a new ministry to implement the transition. The development is, from a stakeholder perspective, described in the paragraph on stakeholders. The green deal is the biggest change to the Danish landscape since the agricultural reforms from the end of the 18^th century and heath cultivation from the middle of the 19^th century.

In total, around 15 percent of the total agricultural area will be taken out of normal operation (9 percent of the country area of 4.3 M ha). First and foremost, 250.000 hectares of forest will be planted. In addition, 140.000 hectares of low-lying soils will be rewetted. A gradually increasing CO₂ tax will be introduced from 2030, but at the same time farmers will be given many incentives to change and be compensated.

The financing will be secured through the establishment of ‘Denmark's Green Land Fund’ of DKK 40 billion. The Novo Nordisk Foundation has put a further DKK 10 billion into the land fund.

The agreement can be adopted by the Danish Parliament in autumn 2024. What is new about this agreement is the consideration of different policy areas at the same time; climate, water, nature (and nature restoration), and air. It is also new that the policy has been developed in a forum that involved the main stakeholders, which reached a consensus on the deal.

In principle, this kind of policies would be applicable in all the Nordic countries. It should, however, be noticed that land use and farm structures are very different, and it might exempt certain types of (small) fares for measures like CO₂ tax. In countries which are not net exporters of agricultural products, and which already have large forested areas, it could also be less desirable to convert farmland to forest. In Denmark, it has been discussed that a CO₂ tax in the future could be replaced by an emission trading scheme if a suitable system is developed in the context of EU.

European Commission, 2023