Agriculture contributes to 18% of greenhouse gas (GHG) emissions in Scotland and is required to reduce its emissions by 31% from 2019 levels by 2032, according to the Scottish Government’s update to the Climate Change Plan.

Reductions to reach Scotland’s net zero GHG emissions targets can be achieved through mitigation and carbon sequestration measures implemented on farms. Taken together with options identified in the wider food chain and land use, such as dietary change, land use change and food waste reduction, there is clear potential to move food production closer to net zero.

This report provides an updated assessment of the emission reduction potential of the most effective mitigation measures in Scotland.

Researchers assessed 25 farm technologies, or 39 when considered for different livestock types, and practices that can reduce GHG emissions in Scotland by 2050 – modelling constraints required using 2050 instead of the net zero target of 2045, which is not excepted to impact mitigation as all the mitigation measures are fully implemented in the model by the early 2040s.

The measures were derived via a systematic process taking forward the most suitable options for Scotland for quantitative modelling, drawing from relevant UK and Scotland reports. Details of the agricultural activity scenarios used can be found in appendix B of the report.

Key findings

• Assuming mitigation measures are taken by 45% of farmers, the total mitigation potential in 2050 is between 0.9 and 4.3 metric tons of carbon dioxide equivalent (Mt CO₂e). The mitigation attributable to changing practices and technologies on farms is between 0.4 and 0.9 Mt CO₂e in 2050, while the remaining mitigation is due to reduced agricultural activity.
• The Tailwinds and Widespread Engagement activity scenario offer the highest total GHG reduction, most of it arising from reduced agricultural activity.
• The Business as Usual activity scenario, which includes no behavioural and technological changes, has the highest abatement potential on farms, consistent with this scenario having the largest dairy herd, grassland area and arable production, but offers the lowest overall GHG mitigation. However, reducing the land areas and livestock numbers, by increasing yield and reducing demand for livestock products, generates higher total abatement, considering uptake of the measures by 45% of farmers.

Five mitigation measures stand out as providing high emission reduction potential at negative or low abatement cost in most scenarios:  

• Growing clover-grass mix instead of pure grass is the most cost-effective mitigation option and also one of the measures that offer the largest abatement.
• Using genomics in dairy breeding could provide net savings to the farmers and offers high emissions reduction potential in most scenarios.
• Increasing the beef output from dairy herds using sexed semen could offer considerable mitigation at zero net cost.
• Finishing beef animals faster is also cost effective and offers high mitigation.
• Using nitrate as a feed additive for beef costs less than the carbon price.

For further details about the findings and the overall study can be found in the report attached.

The Scottish Government has set ambitious targets for reducing greenhouse gas (GHG) emissions from Scottish agriculture; in 2018 these emissions represented 16% of the nation’s total. As part of a commitment to reach net-zero emissions by 2045, the Climate Change Plan update requires the equivalent of a 31% reduction in agricultural emissions by 2032 from 2018 levels. However, between 1990 and 2019 Scottish agriculture’s emissions decreased by only 13%.

This report explores how data on emissions and nitrogen from the Scottish Farm Business Survey, using Agrecalc, can be used to help design policies aimed at reducing emissions in a sustainable way. Agrecalc is a farm carbon calculator developed by SRUC and used widely within Scotland.

Findings and recommendations

• For dairy farms a linear relationship was found between production and GHG emissions intensity– in other words, as milk production per ha increases, GHG emissions per ha increase. Other farm types showed no clear linear trends between production and emissions. 
• Emissions intensity varied both between and within farm types. Variation between farm types largely reflects differences in enterprise mix. For example, ruminant livestock enterprises are intrinsically more intense emitters than arable enterprises.
• Variation within a given farm type can also reflect how enterprises are managed; for example, through adoption of innovations and best practice. The results show some evidence for this, although the patterns are neither linear nor consistent.
• We find little evidence of a clear relationship between lower emissions and stronger economic performance. Nor do we find clear evidence for the effects of managerial efficiency. 
• We found that Nitrogen Use Efficiency (NUE) is a potentially useful agri-environmental metric, as this provides a proxy for farm level efficiency of nutrient use. However, the NUE values calculated from the current SFBS dataset omit important input information, such as legumes. Therefore, its value should be further assessed and measured before potential use as a farm performance metric.
• We found farms with similar structural characteristics have different emissions intensities. Collection of additional SFBS data items could improve subsequent analysis. 
• Although the focus has been on gross emissions, the approach could usefully be extended to consider net emissions, in particular, sequestration into farm soils and woodland. This may, however, need to await further refinements to Agrecalc and collection of additional SFBS variables, such as hedgerow quality.

This project set out to review the current state of knowledge on the potential for carbon sequestration in key Scottish upland open habitats. Upland soils play a vital role in regulating greenhouse gas (GHG) emissions in our environment. Scotland’s soils contain 2500-3500 Mt of carbon, much of which is located in upland soil environments. This is equivalent to more than 200 years of Scotland’s annual greenhouse gas emissions. The management of uplands and their soils will therefore be critical to achieving Scotland’s ambitious net-zero emissions target.

Despite the well-known potential of soils to store carbon, however, there is uncertainty as to the long-term stability of this carbon pool. Increasing temperatures, altered patterns of rainfall distribution, and changes in land use all influence this process and threaten to reduce soil carbon stocks.

This review identifies the key drivers of change and covers three upland habitats: upland dry heath, upland wet heath and upland grasslands, defined by vegetation communities. It assesses potential GHG fluxes and the impact on biodiversity within these habitats.

It found very limited information regarding impacts on soil carbon stocks or GHG emissions; studies giving a full balance sheet of ecosystem stocks and flows of carbon in response to environmental or management change were particularly scarce.

Key findings include:

• Scotland’s soils contain around 2,500-3,500 Mt of soil organic carbon. The various mineral, organo-mineral and organic soils found under moorland, montane, and rough grassland contain around 45% of total Scottish soil organic carbon stock.
• Soil organic carbon accounts for 90% of the carbon stocks in these habitats. Therefore, studies which only consider changes in carbon held within the vegetation severely under-estimate changes in total carbon stocks.
• GHG emissions in open upland habitats in Scotland occur as a result of emissions of carbon dioxide, methane and nitrous oxide. 
• There is some evidence from Scotland that Molinia grasslands contain large carbon stocks within the vegetation, which are reduced by grazing.
• When upland soils are left bare after excessive grazing or burning, there is a significant increase in the risk of soil carbon loss due to erosion.
• The impacts of future climate change on carbon stocks are complex and are likely to depend on current and future management, soil type and vegetation communities. They have not been well researched in the Scottish context: this is a substantial gap in knowledge.
• The review found an important knowledge gap on the interactions of drivers on GHG emissions, carbon stocks and biodiversity.