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.

Creating woodlands and targets for planting trees are important parts of the Climate Change Plan update to contribute to greenhouse gas (GHG) reduction targets.

Agroforestry combines trees and agriculture on the same plot of land, with tree density varying dependent on agricultural land type, tree species and objective. There has been growing interest in agroforestry systems as an opportunity to integrate land management objectives and contribute to meeting tree planting targets and generate GHG reductions and removals. However, currently a very small proportion (3.3%) of the area used for agriculture in the UK is managed as agroforestry. Carbon schemes, such as the Woodland Carbon Code (WCC) could offer a potential route to provide financial support and incentivise agroforestry.

This reports assesses the potential to reduce greenhouse gas emissions through different forms of agroforestry. 

It finds that all forms of agroforestry have the potential to sequester carbon, although the benefits will vary depending on soil type, species, planting density and location.

The research suggests that the fastest rate of carbon sequestration is most likely to be achieved on highly productive lowland areas. Whilst benefits can also accrue on less productive uplands, avoiding disturbance of organic soil layers is a key consideration.

Grasslands cover a large area of Scotland’s land and their management can influence whether grassland soils release or store carbon and by how much.

This project synthesises the best state of knowledge on the effect of management practices on soil carbon sequestration in permanent, managed Scottish grasslands and modelled potential application.

Main findings

• We found some good evidence for the effects of specific practices on carbon sequestration in managed grassland.
• However, we found little evidence on the interaction between factors and the efficacy of these measures under diverse environmental conditions.
• Our modelling simulations suggest increases of 1-2.5 tonnes of additional carbon stored per hectare where carbon inputs to soil can be increased by 10% for a 30-year period. If achievable, benefits would likely plateau as saturation in soil is reached. They also highlight the risk of negative effects of additional grazing.
• Factors affecting sequestration potential include grazing rates, grass species, application of fertiliser and tillage.
• Evidence supports the addition of non-synthetic substances (e.g., plant residue and manure) to soil and the selection of high yielding grass species mixes for increasing carbon sequestration where this is possible to apply. Some evidence exists for the use of synthetic fertiliser to increase soil carbon sequestration although the environmental costs of fertiliser production/ application make this less appealing.
• The application of biochar as a method for increasing soil carbon sequestration would require more research, especially on biomass for production and on its impact on yield and the environment. Evidence for the application of lime for increased productivity is inconclusive.
• The evidence for the effects of managing grassland for carbon sequestration in soil is mixed. We did find more conclusive evidence on the effects of altering inputs than on the effects of influencing carbon sequestration through the turnover (degradation) of existing soil carbon.
• Replacing synthetic fertiliser with carbon-containing fertiliser will lead to stronger increases in carbon sequestration when applied in the correct circumstances. However, this will not apply across the whole of Scotland due to limitations to supply. Sources of additional organic material hold the largest potential for increases as most manure produced on-site is currently also applied on-site.

The Carbon Neutral Island project will support six Scottish islands to become carbon neutral by 2040. It will support islands to run on 100% renewable energy, create circular economies, and explore more sustainable transport options.

This research explores the available data for climate change action on Scottish islands, especially in relation to climate accounting exercises and good practices in dealing with the climate change emergency.

Main findings

• Currently, there is not a consistent approach across Scottish Islands to GHG accounting, and no complete GHG inventories exist at the individual island level.
• Most GHG emissions estimates focus on energy (including buildings and transport) and miss out key sectors such as land use, forestry and agriculture.
• The unique challenges associated with islands, while requiring a tailored mitigation approach, also show their suitability as test beds for the development, trial and deployment of emerging technologies appropriate for decarbonisation strategies.
• Both in Scotland and across Northern Europe there are significant commonalities between the barriers being addressed and sector priorities in projects delivered. The potential for knowledge sharing and adapting successful projects to local purposes provides a resource with significant potential. However, it must incorporate a place-based approach and be suited to local characteristics.
• Financial support within the Scottish Island context needs to connect community-level issues in peripheral islands with the planning agendas of local authorities and central government. Scottish islands’ atypical characteristics are often not fully appreciated and considered.
• It is clear that a one size fits all approach for climate finance is not appropriate in the Scottish Island context due to their unique characteristics such as main emission sources and population size.
• Small islands can house cohesive communities, which support effective working towards shared climate goals. Thus, community funding can be used as a building block for implementing mitigation measures and increasing community-level adaptive capacity.

A key output of the project was a set of databases, available alongside this report, that capture information on the three topics outlined above. This resource can be used by the Scottish Government in implementing the Carbon Neutral Island project, but also by island local authorities and communities as they chart a course, and take actions towards net zero.

Vegetated coastlines, including seagrass, mangroves, and salt marshes, are valued for their capacity to sequester and store large amounts of organic carbon in their soils.

However, coastal habitats are degrading globally, raising fears that blue carbon habitats could largely disappear by the end of this century unless significant protection and restoration efforts are enacted.

The widespread conversion of Scotland’s saltmarshes to agricultural and development land, especially during the 18th and 19th centuries, together with more recent acceleration of sea-level rise, places this important coastal habitat under extreme pressures.

Key findings

• There is significant potential for managed realignment in Scotland.
• However, the rates at which additional carbon stores are accumulating are not clear at these sites nor is their potential to contribute GHG emissions back to the atmosphere.
• We found evidence supporting a perceived growing threat of rising sea-levels, particularly associated with the potential loss of saltmarsh area, and associated soil carbon.
• Managed realignment and the creation of new saltmarsh offers a net gain at most sites over the existing saltmarsh area.
• The lower saltmarsh edge only extends down to the mean high water neap level in a few cases. This means local monitoring of vegetation in relation to tidal variation prior to restoration is needed to model future marsh extent.
• To fully assess marsh vulnerability to relative sea-level rise, evidence suggests inclusion of high-tide levels.

It is still not possible to estimate the time taken for a managed realignment site to reach a stable state with natural rates of carbon sequestration. The approach taken in this study to estimate potential blue carbon gains assumes that the realigned saltmarsh will reach a state where it buries and stores organic carbon in a similar way to a natural saltmarsh but does not include this time-dependent process.

Detailed monitoring of existing restored sites across Scotland would improve our understanding of the additional blue carbon gains in soil profiles at these sites, and to also understand the extent of any losses, including GHG emissions, over periods of time.

Blog

Read a blog about a conference poster developed as part of this project 

This report examines the potential of nature-based solutions to contribute to Scotland’s net-zero emissions target.

Scotland is facing the twin challenges of a climate emergency and biodiversity crisis. Changing the way we use the land and sea is now essential to both store carbon and help society adapt to climate change. Doing so can also help to improve the state of nature, which is experiencing unprecedented threats. 

Nature-based solutions feature prominently in the global biodiversity agenda. Vegetation growth and healthy soils, as well as sea floor integrity, provide a crucial way of locking away carbon emissions. However, it is the additional multiple benefits unique to nature-based solutions – addressing biodiversity loss, and adaptation to locked-in climate change – that makes them such a crucial part of a net-zero strategy. These are widely regarded as ‘no-regret’ actions to address climate change, but the evidence base to support their direct impact is complex. As such, further work is required to understand their practical application in Scottish circumstances.

This study assesses evidence for the greenhouse gas (GHG) mitigation potential of four nature-based solutions in Scotland (agroforestry, hedgerows, un-cultivated riparian buffer zones and the restoration of species-rich grasslands) and how these can help mitigate the impacts of climate change and reduce biodiversity loss. In addition, we provide a synthesis of the strength of evidence for including these as part of net-zero policy objectives and carbon codes.

Regional Land Use Partnerships (RLUPs) are being set up in Scotland to help achieve Scotland’s climate change targets through land use change and a natural capital approach. These partnerships facilitate engagement between local and national government, communities, landowners, land managers, and a range of other relevant stakeholders. Five RLUP pilots will produce a Regional Land Use Framework (RLUF) by 2023 using a natural capital approach which considers key natural assets and the benefits these provide to communities and the regional economy.

This project examines evidence from the UK and Europe for the use of the natural capital approach in successful partnerships, working across multiple sectors and landownership boundaries. It focuses on outcomes for climate change, biodiversity and benefits to local communities. It includes six case studies of partnerships which have incorporated elements of a natural capital approach.

Findings

Based on our analysis, a natural capital approach can help:

• build a balanced overview of the range of ecosystem services and benefits to communities and stakeholders that land and natural assets can provide;
• understanding of how different services may interact in response to projects and interventions, leading to multiple benefits or negative unintended consequences;
• contextualise and respond to the different priorities and interests of specific partners and stakeholders, helping pre-empt and manage conflicts of interest;
• act as a stimulus for local investment; and
• bring stakeholders together to co-produce plans that can meet multiple objectives.

The Land Capability for Agriculture (LCA) classification for Scotland has been used since the 1980s to inform decision-making on land use management, planning and valuation.

This report explores the potential for a new research tool to estimate land capability under future climatic conditions – the Land Capability of Scotland research platform. Development in this project has been based on the original LCA guidelines. The platform is a set of computing tools (not PC based) for data integration, calculation, analysis, mapping and visualisation, allowing models to be run to estimate land capability constraints and generate digital maps.

The Land Capability research platform is designed to be a ‘risk and opportunities assessment’ tool operated by researchers; the Land Capability of Scotland research platform does not replace the existing published LCA classifications.

The platform has initially been developed to produce estimates of Land Capability for Agriculture under different climate change projections and has further potential to support research on a broad range of land uses and benefits, such as forestry and ecosystem services.

Results

• The original LCA guide has been successfully coded and computing structures implemented, integrating multiple spatial data sets and modelling tools to estimate the individual constraints that determine the LCA and its overall classification.
• A key challenge is the ability to model soil water balance appropriately. A soil water balance model was implemented within the platform, but further work is required to better calibrate the model and validate the estimates. 
• Initial analysis between two baseline periods indicates that climate change has already altered land capability and is likely to further impact it in both positive and negative ways in the future. 
• Reduced water availability is likely to be a key determining factor. Initial analysis suggests that soils, especially those with a low water holding capacity, are likely to become drier and with greater frequency. 
• This implies an increased risk of crops, grassland and vegetation experiencing difficulties in accessing water. The LCA and constraint maps indicate where this may occur.
• There is a substantial risk that land currently classed as prime agricultural land (classes 1 – 3.1) may experience reduced production capability due to dry soils in an increasing number of years with drought conditions.
• Conversely, potentially areas such as the north-west Highlands may experience increased precipitation totals in some years, meaning soils there becoming wetter.
• There is likely to be increased annual variability in land capability associated with increasing climatic variability and extreme events, such as wet seasons or years followed by dry ones.
• The platform development has been a ‘learning by doing’ iterative process, and further improvements are possible. The research platform will continue to be used and developed in the Scottish Government’s 2022-2027 Strategic Research Programme.
  

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.

Sustainable management and protection of soils is a priority for Scotland. Soils are a valuable but vulnerable natural asset and underpin environmental, economic, and social functions. The importance of soils is mirrored in the wide range of regulations, policy and guidance that have evolved over time.

This report updates the previous ClimateXChange Soil Governance in Scotland report (McKee 2018) to reflect changes in policy and legislation for the conservation and management of soil in Scotland, with extensions to consider soil carbon and biodiversity.

Key findings

• Since 2018, 29 soil related policies have been updated or introduced across a range of legislative areas, including: agriculture; climate change; forestry; planning; diseases and pest control; plant health and genetically modified organisms.
• Soil biodiversity is included in legislation either as a part of biodiversity as a whole or as a part of soil health.
• Soil carbon is explicitly considered in relation to peat, most predominantly in Scotland’s National Peatland Plan. Soil carbon may also be considered within general climate change legislation, although is not explicitly mentioned.
• There is no single policy for soil conservation and management.
• No updates to policy regarding policy effectiveness have been made since the 2018 report, resulting in a continued a gap in soil monitoring for policy effectiveness.
• Specific gaps can be identified in relation to
  • the role of protection and restoration of peat in climate change mitigation legislation, building on current inclusion in land use plans and legislation, and the Climate Change Plan;
  • the recognition of soil biodiversity as a part of biodiversity legislation; and
  • the explicit inclusion of wider soil carbon into land management and agricultural legislation.