A practical tool and robust framework for evaluating greenhouse gas emissions from land-based activities

Limiting the impacts of climate change will require concerted action across all sectors. Emission reduction polices have previously focussed on fossil fuels, as the major cause of global warming, but the scale of the challenge means that increasing attention is now being paid to other emitters and potential mitigations, including the role of agriculture and land-use in climate change strategies. But while burning fossil fuels mostly produces carbon dioxide (CO2), land-use activities such as agriculture are more associated with nitrous oxide and, in particular, methane emissions, which can complicate efforts to work out their contribution to global warming. The way in which we currently report emissions of different gases as 'carbon-dioxide equivalents' does not always represent their impacts on the climate. This means that land-managers or policy-makers do not always have appropriate information available in order to assess the impacts of different activities, or how best our landscapes can contribute to climate change mitigation.

Our research will overcome this through a new way of reporting different greenhouse gas emissions. This new approach allows emissions to be directly linked to their temperature impacts, by focussing on the change in rate of methane emissions, rather than just the total emitted quantity (which is done to determine how CO2 emissions affect the climate).

We will demonstrate how our framework can be implemented in an existing tool that farmers use to estimate greenhouse gas emissions (these tools are also known as 'carbon calculators'). The tool also allows farmers to appraise how different management strategies, for example, alternative livestock diets, can reduce their emissions. Our addition will take these outputs a step further, to show what this change will mean for the climate, and provide better evidence, and hence inform better decisions, than has previously been possible.

The potential advantages of this approach can be validated by testing results against a simulation model of the Earth's climate system. Climate models such as this can be complicated, and are generally not designed for individual users, such as land managers, to test small-scale, specific scenarios. If we can confirm that our simpler method still provides an accurate representation of the climate response, then we will overcome this difficulty and ensure that the consequences of different activities are clearly communicated.

Our project will then demonstrate how this framework can be scaled up to provide a better indicator of the climate change impacts of bigger interventions, for example, rolling out a new mitigation across a large number of farms, or making landscape-scale policy or management decisions. The research programme would therefore provide both a framework to assess the climate impacts of important landscape decisions based on recent developments in climate science, and a potential route to communicate and promote climatically beneficial activities.

This research is designed to impact the agricultural community directly, as the research will feed into a greenhouse gas footprint calculator (Agrecalc) that is used by farmers. Providing improved information to farmers about interpreting carbon footprints will enable them to make more informed decisions regarding how to prioritise emissions reductions. This will empower the sector to make progress towards carbon neutrality goals, which are currently being developed by both the Scottish government and the National Farmers Union of the UK. Project partners in SRUC manage Agrecalc and have a good understanding of what would be useful for farmers and we will therefore be able to convey scientific information in a form that is accessible to the target audience.

Testing combinations of mitigations and alternative land-uses will demonstrate the possibilities of such actions, and will confirm how this new framework would provide a scientifically robust indicator of how landscape-decisions will impact the climate. By demonstrating a practical approach in the farming sector, this is the first step towards building a tool that is applicable for all land uses and activities.

We have built in the connection to the Agrecalc tool into the proposal and therefore if the project is successful in its aims, it will directly generate impact through improving the Agrecalc tool. This will enable farmers to devise strategies to reach ambitious climate goals for agriculture that are rising up the political agenda. Given the progress that has been made in the energy sector, national focus will be shifting to other areas such as agriculture and land use in the near future. This would be a timely contribution to the evaluation and planning process for land-based climate mitigation.