In 2019, the UK was the first country to legislate the Net Zero target for greenhouse gas (GHG) emissions by 2050. To achieve this target, the Committee on Climate Change have recommended a 64% reduction in gross GHG emissions from the agriculture and land-use sector. This thesis aimed to explore strategies to reach Net Zero on Welsh beef and sheep farms.
In order to assess the effects of various GHG mitigation measures, farms must first accurately quantify their current level of emissions. There are many carbon calculators available for use on beef and sheep farms. A comparison of two of the most widely used calculators in the UK – Agrecalc and the Farm Carbon Calculator, and Bangor University’s own carbon footprinting revealed the tools produced notably different emission and sequestration estimates for the same 20 farms. Therefore, while the results from different carbon calculators are not directly comparable, utilising these tools independently remains valuable for benchmarking within and between farms.
There are many mitigation and sequestration options available for farms to reduce net GHG emissions, all with varying abatement potentials and cost-effectiveness. A range of mitigation measures and afforestation were modelled on real farms to create Net Zero scenarios. Modelling work demonstrated the most efficient farms in term of emission intensities, often had the highest total emissions due to higher livestock numbers. This presents a significant challenge as although food production must be increased to feed a growing population, these increase must be made sustainability to avoid increasing net GHG emissions. Our modelling showed mitigation alone was not sufficient to achieve Net Zero at a farm level and therefore an increase in carbon sequestration (through afforestation) was required. However, care must be taken to ensure this afforestation does not displace production to less efficient systems and increase emissions overall.
With more farms changing their management practices to reduce GHG emissions, it is important now more than ever that emissions are calculated and expressed correctly. Using omega-3 as a functional unit, we demonstrated the importance of considering nutrition when expressing the carbon footprints of lambs on different finishing diets. When a mass-based functional unit was employed, the grass only finishing diet had the highest average carbon footprint, whereas when omega-3 PUFA content was accounted for, the grass diet had the lowest carbon footprint for the longissimus dorsi muscle cut.
Despite the range of mitigation measures available for farms to reduce their emissions, Net Zero will never be achieved unless farmers adopt these measures. Our survey highlighted many socio-economic barriers to achieving Net Zero on beef and sheep farms. For example, the majority of farmers were not aware of any additional benefits of the GHG mitigation measures listed even though most of the measures would increase production efficiencies and represent “win-win” scenarios. Moreover, the level of adoption reported in the survey would notably reduce the maximum technical abatement potential of many mitigation measures calculated in the previous modelling work. Improving uptake of GHG mitigation measures will likely require a combination of economic incentives, targeted regulation, and information provision based on individual measures to overcome these barriers.
Overall, this work highlighted the different challenges and opportunities facing the agriculture industry in meeting the Net Zero target. It also demonstrated the complexity of calculating and quantifying GHG emissions in relation to policy targets. In this thesis, Net Zero was explored at a farm level, however, Net Zero is not a farm-level target but a national-level target. Therefore, future studies should model land use that could deliver Net Zero in the Agriculture, Forestry and Other Land Use Sector at a national scale.