Net Zero requires ambitious greenhouse gas emission reductions on beef and sheep farms coordinated with afforestation and other land use change measures

CONTEXT: The UK Climate Change Committee has recommended a 64% reduction in greenhouse gas emissions from the agriculture and land -use sector to meet the 2050 Net Zero target in the UK. However, it is unclear how this reduction can be achieved at a farm level. OBJECTIVE: Using detailed real farm data and novel modelling approaches, we investigated the management interventions and afforestation that would be required to deliver Net Zero within the farm boundary. METHODS: Baseline carbon footprints were calculated for twenty Welsh beef and sheep farms using the Agrecalc carbon calculator, whilst carbon sequestration was estimated using Bangor University's Carbon Footprinting Tool. Scenarios were created to determine the emissions reductions achievable on each farm through implementation of cost-effective mitigation measures. Mitigation measures and their abatement potentials were sourced from the most recent UK Marginal Abatement Cost Curve, which allow emissions to be reduced mostly through improvements in efficiency thus maintaining the production of the system. Area footprints were calculated for production, with and without offset (afforested) areas needed to achieve Net Zero. RESULTS AND CONCLUSION: Emission reductions following the implementation of cost-effective mitigation measures averaged 28% across all farms, ranging from 19 to 35%. The woodland needed to offset the remaining emissions to achieve Net Zero ranged from 8 to 85% of the farm area, with an average 38%. This offset area was equivalent to on average 17.4 m2.yr kg -1 deadweight (carcass weight). Apparent area efficiency decreased when the offset area was accounted for, however, the ranking of farms in terms of efficiency was largely unaffected. Mitigation scenarios rely on several assumptions and these need to be refined to accurately inform Net Zero pathways. SIGNIFICANCE: Based on the results for these study farms, our modelling indicates that even after implementation of ambitious mitigation across beef and sheep farms, large-scale land use change will be required to achieve Net Zero at an individual farm -level. However, this reform could lead to the unintended consequence of displacing production to less efficient systems and increase overall emissions. Instead, we advocate a combined approach of carbon and land footprints that could help to identify farms on which either food production or carbon removals should be prioritised to move the industry towards achieving Net Zero at a sectoral, regional or national level.