Transformative land use change towards net zero: balancing emissions through woodland expansion and livestock...

This study investigated how two transformative land-use changes, namely multi-functional afforestation and livestock reduction, could contribute to achieving net-zero carbon emissions in Scotland's land-use sector by 2050 (timing of the Paris Agreement). We used assumptions compatible with the Shared Socioeconomic Pathways focusing on Sustainability (SSP1) and UK's Committee on Climate Change (UK-CCC) scenarios, to model spatial and temporal patterns of extensive woodland creation, spatially targeted using a multi-criteria approach to improve biodiversity and ecosystem services. We coupled this with annual reductions of livestock numbers, with associated reduction of greenhouse gasses emissions (methane and N₂O), to compare their relative contribution between 2020 and 2050. Accounting for the spatial dimension of soil carbon loss and the temporal dimension of tree planting was essential to build a realistic picture of net carbon capture by trees. We found that the annual carbon capture by trees could offset the reduced livestock emissions by 2050, balancing livestock emissions per annum. However, cumulative emissions over the 2020-2050 period would still be substantial, and offsetting them will be both delayed after 2050 and only be temporary due to sink saturation. The findings highlight the need for spatially explicit land-use planning, grounded in high resolution data to minimise trade-offs when increasing carbon sequestration, and in particular minimizing adverse effects on ecosystems and food security. While other land-based mitigation measures are possible, the results reinforce the notion that relying heavily on afforestation alone to achieve net-zero by 2050 would be insufficient. Instead, a holistic approach that combines land-use changes with dietary shifts, reductions in food waste, and international cooperation is essential for sustainable climate mitigation.