Sensitivity of global land-based mitigation potential to land-use scenarios and interactions across sectors

Land-based climate change mitigation can help limit global warming to well below 2°C but requires balancing with food production, nature conservation, and biomaterial supply. Previous studies identified major trade-offs between these but limited the analysis to fairly few dimensions of uncertainty. Using the SuCCESs model, we quantified global total and land-based mitigation potentials, sensitivities, and interactions between 2020 and 2100 across six key dimensions, resulting in 864 scenarios with different assumptions for drivers of land utilisation: emission pricing, diets, food distribution, conservation, biomaterial demand, and wildfire activity. Mitigation options included actions across land, energy, and material systems, spanning forestation, halting deforestation, adjusting forest rotation and residue management, shifting agricultural and forestry systems, and substituting fossil fuels with bioenergy or BECCS. Limiting warming to 1.5–2°C required the agriculture, forestry, and land-use (AFOLU) sector to contribute 500–1,700 GtCO₂e of mitigation and supply 100–140 EJ of bioenergy annually. Peak AFOLU mitigation occurred under globally vegan diets combined with emission pricing that incentivised afforestation of freed pastureland. Trade-offs between forestation and biomass production remained, with SuCCESs favouring afforestation over bioenergy. Biodiversity conservation and emission pricing targeted overlapping mitigation areas, offering no combined benefit. High timber demand reduced mitigation potential and increased biodiversity loss, while reduced paper demand avoided the most deforestation but offered no climate benefits. Slight variations in wildfire prevalence had little impact. Our findings highlight the need for integrated policies that manage land competition and account for policy interactions to fully unlock land-based mitigation potential.