Strategic role of integrated agricultural systems in alleviating land-use competition and accelerating climate mitigation

Integrated and agroforestry systems (IS/AS) are increasingly recognised as pivotal pathways to reconcile agricultural productivity, ecosystem services, and climate mitigation. This study assesses the system-level contribution of IS/AS to land-use dynamics and greenhouse gas mitigation in Brazil using the Brazilian Land Use and Energy System (BLUES) integrated assessment model (IAM). Distinct from previous global assessments, we developed and explicitly represented eleven region-specific IS/AS production systems – two Integration-Livestock-Forest (ILF) systems, five Integration-Crop-Livestock (ICL) systems, two Integration-Crop-Livestock-Native Forest (ICLFn) systems and two Integration-Crop-Livestock-Commercial Forestry (eucalyptus/pine) systems – to capture heterogeneous productivity, input intensity, and carbon dynamics across diverse biomes. Our findings demonstrate that IS/AS are not only economically viable but also strategically superior to conventional practices, with their large-scale deployment primarily driven by their systemic expansion potential rather than marginal costs. Under 1.5°C-consistent scenarios, IS/AS substantially abate agricultural emissions, particularly methane (22 MtCO 2 e) and nitrous oxide (35 MtCO 2 e), while accelerating carbon sequestration in soils and biomass (15 MtCO 2 e). Crucially, their adoption alleviates land-use competition by minimising the need for extensive industrial carbon capture and storage (CCS), reforestation and pasture recovery – reductions of 86, 216 and 439 MtCO 2 e, respectively – thereby securing food and bioenergy production. These results underscore the role of IS/AS as foundational structural components of sustainable land-use strategies, providing a benchmark for climate policy in nations with extensive degraded agricultural landscapes.