Assessing Synergies and Trade-offs of National Net-Zero Scenarios

The achievement of net-zero (NZ) greenhouse gas (GHG) emissions is a critical climate change mitigation goal with significant potential for economic, social and environmental co-benefits and trade-offs. Yet, many transition assessments overlook broader sustainability considerations and spatial heterogeneity. This study presents a multi-scale modelling framework that integrates national and regional scales to evaluate potential trade-offs and co-benefits of transition pathways in the Agriculture, Forestry, and Other Land Use (AFOLU) sector. Using the GOBLIN Lite model, this study generates a large portfolio of national-level scenarios, filtered to include only those meeting NZ GHG targets (CO2 e ≤ 0 by 2050), and clustered into distinct input and land use configurations. Representative transition pathways for each cluster were downscaled using pollution impact potential-based rules and analysed across 37 water catchments, representing all of Ireland, using the GeoGOBLIN model. This enables multi-scale assessment of climate, economic, biodiversity, and water quality outcomes. While aggregate results suggest potential for net-positive environmental and economic outcomes, the analysis also reveals regional disparities and spatial trade-offs, particularly in nutrient loading and biodiversity enhancement. These findings demonstrate how spatially explicit, multi-criteria modelling can support more transparent, integrated, and context-sensitive planning for sustainable AFOLU transitions.