The RCP8.5 scenario represents a high-emission pathway with significant greenhouse gas (GHG) emissions, driven by high population growth, slow income growth, and limited technological progress. It is the highest-emission pathway among the Representative Concentration Pathways (RCPs), leading to a radiative forcing of 8.5 W/m² by the end of the century. The scenario is based on the A2r storyline, incorporating assumptions about demographic, economic, and technological trends. Key methodological improvements include spatially explicit air pollution projections, enhanced land-use and land-cover change projections, and the integration of climate mitigation scenarios that reduce radiative forcing to levels comparable to other RCPs (2.6, 4.5, and 6.0 W/m²). The RCP8.5 scenario highlights the need for significant energy system transformations, including a shift towards coal and fossil fuels, and a reliance on domestic resources. It also emphasizes the importance of reducing emissions intensity and improving energy efficiency to limit radiative forcing. The scenario analysis indicates that climate policy can lead to co-benefits for other policy priorities, such as reducing local air pollution. The RCP8.5 scenario also includes detailed projections of land-use changes, with a focus on agricultural expansion and the increased use of bioenergy. The scenario highlights the need for significant reductions in emissions, particularly from the energy sector, to achieve lower radiative forcing levels. The scenario also emphasizes the importance of technological innovation and policy interventions in reducing emissions and mitigating climate change. The RCP8.5 scenario serves as a baseline for developing scenarios that lead to similar radiative forcing levels as other RCPs, highlighting the need for a comprehensive approach to climate change mitigation.The RCP8.5 scenario represents a high-emission pathway with significant greenhouse gas (GHG) emissions, driven by high population growth, slow income growth, and limited technological progress. It is the highest-emission pathway among the Representative Concentration Pathways (RCPs), leading to a radiative forcing of 8.5 W/m² by the end of the century. The scenario is based on the A2r storyline, incorporating assumptions about demographic, economic, and technological trends. Key methodological improvements include spatially explicit air pollution projections, enhanced land-use and land-cover change projections, and the integration of climate mitigation scenarios that reduce radiative forcing to levels comparable to other RCPs (2.6, 4.5, and 6.0 W/m²). The RCP8.5 scenario highlights the need for significant energy system transformations, including a shift towards coal and fossil fuels, and a reliance on domestic resources. It also emphasizes the importance of reducing emissions intensity and improving energy efficiency to limit radiative forcing. The scenario analysis indicates that climate policy can lead to co-benefits for other policy priorities, such as reducing local air pollution. The RCP8.5 scenario also includes detailed projections of land-use changes, with a focus on agricultural expansion and the increased use of bioenergy. The scenario highlights the need for significant reductions in emissions, particularly from the energy sector, to achieve lower radiative forcing levels. The scenario also emphasizes the importance of technological innovation and policy interventions in reducing emissions and mitigating climate change. The RCP8.5 scenario serves as a baseline for developing scenarios that lead to similar radiative forcing levels as other RCPs, highlighting the need for a comprehensive approach to climate change mitigation.