New generation of the China’s climate change integrated assessment model (C3IAM v3.0) and its applications

AbstractIntegrated assessment models serve as key tools for exploring climate mitigation pathways under global temperature targets. This paper introduces C3IAM v3.0, an upgraded version of China’s Climate Change Integrated Assessment Model with expanded economic, technological, and climate systems, and strengthened cross-system linkages. Compared to previous versions, it incorporates seven major improvements: updated base-year data; a global carbon source-sink optimization module; an updated climate system model with explicit physical mechanisms; refined climate impact assessment, enhanced energy technology details in the China multi-regional economic module; improved non-CO₂ and health modeling; and static coupling between the global and China economic modules. Utilizing the upgraded model for climate policy scenario simulations under 1.5°C and 2°C targets, this study systematically presents projected pathways for global energy consumption, land use, emissions, and climate effects, alongside associated assessments of the economic costs and the resulting health co-benefits.