<p>Achieving net-zero emissions has become a long-term target to cope with climate change. Local governments are adopting regional collaborations to gather mitigation efforts and address externality issues. From the multilevel governance framework, this study will estimate regional net-zero emissions and social cost of carbon by constructing the Regional Collaborations Dynamic Integrated model of Climate and Economy. Results indicate that: (1) Each regional collaboration would form a localized pathway toward net-zero emissions. The Yangtze River Economic Belt could reach net-zero emissions under almost all scenarios, whereas the Yellow River Basin might pose the main roadblock in China’s climate governance. (2) Social cost of carbon would exhibit regional variation and dynamic change over time. Global temperature targets would increase social cost of carbon in the Pan-Pearl River Delta. The Beijing-Tianjin-Hebei and Northeast China will require a combination of global temperature targets with regional collaborations or national actions to generate larger climate benefits. (3) The uncertainty analysis validates social cost of carbon for regional collaborations by accounting for model uncertainty and structural uncertainty. Based on these findings, this study proposes policy recommendations to strengthen regional collaborations by combining local conditions, following sequencing principle, and consolidating multilevel governance.</p>