Quantitative Assessment of Carbon Pricing and Green Finance Synergistically Driving Deep Decarbonization in the Building Sector

To quantify the potential of carbon pricing and green finance to jointly drive deep decarbonization in the building sector, this paper extends the MESSAGEix-Buildings model using a policy-endogenous approach. It incorporates the internalization of carbon pricing and carbon emission costs, as well as mechanisms to relax capital constraints in green finance, into the system optimization framework, thereby enabling the quantification of marginal abatement costs and policy interactions. Using civil buildings in Beijing as case studies, four scenarios were devised for simulation analysis. The results show that: (1) carbon pricing alone can achieve a 11.44% reduction in carbon emissions by 2050, whereas green finance can only alleviate investment barriers and deliver only modest additional emission reductions; (2) when the two policies are implemented in tandem, the joint framework generates complementary price constraints and financial incentives, achieving an additional 4.68% reduction in final energy consumption and a nearly 5.27% saving in total investment compared with the carbon-pricing-only scenario. The study elucidates the complementary mechanism of ‘price constraints and cost incentives’, highlighting the methodological value of an endogenous policy approach, and provides quantitative support for the implementation of carbon neutrality in construction and green finance in megacities.