Can green buildings reduce carbon dioxide emissions?

Green buildings are a pivotal strategy for realizing the low-carbon evolution within the construction industry. However, the emission reduction effect of green buildings remains unexplored. This study utilizes prefecture-level data from green building projects in Jiangsu Province, China, from 2008 to 2019, to systematically analyze the nonlinear effects, heterogeneous impacts, and mechanisms of influence that green buildings have on carbon dioxide (CO2) emissions. The research findings are as follows: first, during the early stages of green building development, when the scale of green buildings is relatively small, green buildings lead to an increase in CO2 emissions. However, as the scale of green buildings expands, they can exhibit a significant effect on decreasing CO2 emissions. Second, green buildings have heterogeneous impacts on CO2 emissions: lower-rated green buildings (one or two-star) have an increasing impact on CO2 emissions, while the emission reduction effect of green buildings mainly comes from higher-rated green buildings (three-star). These high-rated green buildings substantially affect the advancement of low-carbon technologies, playing an essential role in achieving emission reduction. Third, the mechanisms through which green buildings influence CO2 emissions are identified: on the one hand, green buildings provide a technical effect that decreases CO2 emissions; on the other hand, by promoting the growth of the construction industry, green buildings would cause an increase in CO2 emissions. Lastly, this study proposes relevant policy implications centered around leveraging the emission reduction potential of green buildings.