Sustainability Under Pressure: Evaluating the Effect of Short-Term Inhibition of EU CBAM on the ESG-Based Environmental Performance of China’s High-Carbon Industries

The European Union’s Carbon Border Adjustment Mechanism (CBAM), the world’s first system to impose tariffs on the carbon emissions of imported products, commenced its transition period in October 2023 and is scheduled for full implementation in January 2026. This mechanism exerts a profound impact on the global trade landscape and corporate environmental management practices. Taking the CSI All Share Index constituent companies as a research sample, this paper empirically evaluates the impact of the CBAM transition period on the environmental scores of Chinese export enterprises utilizing the Propensity Score Matching Difference-in-Differences (PSM-DID) method. The results indicate that the CBAM transition period significantly inhibits the short-term environmental performance of regulated enterprises. Mechanism analysis reveals that increased financing constraints serve as a core mediating channel, wherein escalated compliance costs and compressed cash flows crowd out resources for low-carbon investments. Furthermore, heterogeneity analysis demonstrates that the negative impact is more pronounced among state-owned enterprises, firms with lower audit quality, and firms with a higher proportion of female executives. Accordingly, the study recommends establishing targeted green transition financing mechanisms, accelerating domestic carbon market reforms, and strengthening international technical harmonization to build corporate resilience against global climate governance shocks and promote sustainable growth.