The impact of environmental courts on urban pollution reduction and carbon mitigation: evidence from China

Strengthening the ecological rule of law represents an important form of institutional innovation through which China seeks to achieve its carbon-reduction goals. Using a panel of 285 Chinese cities over the period 2006–2021, this study employs a supervised double machine learning framework to examine both the theoretical mechanisms and the policy effects of establishing environmental tribunals on urban pollution reduction and carbon mitigation. We find that the establishment of environmental tribunals significantly promotes coordinated reductions in pollution and carbon emissions at the city level. Mechanism analyses indicate that this effect operates primarily through the substitution and upgrading of clean industries, technological progress in energy conservation and emissions reduction, and the optimization of industrial land-use structure. Further heterogeneity analyses show that the mitigating effects are stronger in cities with more advanced judicial development, greater public awareness of legal rights protection, and more developed green finance systems. These findings suggest that the gradual expansion of environmental tribunals, together with continued improvements in industrial, technological, and land-use structures and the adoption of more targeted ecological rule-of-law policies tailored to local resource endowments, can enhance the synergistic effectiveness of pollution and carbon reduction.