The impact of environmental tournament on CO2 emissions from the perspective of synergizing the reduction of pollution and carbon emissions

Synergizing the reduction of pollution and carbon emissions is the essential way for the construction of ecological civilization in the new era. Based on the panel data of 278 Chinese cities from 2006 to 2020, we study the effect of environmental tournament on carbon dioxide (CO2) emissions. The results show that environmental tournaments have both effectiveness and limitations. The effectiveness is reflected in the fact that the environmental tournament is beneficial for the reduction of the pollution and CO2 emissions, and possesses a long-term effect. Green technology innovation, official promotion and foreign investment are identified as the main channels of influence. Moreover, the carbon reduction of the environmental tournament involves a positive spatial spillover effect, which means that the CO2 reduction can be radiated to the neighboring areas. However, environmental tournaments also have limitations. The results of the environmental tournament in the last year could bring pressure on cities to reduce pollution in the current year. The present study reveals a positive U-shaped relationship between the pollution reduction pressure and CO2 emissions. The pressure is beneficial to CO2 emissions reduction as the pollution reduction pressure is less than the extreme point; otherwise, CO2 emissions increase. The government's environmental attention strengthens the internal motivation of local participation in the environmental championship through policy orientation, and alleviates the negative impact caused by the limited nature of the environmental championship. The results of this study provide new ideas for improving China's environmental governance policy system and improving the governance efficiency of local governments.