Research On The Impact Of High-Speed Rail Opening On Urban Carbon Emission Intensity

At the 75 th session of the UN General Assembly,President Xi Jinping for the first time put forward China’s "dual carbon" goal,that is,to achieve a carbon peak by 2030 and achieve carbon neutrality by 2060.It can be seen that in the critical period of promoting China’s economic transformation and high-quality development,the development of low-carbon economy is one of the important tasks of the current economic and social development.As a modern,efficient and clean mode of transport,high-speed rail,on the one hand,has lower energy consumption and carbon emissions compared with traditional means of transport such as railway,road,civil aviation and water transport.On the other hand,the opening of highspeed rail greatly improves accessibility and reduces the flow barrier of factors,which brings profound changes in urban economic structure and spatial layout by strengthening the spatialtemporal compression effect.While promoting economic growth,it is conducive to improving resource utilization efficiency and industrial optimization and upgrading,and reducing carbon emission per unit of output(carbon emission intensity).Thus,accelerating the layout of highspeed rail network may become an important starting point to achieve a win-win situation of carbon emission reduction and economic growth.Therefore,based on the perspective of lowcarbon economy and the current practice of high-speed rail development,in-depth research on the impact of high-speed rail on carbon emission intensity has important theoretical value and practical significance.Based on the unbalanced panel data of 285 prefecture-level cities in China from 2004 to2020,this paper uses a multiphase differential method with bidirectional fixed effects to identify the effects of high-speed rail opening and carbon emission intensity.First of all,the baseline regression of carbon emission intensity to the opening of high-speed railway was carried out.For carbon dioxide emission,two methods were adopted,namely energy coefficient calculation and night light data inversion calculation.Different definitions were used for the opening variable of high-speed railway according to the opening time.Secondly,the reasonableness of the difference-difference method was verified by parallel trend test,and the endogenous interference was excluded by placebo test,instrumental variable method,exclusion of special samples and control of other policy impacts,so as to verify the robustness of the conclusion.Thirdly,through the theoretical research and literature review,the possible mechanism of action is also examined.Finally,considering the different characteristics of Chinese cities,the heterogeneity analysis was carried out from the perspectives of geographical location,city size and comprehensive strength.The group regression was used to study the carbon reduction effects of high-speed rail in different samples,and chow test was conducted for the heterogeneity among groups.In addition,the regulating effect of technological innovation on the influence of high-speed rail on carbon emission intensity was further studied.The results show that: First,the coefficient of baseline regression is significantly negative,indicating that the opening of high-speed rail can significantly reduce the carbon emission intensity.Variables of high-speed rail opening and carbon emission intensity calculated under different methods are included in the differential model,and the size and significance level of the estimated coefficients are similar under the bidirectional fixed effect.Secondly,the empirical model satisfies the hypothesis of parallel trends and passes a series of robustness tests such as placebo test.Thirdly,in terms of mechanism of action,transportation substitution effect and industrial structure adjustment are the mechanism of reducing carbon emission intensity caused by the opening of high-speed rail,while economic agglomeration has not passed the mechanism test under the full sample.Finally,the results of heterogeneity analysis show that the carbon reduction effect of high-speed rail is stronger in central and western regions,small and medium-sized cities,and second-tier and lower cities with weak comprehensive strength.In addition,technological innovation strengthens the carbon reduction effect of high-speed rail,and also positively regulates the adjustment of industrial structure.In other words,the higher the level of urban innovation,the stronger the carbon reduction effect of high-speed rail.Based on the above research results,this paper also puts forward relevant policy recommendations: first,improve the coverage of high-speed rail networks under the premise of fiscal sustainability;Secondly,give full play to the role of high-speed rail as a transportation substitution,and make good use of the resource advantages brought by high-speed rail to promote the optimization of industrial structure;Third,it is necessary to take into account the differences in different regions and optimize the distribution pattern of the high-speed rail network;Finally,the government should take the initiative to increase investment in innovation and take multiple measures to achieve carbon emission reduction.