高铁开通的碳减排效应研究——兼议经济与环境双重目标的约束

Research on Carbon Emission Reduction Effect of High-Speed Rail Opening:The Constraints of both Economic and Environmental Objectives

在碳达峰、碳中和背景下,高铁作为高效并有利于碳减排的绿色交通工具而备受关注。本文基于2003—2017年全国285个城市的面板数据,使用渐进双重差分方法检验了高铁开通对碳排放的影响。研究发现:高铁开通对沿线城市具有显著的碳减排效应,且动态效应显示这种减排效应有逐渐增强的趋势。在排除潜在的内生性问题及一系列稳健性检验后,该结论依然成立。高铁开通的碳减排效应具有异质性,内陆城市、资源型城市、三线及三线以下城市以及小规模城市的碳减排效应更加显著。机制分析表明高铁开通主要通过产业结构效应、技术创新效应以及资源配置效应降低碳排放,而交通替代效应在碳减排过程中并不明显。进一步分析发现,经济增长目标约束强化了地方经济发展动机,进而削减了高铁开通的碳减排效果;环境目标约束加强了高铁开通的产业结构效应和技术效应,有助于高铁开通实现碳减排。以上研究结论为深入理解高铁开通与碳排放之间的关系,并在此基础上继续扩大我国高铁网络建设与实现“3060”双碳目标提供重要决策参考。

In the context of carbon peaking and carbon neutrality, high-speed rail has attracted much attention as a green transportation tool to curb carbon emissions. Based on the panel data of 285 cities in China from 2003 to 2017,the progressive differential method is used to test the impact of high-speed rail opening on carbon emissions. The results show that the opening of high-speed railway has a significant carbon emission reduction effect on the cities along the route, and the dynamic effect shows that the emission reduction effect is gradually increasing. This conclusion still holds after excluding potential endogeneity problems and a series of robustness tests. The carbon emission reduction effect of high-speed railway operation is heterogeneous, and the carbon emission reduction effect of inland cities, resource-based cities, third-tier and lower-tier cities and small-scale cities is more significant. Mechanism analysis shows that the opening of high-speed rail can reduce carbon emission mainly through the effect of industrial structure, technological innovation and resource allocation,while the effect of transportation substitution is not obvious in the process of carbon emission reduction. Further analysis shows that the constraint of economic growth target strengthens the motivation of local economic development, and further reduces the carbon emission reduction effect of the opening of high-speed railway. Environmental target constraints strengthen the industrial structure effect and technical effect of high-speed railway, and help high-speed railway to achieve carbon emission reduction. The above research conclusions provide an important reference for further understanding the relationship between the opening of high-speed railway and carbon emissions, and on this basis continue to expand the construction of high-speed railway network in China and achieve the "3060" double carbon target.