【摘要】 文章借助高铁开通这一准自然实验，利用2003—2020年我国1120个县域的面板数据，构建多期双重差分模型评估高铁开通对县域碳排放的影响，并分析其作用机制。研究发现：高铁开通能够降低县域碳排放水平；高铁开通对县域碳减排的影响存在异质性，具体表现为高铁对省会城市下辖县的碳减排效应更为明显，且高铁对县域碳减排的正向影响会随着与中心城市距离的拉大而逐渐减小，相较于非百强县和人口规模较小的县域，高铁对百强县和人口大县的碳减排效应更为明显；高铁主要通过促进沿线县域的经济效率提升、产业结构升级以及市场潜力提升等作用渠道降低县域碳排放，高铁对于推动县域高质量发展具有重要意义。基于此，应进一步完善高铁网络与其他基础设施建设，推动高铁向更多县级地区延伸，同时加强县级地区与中心城市的交流合作。更多还原

【Abstract】 The paper uses the opening of high-speed railways as a quasi-natural experiment and uses panel data from 1,120counties across China from 2003 to 2020 to construct a multi-period double-difference model to evaluate the impact of highspeed railway opening on county-level carbon emissions and analyze its mechanism. The study finds that the opening of highspeed railways can lower county-level carbon emissions; the impact of high-speed railway opening on county-level carbon reduction is heterogeneous, specifically, the carbon reduction effect of high-speed rail on the counties under the provincial capital is more obvious, and the positive impact of high-speed rail on county-level carbon reduction will gradually decrease as the distance from the center city increases. Compared with non-top 100 counties and counties with smaller population, the carbon reduction effect of high-speed rail on top 100 counties and large population counties is more obvious; high-speed rail mainly reduces county-level carbon emissions through improving economic efficiency, driving industrial structure upgrading, and enhancing market potential. The construction of high-speed railways has important implications for promoting the high-quality development of county-level areas. Therefore, it is necessary to further improve the railway network and other infrastructure construction, promote the extension of high-speed rail to more county-level areas, and strengthen exchanges and cooperation between county-level areas and the center city.更多还原