Abstract
This study offers new empirical evidence on the air pollution costs associated with high-speed rail (HSR) operations in China. By integrating a GIS dataset of national transportation infrastructure, daily HSR timetables, and high-resolution air pollution data, I quantify the downstream environmental impact of electricity consumption by HSR. The results show that powering a single HSR train for 1,000 kilometers increases concentrations of PM2.5, aerosol optical depth (AOD), and nitrogen dioxide (NO2) by 2.9%, 3.4%, and 6.6%, respectively, within the 1-kilometer grid cell containing the responsible power plant. A nationwide map of HSR-induced health costs further reveals that while some regions simultaneously gain from improved accessibility and bear the associated environmental burdens, many densely populated areas located in the gaps of the HSR network face substantial pollution costs without enjoying comparable connectivity benefits. These findings underscore an overlooked dimension of HSR’s environmental externalities and provide empirical support for improving cross-regional ecological compensation policies.