Assessing the Impact of High-Speed Rail on Domestic Aviation CO2 Emissions in China

This paper examines the beneficial impact of high-speed rail (HSR) on reducing aviation CO2 emissions in China. As a fast-growing economy and the world's largest CO2 emitter, China has made massive infrastructure investments but has also committed to reducing emissions across all sectors. This study demonstrates that investments in China's HSR can effectively contribute to reduction of emissions from domestic aviation, a sector that is particularly challenging to decarbonize. Although a wide body of literature has assessed the competition between HSR and air transport, little attention has been paid to the climate implications of this phenomenon. It is estimated that, through mode substitution for air transport, HSR generated a cumulative net saving of between 1.76 and 2.76 million tons of CO2 from 2012 to 2015. This was equivalent to 3.2%-5. 1 % of 2015 domestic aviation emissions. Importantly, it is also demonstrated that by not taking into account the electricity consumption of HSR, its environmental benefits could be overestimated. Lastly, through analysis of future energy mix scenarios this study highlights that HSR has a great potential to reduce CO2 emissions even further if China achieved its climate pledge in the Paris Agreement in terms of decarbonizing its electricity generation sector by 2030.