Life cycle greenhouse gas emissions and mitigation opportunities of high-speed train in China

As socioeconomic development accelerates the expansion of high-speed railway (HSR) networks, addressing associated greenhouse gas (GHG) emissions from their production and operation becomes crucial to achieving transportation sector emission reduction targets. This study quantifies and evaluates the life cycle GHG emissions of the CRH380BL high-speed train operating on the Beijing-Shanghai HSR line, covering manufacturing, operation, maintenance, and disposal stages. The data analysis aims to identify key stages and their potential reduction opportunities. Results indicate that the full life cycle GHG emissions of the CRH380BL are approximately 0.026 kg CO₂ eq per passenger-kilometer, totaling 6.5 × 10⁵ tons CO₂ eq over 20 years. Of these emissions, the operation stage contributes the highest proportion (98.0 %), followed by manufacturing (1.2 %), maintenance (0.8 %), and disposal (0.0 %). This study finds that at the operation stage, the electricity mix and passenger load factor significantly impact GHG emissions. In the case of using entirely clean electricity, over 90 % of emissions can be reduced throughout the train's lifecycle, while maintaining a high passenger load factor helps lower per capita carbon emissions. At the manufacturing and disposal stages, the use of recycled materials and material recovery can achieve up to nearly 50 % and 30 % emission reductions, respectively. This study provides valuable insights into the sources and magnitudes of GHG emissions in HSR systems, enabling the identification of effective strategies for reducing emissions and contributing to the overall emissions reduction goals in the transportation sector.