Development patterns, material metabolism, and greenhouse gas emissions of high-speed railway in China

Abstract

China built the longest high-speed railway system by consuming massive construction materials. However, characterization material metabolism in HSR system remains less explored. Here we conducted a bottom-up material metabolism study and revealed the material stocks, flows, and greenhouse gas emissions from 2008 to 2035 in China’s high-speed railway. We show that material stocks temporally amount from 0.6 gigatons in 2010 to 3.7 gigatons in 2020, dominated by aggregate and cement. Spatially, material stock distribution gaps across Chinese provinces are becoming more narrowed. Material flows wise, growing high-speed railway speed increased resource demands, but construction technology and material production advances could offset these increases. Our results demonstrate the carbon replacement value of 1008 megatons by 2020 and the operational emissions of 31 megatons annually. Compared with road and aviation passenger transport, we highlighted the environmental benefits of high-speed railway for informing green transitions.