Carbon, water, land and material footprints of China’s high-speed railway construction

Abstract

The rapid development of China’s high-speed rail (HSR) has caused great concern worldwide, and its various environmental impacts is also a main topic. As such, a comprehensive assessment of these environmental impacts is significant for future HSR construction. In this study, a hybrid input-output life cycle method is applied to evaluate multi-footprints of Beijing-Tianjin intercity HSR, namely, carbon, water, land, and material footprints. Results show that the total carbon, water, land, and material footprints of the entire Beijing-Tianjin HSR construction are 3669.0 kt CO2, 54954.7 kt fresh water, 45830.6 ha land, and 8474.2 kt original materials. In the construction stage, bridge and rail systems have the largest environmental impacts, totally contributing above 74% of the four footprints. The indirect footprints from upstream material production have the dominant effects, accounting over 89% in the four footprints. Metal smelting and rolling, transportation equipment manufacturing, and non-metallic mineral products are high-water-consuming and high-emission sectors in raw material production. Improving industrial production efficiency, optimizing line layout, optimizing production distribution and construction process management are key mitigation ways for multi-footprints.