The sustainability of China's metal industries: features, challenges and future focuses

The metal industry (MI) is the largest energy consumer and producer of environmental pollution within the industrial sector in China. This paper investigated the sustainability of China's metal industry since the 21th century through an overview and an analysis of green total-factor productivity (GTFP) of this sector. The results showed the following: (1) since the beginning of the 21th century, the scale of China's MI expanded rapidly. However, the rapid development of this sector relies on an extensive mode that has triggered off a series of resources and environmental problems. The promotion of green development in this sector becomes urgently. (2) The GTFP of China's MI increased from 2000 to 2015, and technological progress (or technological innovation) was the key driver. The GTFP growth of the mining and processing of ferrous metal ores occurred due to technological progress and efficiency improvements. In other industries, the GTFP growth mainly resulted from technological progress/innovation. (3) The industries involved in the mining and processing of ferrous and nonferrous metal ores were on the state of increasing returns to scale, the returns to scale of the smelting and pressing of nonferrous metals and the manufacture of metal products transformed from increasing to constant, and the returns to scale of the smelting and pressing of ferrous metals experienced three states: increasing, decreasing, and constant.