An improved emergy evaluation of the environmental sustainability of China's steel production from 2005 to 2015

摘要

CISS (Chinese iron and steel sector) plays an important role in Chinese economic development. As one of energyintensive and high pollution industries, China's government has taken a serial of measures to improve its performances in recent years. How about the environmental sustainability of CISS under the intervention of these measures? However, few studies have explored CISS's trends of environmental sustainability using a systematic method based on a time series analysis in recent years. To this end, this study investigates the trends of environmental sustainability of this sector during the 2005-2015 periods using an emergy-based integrated approach. Different from other evaluation methods, the proposed approach can reveal the resources' structure, reflect the production efficiency, describe the environmental loading and show the sustainability level by considering the environmental and human contributions as well as the environmental emissions' impacts. By doing so, this work provides more complete and comprehensive information. The research results show that (1) iron ore contributes about 55% to the input of CISS; (2) on the average, water pollutants (mainly volatile phenol and NH4+-N) contribute 99.86% to extra environmental loading; (3) air emissions (mainly dust and CO2) contribute 99.63% to the total potential environmental cost; (4) this sector has a slightly decreasing economic benefit, and the emissions' impacts weaken this indicator by 0.94-2.08%; and (5) CISS has an ascending environmental loading, and environmental emissions increase the environmental loading by 6.39-99.80%. Generally, the CISS's sustainability level decreases by 31.49%, which is weaken by 6.39-99.80% due to environmental emissions. Finally, the related policy suggestions are proposed.