The roles of the metallurgy, nonmetal products and chemical industry sectors in air pollutant emissions in China

Abstract

The metallurgy, nonmetal products and chemical industry sectors (MN&C) are the three major industrial sources of air pollutants in China. Previous studies have focused on calculating emissions from MN&C via production-based accounting and identifying the drivers of MN&C using consumption-based accounting. However, these previous studies did not discuss how the total outputs from MN&C upstream and downstream industries influence air pollutant emissions. In this study, we use a pure backward linkage (PBL) method to quantify emissions from industries upstream of MN&C and to evaluate how the downstream industries drive the outputs of MN&C in China. We find that the emissions from industries upstream of MN&C are generally higher than the production-based emissions of MN&C. In particular, the chemical industry largely increased its contribution to air pollution according to the PBL method. Furthermore, much of upstream emissions of MN&C are embodied in the interregional trade, transferring substantial emissions from the eastern region to inland provinces. Regarding the drivers of MN&C, our results reveal that consumption-based accounting underestimates the importance of many sectors. The outputs of these previously underestimated sectors could maximally cover 80% of metallurgy, 85% of nonmetal products and 25% of chemical industry outputs. We suggest that improving the structure of MN&C would considerably help decrease the environmental burden on the entire supply chain. Additionally, improving the productivities of MN&C downstream industries could also address the air pollution caused by MN&C.