Key transmission sectors of energy-water-carbon nexus pressures in Shanghai, China

Previous studies examining the energy-water-carbon nexus mainly use consumption-based accounting and focus on one individual sector. This study employed a betweenness-based method and principal components analysis (PCA) to target the energy-water-carbon pressure transmission center sectors in Shanghai, China IEA, 2012. The betweenness-based method is to analyze the transmission effect of each urban sector regarding one single environmental pressure, and PCA is applied to discuss the energy-water-carbon nexus pressure transmitted by each urban sector. The consumption-based results are also calculated for comparison. The findings show that critical energy-water-carbon nexus transmission sectors included sector 20 (manufacture of communication equipment, computer, and other electronic equipment), sector 12 (manufacture of chemicals and chemical products), sector 14 (manufacture of processing metals), sector 35 (renting and leasing, business services), and sector 30 (transport, storage, and post). The consumption-based results showed that sector 20 and sector 12 generate remarkable energy-water-carbon nexus pressures. The results highlight the sectors that exert a significant amount of environmental pressures and suggest that policymakers should pay attention to the role that transmission sectors play in urban resource conservation and emission reduction. These betweenness-based and consumption-based results can be combined to provide a benchmark for evaluating the mitigation of energy-water-carbon pressures in cities.