Finding environmentally critical transmission sectors, transactions, and paths in global supply chain networks

- The edge betweenness centrality for Input-Output analysis is proposed.
- The vertex betweenness can identify key sectors for reducing life-cycle CO2.
- The edge betweenness can identify key transactions for reducing life-cycle CO2.
- Critical supply-chain structures can be visualized by the betweenness centralities.

In this article, we develop an economic network analysis to find environmentally critical transmission sectors, transactions and paths in global supply chain networks. The edge betweenness centrality in the global supply chain networks is newly formulated and a relationship between edge betweenness centrality and vertex betweenness centrality is further provided. The empirical analysis based on the world input-output database covering 35 industrial sectors and 41 countries and regions in 2008 shows that specifically, China's Electrical and Optical Equipment sector, which has a higher edge and vertex betweenness centrality, is the most critical sector in global supply chain networks in terms of spreading CO2 emissions along its supply chain paths. We suggest greener supply chain engagement centered around the China's Electrical and Optical Equipment sector and other key sectors identified in this study.