Linkage analysis for water-carbon nexus in China

The shortage of water resources and threat of climate change are two major global problems associated with economic development. One vital issue is to coordinate water resource utilization and CO2 mitigation considering their coupling mechanism in socio-economic systems. This study employed linkage analysis based on a multi-regional input-output database to identify the roles of economic sector and pathway with respect to water resource utilization and CO2 emissions, and to characterize each sector along the entire supply chain. A case study was conducted to address the status of coupled water and CO2 in China. The results showed that Hebei, Shandong, and Inner Mongolia provinces are the major water-carbon nexus nodes for net forward linkage (net exports), i.e., mainly exporting products, embodied with large amounts of scarce water and CO2 emissions, to fulfill the demands of other economic sectors. Guangdong, Zhejiang, Shandong, Jiangsu, and Shanghai were found to be the major water-carbon nexus for net backward linkage (net imports), i.e., mainly importing products, embodied with large amounts of scarce water and CO2 emissions, from other sectors to meet their requirements. It can be concluded that exporter nodes are under severe water stress and have stringent CO2 emission reduction targets, while importer nodes might transfer water stress and CO2 emissions to the other regions via the supply chain.