While the global supply chains (GSCs) of industries cause excessive pressure on sustainable freshwater availability in the regions involved in the GSCs, they simultaneously deliver socio-economic benefits which have attracted less attention in the context of water footprinting. Using a multi-regional input–output analysis, we proposed a framework to analyze the balance between the economic value-added (VA) and the environmental pressure of freshwater “over” consumption (WOC) that exceeds the sustainable freshwater availability in 120 sectors of 164 countries, which are induced in each country’s GSCs from both global and regional scale perspectives. The results revealed that the VA-based efficiency of WOC (i.e., the balance between both positive and negative effects) in each country’s GSCs in 2015 largely varied reflecting the absolute amount of both effects (i.e., the global scale perspective) and those relative contributions to each country within the relevant GSCs (i.e., the regional scale perspective). Furthermore, the proposed framework demonstrated the possibility of identifying country- and sector-wise key points for enhancing the efficiency in the relevant GSCs: Even in the cases where the domestic sectors within the GSCs exert substantial WOC at the global scale, one case indicated the priority of measures to reduce water consumption in the domestic sector with respect to those positive contributions to the relevant domestic economy, while another case suggested an advantage of outsourcing of relevant products within the GSCs considering the efficiency gap in the balance of both effects between the domestic and foreign relevant sectors. We highlighted that the inclusive assessment of the positive and negative effects in the GSCs will contribute to promoting global investments and governmental support toward establishing more appropriate GSC structures for sustainable freshwater use.
Maeno et al. (Wed,) studied this question.