Grey water footprint for global energy demands

With a Multi-Regional Input-Output model, this study quantifies global final energy demands' grey water footprint (GWF) based on the latest available data. In 2009, 9.10 km(3) of freshwater was required to dilute the pollutants generated along the life-cycle supply chain of global energy final demands to concentrations permitted by relevant environmental regulations. On a national level, final energy demands in China, USA, India, Japan, and Brazil required the largest GWF of 1.45, 1.19, 0.79, 0.51, and 0.45 km(3) respectively, while European countries have the highest energy demands GWF per capita. From the producer perspective, the largest GWF was generated in BRIC countries, i.e., Russia (1.54 km(3)), China (1.35 km(3)), India (0.92 km(3)) and Brazil (0.56 km(3)) to support global final energy demands. Because of global trading activities, a country or region's final energy demands also give rise to water pollutants beyond its territorial boundaries. Cyprus, Greece, Luxembourg, and Malta almost entirely rely on foreign water resources to dilute water pollutants generated to meet their final energy demands. Energy demands in BRIC countries have the least dependency on external water resources. On a global average, 56.9% of GWF for energy demands was generated beyond national boundaries. Energy demands in the global north are inducing water pollutions in the global south.