Income impacts on household consumption's grey water footprint in China

Highlights: • This study assesses the household consumption's GWF in China from 2002 to 2017. • Total nitrogen determines the grey water footprint (GWF) of household consumption. • The change of household consumption's GWF was greatly driven by increasing consumption expenditure. • The increasing GWF from the poor to the rich is retarded by the changing consumption pattern. Urbanization is accompanied by growing household consumption and changing consumption patterns, with both having impacts on the life-cycle water pollution generated. This study uses the indicator of grey water footprint (GWF) within an Input-Output framework to examine the decadal change from 2002 to 2017 of the life-cycle water pollution change for household consumption in China, where rapid urbanization has particularly posed looming environmental challenges. Against the background of enlarging inequality, the results also shed light on the impacts of households within different income groups. From 2002 to 2017, GWF required by urban household consumption has increased significantly from 1586 to 2195 km³ while that for rural households have decreased slightly from 1139 to 964 km³ during the same period. Total Nitrogen required the largest GWF throughout the whole period and throughout all different income groups. Food consumption dominated the GWF for household consumption. However, the share of GWF for food consumption decreases with income increases, from 83% for extremely poor rural households to 71% for very rich urban households in 2012. Urbanites on average require higher GWF for their consumption than their rural counterparts. An average person from the highest income rural households required 2033 m³ GWF for household consumption, which is higher than a person from a very poor urban household (1685 m³) but lower than that of a person from poor urban household (2149 m³). While household consumption volume increase has been the primary driver for GWF increase, pollution intensity reduction has offset such impacts. Household consumption pattern change's impacts differ by household income and by pollutant considered.