Projecting China’s future water footprints and water scarcity under socioeconomic and climate change pathways using an integrated simulation approach

Abstract

Future changes in climate and socioeconomic systems will exacerbate water scarcity. Previous studies on China’s water footprint and scarcity often consider only climate change or socioeconomic factors in isolation. Here, we address these issues by coupling an integrated assessment model, the Global Change Analysis Model, with a global hydrological model to project China’s future water footprints and water scarcity, considering both climate change and socioeconomic factors. We simulated China’s water footprints under 52 scenarios, which include four global climate models (GCMs) and 13 combinations of Shared Socioeconomic Pathway (SSP)–Representative Concentration Pathway (RCPs) scenarios. We then projected the intensity of water stress (WSI), defined as a ratio of water footprint to renewable water volume, based on the simulations of the SSP2-RCP6.0 scenario. Our results align well with statistical data on water footprint variations between 2005 and 2020. China’s water footprints are likely to peak around 2030 and then decrease. We find through a scenario matrix analysis that emission-mitigation measures will significantly impact the water footprint, particularly in the electricity sector, which will become the largest water use sector in the future. This means that the low carbon energy option on China’s path to carbon neutrality may aggravate water scarcity. Water stress in China is projected to be greatest in 2025–2035, and all northern basins will experience water scarcity. Projections based on all GCMs consistently show a decline in WSI in China after 2050.