Global water scarcity including surface water quality and expansions of clean water technologies

Abstract Water scarcity threatens people in various regions, and has predominantly been studied from a water quantity perspective only. Here we show that global is driven by both quality issues, quantify expansions clean technologies (i.e. desalination treated wastewater reuse) to ‘reduce the number of suffering scarcity’ as urgently required UN’s Sustainable Development Goal 6. Including temperature, salinity, organic pollution nutrients) contributes an increase percentage world’s population currently severe annual average 30% (22%–35% monthly range; only) 40% (31%–46%; quality). impacts are particular high such eastern China India. In these excessive sectoral withdrawals do not only contribute perspective, but polluted return flows degrade quality, exacerbating scarcity. We expanding (from 2.9 13.6 billion m 3 month ?1 ) uses 1.6 4.0 can strongly reduce levels affected, especially Asia, although side effects (e.g. brine, energy demand, economic costs) must be considered. The presented results have potential for follow-up integrated analyses accounting technical constraints reuse across world.