Future global urban water scarcity and potential solutions

TLDR

Urbanization and climate change are jointly exacerbating water scarcity, where demand exceeds availability in cities worldwide. The study aims to quantify global urban water scarcity in 2016 and 2050 under four socioeconomic and climate change scenarios and explore potential solutions. The authors use scenario‑based analysis of socioeconomic and climate projections to assess water scarcity. Projected urban water‑scarce population will rise from 933 million in 2016 to 1.693–2.373 billion by 2050, with India most affected; large cities exposed will grow from 193 to 193–284, including 10–20 megacities; over two thirds of water‑scarce cities could alleviate scarcity via infrastructure investment, though environmental trade‑offs must be guarded against.

Abstract

Urbanization and climate change are together exacerbating water scarcity-where water demand exceeds availability-for the world's cities. We quantify global urban water scarcity in 2016 and 2050 under four socioeconomic and climate change scenarios, and explored potential solutions. Here we show the global urban population facing water scarcity is projected to increase from 933 million (one third of global urban population) in 2016 to 1.693-2.373 billion people (one third to nearly half of global urban population) in 2050, with India projected to be most severely affected in terms of growth in water-scarce urban population (increase of 153-422 million people). The number of large cities exposed to water scarcity is projected to increase from 193 to 193-284, including 10-20 megacities. More than two thirds of water-scarce cities can relieve water scarcity by infrastructure investment, but the potentially significant environmental trade-offs associated with large-scale water scarcity solutions must be guarded against.