Future global urban water scarcity and potential solutions

Chunyang He,Brett A Bryan,Jingwei Li,Zhifeng Liu,Jianguo Wu,Xinhao Pan,Zihang Fang

doi:10.1038/s41467-021-25026-3

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.

Highlights

Urbanization and climate change are together exacerbating water scarcity—where water demand exceeds availability—for the world’s cities
933 million (32.5%) urban residents lived in water-scarce regions in 2016 (Table 1, Fig. 1b) with 359 million (12.5%) and 573 million (20.0%) experiencing perennial and seasonal water scarcity, respectively
We have provided a comprehensive evaluation of current and future global urban water scarcity and the feasibility of potential solutions for water-scarce cities

Summary

Introduction

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. 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. Population growth, urbanization, and socioeconomic development are expected to increase urban industrial and domestic water demand by 50–80% over the three decades[4,7]. A comprehensive understanding of water scarcity and the potential solutions for the world’s cities is urgently required to promote more sustainable and livable urban futures[7,18,19]

Methods

Results

Conclusion