As the world grapples with the escalating effects of climate change, a startling new analysis has revealed that half of the planet’s 100 largest cities are facing severe water stress. From Beijing to Los Angeles, major metropolitan areas are dangerously close to exceeding their available water supplies, a crisis exacerbated by poor resource management and the warming climate.
The study, conducted by Watershed Investigations and the Guardian, has mapped out the water-stressed catchments of these global hubs, with cities like New York, Rio de Janeiro, and Delhi emerging as some of the worst affected. Meanwhile, London, Bangkok, and Jakarta are also classified as highly stressed, underscoring the widespread nature of this impending crisis.
Separate analysis of NASA satellite data, compiled by scientists at University College London, paints an even more concerning picture. Over the past two decades, cities like Chennai, Tehran, and Zhengzhou have experienced stark drying trends, while Tokyo, Lagos, and Kampala have seen significant wetting. Alarmingly, around 1.1 billion people live in major metropolitan areas located in regions experiencing long-term drying, compared to just 96 million in cities situated in wetting zones.
“By tracking changes in total water storage from space, [the NASA project] Grace shows which cities are drying and which are getting wetter, offering an early warning of emerging water insecurity,” said Mohammad Shamsudduha, professor of water crisis and risk reduction at UCL.
The situation has become so dire that the United Nations has declared a state of “water bankruptcy,” where the deterioration of some water resources has become permanent and irreversible. Professor Kaveh Madani, director of the United Nations University Institute for Water Environment and Health, warned that poor water management, rather than climate change alone, is often the primary culprit.
“Climate change is like a recession on top of bad management of business,” Madani said.
The World Bank Group has also sounded the alarm, reporting a sharp decline in global freshwater reserves over the past 20 years. The planet is losing approximately 324 billion cubic metres of freshwater annually, enough to meet the annual needs of 280 million people, or roughly the population of Indonesia.
In the UK, the Environment Agency has warned that by 2055, England could need to find an additional 5 billion litres of water per day to meet public water supply demands – more than a third of the current 14 billion litres supplied. Shamsudduha acknowledged that groundwater could offer a more climate-resilient solution, but cautioned that “without sustained monitoring and better management, we risk managing it blindly amid intensifying development and climate pressure.”
As governments scramble to address this looming crisis, the UK has published a water white paper aimed at overhauling the water system, including the establishment of a new chief engineer role and “MOT checks” on water infrastructure. With the stakes higher than ever, the race is on to secure the future of water supplies for the world’s rapidly growing urban centres.
