The number of people lacking access to safe drinking water in cities around the world will double by 2050, research has found, amid warnings of an imminent water crisis that is likely to “spiral out of control”. Nearly 1 billion people in cities around the world face water scarcity today and the number is likely to reach between 1.7 billion and 2.4 billion within the next three decades, according to the UN World Water Development Report, published on Tuesday ahead of a vital UN summit. Urban water demand is predicted to increase by 80% by 2050. Water shortages are also becoming a more frequent occurrence in rural areas, the report found. Currently, between 2 billion and 3 billion people experience water shortages for at least a month a year. Audrey Azoulay, director general of Unesco, the UN agency that produced the report, said governments must cooperate over water. “There is an urgent need to establish strong international mechanisms to prevent the global water crisis from spiralling out of control. Water is our common future, and it is essential to act together to share it equitably and manage it sustainably,” she said. The UN is holding its first water conference since 1977 in New York this week, co-hosted by the governments of the Netherlands and Tajikistan, at which global water issues will be discussed by ministers and a small number of heads of state from around the world. They will hear warnings of a looming water crisis, which has been largely neglected by governments. About 2 billion people globally do not have safe drinking water, while 3.6 billion lack access to safely managed sanitation, according to the report. Water use has been growing globally by about 1% a year for the last 40 years and this will continue, driven by population growth and development. About a 10th of the global population live in countries with high water stress. But experts told the Guardian that governments were failing to take the water crisis seriously. Johan Rockström, director of the Potsdam Institute for Climate Impact Research and co-chair of the Global Commission on the Economics of Water, said: “The scientific evidence is that we have a water crisis. We are misusing water, polluting water and changing the whole global hydrological cycle through what we are doing to the climate. It’s a triple crisis.” A landmark report published last week by the Global Commission on the Economics of Water found that demand for fresh water would outstrip supply by 40% by 2030. This would have huge implications for the global economy, for nature, for urban living and for the climate, but few governments were taking action to preserve water supplies and cut pollution, the report found. Rockström said addressing the problems with water was essential to tackling other global crises, including food and the climate. “There will be no agricultural revolution unless we fix water,” he said. “Behind all these challenges we are facing, there’s always water and we never talk about water.” Richard Connor, lead author of the report, called for the creation of new water funds and finance schemes that bring together users of water in cities with businesses and utilities to invest in water resources, such as habitats and river systems managed by farmers, to protect their water sources. He said such partnerships had shown promise in countries such as Mexico, where a water fund in Monterrey launched in 2013 had reduced flooding, restored natural habitats and maintained high water quality for urban users through a new financing arrangement. Overseas development aid for water has grown from $2.7bn a year in 2002 but was still small at $8.7bn a year in 2022, the report found.