Billions of people will face water shortages in the coming decades as climate change, population growth and changing agricultural practices strain water supplies like never before, the UN has warned. Water consumption historically has increased about 1 per cent annually and that trend will continue, with the world projected to use about 25 per cent more water in 2050 than it does today, the UN's annual World Water Development report stated on Wednesday. The report said water scarcity was becoming endemic due to overconsumption and pollution, with global warming expected to increase seasonal shortages. Cities will experience the greatest strain: In 2016, about 933 million people in cities faced water scarcity. By 2050, that number is forecast to hit 2.4 billion, with India the most affected, the report found. “Urban water demand is projected to increase by 80 per cent between now and 2050, and [the] global urban population facing water scarcity is projected to double during the same time,” said report editor Richard Connor. The report's release was timed to coincide with World Water Day and the start of a high-level water conference at UN headquarters in New York. The conference is the first event since 1977 aimed at tackling the global water crisis. Mr Connor said a growing global population means an increasing demand for agriculturally thirsty products such as meat, as well as an increase in demand from developing countries for appliances such as dishwashers. He told reporters that nearly one third of the world's cities that rely primarily on surface water are facing competition from increasing agricultural demands. Seasonal water scarcity is expected to increase in regions where it is currently abundant — such as Central Africa, East Asia and parts of South America — and worsen in regions where water is already in short supply, such as the Middle East and the Sahel in Africa, the report stated. North Americans were found to have the highest water consumption rates per capita. The report also found that water is being wasted at increasing levels, with governments failing to place a proper value on water. Mr Connor said that real growth in water demand will be dependent upon whether measures to improve water use efficiency are enacted. Co-operation between cities and surrounding agricultural communities is “absolutely essential to meeting the water needs of both” and improves water governance and decision-making, he said. Johannes Cullmann, scientific adviser to the President of the UN General Assembly, told reporters the increase in water demand is being driven by “industrial growth and particularly rapidly increasing urban populations”. UN experts said on Tuesday that water was a human right and should be managed as a “common good”. “Considering water as a commodity or a business opportunity will leave behind those that cannot access or afford the market prices,” said the experts.