Using water more efficiently in everything from daily life to agriculture and industry would help reduce planet-warming emissions and curb climate change — a potential benefit that has yet to be widely recognized, the United Nations said on Sunday.

In a report issued on World Water Day, U.N. agencies said global warming would "affect the availability, quality and quantity of water for basic human needs," threatening the right to water and sanitation for "potentially billions of people."

But as well as using limited supplies more wisely and fairly, policymakers and businesses should also seek to manage water resources better to economize on the electricity and fuel needed to pump, clean and deliver water, the report said.