There will be enough water to produce food for 10 billion people in 2050, but over-consumption and the impact of climate change threaten food security and water supplies in many regions, the U.N. Food and Agriculture Organization (FAO) said on Tuesday.

By 2050 some 60 percent more food will be needed to feed the world's people and as farming remains the largest user of water, food must be produced sustainably to ensure future supplies of food and water, the FAO and the World Water Council (WWC) said in a joint report.

"In an era of accelerated changes unparalleled ... in our past, our ability to provide adequate, safe and nutritious food sustainably and equitably is more relevant than ever," Maria Helena Semedo, FAO Deputy Director-General Natural Resources, said in a statement accompanying the report.

"Water, as an irreplaceable element of achieving this end, is already under pressure by increasing demands from other uses, exacerbated by weak governance, inadequate capacities, and under-investment."

Water scarcity already affects more than 40 percent of the world's population, largely because too much water is used to produce food.

Excessive use and pollution of water resources in key food-producing regions are threatening the sustainability of jobs that depend on water and agriculture, the report said.

"Agriculture has to follow the path of sustainability and not the one of immediate profitability," said Benedito Braga, president of the WWC, an international think tank.

The two organizations called for government policies and investment by both private and public sectors to ensure that crops, livestock and fish are produced sustainably, and in ways that also protect water resources.

This is essential to reduce poverty, increase people's incomes and ensure food security, the report said.