To contend with worsening water woes, experts have launched a new global commission to study the value of the world's water, and work out ways of ensuring supply.
The work by the Global Commission on the Economics of Water is meant to offer advice on water management worldwide.
This comes as climate change and deforestation take an increasing toll on the water and rainfall supplies, co-chair Johan Rockstroem told Reuters at the unveiling of the new group at the World Economic Forum in Davos.
"For centuries we've been able to consider freshwater a free resource," said Rockstroem, who is also director of the Potsdam Institute for Climate Impact Research in Germany.
Comprised of economists, scientists, community leaders and policymakers, the commission will investigate governance models to protect water resources and may consider pushing for a global price for freshwater, similar to what is being attempted with carbon markets.
"We need to put value on freshwater in order to manage it in a more resilient and responsible way," Rockstroem said.
Water stress driven by climate change is already affecting billions of people.
Millions in the Horn of Africa are living through the region's worst drought in 40 years, while the US West is also suffering its worst drought in decades.
Elsewhere, increasingly unpredictable rainfall is jeopardising crops or unleashes extreme flooding in some areas, such as central Europe last year or India and Bangladesh this month.
Such extremes are likely to become more common with global temperatures rising in coming decades, the Intergovernmental Panel on Climate Change said in a 2021 report.
Meanwhile, tropical forests, which through evaporation can generate their own rain, are vanishing due to deforestation.
"What's new is that because of climate change and deforestation, we are changing the very source of freshwater - which is rainfall," said Rockstroem.
Water scarcity could cost some countries up to 6% of their annual gross domestic product by 2050, researchers estimated in a 2016 World Bank report. They also warned of the potential for drought to drive migration or exacerbate conflict.
Rockstroem said the commission would explore incentives for ensuring water supply, for example paying nations, such as Brazil, Indonesia or Congo to protect their rainfall-generating forests, or compensating countries for water used in growing food for export.