CNN
 — 

The world is facing an “unprecedented water crisis” driven by soaring demand and the accelerating climate crisis, according to a new report.

A quarter of the world’s population currently faces “extremely high water stress” each year, with an additional 1 billion people expected to be affected by 2050, according the World Resources Institute’s Aqueduct Water Risk Atlas published Wednesday.

Extremely high water stress means countries are using almost all the water they have – at least 80% of their renewable supply, according to the report, which is published every four years.

The report found that 25 countries, representing 25% of the global population, experience extremely high water stress each year, with Bahrain, Cyprus, Kuwait, Lebanon and Oman the five most affected. Even a short-term drought could put these places at risk of running out of water.

“Water is arguably our most important resource on the planet and yet we’re not managing it in a way that reflects that,” said Samantha Kuzma, Aqueduct data lead from WRI’s water program and a report author.

“I’ve been working in water for close to 10 years, and unfortunately, the story has been the same almost the entire 10 years,” Kuzma told CNN.

Globally, demand for water has more than doubled since 1960, and the report projects that it will rise by a further 20 to 25% by 2050.

Increased water demand stems from a range of factors, including growing populations and the demands of industries such as agriculture, along with unsustainable water use policies and a lack of investment in infrastructure.

In the Middle East and North Africa, the world’s most water-stressed regions, the entire population will live with extremely high water stress by mid-century, the report predicts, affecting drinking water supplies, damaging industries and potentially fueling political conflict.

The biggest change in water demand will occur in sub-Saharan Africa according to the report, which projects a 163% increase in water demand by 2050.

“One look at sub-Saharan Africa, we see demand for water skyrocketing,” Kuzma said, mainly for domestic water use and crop irrigation.

In North America and Europe, water demand has plateaued, helped by investment in water use efficiency measures. But that doesn’t mean parts of these regions aren’t affected.

In the US, six states experience extremely high water stress, according to the report. Six of the seven states in the Colorado River Basin, including Arizona and New Mexico, are in the top 10 most water-stressed states in the US.

Water resources also extend beyond country borders, Kuzma said. “We’re all impacted if water stress is essentially turning off the tap and preventing different countries from producing certain commodities.”

And, under it all, climate change is worsening the crisis.

“Water is how climate change most directly impacts people around the world,” said Charles Iceland, global director of water with WRI’s Food, Forests, Water, and the Ocean Program.

Climate change fuels increasingly severe and prolonged droughts and heat waves, which make water supplies much less reliable. A lack of water also makes it harder for people to survive these extremes.

Even if the world manages to limit warming to 1.3 to 2.4 degrees Celsius above pre-industrial levels – an “optimistic” scenario according to the UN Intergovernmental Panel on Climate Change – an additional 1 billion people are expected to live in extremely high water stress conditions by 2050, according to the report.

Water stress costs lives, threatens food security and causes energy outages.

The report suggests various measures to prevent water stress spilling into a water crisis. These include nature-based measures, such as preserving and restoring wetlands and forests, farmers adopting more efficient watering techniques such as drip irrigation, and policymakers focusing on energy sources that don’t rely so heavily on water, such as solar and wind.

Places like Las Vegas and Singapore have shown it’s possible to manage very scarce water resources through policies such as wastewater treatment and reuse and removing water-thirsty plants, the report authors wrote.

But globally, action is lagging, according to the report.

Dieter Gerten, research group leader at the Potsdam Institute for Climate Impact Research, who was not involved in the report, told CNN that the findings bring home the scale of the challenge the world faces and the need to urgently implement measures to tackle it.

“This report once more reminds us that the sheer sum of acute and chronic water stress symptoms – which now affect large parts of the Earth and the life of billions of people – leads us to the brink of a global water crisis.”