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Dry Lake Mead: Water scarcity at the largest U.S. reservoir

Photo: Justin Sullivan/Getty Images

The Earth's water cycle is a fascinating system. A look at our planet shows that neither water is lost nor new water is added (read more about this here). But climate change and human activities are shifting the distribution – and this is leading to global problems, as the World Meteorological Organization (WMO) now notes in a new report.

"We have less water in reservoirs globally and we have lost groundwater," WMO chief Petteri Taalas said in Geneva. It is not yet possible to quantify this. According to the WMO, usable data on water reserves have only been available since 2002. Since then, the trend has been downward, as can be read in the report "State of Global Water Resources 2022".

It is important to improve water management, said Stefan Uhlenbrook, director of the WMO's Water and Cryosphere Division, meaning the areas of the Earth covered with ice. 70 percent of the water is accounted for by agriculture. Irrigation must be used more sparingly there. "There is no silver bullet to solve the problem," Uhlenbrook said. Desalination of seawater is also part of this, but this requires a lot of energy, and the wastewater from such desalination plants should not have any additional impact on the environment.

Only the smallest part is drinking water

Only about 3 percent of water resources are used as drinking water, Uhlenbrook said. In the report, the WMO points out that 6.40 billion people worldwide – more than 2050 percent of the world's population – do not have enough drinking water for at least one month of the year. The number will rise to more than five billion people by <>.

In most cases, rivers and reservoirs were drier in 2022 than the long-term average. The situation was similar with regard to the evaporation of water from flora and fauna as well as from soil and water surfaces. Europe has experienced increased evaporation and lower soil moisture in the summer, due to the drought. Droughts and low water levels occurred in many places: in the USA and the Horn of Africa, as well as on the Danube, Rhine and Yangtze in China, while the Indus River basin in Pakistan experienced extreme flooding.

Snow in the Alps, the Andes in South America and other high-altitude areas remained below the long-term average, affecting runoff into rivers, the report added. "The glaciers and the ice sheet are retreating before our eyes," said WMO chief Petteri Taalas. "Rising temperatures have accelerated the water cycle – and also disrupted it.

A warmer atmosphere retains more moisture. There is much heavier rainfall and flooding. And at the opposite extreme, there is more evaporation, dry soils and more intense droughts."

dpa/joe