More children in South Asia are struggling due to severe water scarcity made worse by the impacts of climate change than anywhere else worldwide, the United Nations said Monday.

As of 2022, 739 million children were exposed to high or extremely high water scarcity, with 436m children —mostly in low- and middle-income countries — living in areas of “high or extremely high water vulnerability.”

The term is defined as a combination of high or very high water scarcity and low or very low drinking water service levels. Extreme water vulnerability is one of the key drivers of deaths among children under 5 from preventable diseases, the Unicef report stated.

The most impacted regions are countries in the Middle East and North Africa and South Asia regions.

The eight-nation region of South Asia is home to more than one-quarter of the world’s children.

Climate change is a key driver in water scarcity, leaving an additional 35 million children vulnerable to water stress by 2050 and affecting their mental and physical health, the UN said in its report.

“In these circumstances, investment in safe drinking water and sanitation services are an essential first line of defence to protect children from the impacts of climate change,” the report read.

At the upcoming COP28 summit, Unicef is calling for the inclusion of children in the Global Goal for Adaptation (GGA), and that children’s rights are embedded in the Loss and Damage Fund’s governance and decision-making process.

“Safe water is a basic human right,” said Sanjay Wijesekera, Unicef chief for South Asia.

“Yet millions of children in South Asia don’t have enough to drink in a region plagued by floods, droughts and other extreme weather events, triggered increasingly by climate change.”

Last year, 45m children lacked access to basic drinking water services in South Asia, more than any other region, but Unicef said services were expanding rapidly, with that number slated to be halved by 2030.

Behind South Asia was Eastern and Southern Africa, where 130m children are at risk from severe water scarcity, the report added.