The water resources we receive from mountains are literally melting away before our eyes. Mountains and alpine glaciers – often referred to as the world’s ‘water towers’ – are becoming increasingly vulnerable to climate change and unsustainable human activities, threatening the water resources upon which billions of people and countless ecosystems depend. The United Nations World Water Development Report 2025 – Mountains and glaciers: Water towers, calls attention to the essential services and benefits mountain waters and alpine glaciers provide to societies, economies and the environment. With a focus on the technical and policy responses required to improve water management in mountains, the report covers critical issues such as water supply and sanitation, climate change mitigation and adaptation, food and energy security, industry, disaster risk reduction and ecosystem protection. Addressing the global water crisis begins at the top.