For the first time ever, scientists from around the world have assessed the planets 78 mountain glacier-based water systems, ranked them in order of their importance to adjacent lowland communities, and evaluated their vulnerability to future environmental and socioeconomic changes.
These systems, known as mountain water towers, store and transport water via glaciers, snow packs, lakes and streams, supplying invaluable water resources to 1.9 billion people globally - roughly a quarter of the world's population.
The study was led by Profressor Walter Immerzeel and Dr Arthur Lutz of Utrecht University, both longtime researchers of water and climate change along with 32 other scientists from around the world.
Prof Immerzeel said they assessed the water towers' importance not only by looking at how much water it can store and provide, but how much mountain water is needed downstream and how vulnerable these systems and communities are.
They also accessed the number of likely changes based on predictions of future climate and socioeconomic changes.
Dr Lutz said by assessing all glacial water towers on Earth they identified the key basins that should be on top of regional and global political agendas.
The research, published in the scientific journal Nature, provides evidence that many global water towers are at critical risk from climate change, growing populations, mismanagement of water resources and other geopolitical factors.
The researchers concluded that it is essential to develop international, mountain-specific conservation and climate change adaptation policies and strategies to safeguard both ecosystems and people downstream.
According to their research the most relied-upon mountain system is the Indus water tower in Asia and the most vulnerable as it makes up vast areas of the Himalayan mountain range and covers portions of Afghanistan, China, India and Pakistan.
High-ranking water tower systems on other continents are the southern Andes, the Rocky Mountains and the European Alps.
Of the 78 global water towers identified, the following are the most relied-upon systems by continent:
- Asia: Indus, Tarim, Amu Darya, Syr Darya, Ganges-Brahmaputra - Europe: Rhine, Po, Rhine, Black Sea North Coast, Caspian Sea Coast - North America: Fraser, Columbia and Northwest United States, Pacific and Arctic Coast, Saskatchewan-Nelson, North America-Colorado - South America: South Chile, South Argentina, Negro, La Puna region, North Chile
The research was supported by National Geographic and Rolex as part of their Perpetual Planet partnership which aims to shine a light on the challenges facing the Earth's critical life-support systems, support science and exploration of these systems, and empower leaders around the world to develop solutions to protect the planet.
Jonathan Baillie, executive vice president and chief scientist at the National Geographic Society said mountains are iconic and sacred places around the world.
"The critical role they play in sustaining life on Earth is not well understood," Dr Ballie said.
"This research will help decision-makers, on global and local levels, prioritise where action should be taken to protect mountain systems, the resources they provide, and the people who depend on them."