New study reveals need for immediate action to protect Earth’s “water towers”
Mountains are called the “water towers of the world” because they supply water to almost two billion around the world, or a quarter of the human population. Much of this water is available in the form of streams, lakes, snowpacks, ice and glaciers, which are highly vulnerable to climate change, as well as population growth and poor management.
Mountain glaciers, ice and snowpacks around the world are melting due to climate change. At first, this melting will actually generate more water. However, over a few decades, less and less water overall will be available to people downstream, and frozen water stored for millennia in these mountain ranges will eventually be depleted. Moreover, melting glaciers also increase the risk of flooding and landslides.
Until now, the importance and vulnerability of these mountain ranges, which are crucial for our water supply, had not been quantified at a global scale. A group of 32 international researchers have just published a landmark paper in the journal Nature on the importance and vulnerability of mountains for our global water supply. One Canadian researcher, Dr. Michelle Koppes, was also involved in the study. She is Associate Professor of Geography at the University of British Columbia, Canada Research Chair in Landscapes of Climate Change and has been studying glaciers for 22 years.
The research group assessed 78 mountain ranges around the world (or “water towers”), and ranked them according to their water-supplying role and the downstream dependence of ecosystems and society. The study examined the impacts of climate change on supply of fresh water, and also looked at the demands on that fresh water.
Each mountain range was found to have a different level of vulnerability related to water stress, governance, hydropolitical tension and future climatic and socio-economic changes. The researchers then pinpointed the most vulnerable water towers from each continent and compared them.
They found that the most important water towers are also among the most vulnerable, and that climatic and socio-economic changes will “affect them profoundly”. This could negatively impact 1.9 billion people living in or directly downstream of mountain areas. The most vulnerable river system was the Indus River in Asia, fed by the Himalayas and covering parts of India, Pakistan, Afghanistan and China.
The authors conclude that immediate action is required to safeguard the future of the world’s most important and vulnerable water towers. This information can help decisions-makers conserve water and better manage these resources.