Climate Change Daily Earth Science Repost

The world’s water towers

I read two articles today; one about skiing and the other about human survival. These articles talked about the same problem but from different perspectives. The common theme between the two was: loss of high mountain ice. Environmental research focuses on key components of the earth’s biosphere like oceans and rain forests. High Mountain ice is another critical component of the environment. For clarity, we are not adding it because of first world recreational tastes. Disappearing water towers and human survival, however, do get this issue on the environmental concerns list.

Water tower is a term referring to freshwater locked away in the form of mountain ice. These mountain reservoirs hold more ice than anywhere else on earth, other than the polar regions. 

The winter snowpack at one ski resort in the Swiss Alps is currently 40% less than the average from 1990-2008. Changes like this force resorts to invest heavily in snow blowers. Snow-blowing technology does not come cheap, and it is not necessarily environmentally friendly. While skiing was originally a necessary means of mobility and transport, today it is almost wholly to satisfy the recreational needs of the first world. 

Over 60% of the world’s ski slopes need some assistance from snow machines. They are battling on the margins of climate change to sustain their businesses because the annual window for freezing weather is narrowing. Snowpacks and high mountain ice are shrinking worldwide. 

Now for the real problem

The loss of access to ski slopes is not a critical problem. However, the inability of subsistence farmers to raise crops is a real problem. High mountain ice, locked in glaciers, serves as a storage tank for water and a stabilizer for critical river flow. Precipitation collects as a reservoir of water that is stored in the ice.

During dry seasons, the ice melts and forms a steady base level flow for major rivers. So the ice evens out the river’s flow over the year. Without it, rivers would receive their annual allotment of precipitation and go into flood stage each wet season. During the rest of the year, the rivers would shrivel and suffer drought.

The Indus river is one of the most important river systems reliant on water towers. Meltwater from glaciers of the Karakoram, Hindu Kush and Himalayan ranges feed this river. The river then flows across the dry Indus plains, where it provides life to over 120 million people. But the glaciers are melting faster than ice accumulates. The average annual temperature increases in the high Himalayas are now twice as high as the average global temperature rise.

The problem of disappearing water towers is not limited to Asia. The Pacific Northwest Columbia River system in North America also relies on high mountain ice. Likewise, the Andes in South America and the Alps in Europe are critical water tower provinces.

Without freshwater Homo sapiens don’t survive. Water towers affect 1.6 billion people on our planet. Therefore their future is an important part of the calculations we need to make on climate change. 


Climate change and surface water (Source: ArcheanWeb) – Also:


Feature Photo: Dôme du Goûter depuis la gare des glaciers – Alexandre Buisse (Nattfodd) – This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. – Also:

Melting Ski Resorts have a Snow Machine Problem (Chris Baraniuk, WIRED UK)  – Also:

The world’s supply of fresh water is in trouble as mountain ice vanishes (National Geographic article  – Alejandra Borunda December 9, 2019) –

William House
William is an earth scientist and writer with an interest in providing the science "backstory" for breaking environmental, earth science, and climate change news.