Three river systems in western Canada are on a list of the world’s most threatened by climate change.
The Fraser and Columbia river systems in British Columbia and the Saskatchewan-Nelson are three on a list of 78 mountain glacier-based water systems around the world determined by scientists to be at risk from the climate’s warming, as glaciers shrink and river flow declines.
Scientists ranked the 78 rivers 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, are critical to the water supply for a large part of the world’s population. They store and transport water via glaciers, snow packs, lakes and streams, thereby supplying invaluable water resources to 1.9 billion people globally – roughly a quarter of the world’s population.
The research, published in the prestigious scientific journal Nature, provides evidence that global water towers are at risk, in many cases critically, due to the threats of climate change, growing populations, mismanagement of water resources, and other geopolitical factors. Further, the authors conclude that it is essential to develop international, mountain-specific conservation and climate change adaptation policies and strategies to safeguard both ecosystems and people downstream.
The study, which was authored by 32 scientists from around the world, was led by Prof. Walter Immerzeel and Dr. Arthur Lutz of Utrecht University, longtime researchers of water and climate change in high mountain Asia.
“What is unique about our study is that we have assessed the water towers’ importance, not only by looking at how much water they store and provide, but also how much mountain water is needed downstream and how vulnerable these systems and communities are to a number of likely changes in the next few decades,” said Immerzeel. Lutz added, “By assessing all glacial water towers on Earth, we identified the key basins that should be on top of regional and global political agendas.”
Hydropower production and cooling for thermal power plants are just two of many systems that can be affected by diminished river levels.
Of the 78 global water towers identified, the following are the five most relied-upon systems by continent:
Asia: Indus, Tarim, Amu Darya, Syr Darya, Ganges-Brahmaputra
Europe: Rhône, 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.