A large number of people are starting to get very concerned about the melting glaciers in the Himalayan mountains. The problem: billions of people could be left without water:

The Tragedy of the Himalayas

Reports from Leh indicate that precipitation has dropped during the past quarter-century as temperatures have risen, a possible consequence of climate change. But the real threat is to the heart of the greater Himalayas and the vast Tibetan Plateau, where more than 40,000 sq. mi. of glaciers hold water in the largest collection of land ice outside the polar regions. “These glaciers are central to the region,” says Hasnain, looking over Khardung La. “If we don’t have snow and ice here, people will die.”

Scientists call it the third pole — but when it comes to clear and present threats from climate change, it may rank first. The high-altitude glaciers of the Himalayas and the Tibetan Plateau — which cover parts of India, Pakistan, Nepal, Bhutan and China — are the water tower of Asia. When the ice thaws and the snow melts every spring, the glaciers birth the great rivers of the region, the mightiest river system in the world: the Ganges, the Indus, the Brahmaputra, the Mekong, the Yellow, the Yangtze. Together, these rivers give material and spiritual sustenance to 3 billion people, nearly half of the world’s population — and all are nursed by Himalayan ice. Monsoons come and go, filling the rivers at times and then leaving them lethargic, but the ice melt has always been regular and dependable in a region where water — or the lack of it — defines civilization. “This isn’t like the polar ice caps,” says Shubash Lohani, an officer with the Nepal program of the World Wildlife Fund (WWF). “You have a huge population downstream from the Himalayas who are dependent on it.”

More info:

NASA points out that carbon particles may be making the glaciers darker, so they absorb more sunlight and melt faster:

The Dark Side of Carbon: Will Black Carbon Siphon Asia’s Drinking Water Away?

At a smaller scale, the same kind of thing is happening in parts of the United States. Lake Mead (the largest reservoir in the U.S.) has been falling for many years, and there is concern that lack of rain + huge demand for the water from places like Las Vegas could suck it dry.

What are our options? There are four:
1) Decrease the number of people who need water
2) Find other sources of water (e.g. desalination)
3) Fix climate change
4) Conserve water

Of those 4, by far the easiest and least expensive is conservation. The surprising thing about conservation is that there are many ways to do it. The following video shows how a single person can save over a thousand gallons of water a day with simple choices:

Given that a typical American household uses only 100 to 200 gallons of water per day, you might be wondering how a person can save 1,000 gallons per day. It is because many products we use need a lot of water. Meat is especially water-intensive, as pointed out in the in-vitro meat post. The cow drinks a lot of water, and the corn used to feed the cow was irrigated with a lot of water:

“To produce 1 pound of feedlot beef requires about 2,400 gallons of water and 7 pounds of grain.”

If you cut back on meat, it saves a huge amount of water in other places. Many other products work the same way. In the post on bottled water it was pointed out that making the bottle uses 3 times more water than filling the bottle.