For villagers living near the base of Kilimanjaro, a tub of water is more valuable than a pot of gold. Two young men guard their stash.

A 1912 photo snapped by a German explorer of Mount Kilimanjaro, the highest point on the African continent, shows a thick crown of ice. Today, just a few wisps of white cling to bare rock. The nearly 12,000-year-old glaciers atop Kilimanjaro are melting -- about 80 percent disappeared between 1912 and 2000. But scientists now predict they could disappear completely within the next 10-15 years.

When they go, some climate experts and government officials fear, a crucial portion of the region's water supply also will be lost. More than a million people -- the Chagga -- who live in the shadow of Kilimanjaro depend on this mountain water to sustain their families, crops, and livestock. Warmer temperatures and an ongoing drought exacerbate the water shortage, say locals, causing tension on the mountain: Upstream villagers horde water from downstream villagers, and neighbors have been known to attack one another with machetes.

Water wars: Rapidly melting glaciers, such as Tanzania’s Kilimanjaro (above), could create water shortages across the globe—from the vast Indian subcontinent and China, which depend on melt from the Himalayas, to South American villages that rely on glaciers in the Andes.

Adding to Kilimanjaro's woes are its disappearing forests. Clear-cutting and fires have decimated about 40,000 acres of sub-alpine forest over the past century. These changes, say some scientists, ultimately will have a far more devastating impact on Kilimanjaro's water than that of melting glaciers.

German ecologist Andreas Hemp has been studying the forests on Kilimanjaro for more than a decade. He says the forest belt produces 500 times more water than the glaciers each year. In a process called "fog-stripping," large, leafy trees in the upper mountain capture water vapor and funnel it in the form of droplets down to the forest floor. According to Hemp, the loss of fog water each year roughly equals the annual requirement for the entire population living on Kilimanjaro. "It's a parallel trend," he says. "[If] we lose the upper forest regions during the same time that we lose the glaciers … it really would be a catastrophe."

Kelly West, an American scientist with the World Conservation Organization, agrees. She is helping organize a water conservation project for the Kilimanjaro region to ward off an impending water crisis. "One of our big messages in this project is we're not just in a period of a few bad years," she says. "Climate change is happening and people need to change the way they use water."