Disappearing Act

Sometimes four pictures are worth a thousand data points. That's what Michael Coe MS'92, PhD'97 and his colleagues at the Center for Sustainability and the Global Environment have discovered after creating a media stir with their study of Africa's Lake Chad, a once-formidable body of water that is slowly, remarkably, turning into a puddle.

As part of a thorough probe of the lake's climate and environment, the researchers published a series of pictures taken from space — the first from 1963 and the most recent from 1997 — that shows dramatic change. Once one of Africa's great internal bodies of water, with some 9,700 square miles of surface area, Lake Chad now covers only 380 square miles.

Coe says the researchers were surprised to find the lake so diminished. They had been doing computer climate models on the region and comparing their predictions to current conditions when they realized, he says, that there was something "terribly wrong."

Climate models suggest that Lake Chad would eventually recede, but not by so much. The difference, the team found, comes from the human demand for water. The lake is bordered by four nations, all of which are siphoning off increasing amounts of its water to support agriculture and other needs. With the area's growing population and variable climate, it's a dangerous equation, one that threatens to suck the lake dry. "We've already reduced the water there to what is essentially a trickle," Coe says. "If the rain doesn't increase drastically, it would be very easy to use up all the water."

Lake Chad's sad story, though visually striking, isn't unique. "Unfortunately, this story is being repeated all over the world," says Jonathan Foley '90, PhD'93, a professor of atmospheric and oceanic sciences who formed the sustainability center just this year to start drawing attention to the world's shrinking resources.

With research projects already under way in many parts of the world — from the Mississippi River basin to the remote Amazon jungle — Foley hopes the center will help advance wiser ways of using water, land, food, and other diminishable resources.

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