Land, Water And Conflict.(Cover Story: Who Is the Greenest of Them All?; POINT OF VIEW)

As drylands get drier and violence grows, new crises resembling Darfur will arise.

The world will experience a growing risk of conflicts over food, energy and water in coming years. The population rises each year by about 80 million people, with most of the increase in impoverished regions already facing environmental stress. Climate change, water scarcity and tighter oil supplies will add to the stresses. As violence increases, in new crises resembling those now underway in Darfur, Somalia and Afghanistan, the tendency might be to look to the military for solutions. We'll need to keep in mind that engineers and doctors will be the only ones who can truly keep us safe.

Hundreds of millions of people live on the margin of survival, and their numbers will increase if we continue on our current trajectory. The poorest of the poor tend to be found in remote, environmentally stressed regions, such as the drylands of Africa, the Middle East and Central Asia, which is evident in Yale and Columbia's Environmental Performance Index. In these places, droughts are becoming more frequent and land more scarce. Rural populations head for the slums in cities unequipped to provide jobs, safe water, sewerage and other basic services.

With a business-as-usual approach, more regions are likely to experience intensifying stresses. Human-induced climate change is predicted to make drylands drier and increase the risk of floods and powerful cyclones in more-humid regions. Increasingly crowded coastal areas will face greater risks of devastating storms. In places that currently rely on groundwater, such as in India, China and the American Southwest, wells will run dry, or become too expensive to drill. And in places in the Andes and in South Asia that depend on the seasonal melting of glaciers for irrigation, these water flows may stop as the glaciers disappear.

The results are unlikely to be pretty. Poor and hungry people are vastly more likely to fall ...