Peak Oil has made it into the mainstream media, if not into the national consciousness. But two other issues may prove to be even more important; peak water and peak food.
Water is in short supply in the Southwest, where growth is fastest and rivers are already over-tapped. Even back East, we use so much water that supplies can run short. The Ipswich River near Boston now “runs dry about every other year or so,” according to Sandra Postel, director of the Global Water Policy Project. “Why? Heavy pumping of groundwater for irrigation of big green lawns.” In drought years like 1999 or 2003, Maryland, Virginia and the District have begun to fight over the Potomac — on hot summer days combining to suck up 85 percent of the river’s flow.
As for food, total production has leveled off in recent years, while per capita production of grain has been declining for ten years. Global warming may only make things worse.
Global warming will almost certainly stress water supplies in dramatic ways: In the western mountains, for instance, where the snowpack serves as a natural reservoir for the winter’s precipitation, more rain and earlier melt will mean less storage. The same rise in temperatures will almost certainly make farming harder. Earlier snowmelt means more parched fields by midsummer — and when the temperature rises into the mid-90s for long stretches, crops like corn begin to have trouble fertilizing. The summer of 1988 was the warmest yet across America’s grain belt, and yields dropped as much as a third.
Surviving this trifecta of limits will be challanging indeed