By Doug Struck
Forget peak oil. It’s peak water we should worry about, says Lester R. Brown.
Brown, whose early warnings about the dangers of climate change and resource overuse have made him a respected elder of the environmental movement, focused on the looming water shortages while promoting his memoir, "Breaking New Ground: A Personal History," the latest of his 50-plus books. He spoke Friday at the Harvard University Center for the Environment.
His point: It’s not that we will run out of water to drink; it’s that we won’t have enough to grow the food to feed the world.
“Water supply may be the principal constraint on the production of food. There’s a lot of land to produce food, if we have the water to go with it,” he said. “What happens to the water supply is going to affect the food supply and the world food prices.”
Overuse of water supplies already is driving aquifers to lower and lower levels around the world, he noted. The culprit is not simply personal use, Brown said. Some 80 percent of water is used for irrigation.
“We drink four liters of water a day, but we eat 2,000 liters of water per day” when the water used to produce our food is calculated, he said.
The situation is compounded by growing affluence in the world, which leads to higher meat consumption. It takes far more grain to feed animals for their meat than it would to feed humans directly.
“The average person in India consumes about 400 pounds of grain per year,” with minimal meat in their diet, he said. “In the United States, we consume 1,600 pounds per year,” most of it through meat, milk and eggs.
Growing the grain feed to produce those animal proteins is sucking dry the water supply in many parts of the world, he said. “I think food is the weak link in our system. If we look back at civilizations that failed, more likely than not, food was the weak link in their system. Despite the very sophisticated agricultural system in this country, I think it could be our weak link, too.”
More water-efficient agricultural practices are helping, but may not be enough, he said. Brown predicted farmers increasingly will turn to less water-hungry crops as supplies dwindle. They might switch, for example, from growing rice to wheat, which requires half the water. Such decisions already face farmers in the US Midwest, as the giant Ogallala Aquifer, which underlies eight states from Texas to South Dakota, has been dropping precipitously and may be depleted in a few decades.
Brown said the best strategy would be to reduce demand. “If I were to predict one single thing we could do to reduce water use, it would be to move down the grain food chain. We could cut our consumption in half and still have a healthy diet.”
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Helping Boston live a greener, more environmentally friendly life.
Christopher Reidy covers business for the Globe.
Doug Struck covers environmental issues from Boston.
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Dara Olmsted is a local sustainability professional focusing on green living.