A sea change in the consumption of a resource that Americans take for granted may be in store - something cheap, plentiful, widely enjoyed and a part of daily life. And it isn't oil. It's meat. Global demand for meat has multiplied in recent years, encouraged by growing affluence and nourished by the proliferation of huge, confined animal feeding operations. These assembly-line meat factories consume enormous amounts of energy, pollute water supplies, generate significant greenhouse gases and require ever-increasing amounts of corn, soy and other grains, a dependency that has led to the destruction of vast swaths of the world's tropical rain forests. The world's total meat supply was 71 million tons in 1961. In 2007, it was estimated to be 284 million tons. Per capita consumption has more than doubled over that period. (In the developing world, it rose twice as fast, doubling in the last 20 years.) At about 5 percent of the world's population, [Americans] process" (that is, grow and kill) nearly 10 billion animals a year, more than 15 percent of the world's total. Growing meat (it's hard to use the word "raising" when applied to animals in factory farms) uses so many resources that it's a challenge to enumerate them all. An estimated 30 percent of the earth's ice-free land is directly or indirectly involved in livestock production. Livestock production generates nearly a fifth of the world's greenhouse gases - more than transportation. Though some 800 million people on the planet now suffer from hunger or malnutrition, the majority of corn and soy grown in the world feeds cattle, pigs and chickens.

"