A diet for a small planet that includes some (but not much) meat

Carnivores, relax. You are not necessarily destroying the earth. Notes from a veggie vs. steak diet showdown.

Published October 9, 2007 10:06PM (EDT)

The average American eats about 5.8 ounces of meat and dairy products every day. The rest of the world is lining up at the trough behind us. According to one estimate, "total global meat consumption is projected to grow 65 percent between 1993 and 2020." And as any vegetarian will be eager to inform you, the production of a pound of beef requires 31 times the land area as does an equivalent amount of grain.

The environmental implications seem clear. Stop eating meat: The world can't handle it. Or, as the good folks at PETA like to say, meat eaters can't be environmentalists. It is difficult to argue with the conclusion made by the authors of a recent study exploring the relationship between diet, agricultural productivity and population: "The global transition to a diet rich in meat and other animal products may not be possible or desirable to maintain in the long run."

But meat eaters need not collapse in total despair. In "Testing a complete-diet model for estimating the land resource requirements of food consumption and agricultural carrying capacity: The New York State example," three Cornell researchers hold out some hope for incorrigible carnivores. (Thanks to BioPact for the link.)

First, the obvious news: A completely vegetarian diet would allow New York to support a larger population than a high meat-and-fat diet. But here's the head-twister: Add a little bit of meat and dairy, and you can feed even more people. (Although one might also observe, none of the above diets comes close to allowing New York to support its current population.)

But how is this possible? From a summary of the research provided by the Cornell Chronicle:

The reason is that fruits, vegetables and grains must be grown on high-quality cropland, [explains lead researcher Chris Peters]. Meat and dairy products from ruminant animals are supported by lower quality, but more widely available, land that can support pasture and hay. A large pool of such land is available in New York state because for sustainable use, most farmland requires a crop rotation with such perennial crops as pasture and hay.

Thus, although vegetarian diets in New York state may require less land per person, they use more high-valued land. "It appears that while meat increases land-use requirements, diets including modest amounts of meat can feed more people than some higher fat vegetarian diets," said Peters.

But best not to go overboard! The researchers conclude that about two ounces of meat and dairy a day is the most the land can support.

The mixed message pleases How the World Works, where we tend to look askance at totalizing discourses that anathematize lifestyle choices as categorically verboten. We are also inclined to applaud any research study that includes sentences such as "Our analysis shows that kernels of truth exist in both the claim that livestock production decreases the food supply and the claim that livestock production increases it."

So save the porterhouse steak for a special occasion, and eat more veggies the rest of the time. And always go grass-fed.

By Andrew Leonard

Andrew Leonard is a staff writer at Salon. On Twitter, @koxinga21.

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