Drop That Burger

Patrick O. Brown, a Stanford University biochemist, has changed science twice by giving stuff away. In the early 1990s Brown invented the DNA microarray, a tool that measures how cells make use of their DNA; he then showed researchers how to make their own, transforming genetic research. In 2000 he was one of three scientists who launched a free, online scientific journal called the Public Library of Science (PLOS); it has already broken the stranglehold of $200-a-year scientific publications like Science and Nature.

Now he is tackling an even bigger foe. Over the next 18 months Brown, 55, will take a break from his normal scientific work (finding out how a small number of genes are translated into a much larger number of proteins) in order to change the way the world farms and eats. He wants to put an end to animal farming, or at least put a significant dent in our global hunger for cows, pigs and chickens.

Brown, who has been a vegetarian for more than 30 years and a vegan for 5, notes that while livestock accounts for only 9% of human-caused carbon dioxide emissions, it accounts for 37% of human-caused methane (most of it emanating from the animals' digestive systems) and 65% of human-caused nitrous oxide, according to the Food & Agriculture Organization of the United Nations. Both are far better at trapping heat than carbon dioxide, meaning that cows, chickens and their ilk have a larger greenhouse effect than all the cars, trucks and planes in the world.

The green cognoscenti are choosing animal husbandry as their new enemy. Jonathan Safran Foer, the bestselling novelist, has published articles declaring that he is raising his kids vegetarian because of the environmental consequences of meat farming and that if people are going to eat meat, they should consider eating dogs. Lord Stern, a professor at the London School of Economics, told the Independent that the West would have to become more vegetarian in order to combat global warming; without change in present trends, meat and milk output will double by 2050.

Brown brings scientific clout to the debate--he's a member of the National Academy of Sciences and an investigator for the Howard Hughes Medical Institute--and a realization that the arguments for change need to be economic, not just ethical. Growing crops to feed animals requires a lot more land, energy and fertilizer than growing them to feed people, he says: 70% of the land that was once Amazon rain forest is dedicated to grazing. Even if scientists figure out how to make milk with stem cells, it's unlikely they will be able to create milk with the same efficiency as they can corn or wheat.

"There's absolutely no possibility that 50 years from now this system will be operating as it does now," says Brown. "One approach is to just wait, and either we'll deal with it or we'll be toast. I want to approach this as a solvable problem." Solution: "Eliminate animal farming on planet Earth."

Diets are malleable. Thirty years ago nobody drank high fructose corn syrup. Now it's a dominant part of the American diet. As Western diets move into China, people there are eating more beef. Brown argues that the key to removing meat from diets is to give foodmakers an incentive to make yummy vegetable-based fare. If vendors push the new foods, palates will follow.

Incentive? Brown thinks if he can convince food manufacturers that the costs of selling meat are too high, and rising, they'll come around. Seemingly tiny changes in economics could make animal farming a lot less affordable. At the moment farmers around the world are arguing they should be immune from taxes and ceilings on greenhouse gases; if they are not exempt, the cost of meat will go up. Raising the price of water would have the same effect. It takes 1,000 liters of water to produce a liter of milk.

Brown plans to spend the first six months of his project hammering out economic models with colleagues, illustrating ways that animal farming is likely to become onerously expensive. Then he'll take a year off to work with famous chefs and food researchers on tastier vegetarian dishes, and to develop a strategy to tackle the political, economic, legal, behavioral and food-security issues he's sure to face.

If Brown can work it so that McDonald's ( MCD - news - people ) puts less meat in each Big Mac, that could count as a win. Until now little research has gone into making foods friendly to the environment.

"If you're a big food producer now, this is absolutely inevitable," he says. "You'd better start thinking ahead. You'd better seriously start investing and trying to find alternatives in order to stay alive."