What Will We Eat in a Hungrier World?

The world's appetite is growing, and the global larder is suddenly looking bare. The oceans are all but fished out. New arable land is scarce. People now compete with ethanol-slurping cars for corn. And the population will hit 9 billion by 2050, 2.5 billion more than now. No wonder food costs are soaring.

At the same time, meat eating is more popular than ever, with newly affluent people in China and India chowing down on pork, beef, and chicken. Yet the factory-farming practices that feed that global appetite are increasingly criticized for generating vast amounts of greenhouse gases and toxic waste, and for being inhumane. And despite centuries of breeding, animals remain woefully inefficient at converting feed into meat: The ratio of plant protein in for meat protein out varies from 4 to 1 for chicken up to 20 to 1 for feedlot beef. Given all the problems with ani-mal husbandry, maybe it's time to put Bossie out to pasture and grow animal-free flesh. Welcome to the future of in vitro meat.

Lab-based production would be "cleaner, more efficient, more sanitary," says Jason Matheny, a health economics graduate student at the Johns Hopkins Bloomberg School of Public Health. "It would solve all of the animal welfare problems." Matheny, who in 2004 founded New Harvest, a nonprofit devoted to advancing meat substitutes, is not the only one considering the idea. The Netherlands is financing research aimed at making lab-grown meat commercially viable. Faux flesh gained further attention in April, when People for the Ethical Treatment of Animals offered a $1 million prize to any person who can develop marketable in vitro chicken by 2012.

The notion of lab-grown meat is not as nutty as it sounds. Scientists have grown living tissue in the laboratory since the 1880s, though generally with medical uses in mind. In 1912, Alexis Carrel, a French surgeon and Nobel Prize winner, started growing embryonic chicken heart cells in a flask in his lab at the Rockefeller Institute for Medical Research in New York and maintained the culture for over 20 years. The experiment sparked intense popular interest in science's potential to grant humans immortality. (Carrel went on to work with aviator Charles Lindbergh in developing a precursor to the heart-lung machine.) In recent years, tissue culture has become commonplace in biomedical research and has been refined to generate human tissues. Lab-grown human skin is used to treat burn victims, and, in 2006, doctors at Wake Forest University successfully implanted lab-made bladders grown from the recipients' own cells. They worked just fine. Researchers are now developing more complex organs, such as hearts.

But growing organs for transplant is an art form. Growing meat to meet the world's appetite would require Wal-Mart-like efficiency and economies of scale. So far, even boutique-style meat production has proved problematic. NASA has spent years funding these efforts as part of its exploration of extraterrestrial food. The most recent project, in 2001, at Touro College in Bay Shore, N.Y., produced minute swatches of goldfish muscle. Given the paltry output, NASA concluded that it makes more sense for hungry astronauts to grow veggies instead. Michele Perchonok, NASA's Advanced Food Technology Project manager, says the agency will provide hydroponic systems for the moon or Mars so astronauts can grow lettuce, tomatoes, carrots, peppers, and strawberries. Those will supplement prepackaged meals, as well as wheat for milling into pasta.

Plant breeding is undergoing a renaissance on terra firma, too, in part thanks to funding from the Gates Foundation and other big-wallet philanthropies. The goals are to improve crops such as sweet potato and upland rice, which remain the key source of nutrition for people in sub-Saharan Africa and other impoverished regions, and to fend off threatening new pathogens, including a variety of wheat rust.

It would make sense, of course, for the whole world to become vegetarian: A plant-based diet is more healthful, more economical, and more environmentally benign. (Cows are major contributors to global warming because they generate methane.) But it has proved to be a difficult sell in a world of committed omnivores. "It's hard to convince 6 billion people to be vegetarian forever," says Matheny. Although about one third of the people in India eat no meat, only about 3 percent of Americans are vegetarians, according to a 2008 Harris Interactive survey for Vegetarian Times. Meat, it seems, will remain on the menu.