The challenges of meat

Global meat consumption has more than doubled since the 1960s, and meat production is set to double again by 2050. In one way, that’s a good thing — proof that rising incomes are supporting higher living standards in developing countries. But Americans, famous for enjoying too much of a good thing, still eat three times as much meat as the global average. For solid self-interested reasons, they and other richworld diners ought to curb their appetite.

Consider this: Livestock are responsible for 12 percent of man-made greenhouse-gas emissions, more than the entire aviation industry. Most of that comes from just one animal: the humble, gassy cow. On a per-calorie basis, cattle are responsible for vastly more emissions than chickens and pigs, in part because their digestive systems produce methane, a potent greenhouse gas. From a climate-change perspective, serving your family roast beef at dinner is as bad as driving about 100 miles in the average car.

In fact, thanks to climate change, the world’s system of beef production is on course to destroy itself. A warming planet is already threatening the world’s food supply. After decades of steady decline, global hunger has begun inching up over the past five years — not coincidentally, the hottest five years on record. If the global temperature rises by 2 degrees Celsius, scientists predict global wheat output will fall by 10 percent, with months-long heat waves damaging crops that feed humans and animals alike. Heat stress will reduce meat and milk yields and could kill off thousands of cattle.

Curbing meat consumption voluntarily seems a better bet than letting the industry self-destruct after years of contributing to climate change. Most climate scientists agree that eating less meat would help to avert a worst-case scenario. But how much less? If all the world swore off meat, it would cut global emissions by 8 gigatons a year - roughly the same as shutting down 2,000 coalfired power plants. But if you’re not cut out for veganism, just eating less meat would help. (It would also thrill your doctor.)

Or you could join the “Meatless Mondays” movement, now active in 40 countries. Despite some backlash from American agribusiness and politicians (this issue is red meat to culture warriors), dozens of U.S. schools, businesses and hospitals - plus thousands of families have committed to going vegetarian one day a week. The effects add up : Skipping a single quarter-pound hamburger can save more than 400 gallons of water and the energy it takes to power a smartphone for six months. Do it every week for a year, and the greenhouse-gas savings are equivalent to biking 1,000 miles instead of driving.

Not everyone can or should go meatless, of course. And spontaneous voluntary action alone won’t suffice. Lawmakers need to take the initiative, by reining in meat subsidies and encouraging sustainable agricultural practices, and perhaps by rewriting their dietary guidelines as the Netherlands and Sweden have done.