But it's not just about the belching. Livestock manure also emits methane (especially when it's stored in lagoons) and nitrous oxide, better known as laughing gas. There's nothing funny about this gas: It has 296 times the warming potential of carbon dioxide, and livestock are its leading anthropogenic (human-caused) source. The best way to reduce these gases is to better manage the manure; storage methods and temperature can make a big difference. The California Air Resources Board is studying manure-management practices as part of a sweeping effort to identify ways of cutting greenhouse-gas emissions, work that by the end of next year might lead to regulation of the state's ranches and dairies. Other states should do the same.
There are also smart ways of treating or converting animal waste. Manure lagoons can be covered, capturing gases that can be used to generate power or simply be burned away (burning the gases converts most of the emissions to CO2, which is far less destructive than methane). That's the strategy being pursued by American Electric Power Co., a gigantic utility based in Columbus, Ohio, whose coal-fired power plants make it the nation's biggest emitter of carbon dioxide. This summer, the company began putting tarps on waste lagoons at farms and ranches and sending the gases they capture to flares.
American Electric is under heavy regulatory pressure. Last week, it was on the wrong end of the biggest environmental settlement in U.S. history and agreed to spend up to $4.6 billion to clean up its smokestacks. Its work on manure is part of an experiment in carbon offsets; the company anticipates that someday Congress will cap the amount of carbon dioxide that can be emitted and allow polluters to trade pollution credits. As a previous installment of this series noted, that's a less effective way to combat global warming than carbon taxes, but the American Electric example shows that it would also direct the economic might of industrial polluters toward solving off-the-beaten-path problems such as livestock waste.
Other possible solutions include providing more aid to ranchers in places like Brazil, where forests are rapidly disappearing, to make cattle operations more efficient and thus decrease the need to cut down trees. Changes in farming practices on fields used to grow livestock feed could help capture more carbon. And U.S. agricultural policy is overdue for changes. Subsidies on crops such as corn and soybeans have traditionally kept the price of meat artificially low because these are key feedstocks.
Broccoli: It's what's for dinner
Such policy shifts and new technologies would help, but probably not enough. A recent report in the Lancet led by Australian National University professor Anthony J. McMichael posits that available technologies applied universally could reduce non-carbon dioxide emissions from livestock by less than 20%. The authors advocate another, fringe approach that has long been embraced by dietitians and vegans but is a long way from going mainstream in the United States: eating less meat.
Americans love beef. According to the 2000 census, the U.S. ranks No. 3 in the world in per-capita consumption of beef and veal (after Argentina and Uruguay), gorging on 100 pounds per year. We're also among the leaders in obesity, heart disease and colorectal cancer, and there is a connection -- fatty red meat has been linked to all of these conditions.
McMichael's idea isn't likely to gain much traction outside Australia; he proposes that developed countries lower their daily intake of meat from about 250 grams to 90 grams, with no more than 50 grams coming from ruminant animals -- that's less than 2 ounces, or half a McDonald's Quarter-Pounder.
Still, as evidence mounts that cutting back on beef would both improve our health and help stave off global warming, a campaign urging people to do so is clearly in order. It's understandable why political candidates are wary of bashing beef, but less understandable why environmental leaders with nothing to lose are reluctant to raise the issue. They would be more credible in targeting polluters if they were equally assertive in pointing out what all Americans can do to fight global warming, and at the very top of that list -- way ahead of more commonly mentioned approaches such as buying fluorescent lightbulbs or energy-efficient appliances -- would be eating less red meat.
A University of Chicago study examined the average American diet and found that all the various energy inputs and livestock emissions involved in its production pump an extra 1.5 tons of CO2 into the air over the course of a year, which would be avoided by a vegetarian diet. Thus, the researchers found, cutting out meat would do more to reduce greenhouse gas emissions than trading in a gas guzzler for a hybrid car.
The U.S. Department of Agriculture assesses ranchers, dairymen and producers of other commodities to pay for marketing campaigns to promote their products, raising millions of dollars a year and turning such slogans as "Got Milk?" and "Beef: It's What's for Dinner" into national catchphrases. This isn't quite tantamount to a government-mandated campaign to promote cigarette smoking, but it's close. The government should not only get out of the business of promoting unhealthful and environmentally destructive foods, it should be actively discouraging them.