Carnivores Like Us

Environment & Ecology / by Paul Roberts /

Humanity's rapidly increasing appetite for meat is fast becoming a matter of global consequence. Paul Roberts on the science, and morality, of our planet's modern palate.

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Interestingly, even as science has revealed how necessary meat was in our past, science has also shown how dispensable meat is today. A full-grown, active man could thrive for a month on what the typical American eats in a week—or on no meat at all, as millions of vegetarians prove every day. Indeed, nearly 100 years ago, government researchers in the then-new field of nutrition discovered not only what it is about meat that the body needs—protein, for example, and micronutrients such B-12—but also how most of those beneficial components can be obtained elsewhere. Today we know that certain food combinations, like rice and beans, will provide the same complement of amino acids as are found in meat, and that the soybean, a Chinese transplant, contains a complement of proteins nearly as complete as an animal variant.

Swift & Company butchery and meatpacking plant in Marshalltown, Iowa. Photo: Sally Ryan/The New York Times/Redux©

But we’ve also learned just how challenging it will be to shift our dietary trajectory. As consumer incomes rise across much of the world, people are buying more of the things they like, and meat is near the top of the list. We’ve learned that, historically, vegetarian diets had less to do with health or spiritualism than with economics: In nearly every country where meat consumption was low (even in countries such as China, where some Buddhist practices encouraged vegetarianism), per capita intake has paralleled economic development.

Some of this is a simple reflection of rising purchasing power—a wealthier population buys more of everything. But rising intake reflects another, deeper change: Many of the scientific breakthroughs that elevated our understanding of meat also enabled us to make meat in vastly greater volumes, and for a fraction of the historical costs. Decades of innovation in the field of “meat science” has given us livestock breeds that grow faster, larger, and more uniformly. Parallel developments in farm science—such as synthetic fertilizers and pesticides, mechanized equipment, and fast-growing, high-yielding grains, especially—means we can generate oceans of cheap corn, soybeans, and other feed grains. Such feed not only fattens livestock faster than pasture or forage does, but allows the animals, fortified with antibiotics, to be raised in huge, factory-like farms.

Today, in much of the developed world, every phase of the once-decentralized meat business—from calving to feedlots to slaughtering plants—has been integrated into massive and efficient supply chains. In all but the poorest countries, science, technology, and new management systems have allowed us to transcend long-standing limits on meat. Even in traditionally vegetarian societies like India and China, meat intake is increasingly aligned less with culture or philosophy than with how many hours one works each week, or how close one lives to the supermarket. As Yang from the China Nutrition Association puts it, after centuries in which meat consumption was essentially limited by poverty and lack of technology, China’s consumers find themselves in a world “with no limits.”

Of course, our breaching of those limits was largely an illusion. As we’ve mastered the traditional economic and technological constraints on meat production and consumption, we’ve found new costs—from obesity, land scarcity, and declining water tables to soaring energy costs and shifting climate—that, if included in the price of the meat we eat, would completely undermine the idea that meat is cheap.

Already more than 8 percent of the world’s entire water supply is devoted to livestock production, and more than one-third of the world’s farmland is devoted to growing animal feed. The livestock sector is the largest source of water pollution—a slurry of animal wastes, antibiotics, hormones, fertilizers, and pesticides; fully half of all nitrogen and phosphorous contamination in the world’s water comes from the animal farm chain. Once a major proponent of a global meat economy, the FAO now calls the meat industry “one of the major causes of the world’s most pressing environmental problems.”

Even the global meat industry (and its supporters in government) quietly acknowledge that the business must change, although insisting that the existing high-volume, low-cost model can be preserved by making it lower-impact, safer, and more efficient. Many environmentalists and public policy advocates believe the changes must be deeper, and more systemic, and that they must be driven either from the very top, by way of tough new government regulation, or, preferably, from the very bottom, from consumers themselves. That may not be far-fetched: As media stories about sewage problems, E. coli outbreaks, antibiotic-resistant bacteria, and animal cruelty have surged, concerned consumers have begun to demand changes in the way meat is made.

Yet for all the calls for revolution, there is little consensus among advocates as to what this new meat economy would look like. For example, many who approach meat from a largely ethical standpoint, such as animal rights, argue for a completely meat-free culture; others accept some level of meat-eating as long as the animals are produced using “free range” or other humane methods. Among consumers motivated by health concerns, meat eating may be acceptable as long as livestock are fed organic grains or better yet, are raised on grass. The eco-friendly consumers, meanwhile, might tolerate a steak as long as the cow was raised on a carefully rotated pasture (to avoid erosion and over-grazing), or on a local ranch, thus reducing the “food miles” traveled and the associated carbon emissions. And yet, for all the awareness, and despite the eagerness of the food industry to exploit these concerns with a full range of “correct” meats (organic, cruelty-free, local, even soy-based), the result has been a confusing cacophony of choices whose benefits—to health, to the animals, to the planet—are hard to discern. Is, say, a Tofurky burger made from organic soybeans grown in Argentina really that much better? Is it still ethical, even, to eat grass-fed beef when the worldwide supply of sustainable pastureland is so small that only the rich can afford it?

What becomes clear is that when it comes to the future of meat, the debate itself also needs to evolve—from today’s fragmented and heavily politicized shouting match to a conversation that is at least informed by a scientific framework. In short, the discipline of “meat science,” traditionally focused on generating the most meat for the least cost, must organize itself around a fundamentally different set of questions. How much meat can the world sustainably produce? How little meat do humans actually need? And are there ways to produce meat, or meat protein, or protein with similar biochemical characteristics, without such high external costs?

Such questions are far from settled—and indeed, a great many critics of the modern food system refuse to trust the scientific methods that spawned many of the current problems in the first place. Yet amidst the debate, a great deal of research into methods for understanding, and reducing, meat’s external costs is now underway.

For example, in addition to the now familiar concept of “carbon footprint”—a product’s complex tally of all greenhouse gas emissions incurred from source to sink—we’ve now added an analogous “water footprint.” We’ve begun to pay more heed to the relationship between food and fuel: As we’ve seen most recently in the case of ethanol and biodiesel, growing more corn and soy for “clean” energy has displaced food agriculture into places like Brazil and Indonesia, where the costs of increased farm acreage—both in terms of carbon emissions and biodiversity—are so enormous that they threaten to tank the entire industry. With this more complex ecological calculus, science is slowly gaining an ability to quantify just how costly our foods really are—and how the proposed alternatives stack up. Seldom, we’re learning, are the answers clear-cut.

When the answers are evident, they’re often are unsettling. Because of meat’s high inputs, many proposals for sustainable food production call for reductions in meat intake that would stun most consumers. To reduce the ecological damage caused by runoff nitrogen, for instance, experts suggest using manures or planting cover crops such as legumes that naturally “fix” atmospheric nitrogen into the soil. But according to Tim Crews of Prescott College in Arizona and Mark Peoples of CSIRO Plant Industry in Australia, this approach would require converting half the nation’s current feed grain acreage into nitrogen-fixing crops. And that would bring such a large drop in grain supplies that Americans would need to reduce their meat intake to roughly one-eighth the current level.

And yet, as dramatic as such reductions may seem, they’re not out of line with the larger shift in thinking about meat. From a health standpoint, modern meat is often so fatty that the USDA and other health authorities are already recommending a serious reduction in intake—to just two to four ounces of lean meat a day, or from a quarter to a half of what most of us now eat.

Further, even as our traditional livestock sector may need to shrink to protect the environment, we’re learning how to produce high-quality protein in ways that don’t kill the planet. Eating soy products directly, instead of running the beans through livestock, would dramatically reduce the acreage required to feed the world. Nor must we stick to land: Farmed salmon, for example, not only contains more protein per gram than most terrestrial animals, but is far cheaper to raise, requiring about 1.4 kilograms of feed per kilogram of edible weight, or three times better than chicken. To be sure, the way most fish farming is practiced today is an environmental disaster: The large near-shore operations can generate as much sewage as a small city and the fish are heavily dosed with antibiotics and other additives. But newer methods, most notably, the large, deep-water fish pens, are much cleaner and could generate substantial volumes of high-quality protein.

We even have ways to make meat without livestock at all. Inspired by NASA research into solutions for long-term space travel, scientists are advancing with in vitro meat: Seeded on thin membranes or small three-dimensional beads, muscle tissue stem cells can be grown into animal-free beef, chicken, or pork. Scalability remains the major barrier to this avant-garde approach, but if implemented, it would simultaneously address environmental, food safety, and animal welfare concerns, if not those surrounding biotechnology. For people not quite ready to embrace cultured hamburger, there is always milk and eggs, which gram for gram yield more protein with less environmental impact than even chicken.

Clearly, these alternatives won’t be an easy sell to a species that not only evolved on meat, but which still regards meat as a just reward for economic success. And yet, as the true economics of meat become apparent, it’s clear that our ancient appetites will need to be balanced against modern limits, and that we won’t be able to address other issues, like deforestation or climate change, without first addressing our relationship with meat. The bad news is that any attempts to transform our meat culture will raise the same kind of moral storm that surrounded such controversies as second-hand smoke and seatbelt laws. The good news is that we won’t be arguing for change on moral grounds alone. As our scientific understanding of meat becomes more complete, we can point with increasing confidence not only to the costs of meat, but toward ways to reduce those costs—information that will not only make our arguments more persuasive, but will ensure that our vision for the future is more plausible. In the end, the same scientific methods that showed us just how important meat was in our species’ spectacular rise must now help ensure that meat doesn’t contribute to our fall.

Adapted from the book The End of Food by Paul Roberts. © 2008 by Paul Roberts. With permission of Houghton Mifflin Harcourt Publishing Company. All Rights Reserved.

Originally published May 15, 2008

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