Steven Cherry: Hi, this is Steven Cherry for IEEE Spectrum’s “Techwise Conversations.”
Should we eat meat?
Meat is nutritious. It’s tasty. It’s at the center of our culture and our dietary traditions. Most peoples that largely do without it suffer from widespread malnutrition. Yet meat is a major cause of coronary and other disease. It’s cruel to animals in the ways they’re reared and slaughtered, and it’s a major contributor to global warming.
So, should we eat meat? It’s one of the foremost questions of our time.
Here to attack that question is a man who has studied it for decades in the purest way imaginable. How much protein goes in the foodstuffs that we use to produce meat? How much protein do our cattle, pig, poultry, and other meat industries produce? How much protein does our planet and its 7 billion people, and then 8, and 9, and then 10 billion people need?
My guest today is Vaclav Smil. He’s a distinguished professor emeritus of the University of Manitoba and the author of 400 papers on a wide range of topics that include energy, environmental and population change, food, technical innovation, risk, and public policy. He’s also written more than 30 books, one of which, published just this month by Wiley, is titled Should We Eat Meat? He joins us by phone.
Vaclav, welcome to the podcast.
Vaclav Smil: Thank you.
Steven Cherry: Your book looks at the entire history of food production, the actual dietary needs of the planet, and what technological and social changes are needed to meet it. It’s hard to know where to begin, but you begin with protein. Meat seems to be a key but dangerous provider of it.
Vaclav Smil: Well, I don’t know if it’s dangerous, but it’s certainly key, because lean meat, lean meat in particular, of course, is nothing else but protein. No matter which lean meat you take, let’s say if it’s chicken breasts or very lean pork or very lean beef, it’s just basically, fresh weight, is 20 percent protein and 80 percent water. So, of course, there is protein in milk, there is protein in eggs, there is protein in fish, and fish, very similar, but there is no better source of high-quality protein than meat. And as far as dangerous, it all depends.
Steven Cherry: You look at this in terms of the annual consumption per capita, and I guess there are places where it was as low as 5 kilograms per capita, annually.
Vaclav Smil: Well, even less than that. Actually, this is almost a meaningless figure, because if you take, say, China of the 1920s, 1930s, and you have a figure like 2, 3, 4, 5 kg a year per capita, that means that most of it was consumed by richer people and people in cities. And that means that most of the peasants ate no meat at all, or maybe they ate meat like twice a year, some special occasions like weddings, funerals, New Year celebrations. So it was practically completely a vegetarian diet.
But I should add that many groups, even in rich countries, let’s say, women in France—we have excellent statistics from France—women in France also are eating less than 20 kilos of meat per year per capita.
Steven Cherry: And by contrast, we should say the U.S. is up to over 100 kg per capita.
Vaclav Smil: I should mention—yes.
Steven Cherry: So we’ve really industrialized the production of meat in the last century.
Vaclav Smil: Well, even a few generations ago, what you had, most of the meat, let’s say certainly before the Second World War, in U.S., in Europe, and the first decade after the Second World War, it was mixed farming. So farmers had crops, and farmers had animals. Most of the feed for those animals came from the very same farm. Some feed was brought from outside, the commercial feed, imported, but most of the feed came from the farm. This basically is now gone and done. There are farmers who specialize in growing crops only, and they never ever have a single animal, and there are these farmers which simply have no crops but buy commercial feed on a massive scale and feed it to their animals. So there’s been a separation of animals and crops, which has all sorts of problems. What do you do with the manure? Because that manure before was just distributed on those nearby fields in that mixed farming, and now you have these masses of manure, which you have to dispose of.
So this is a new model, and it led to some massive centralization of farming. And in the U.S., you could see it. You know that, of course, every state produces some chickens, some broilers, but the concentration in Southern states, Arkansas, Georgia, is just immense. So it has become like everything else. Before too long, facetiously saying, every chicken will come from one place in Arkansas.
Steven Cherry: And they differ wildly in terms of the efficiency of production.
Vaclav Smil: Well, again, if you do it the old-fashioned way. So let’s say 50 years ago, even today in rural China, there are these chickens running in your rear yard. So a few times a day, maybe, maybe you just leave them totally alone, and they are fending for themselves, and pecking here and pecking there, and eating a little bit of stray grain or some earthworm or whatever. Or maybe a few times a day you throw them a handful of grain, and that’s it. And these chickens will take, like, whatever, you know, six, seven, eight months to mature to some slaughter weight, like 1 kilo, while we put these chickens in these feeding bays and we just feed them this mixture of corn and soya beans and they are done in six weeks. In less than two months you have a chicken [unintelligible]. So this commercial production of meat is extremely rapid and extremely efficient.
Chicken is most efficient, then comes pork, and then comes beef, and especially, of course, if it’s the beef, which part of the time has been fed in these central operations, in these silos. Because you can do the other beef, that is, you can produce beef all the way from weaning to slaughter on the grassland. And, of course, it costs you no artificial feed.
Steven Cherry: So I guess almost all poultry and hogs in developed nations are reared in confinement, but cattle, it’s. . .
Vaclav Smil: This has now increased, yes. Exactly. And it’s not only, you know, it’s also in all large urban areas of modernizing countries. So in China it’s the same thing. In Shanghai you don’t produce pigs by the old-fashioned method as the farmer who had, like, whatever, 10 heads of animals. So these mass-production operations, they are not only throughout the rich world, but they are in the suburban areas of every large urban area in China, in the Philippines, in Thailand, Brazil. That’s now the norm worldwide for urban areas.
Basically many people agree that we’ve gone too far, really, because these, what is called these “mass central feeding operations,” they are just simply too big—thousands, tens of thousands of animals, and they are so efficient, basically. In the case of chickens, really, they have hardly any room to move. And then because of the proximity of these animals, you have to feed them preventive antibiotics, because once one chicken would get sick, then you have 80 000 sick chickens. So it’s simply the scale is too large, but, of course, it has driven prices so low, so it’s now massively affordable. But there are quite a few new steps being taken, which show that you don’t have to at that scale, and you don’t have to put so many chemicals into it. So we can do better. The model is here to stay. We have to produce meat in large quantities. The mom-and-pop operations cannot satisfy mass markets, but it could be done better.
Steven Cherry: You single out broiler chickens as perhaps the greatest objects of mistreatment.
Vaclav Smil: Well, you see, because it’s real tough. You want to maximize everything, and so you make the life miserable for these animals. And there is abundant documentation of all of this. Let’s say, you know, these animals don’t even have enough light. You kind of keep the light subdued so they would keep as little active as possible. Because the more active the bird will be, the more it will spend on its own metabolism, and less energy will be put into that meat, which you want to harvest. So they live in the semidarkness. They live in these very crowded conditions. They are not what we would call the “free-range chicken.” You have the option now. You can go, and in many stores now you can buy free-range chicken, and you can have free-range eggs, but that’s a very small percentage of the market. So basically it’s a deprivation, right? If animals are too crowded in this subdued lighting, they can hardly move. They are just simply—plus when you look at the object of this exercise, it is large breasts. So these animals’ rib area, they are skewed forwardly. So their basic physical structure has been affected by that breeding. So it’s not a pretty picture.
Steven Cherry: Yeah, the standard industry defense is that the end product, the food, would be less affordable if the animals were to suffer less.
Vaclav Smil: Well, exactly. You see, that’s the trade-off, right? There is always a trade-off, and the trade-off here is that the treatment of animals leaves lots to be desired. But the prices, you cannot beat the prices.
Steven Cherry: You call meat “environmentally expensive,” and it seems that the larger animals, cattle, are the most environmentally expensive.
Vaclav Smil: Exactly, because they are the least-efficient converters of feed because they spend most of the feed, which they eat, of course, will be spent on their own metabolism, maintaining their body temperature. It’s a larger animal. They take a long time to mature. Chicken can be ready for slaughter in a matter of weeks, less than two months, while there’s no way how you could have a cow, steer, or beef ready to slaughter in less than many, many months or more than a year. So they are expensive in the sense that most of the feed you put into them goes into something other than meat, which you want to harvest.
Which means that, especially in these industrial operations, you have to plant large areas to feed whatever it is—corn for carbohydrates and soya bean for protein. You have to fertilize those crops, which of course creates the runoff of nitrogen into waters, creating all sorts of problems there. And, of course, these animals, during their metabolism, they are the ruminant animals. Beef, they are the sources of rather large amounts of methane, which is, is well known, is a greenhouse gas more powerful than carbon dioxide. So there are all kinds of environmental problems. The land affects nitrogen, affects water pollution, manure, greenhouse gases, so beef certainly is the one which has the greatest environmental impact.
Steven Cherry: Yeah. One thing that surprised me was how much the total body mass of food animals exceeds the weight or volume of wild animals, and it’s even greater than the mass of humanity.
Vaclav Smil: That’s a calculation which I deliberately engaged in, because most people don’t think that way really. But, you know, it’s as soon as you start thinking about it, it’s quite obvious, right? You’re saying 7 billion people, but you have to take into account the structure of the population, especially in developing countries. So most of these are young people or children, so the average mass is not like 70 or 80 kilos, like for adults in the rich countries. But it’s less than 50 kg. If you take the weighted life mass of all humans, so let’s say 40, 45 kg. So you multiply 7 billion by 40, 45 kg, but, you see, you have 2 billion large animals. You count not only the cows but the camels and the water buffalos and a few horses. And, of course, these animals, easily each of them on the average weigh 200, 300, 400 kg, so you have a difference in mass. And then, of course, you have these huge chickens, it’s like 1, 2, 3 kg, but they are literally, because they are slaughtered so rapidly, through the year we run through billions and billions of them. So, yes, all together the mass of domestic animals now far surpasses the mass of humans.
So if you’ll be a Martian visiting the planet Earth and you’ll be looking at the dominant living form on the planet, you would think, well, this is the dominant living form, these domestic animals.
Steven Cherry: So how does meat stack up in terms of, I guess you looked at sort of the pure energy inputs and outputs as well.
Vaclav Smil: Well, you see, this is a tricky question, because it could be done in a way which almost, it costs almost nothing. Let me explain. We have to eat, okay. So with any meat, you have to harvest grain. You have to harvest wheat. You have to harvest rice. Both of these grains, of course, you have to mill them. We don’t eat them whole. You could eat them whole, but most of the people don’t; I’m very sure they haven’t been eaten whole. When you mill wheat to make wheat flour, it’s about 15 percent loss.
You harvest, whatever, a billion tons of rice—again, not an actual figure—and it’s milled even deeper, because in Asia people like well-milled white rice. And you easily lose 30 percent of that grain. So all of these residues we don’t throw away. All of these milling residues [unintelligible] we feed to animals. Then we have all sorts of processing residues. When you squeeze grapefruit or oranges, well, you know, what remains could be fed to cows. It’s actually pretty good cow feed. So all sorts of food-processing residues create a tremendous amount of feed for animals.
And, of course, we are using quite a bit of it, or most of it, actually, for feeding, and so if we would limit our feeding operations to, let’s say, some waste grain or waste potatoes, these food-processing residues, literally it still adds up to hundreds and hundreds of millions of tons of feed. So we would be eating less meat. We could produce quite a bit of it or most of it just by feeding the processing residues and some waste products rather than growing soya beans and corn and other feed and occupying lots of arable land, which could be used for food crops directly.
Steven Cherry: It’s an interesting thing. I mean, farms used to be self-contained, right, with pigs foraging plants and then replenishing the soil with their waste.
Vaclav Smil: Exactly. And there’s this broken link between the land, between animals, land, and crops. It’s something we should really, something which is to be regretted, but it’s unlikely we will get back, because to get back you would have to have many more people working on the farms. This is one part how we reduced the farm population to less than 2 percent in the United States or a few percent in Europe, because we just basically have given up, to a large extent, on recycling this manure and just simply go for synthetic fertilizers.
So things could be done in a much better way, but it’s not an easy change once you get a system as we have it now in operation. It’s so embedded now. It’s so efficient, and there are so many vested interests in it. Plus, you would have to have many more people returning to farm. It’s just very difficult to do something more “organic,” less intensive, without less labor. That will be very difficult. There will be more agricultural labor required and not get many people who are willing to do that.
Steven Cherry: So let’s get to the bottom line. You think major changes in the way that we rear and transport and slaughter animals are needed on both environmental and ethical grounds, but that’s not enough to say that we shouldn’t eat meat.
Vaclav Smil: No, it’s not, actually, because in terms of evolutionary background, we are omnivorous creatures. We are not herbivorous. You look at our gut, our gut is like half a kilometer long. To say facetiously, our gut is relatively short, and we put more into the development of brains and hearts. We are great runners, we are great thinkers, so we are definitely omnivores. We are not by evolution [supposed] to be vegetarian.
So meat has a place in the human diet. It’s an excellent source of protein, some vitamins, many minerals, and it’s a question of quantity. This planet would not be a bad place at all if people would eat a limited amount of meat, whatever that may be, depending how it’s grown—10, 20, 30, 40 kg, something like that. But this planet would have a hard time to support sort of an American or European style of meat eating for everybody: 7 billion people eating more than 100 kg of meat, that will be a very tough proposition. So it’s not a question if—definitely yes—it’s a question how much and how it would be grown.
Steven Cherry: So I think you estimate in your book that with more rational and ethical ways to raise animals, we could rear maybe two-thirds of the number we raise today, and that maybe with better crop management we could make up the remaining third?
Vaclav Smil: Absolutely. There are many ways how to do it. In large systems of this kind, there are always inefficiencies at every possible level. So although we got pretty efficient in feeding, there are still inefficiencies in feeding. But there are inefficiencies in handling animals, inefficiencies in producing that feed, and producing that corn and soya beans and [unintelligible]. So there are inefficiencies at every possible step, but, you see, overall the system is pretty efficient. So it’s just not like, you know, you cannot approach it and say, “Oh, it’s so inefficient. We can get rid of the whatever, half.” No. Maybe 10, 20, 30 percent, certainly. Something like that. So it has to be a combination of efforts.
We can make everything more efficient, but that will not kind of lower the input by half—maybe be like by a third. We should eat less meat, but again, most people will consider, okay, “I’m willing to eat, like, 20, 30 percent less,” but most people will not say, “I’m willing to eat 80 percent less.” So maybe, again, you lower the demand by 20, 30 percent, you lower the input by 20, 30 percent, you bring some alternatives, more milk, more cheese, more yogurt, more aquaculture fish, maybe this will get you another whatever, 10, 20, 30 percent. So it’s all a complex system.
Steven Cherry: At the same time, there are some forces requiring total meat production to rise, right? Because the world population is rising.
Vaclav Smil: We’ve seen these dietary transitions from grain, basically a vegetarian diet, to more meat. We’ve seen it everywhere, in the early 20th century in Europe, the United States, Canada, and unfolding very rapidly during the past 40 years in China, in Japan. So this is yet to come. This is yet to come in large parts of Southeast Asia, India, Pakistan, large parts of Africa. Of course it happened mostly in Brazil. Brazil is a high meat-eating nation. But literally billions of people are there who still want to increase their meat intake from maybe, like, 5, 10, 20 kilos of meat per year per capita to maybe, like, 30, 40, 50.
So, yes, the potential demand for meat is huge. You could easily make the forecast that it’s for doubling what we are consuming today, depending how far the income in those developing countries will go.
So something will have to give. Either we will become so much more efficient, but I don’t see it. The next 30 years we will not have corn which is yielding double the amount it’s yielding now. We will not have soya beans which are double yielding as now. We will not have nitrogen fertilizer, which will cost half as much energy as they do now. These are incremental processes. You are constantly getting better at these things, but you can see doubling in a matter of more like 50, 60 years. You don’t see the doubling in a matter of, like, 20, 30 years.
So something will have to give, and actually something is giving. You look at many of these rich nations, and many rich nations have either stabilized or have gone down in average meat consumption. Japan is eating less meat than it did 20 years ago. Germany is eating less meat than it did 10 or 15 years ago. France is eating less meat. So in most of the rich countries, actually, the meat consumption has stabilized and has gone down. So actually it doesn’t mean that the poor world would have to replicate the experience of the rich world in the future.
Steven Cherry: Well, Vaclav, it’s an amazing book. I think its facts-per-page ratio might be the highest of any book I’ve ever read. Thank you for writing it, and thanks for joining us today.
Vaclav Smil: Okay. Thank you.
Steven Cherry: We’ve been speaking with Vaclav Smil, author of the book Should We Eat Meat? about protein, population, and the technologies of food production.
For IEEE Spectrum’s “Techwise Conversations,” I’m Steven Cherry.