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Sustainability Videos & Lecture Series

The Way We Eat: Why Our Food Choices Matter

April 28, 2008 | Peter Singer has been called “the world’s most influential living philosopher,” by The New Yorker and Time Magazine listed him in “The Time 100,” their annual listing of the world’s 100 most influential people. Singer specializes in practical ethics, approaching ethical issues mostly from a preference utilitarian perspective.

Dr. Singer supports and is actively involved in several humanitarian organizations worldwide, including Oxfam, an organization that works directly with local grass roots organizations in developing countries, and supervises the way its money is used to prevent corruption and waste. He is also the President of Animals Rights International and Chair in the Board of Directors of The Great Ape Project, and has published over twenty books.

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Transcript

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Peter Singer: Thank you very much for that warm welcome. Thank you, Dean Wheeler, for that generous introduction. And thank you, Dr. Fink, for the support of the Global Institute on Sustainability. And above all I want to thank Tito Cavalieri, who has made this possible through a lot of hard work and contact. We've been emailing for quite while before it all came off. But it has now, and I'm delighted to be here to speak with you.

So my topic, you know. We don't usually see what we eat as an ethical choice. At least most people in this society don't. When we think about ethics, it's not the first thing that comes to mind. What I want to argue today is that what we eat is, in fact, one of the most important ethical choices that we make in a range of different ways. And that we ought to reflect on it because of the very large implications that our food choices have in all those different ways.

So let's have a look at this. If you look at human evolution, you see it as, eating is just something as basic as survival and reproduction. And we've just eaten whatever it is that we could eat, that we could digest. And now, of course, we get to this point where we're capable of reflecting on our choices.

So this is one of those basic things that we didn't originally reflect on and decide what would be the right thing to eat, we just ate what was there. And now I think we come to the point where we can say, well, what's it all about?

What should I be eating? Why is that a choice? Well, here are some of the different options that we might want to consider in terms of what we should eat.

We might consider, for example, whether we should eat animals. That's an ancient question, but one that is still very much around-- in fact, I would say, more central than it has been ever before. Not only questions about being vegetarian, but whether we should eat any animal products at all, whether we should go vegan.

And then, independently of that, there are other choices. We have now possibilities of choosing foods that are grown under various constraints that avoid the use of pesticides and herbicides and artificial fertilizers and so on. We need to ask, is that better? Not just better for my health, but is there in some way an ethical preference for food grown that way?

What about food that comes from immediately around me? From my local community, rather than food that is brought from hundreds or thousands of miles away. Is that better? And if so, why?

And when we buy food, we're interacting with other people who've produced that food. Is that interaction a fair one? Are they getting reasonable compensation for what they're working to grow and produce? So that's a range of the questions. I will try and say something about all of them, but I'll be much briefer about the ones towards the bottom of the list and focus on some of the other ones.

So these are, then, the ethical issues that I'm going to talk about most. Questions about the ethical status of animals and how that relates to our food choices. That's something that I've been writing about for a very long time now, since back in the 1970s when I wrote a book called Animal Liberation. So I want to talk about that and the choices that it should lead to.

We're now more aware than we were when I first wrote that about questions about the environmental impact of what we eat. And that has both local concerns and larger concerns relating to climate change, greenhouse gas emissions. So we need to look at that.

And just very recently, of course, you will have been reading headlines about the world food crisis. And maybe some discussion about whether our food choices have some impact on that, and if so, what it might be. So those are the ones that I'll perhaps say most about.

OK, so coming now to the questions about animals. What I've got up here are some expressions of what I call the traditional ethical view about animals, that is, the one that I think has been dominant for much of the history of Western civilization. Perhaps not for the most recent portion of that history, but if we go back to look at these thinkers who span from ancient Greece with Aristotle through the Middle Ages with Aquinas and right up to the end of the 18th century with Immanuel Kant, what we have in common here is that the animals don't count in themselves.

Aristotle says they exist for the sake of us. The brute beasts exists for the sake of man. Because he thinks everything in the universe exists for a purpose, except rational human beings. That's what the universe really exists for, and everything else works up to that.

vOf course, it was part of Aristotle's view, in fact, that even less rational humans exist for the sake of more rational humans. And since the Greeks were supremely rational, that entitled them to enslave non-Greek barbarians. So it's a hierarchy that includes that as well. We don't accept that bit of it, but in some way, perhaps at least implicitly, deep in our psyche the attitude is still there.

And Aquinas, as well as accepting a lot of Aristotle's views, also brings in a kind of divine justification that, in the Judeo-Christian tradition, we have for using animals. The claim in Genesis that God gave us dominion over them, and the interpretation of that as saying, essentially, we can do what we like with them. It's not the only possible interpretation, of course. But that's certainly how Aquinas and most Christian thinkers, at least up, again, to relatively recent times, interpreted it.

And for Kant, it's a matter of self-consciousness, and everything else is there merely as a means.

So that's the view, as I say, which for all of those centuries-- maybe two millennia-- dominated our views and still, I think, has this residual influence. Even though, certainly, if you really asked your friends and people around, do they accept that animals don't matter at all, that they only exist for human beings, that the end of everything is humans, probably you wouldn't get much agreement with that now. You'd get something a little different, which I'll come to.

Now I want to develop, then, a different view which says that animals matter. And it's crucial for my argument that we accept that animals are conscious, that they can feel things. And that, for example, therefore they're different from plants. Plants, I believe, don't feel pain, whereas animals do.

And that's important because that means that they have subjective experiences. And I think those experiences matter in something like the same way that our experiences matter. There are differences, of course. But if we can feel pain, and that pain is bad because we are in pain, because we're suffering, just for that reason, then it's important to my argument that animals can feel pain as well. And these are some of the reasons why I think we should believe that that is the case.

Now, of course, when I talk about animals that's a huge continuum, that's a huge spectrum. We tend to think, well, there's humans and then there's animals. As if all animals are more like each other than any of them are like humans. But certainly in evolutionary terms, in genetic terms, we are very closely related to chimpanzees. In fact, we're more closely related to chimpanzees than chimpanzees are to gorillas. And compared to the gulf between us and chimpanzees, it's tiny when you compare that between the gulf of, say, chimpanzees and a lobster. Huge gulf in evolutionary terms and yet we lump them all in as animals.

So I'm not concerned to argue, necessarily, that all animals are conscious. Certainly if you get down to the bottom of this list, I don't think one could plausibly argue that clams and oysters are conscious. It's hard to see, with their nervous system, that they could be. But certainly I would want to argue that birds and mammals-- in fact, I would argue that all vertebrates, we can be pretty confident, are conscious.

And probably some invertebrates. If you've seen film, TV programs, about octopus, and I think there's a video on YouTube of an octopus opening a jar, a screw-top jar which has been put in its tank. It does seem like they are-- hard to believe they are not conscious if they can do those things.

But anyway, most of what we're talking about is going to be concerned with vertebrates. So that's where I think the evidence for consciousness is strong enough that I don't really need to lay it out now. But if somebody wants to ask a question about it, I'm happy to discuss that.

OK, so given that, then here is the view that I would say today has replaced what I call the traditional view. What we can call the mainstream view today, which is about, essentially, being kind to animals and avoiding cruelty to them. But it doesn't have a clear stance on how we make decisions where their interests are contrary to ours, except that it seems that in most cases our interests are allowed to outweigh their interests as long as we're not being actually cruel.

So that's why I say here, deliberate cruelty is considered wrong on this view, but our interests in eating eggs or dairy products or meat outweighs, it seems, the interests of animals in these areas. And what I want to do now is to show you just what that means in terms of the animals' interests and how significant they are. Because this is something that it's still the case that a lot of people in our society don't really know about.

So this is the question I want to deal with. If we really understand what modern farming is like, is it compatible with this kindness/cruelty view? With the view that most people would hold about how we're entitled to treat animals? And furthermore, is there an ethical question about the fact that most people still don't know very much about it?

So I've got a quote here which is not from any kind of animal rights activist, or even a philosopher like myself sympathetic to those issues, but someone who is an expert in teaching animal science at Oregon State University.

Which really means that he is teaching future producers of animal products. So it's somewhat surprising, coming from someone who you would expect, therefore, to be on-side with animal production, that he's prepared to say that if the general public knew more about how their animal products are produced, they might stop eating them. They might be put off them.

And that surely is an ethical question itself. Is it ethical to make it difficult for people to know how their food is produced for fear that they won't want to eat it if they do more know more about it? Generally we think that transparency, shining a strong light on the way things are, is a good guarantee that they will be more ethically produced. That's something that doesn't seem to apply to the animal industry.

Now in saying that, I realize, of course, that probably here in Arizona you know more about it than most Americans because you had, less than two years ago, a popular initiative on a proposition to ban the individual sow crates and veal crates. And I wasn't here in the state at the time, but I imagine that that produced a certain amount of additional information and discussion. So you may know at least something more about it. But that's only two aspects, of course, of intensive production.

So let's have a quick run-through of the major forms of animal production.

This is a standard chicken production. Broiler chickens, as they're called. Chickens for eating. Raised for meat, in other words, not egg production. And you see this vast shed stretching into the distance, which may hold 20,000 to 25,000 chickens all in this one unit. They get very densely packed, as you can see.

If you ever walk into one of these places the, first thing you'll notice is the ammonia in the air. Because it's full of chicken droppings, not just from this particular group of chickens.

These chickens, incidentally, will be here about six weeks. Chickens have been bred to grow so fast now that essentially people are eating overgrown babies that have swelled up to this normal chicken size in six weeks, because that's the most profitable way to do it.

But the droppings won't be cleaned out after this batch is taken off to the slaughterhouse. Another batch will be put in there, and typically they may be cleaned out only once a year or something like that. So the reek of ammonia from the droppings is intense. It stings your eyes. It undoubtedly must sting the eyes of the chickens and can be there permanently, get into your lungs as well. But they're not there that long.

Because they grow so fast, they put on weight so fast, their bones are often not mature enough to support them. And it's not unusual for chickens' legs to collapse under their weight as they get close to slaughter age. And then they will just essentially lie on the floor because they can't move anymore. So if that happens, say, here, they're too far away from the water and food. These pipes that you see running down the shed bring food and water.

And if they're in the middle and their legs collapse, they're just going to die of dehydration. Because there is essentially nobody looking after individual chickens. 25,000 in a shed, it's not worth providing the labor that could look after them. Someone might walk through the shed and pick up the dead birds so the carcasses don't become too rotten, but that's about as much as you would get. In other words, zero in terms of veterinary attention.

So that's chicken production. That's another view, from the chicken's-eye view, more or less. How densely packed they are. And turkey production is essentially much the same. So think of that next Thanksgiving, with the additional wrinkle that every one of these turkeys is a result of artificial insemination. Turkeys have been bred with such large breasts that they can no longer mate naturally. So there's an interesting topic for your next Thanksgiving dinner.

Now-- whoops, sorry. That one we skipped. This is probably what you do know about. This is what has been prohibited. I think it's being phased in. It will be prohibited by the initiative that Arizonans voted for by a very clear majority, to give sows room to turn around. Which they typically do not have in factory farms. But although you prohibit that in this state, of course, most of the pig products that are eaten in this state are not produced in Arizona.

Arizona is not one of the great pig-producing states, which no doubt made it easier to get the initiative passed.

So that's how the breeding sows are typically confined. And this is the other thing that you banned, the intensive veal production. Again, not produced in-state. Most of it comes from Wisconsin, states with a dairy industry. But they're also confined so that they can't move around. That's another sow, another shot of the sows. You see that can't even fit their legs into their stalls when they lie down.

But this is still allowed here. This is a farrowing crate, so-called. That is for when after they've sow has given birth, she is put into a different kind of crate and the piglets, therefore, just suckle as she really becomes a milking machine. After having been a breeding machine, she's now a milking machine.

And she's confined in this way because farmers fear that she will crush her piglets. If they gave her plenty of room, and straw and things like that to bed on, she wouldn't. But straw costs money, space costs money, so this is a more economically efficient way of doing it.

And these are the growing pigs. Those little piglets that you saw there, after they're taken from their mother after a few weeks, they're put in pens like this.

And again, they get very crowded. There's not as many in each pen as you have with the broiler chickens, but they are still indoors, they're still in these big sheds. They're extremely crowded. And there's no doubt, of course, that pigs are highly intelligent animals who easily get bored with nothing much to do. And you can see there is nothing to do for them, except occasionally eat, in these confined quarters.

Egg production. This is a typical battery egg unit, where you can see the hens are, again, very much confined. Also, the droppings have fallen to the sort of shelf beneath the cages. And these birds will be in much longer than the broiler chickens. They're put in the cages when they are ready to lay, at a few months of age, and they'll be there for a year to 18 months.

At that rate, they could still live several years, but their rate of laying drops off, so they're no use to the egg producers, so then they get taken out. But for all that time, they're in these cages, they never get to go outside, they never get to stretch their wings, even, because the cages are too small to stretch their wings in. Here's another shot of how tight the confinement is.

Incidentally, after Arizona showed the way, actually, Florida also had an initiative on these things. Arizona showed that it was possible. It was the first one to include both veal crates and sow stalls.

Some of the animal societies are now moving on to California at the next election, 2008 initiative, and have included the battery cage in the forms of confinement to be prohibited. Which would be an even bigger step, because there are 19 million hens in these sorts of cages in California alone at the moment. And of course, that would send a message across the whole country.

So if any of you are from California or have friends or family in California or can spend some time there between now and November, and you're interested in this issue, contact the animal groups and see if you can help educating people about the initiative that will be voted on.

OK, so now let's come to the ethics about this. What have we seen? I could go into a lot more detail, but I would argue that these methods of animal production frustrate all the basic desires that these animals have. From very simple physical desires, like in the case of the hens, stretching your wings, or the instinct to dust bathe, which is something that hens still have. And if you take one of those hens that's never been out in a field and give it somewhere where it can dust bathe, it'll very soon be dust bathing like any hen that grew up in a farmyard.

So these are instincts that haven't gone, but they're constantly thwarted. Laying an egg in a nest is another thing that a hen will instinctively do if you give it some nesting material, which she doesn't have, of course, in the cage.

So I think these methods cause suffering of various sorts to conscious animals. I think that it's wrong to do that without a good enough reason. And I think these methods do that. We could nourish ourselves adequately without doing this. And there are many examples in this society, of course, of people who do nourish themselves without eating meat or without eating animal products at all. So it can be done.

Our enjoyment of the way meat tastes is not a good enough reason for inflicting this kind of suffering on animals, I'd suggest, and therefore we should stop eating the products of modern meat. Or perhaps I should have said modern animal production, if we include egg production there, too.

So that's a basic argument which doesn't, I think, require an ethical view about the treatment of animals that is different from what I've called the mainstream view. So the mainstream view says that we should not be cruel to animals, we should be kind to them. It says, for example, that even if we enjoy certain activities, that may not justify animal suffering.

So we had a lot of publicity in this country not that long ago about dog fighting in relation to Michael Vick's activities. And I think the overwhelming opinion was that it's right that dog fighting should be banned. And if people had come out and said, but look, I really enjoy dog fighting, I enjoy dog fighting more than I enjoy watching baseball, so it should be OK to have dog fighting even if it does cause some suffering to the dogs. We would have said, no, your enjoyment of dog fighting doesn't justify inflicting that suffering on animals.

So I think this is really a parallel case. Some people will say they enjoy eating meat and they want to get it cheaply. But that may not justify the infliction of the suffering on animals.

So that's the conclusion. And note that this conclusion actually stops short of saying that we ought to be vegetarian or vegan. It says we should stop eating the products of modern animal production, what I've been showing you in previous slides. I'll say a bit more about whether one ought to go further than that before I conclude.

OK, but now let me switch to some of the environmental questions of animal production. Firstly, there are local issues which are worth attention. A lot of different local issues. This just shows water pollution. This is a holding lagoon. This is not actually just going into a river, this is an intensive farm. But it goes into one of these so-called lagoons. I was always puzzled when I first saw the word lagoon used in this context, but that's what they call them.

Here's another slide which talks about lagoons. This is a overview of a giant intensive pig farm. You see these sheds here. Each one of these sites holds 8,000 hogs, and there's more of them. There's another set there. There's another one over here. There's probably one back there behind that lagoon. So it's a very large thing. And these so-called lagoons are holding, basically, the pig manure with water.

And the idea is that it should then sprayed on surrounding fields, but what sometimes happens is you get big storms and the lagoons overflow. It gets into the water supply. Or you have so many hogs in such a dense area that the manure is sprayed too thickly on surrounding fields for the field to be able to use. Because it costs money to transport it further, and so when it rains it runs off the field and into the streams and pollutes the streams.

So where there are these intensive industries there are big water pollution problems. And that's a significant local issue. There are other environmental issues, too. There's air pollution for the people who are close in the neighborhood. There's questions about water use, which are very relevant here in dry states like Arizona.

But I want to move-- sorry, that was too fast. I want to move to looking at what is the most pressing environmental issue that faces us and the world today, and that is climate change. So here, I didn't show you before, cattle production. It's less intensive than pig, egg, chicken production or veal production, but it's still highly intensive.

This is a cattle feedlot. Again, a vast thing stretching into the horizon. Maybe 100,000 cattle confined in this area. They do have room to move around and they are outside, but it's still like a pretty dull kind of existence for them.

And they're being fed on grain, grain and some soy, which fattens them up faster, but they don't digest very well.

Also they produce a lot of manure, and the other thing is, cattle produce a lot of methane. Cattle produce methane in the digestive process. It's a gas. Most of it actually, contrary to myth, comes from belching rather than out of the other end. But they do produce methane, and methane is an extremely potent greenhouse gas. So we have to look at that.

We also have the fact that, as I said, it's not really an efficient form of producing food to feed grain or soy to ruminant animals in particular. And that has an impact on greenhouse gases as well, because we use a lot of fertilizers to grow our grain and transport our grain. And so that contributes to fossil fuel, especially if you consider that we are actually wasting most of the food value of this grain.

So here are some figures on that. We are actually feeding 70% of the grain we produce to animals rather than eating it directly. Or now some of it, of course, is going into biofuel, ethanol. And I'll talk about that in a moment.

But of this, we're only getting back about one-sixth of the food value. Or actually less than one-sixth if you're talking about overall food value, which includes carbohydrate. But since people say, well, we eat beef for its protein, that's what's important. Even if we just focus on protein, we are wasting a lot of the protein value of the grains and soy we're feeding to cattle. So it's a very inefficient process.

Another way of looking at that is by asking, how much protein can you get per acre if you use your acre for different kinds of usage? And the soybeans come out by far the best, followed by rice and corn, and then peas and beans, the legumes, wheat. And it's only these bars down the bottom. If you're at the back and have trouble seeing, this is milk here. This is eggs. This is meat, all types of meat, and this is beef in particular.

So all of these columns are the direct consumption of plant products. And these ones are the meat production, because of the wastefulness of feeding grain to meat. So that clearly has an environmental impact. Puts more stress on the environment that we need to grow more in order to get these amounts of food.

So let's come to this issue about the recent food crisis which has been in the papers quite a lot recently. You might have read that there have been food riots in some countries, that in a lot of countries more food has to be distributed because there suddenly seems to be in many countries a shortage of food. I think the UN Food and Agriculture Organization says that there are 37 countries where there is now a shortage of food, which is a steep jump over just a year or two ago.

And you might say, why? So a lot of people are blaming biofuels. They're saying, well, if the US, and to some extent some other countries, but it's mostly the US as far as making biofuels from grain is concerned, from food. They are now feeding a lot of corn into, basically, our gas tanks by trying to produce ethanol, which is heavily subsidized in the United States. And that's devoted food that could have been used for humans to fuel production.

But in fact, although no doubt that's a factor, it's a relatively small factor compared to feeding grain for animals. So here are the figures. About 100 million tons of grain is being used for biofuels as compared to 756 million tons which is being fed to animals.

So that's the larger factor. And that's also something that has been increasing in recent years, particularly as countries like China become more prosperous, develop a prosperous middle class, and that middle class wants to eat more meat. Essentially following the consumption patterns that we've had for a long time.

So I think that's a major factor in the world food crisis, and we could solve that rather easily if, in fact, we stopped or reduced our feeding of food we can eat directly to animals. And that 756 million tons, as I said, doesn't even include the soy. We're only talking about grain here.

OK, let's go back to climate change. It's only relatively recently that people have started to talk about how important an issue the food we eat is in a contribution to climate change. Most people think, have thought for years, that it's things like transport that are the big factors. The fact that we drive these gas-guzzling SUVs, the fact that we all have our own cars rather than using public transport, and so on.

But as the UN Food and Agriculture Organization has said quite recently, actually the livestock sector is bigger than all transport, both private and public transport. The livestock sector is a bigger contributor to greenhouse gas emissions measured in CO2 equivalent.

So what you do is you convert the methane into carbon dioxide. Much smaller amounts of methane produced than carbon dioxide, but it's a much more potent greenhouse gas. And that's why it comes out as a higher figure. So this is going to be significant if we want to deal with this immense problem, which I think is one of the great challenges for us.

I think climate change is already with us, already happening. We can't stop it but we can at least try and mitigate it so that it doesn't get worse and it doesn't spiral unpredictably out of hand with things like changes in ocean currents, rising sea levels. On one model, for example, rising sea levels over the next century could put a third of the state of Florida underwater.

And that would be much worse, even, for other countries where poorer people cannot move. For example, Bangladesh has tens of millions of people living on land that is no more than three meters above sea level. That's because it has all these very fertile delta regions that they farm, but they're very low-lying. So this is a major crisis which will affect hundreds of millions of people, billions of people.

And this is one thing we can do about it. Changing our diet to make it less livestock-intensive.

Here's another quote on this. You may have heard of Jim Hansen. He's the NASA scientist who was one of the first, right back in the '80s, to warn about human-caused climate change. And essentially what he predicted in the 1980s in testimony to Congress and in scientific articles has now come about. In fact, global warming has happened even more quickly than he and other scientists in the '80s realized. It seems we have less time to try and change than he said.

Now here's a statement that will surprise many people that he's made. And that is that he thinks that the global warming that we've had for the last 40 years was actually primarily a consequence of the activities producing trace gases, CFCs and methane.

Now, CFCs are chlorofluorocarbons, the propellants that used to be in aerosol cans. And since the Montreal Protocol was signed, basically we've stopped producing CFCs. The industrialized nations phased them out fairly rapidly. And the developing nations have almost completed phasing them out. So that was really, essentially, to stop the destruction of the ozone layer rather than to stop climate change, but we now understand that they were playing a big role in climate change as well, and it's very good that we have been able to phase them out.

But that leaves methane as the other thing that Hansen says is mainly produced this warning. Now you might say, why would that be? Haven't we all been talking about carbon dioxide? And isn't that the major greenhouse gas that's produced most of this global warming?

In the long run, it is carbon dioxide. Because carbon dioxide stays up in the atmosphere for a long time, longer than methane. So the carbon dioxide that was produced by the first Model T Ford that Henry Ford produced is mostly still up in the atmosphere and still producing climate change.

But some of that, at least, is a given. The other thing to know about the carbon dioxide is the largest emitters of carbon dioxide are coal-burning electricity plants. Power plants. And they have contributed a lot of carbon dioxide into the atmosphere, and that's why we're talking about having to phase out coal.

But it's also a fact that coal-burning power plants produce what are called aerosols, that is, tiny little particulates that go into the atmosphere. And it's now being learned that they actually have a cooling effect. They block out a little bit of sunlight and cool the Earth. So the particulate effect and the carbon dioxide to some extent cancel each other out.

Now, that doesn't mean that coal-fired power plants are OK. We don't want to have more particulates up there, and eventually the carbon dioxide is going to continue to build in a way that will be disastrous.

But in the short term, it's the methane, Hansen says, that has been doing most of the warming. Because the methane is, if you like, pure warming, whereas the coal-fired power plants are a bit more mixed. And that also means that the quickest way to slow this warming would be to cut out the methane. Reduce it as far as possible. Because that would like a pure slowing effect.

Whereas if you just close down all the coal-fired power plants, you'd also reduce the aerosols in the atmosphere. And therefore that would produce a bit of warming that would balance the loss of carbon dioxide, which in the long run, though, will cause more warming.

So that's something we can do something about now, and I think that's an important point that most people still don't really understand, the crucial role that methane from livestock has played.

And here's what the chair of the IPCC, the International Panel on Climate Change, has also said. Again, quite recently, at the beginning of this year. He said please eat less meat, it's a very carbon intensive-- he perhaps wanted to say carbon-equivalent intensive, but that's a little difficult.

And he's admitted that it's something the IPCC was afraid to say earlier. That it would meet such political resistance, because people want to eat meat, that it didn't really dare to say it. But they now feel that it's so important that they have to say it and have to make people more aware of this as an issue.

So here's an example that comes from a study that a couple of researchers, Gidon Eshel and Pam Martin, then at the University of Chicago, did. This is what people mostly think you should do for climate change. Switch your car from your whatever it is, I think that's the sort of median car in terms of greenhouse gas emissions in America, a Toyota Camry. Switch that to a Prius, a fuel-efficient hybrid, and you save a lot of carbon. That is a good thing to do, no question about that.

But by their calculations, actually this switch, from your steak to a vegan diet, will save even more carbon per year. So that's, if you like, the summary. 50% more carbon by switching your diet than by switching your car. That's the summary of the climate change story on food.

Now, I promised that I would come back to the question of the ethics of eating animal products that are not produced by factory farm production. What I've put up here is a position called conscientious omnivorism, developed by Roger Scruton, a British philosopher and writer.

And perhaps more of you have heard of Michael Pollan than of Roger Scruton. Michael Pollan has had a very popular bestselling book called The Omnivore's Dilemma that came out a year or so ago. And he takes a somewhat similar line of argument.

So both Pollan and Scruton would agree with everything I've said about factory farming, about intensive farming. But they would say there are other ways of producing animals. We can produce animals in ways that are conscientious, that look after them.

This is a quote from Scruton here, about "when all duties of care are fulfilled, when the demands of sympathy and piety--" Scruton is taking a religious viewpoint in a way, but not one that gives us absolute dominion but rather says we have stewardship over them and we must respect them and we must respect their true natures if we are to use them.

Incidentally, since we've just had the visit of Pope Benedict to this country, when he was Cardinal Ratzinger he made a somewhat similar statement. He made a statement deploring factory farming, which doesn't respect the nature of God's creatures. So you certainly can come at this from a religious point of view that's different from that of Thomas Aquinas. Various animal groups have been trying to persuade Pope Benedict to repeat his statement now that he's Pope rather than just a cardinal. So far with no luck, but we can keep trying.

So if that happens, then what we have, of course, still, is this question that the animals are killed. At least when we're talking about meat production, clearly. And the question there has to be, well, is that wrong? And if, so why is that wrong?

And that's a difficult question philosophically. Because it requires us to ask, well, why is killing wrong? Why is killing in general wrong? And there we've had a lot of debate. And people take different views because in part it depends on whether you think that simply being human is enough to make killing wrong, and if you're not human then it's not wrong, or whether you think, as I do, that you can't just say that what species you are determines whether killing is wrong.

That just being a member of one species rather than another isn't really the kind of morally significant property that should determine the wrongness of killing a being. That it must depend on something else. That in a way, to use just a biological line like species would be a little bit uncomfortably close to using a biological line like race or sex to say one being is superior to another. It ought to be something that's more relevant to the actual wrongness of killing than that.

Now what Scruton says is that some kind of self-awareness is what makes killing really wrong, because if a being is self-aware, you cut off its plans for the future. Whereas if it doesn't even have the capacity to understand that it lives through time, you can't do that. So he says the killing of a normal human being is tragic because you prevent that human being from achieving what they would have achieved or what they might have wanted to achieve. But animals don't have achievements in that sense, he says, and so killing them is not tragic.

So if you accept that view, and that seems to be much more defensible than just saying it's a matter of species, you could perhaps accept some forms of farming.

So here, for example, is a much better kind of beef production. This is a farm quite near Princeton in New Jersey, where they don't send them to the feedlot. They keep them on grass until the time when they're slaughtered. And I've visited this farm. I couldn't say that the animals are having a bad life there. They've got grass, they've got shelter in winter, they can move around freely.

So yeah, you could say that's not a bad life, except for the fact that they do get killed. So if you're prepared to take that view about killing that Scruton does, you could perhaps defend this, assuming, of course, that you think that cattle are not self-aware beings in this sense. And because I'm not giving a full lecture on ethics and animals, I'm not going to go take that a lot further today. I think if we have questions about it we could certainly discuss it.

Let me say I think it's not my preferred position to say that conscientious omnivorism is all right for a variety of reasons. It still regards animals as things for us to use. It still makes them economic commodities, which means that corners are likely to be cut in producing them cheaply.

But I think there is a huge ethical step forward if you do move from the standard American diet, which eats factory farmed produce, to moving towards conscientious omnivorism if you're really scrupulous about finding the right producers to buy from. Because both in terms of animal welfare and, in many ways, in terms of the environment, although these cattle are certainly still producing methane, it's a preferable system.

And if we talk about egg production-- this is the same farm, also produces some eggs-- again, this is a good life for the hens although they also will be killed prematurely once their rate of lay drops off.

But this is pretty unusual, I have to say. Don't be fooled by, if you go into a supermarket or even Whole Foods, and it says cage-free eggs, it doesn't mean that they're being kept out on grass like that. This is genuinely free-range, grass-raised egg production. And that's an unusual system.

This little shed here is on wheels. You can move it around so that the grass doesn't get worn out in particular spots. The hens go into it at night to protect them from foxes and things like that. They lay their eggs there in the morning and then they're let out onto the grass.

OK, let me just briefly, I said I want to say a little bit. I know we're running on for time and I want to give you time for questions. But very briefly, should we buy organic food? Is that an ethical choice? Well, ideally, organic food is sustainable in the long run. Although that becomes more difficult if you're talking about organic beef production, particularly for the reasons I've said. They're the biggest methane producers. Well, cattle and sheep are the biggest methane producers.

So it's difficult to say that. It's definitely better on the environment because of the lack of synthetic fertilizers, herbicides, pesticides. No genetically modified plants or animals used.

That's pretty controversial, pretty debatable, whether you think that's an important point or not. Whether you think GM is safe or unsafe. I think it does carry some environmental hazards, but so far nothing really serious has been tracked to the use of GM products. So you might say at least the varieties we have out now seem to be reasonably safe.

Only organically grown feed, so that also relates to how the crops are produced. And this last point. You might think that if you're getting organically produced food the animals are outside like in that last shot, because that's what the USDA-- Department of Agriculture-- rules actually say, that they should be able to go outside in suitable weather. But in practice I've found that that's not actually always the case.

Here's a big organic dairy, one of the biggest in the country, Aurora Organic Dairy. Aurora is up near Denver in Colorado. And this is how they advertise their organic dairy products. You think that you're getting milk from cows on grass.

This is what Aurora Organic Dairy actually looks like from the air.

These are sheds where the cows are milked and fed. They do get to go outside, so the cows that are in this shed get to go outside in this area. But there's far too many cows for there to be any grass on that. That's basically just packed dirt. Far too densely populated for there to be grass. So they're not really out and on grass. The only time these cows get to go on grass is when they're not giving milk.

For those of you who don't know about dairy production, you have to keep making cows pregnant and remove their calves to get them to give milk. Basically just like us. They're mammals. Women will produce milk, they'll lactate after giving birth. After a while that milk will stop being produced.

For cows, to make them give the quantities of milk the dairy farmers want, they make them pregnant about every year. And then they remove their calves. So during the time that they're pregnant and not giving milk, they will take them away from this complex and they'll put them on grass. But while they're actually producing milk, which is most of their lives, they're not on grass at all.

So organic, you have to be careful. They're not all as good as they should be.

And here's-- it's a bit dark-- here's an organic egg unit that I visited in New Hampshire. These birds are inside the shed, they're not in cages. Again, it's definitely better than caged eggs. But they're very densely packed. And they had sort of an open door to a small dirt run outside, but basically there was no food put there, there was no water put there. It wasn't very attractive to them.

And quite often the doors were actually closed. So I visited in the fall, in October or something, and although it was quite pleasant outside, the producer was closing the doors and said that they would be closed until April or something like that, because it was too cold for them to go out. But they would have gone out. In England I've seen birds go out in snow.

He's a bit worried about that possibility of getting avian flu from contact with wild birds, so I think that's his reason. But they're not always outside, so the one that I showed you before is exceptional.

OK, very briefly, what's the issue about local food? Well, there's some benefits to it. Fewer food miles means less fossil fuel. Support your local economy, build relationships with your food producers, that's all good. But it's not always better for the environment. For example, here you may not have enough water to produce some local food. That may be wasteful.

Other places in the north of the country don't have the warmth to produce vegetables all year round. So people may buy locally, but they're buying, say, tomatoes in June that have been raised in a hothouse that was heated with oil. Well, when you calculate the amount of oil that went into producing that local food, you might as well have trucked them up from Florida. You're not reducing the amount of fossil fuel involved.

So it's not always better for the environment to buy local. You have to be selective about that.

And finally, I asked is it always better to strengthen the local economy? Well, you might say, why not? One reason might be that your local economy might be quite a prosperous one and you could buy from developing countries where people are much poorer and need to get some income. Much more vital for them to get some income than for local producers. So if you can do that in a way that gives them a genuine return, you should.

And that's why we get finally to this question about Fair Trade. If you see this Fair Trade label, you know that arrangements were made to try and give a fair return to small local producers, individual producers or producers organized in a cooperative. Or if it's a larger unit, producers who allow their workers to organize, to unionize, and give them basically decent, minimally decent conditions.

So mostly Fair Trade in this country at the moment is still things like coffee and chocolate, and bananas perhaps. But in Europe there are many more Fair Trade products available, and I think that's something that is spreading here. And I think it's worth doing from a social justice point of view. It adds another dimension to the ethical choices you have about your food.

So let me more or less stop it at that point so we do have time for questions.

Here's a very brief summary of what I would say. So one of the take-home points for acting, by far the largest is to avoid, CAFO stands for concentrated animal feeding operations. In other words, basically, factory farms.

Concentrate the animals together and then you feed them. So avoid products from factory farms, I would say, is the first and clearest conclusion when you look at ethical eating.

It's preferable to buy organic, it's preferable to be vegetarian or vegan. Failing that, to be a conscientious omnivore. It's preferable to buy Fair Trade. Sometimes it's preferable to buy local, sometimes not. That's certainly something always worth thinking about. But it will depend on the circumstances.

OK, that's a very quick run-through of a very large area, I think you can see. Thanks very much for your attention and I look forward to your questions and discussion.

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