Horizon (1964) s53e11 Episode Script
Should I Eat Meat? - How To Feed the Planet
Meat, we love the stuff.
Globally, we consume nearly twice as much as we did 50 years ago.
But our increasing carnivorous cravings come at a price.
This mini meat mountain weighs 80 kilos and it represents the amount of meat the average Briton gets through in a year.
I want to find out how it gets onto our plates and what the environmental impact is.
We already devour 65 billion animals every year.
And that number is predicted to double, again.
The scale and the growth in livestock production is inherently unsustainable.
We can't do it.
If we want to eat meat, is there a way to do so without destroying the planet? Does it matter what kind of meat we eat or how it has been raised? This is the reality, and the reality says this is green.
So what should I be eating if I want to become a more eco-friendly carnivore - chicken or beef? Free-range or intensively farmed? The answers are far from obvious.
Getting to grips with the scale of the livestock industry is a truly sobering task.
Every year across the planet we slaughter and consume an extraordinary number of animals.
300 million cattle.
1.
4 billion pigs.
A billion sheep and goats.
Five million horses, two million camels.
3½ billion ducks and turkeys, and 60 billion chickens.
That's an average of nine animals for every person on the planet.
Beyond the moral considerations, there are serious environmental issues.
The amount of the earth's resources devoted to raising these vast numbers of animals is both controversial and difficult to measure.
Fortunately, the UN Food and Agriculture Organisation has put together some very comprehensive reports on the scale of the livestock industry.
Let's start with an overview.
This, of course, is a map of the Earth.
Now, the area in green, it is grazing land and it accounts for more than a quarter of the entire ice-free landmass of the Earth.
Now, the area in orange is arable land, that is land given over to growing crops.
Now, crops are mainly eaten by humans, but about a third goes to feeding animals.
If you add it all up, then you get an extraordinary figure.
A third of the entire landmass of the earth is given over to animals that we either eat or milk.
That's 70% more land than a century ago, and with meat production set to double in the next few decades, we could rapidly run out of space.
But the trouble with livestock is not just a matter of the land they occupy.
Keeping animals in such huge numbers has other, less obvious effects on the environment.
To find out what they are, I have come to America, where they eat more meat than any other country on Earth.
Come on, ladies, down the hill.
These are the Flint Hills in Kansas.
They were once part of the Wild West.
What do you reckon, Bill? And they are still home to cowboys, cowgirls and, of course, their cows.
Whoa, Bill.
When I'm eating meat, this is how I like to imagine that meat has been raised - in the open air, lots of space, but is this really the best way? If you want to be an ethical carnivore, what sort of meat should you be eating and how should it be raised? Even a farm like this, where the cattle are free to roam and seem in such harmony with the land, has a hidden environmental impact.
The problem comes from within the cattle themselves and it starts with what they eat.
Now, grass is curious stuff.
It's made out of tough fibrous cellulose and most mammals find it completely indigestible.
If I was to chew away and swallow it, then it would pass through my digestive system virtually unchanged and come out the other end, but cows absolutely thrive on this stuff.
A cow can eat around 50 kilos of grass every day and convert it into a kilo or so of muscle, the muscle that we then eat.
It's a neat metabolic trick, but it also has an unfortunate side effect.
Nothing at the moment, but as I get closer I expect to get something.
There we go.
2,876, that was a very high reading.
This is a laser methane detector.
It's not normally used on cows, but used to detect gas escaping from gas pipes.
Anything over 100 parts per million, it makes a bleep.
I am going to see if I can detect methane coming from these cows.
1,700, there is a lot of methane coming out of these cows, and interestingly, it's not really coming out of their back ends, which is what you might expect, but it's from the belching of the cows.
All the time, every moment I'm here, they're producing methane.
4,976 parts per million, that is a lot of methane! One of these cattle has obviously just done a giant belch.
If I got a reading of 1,000 parts per million from a leaking gas pipe, that would be alarming, but cattle churn methane out at an incredible rate.
An adult cow can produce up to 500 litres every single day.
'The cattle aren't at risk of exploding, 'but all that methane has other serious consequences.
' The problem is that methane is an incredibly potent greenhouse gas, 25 times more so than carbon dioxide.
In fact, it's been calculated that the average cow produces the same effect on global warming as a family car.
'Now, cattle and other ruminants have been producing methane 'for millions of years, but it only became a problem 'in the 20th century, and one surprising reason for that 'was an invention that has come to symbolise modern America.
' What can I get for you? Hello, could I get a burger and fries, please? OK.
Anything else for you? No, that's great, thank you.
OK, one with! Now, the hamburger was a technological marvel - cheap, tasty, it was easy to mass-produce.
'The hamburger was an instant success, 'the perfect meal for an increasingly automated convenience culture.
'Originally the burger patties could have been made from any meat, 'but after intense lobbying from the cattle industry, 'an Act of Congress in 1946 stipulated that all burgers should be 100% beef, 'and a diet already rich in meat saw a huge increase in beef consumption.
' There you are, sir.
Great, thank you very much.
Not a problem.
The popularity of the hamburger meant that demand for beef absolutely soared.
By the 1970s, the average American was consuming an incredible 90lbs of beef a year, that is a quarter-pounder every single day.
All that beef meant lots of methane, it also meant that they had to find a way to produce more beef.
'The success of the hamburger played a large part 'in an explosion in the global population of cattle.
'Up from 400 million a century ago to an estimated 1.
5 billion today.
'As a result, methane produced from cattle is now seen 'as a major contributor to climate change.
' About 10% of all human activity in terms of greenhouse gas emissions comes from feeding cows, so are there too many on the planet? Well, if we're trying, really trying to think about moving into a lower emissions world, then the answer has got to be yes.
So if we want to reduce the environmental impact of our diet perhaps we should stop eating beef altogether.
But is there another way? Is it possible to make cattle more environmentally friendly by reducing the amount of methane they emit? 'To find out, scientists have been studying how that methane is produced.
'I've come to the Animal Sciences Department of the University of Nebraska 'to see a remarkable animal experiment 'run by Dr Samoda Fernando.
' Well, that is extraordinary.
I've sort of read about it but I've never seen anything like this before.
He seems quite comfortable he, she? It's a he, it's actually a steer.
OK, so this has sort of been surgically implanted, that's right? Yeah, this is called a fistula or a cannula.
And presumably it's pretty well the only way of studying? Yeah, because this allows actually direct access to what's happening inside the animal and I can actually take this one out.
And.
.
Presumably that's to stop getting infections and things.
Oh, wow.
Yeah.
So I'm looking into one of the stomachs? Yes, you are actually looking to the largest compartment, the rumen.
It can hold 50 to 60 gallons of rumen fluid and it accounts for about 65% of the gastrointestinal tract of the animal.
The rumen is the largest of the four chambers of a cow's stomach and it is through having direct access into that chamber that scientists are better able to study how cattle digest grass and why they produce so much methane.
'I'm assured the animal won't feel a thing.
' Can I stick my hand in? Yeah, absolutely.
OK, ooh, gosh.
Ah, ooh that is odd, that is so strange.
It is incredibly hot.
Really very smelly now.
I'm holding my breath.
That isreally odd, having my hand inside a living, breathing cow like that in its gut.
He doesn't seem to mind in the slightest, does he? No, no.
Hello, are you all right here? So this is partially digested, is that right? Yes.
It still looks like straw, doesn't it? Yes.
So where's all the methane production going on? So the majority of it is actually going on in the rumen, so if you feel some of the methane might be just coming out from here Is that the major gas by-product? What am I smelling at the moment? It should be methane.
This rumen is full of bacteria, viruses and fungi and those microbes are the ones that are actually digesting the hay, or the cellulose that's in the hay.
'When cattle eat grass, they are not just feeding themselves, 'but also the trillions of microbes that live in their rumen.
'It is those microbes that produce all the methane 'but they are also performing a vital service - 'breaking down cellulose into more nutritious molecules 'that the cow can absorb.
' So this great big sort of mixture of microbes is converting the hay into something which the Energy-dense molecules that is absorbed by the animal and used for energy for the animals.
Right.
Some of these microbes that's already in the rumen actually bypass to the small intestines and provide them as microbial cell protein, so they don't have a protein requirement like we would have because the microbes actually become protein, microbial protein for them in the small intestines.
So the cow is actually digesting the microbes as part of its meal? Yeah, in the small intestines, microbial cell protein.
So in a funny way a cow iswell, not exactly a carnivore, but not entirely a herbivore, it's actually living, itself, on living microbes? Yeah.
The cow's ability to harness these microbes' digestive skills to feed itself is a brilliant adaptation and, crucially, it has been shown that you can change the balance of microbes within the rumen and dramatically reduce the amount of methane they produce by simply changing the cow's diet.
This means raising cattle on grass might not be the greenest way of farming them.
So I'm going to see an alternative farming system that some people claim is more eco-friendly.
It was first devised in the 1950s, helping to produce the huge amounts of beef demanded by the hamburger industry, and it is still used to produce the majority of American beef.
I'm going towards a different sort of farm, the sort of farm where a lot of the hamburger meat comes from.
It's charmingly called a CAFO - a Concentrated Animal Feeding Operation - and it's just over here on the left.
This is the Wrangler Feed Yard, just outside Amarillo in Texas.
Its 500-acre site is a temporary home to 50,000 cattle.
They are brought to feed lots like these at about a year-old and are fattened on a carbohydrate and protein-rich diet based on corn.
They stay six months, put on about 300 kilos in weight, then they are shipped off to be slaughtered.
'If you go to America, the chances are that any beef you eat 'will have come from a feed lot like this, 'and similar operations are beginning to appear in the UK.
' Here's the most extraordinary thing I think I've seen for a long time.
Just the scale is awesome.
I mean, really quite awesome.
It is bleak and there's something about them all, eating and staring at you, I'm trying to separate my sort of feelings of, frankly, a little bit of guilt as a meat eater with just the way it's done.
'Seeing this could put you off eating beef altogether.
'Raising cattle in these vast numbers seems to be 'the very antithesis of eco-friendly farming.
'Some feed lots have been criticised for poor welfare standards 'and for polluting the local environment.
'Not surprisingly, Dr Mike Engler, the CEO here thinks 'they deserve a better reputation.
' Hello.
Michael, welcome to Wrangler Feed Yard.
The first thing that strikes you is it is a little bit bleak, it's not a romantic vision, a sort of green vision.
You wouldn't think so, would you? No.
Well, you know, we can get the animal to market weight in less days of their existence than they can on grass, and so we've reduced the total amount of methane emitted.
So if the goal is to produce the most amount of beef with the least amount of resources, this is where you can accomplish part of that solution.
We are part of the solution not the problem.
Are they happier? Looking at them, it's difficult to tell, I have no idea what a happy I mean, to be honest they look neither more nor less happy than most of the ones I see in a field, but.
.
They're herding animals and they don't want to be alone, so what we've given him here in this pen is a herd of animals.
Their behaviour is very similar to an animal's out on range or on pasture.
It doesn't look green, it really doesn't look green.
But you would argue that this method is, oddly enough and paradoxically enough, more green than sticking them out in a field, would you? Absolutely.
One of the things I have a pet peeve about here in the United States, we hear it in politics all the time, perception is reality.
It's not.
It doesn't change reality.
In advertising and in politics, perception is reality, I understand, but in the world where we're trying to produce food for people, this is the reality and the reality says this is green.
Of course, it all depends on what you mean by "green".
The secret to the feed lot's ability to produce more beef in less time, and therefore to reduce their methane emissions, lies in the vast amount of grain they feed the cattle.
Nearly 40% of the corn grown in America is fed to livestock.
To critics, this is a tremendous waste of land and grain, but to Dr Engler and others, it is this diet that is the key to the farm's success.
The main ingredient in the cow's feed is corn, turned into cornflakes, much like we eat.
'But those flakes are also mixed with a number of other ingredients 'into a carefully formulated diet.
' That's a relief, it's very noisy out there, isn't it? Absolutely.
This is what I saw the cows eating earlier, is it? Yes, this is what's in most of the feed box.
When the cows first arrive, we actually start 'em on this ration.
Don't be deceived, though.
It's green because of blue food dye.
What it's actually made from is the by-product, the wet by-product from a high-fructose corn syrup plant.
We also feed a by-product from the ethanol industry which, of course, starts with corn.
This one is the corn gluten feed in a pelleted version.
We feed this for protein.
I nearly forgot, though, we also have liquid fat that we add.
About 2% of the ration would be in this.
Do they also influence the amount of methane that the cow's producing? Absolutely.
It's not quite a reduction to 50% but it is a significant reduction.
OK, so close to 50%.
In addition, he'll gain weight faster on this high-caloric diet, so on the same number of days on this diet, we'll have twice as much weight gain with about half as much methane production.
Right, so that's a kind of win/win situation? Absolutely.
'But there is something that worries me.
'They also feed their cattle growth hormones and antibiotics 'such as Rumensin, which in Europe are banned from the diet of livestock.
' Doesn't that give you pause for thought? No, because there's been no medical reason to ban that use in animal agriculture.
Aren't you worried about feeding resistance or doing something? No, because no-one uses it in human medicine.
You see, nonetheless, it is the one thing that has disturbed me, in a way.
I am just brought up in the tradition you absolutely do not use antibiotics unless you have to.
Well, they're very complementary technologies.
Because, you know, if you're going to go to all this trouble to formulate a scientific diet and you don't avail yourself of the things that have been developed to make the most out of what you've done, then in some cases you've just wasted your money.
OK, that's fairly hardcore.
Yeah.
'The feed lot is not a system that was designed to be eco-friendly.
'But it is a surprising 'and uncomfortable truth that the economic efficiency demanded 'by farms like these can also equate to environmental efficiency.
' Studies show that cows raised this way produce up to 40% less emissions per kilo of meat than grass-fed cattle.
By those measures, this intensive form of farming is more environmentally friendly than raising cattle on the plains.
Now this place is a real paradox.
In many ways it's about as far from a conventional green vision of the future as you can possibly imagine.
Animals in pens, fed corn, antibiotics and hormones.
On the other hand, if you do it this way, then you can get more meat in less time with much lower levels of methane gas production.
So which method is genuinely greener? And this is one of the great problems of trying to be an eco-friendly meat eater.
Different farming systems can be better for different aspects of the environment.
If you want a system which uses a relatively small amount of land or produces a relatively small amount of emissions, or uses a relatively small amount of water, they're all facing in different directions, so there isn't a kind of right answer to what environmental sustainability means.
Does it mean an extensive grazing system where animals are largely living on pasture? Or does it mean an intensive system where you're putting a lot of food into the animals and ending up with a relatively low emissions-per-unit weight? Those two things are both ways of looking at environmental sustainability but they're both quite different.
And this point is reflected around the world.
Wherever we look, we find different farming systems and conditions that raise very different environmental issues.
In Britain and Ireland, we have lots of lush green grass, and well-managed grazing is relatively low impact.
But in other areas, like Sub-Saharan Africa, where grasslands are less fertile, overgrazing risks permanently degrading the land, even turning some areas into desert.
In South America, demand for new pasture has meant the cutting down of millions of hectares of Amazon rainforest.
That in turn has led to a massive loss of wildlife and the release of huge amounts of carbon into the atmosphere.
Elsewhere in Brazil and Argentina, vast areas of natural land are still being ploughed up to create soya plantations, soya that is then exported around the world to feed livestock.
If you had chicken or pork for your Sunday roast, it was probably fed on South American soya.
'Assessing the combined effect of all these factors 'is extraordinarily difficult.
' But the United Nations have had a go, by focusing down on the carbon footprint, the effect of all that activity on man-made greenhouse gas emissions.
'They have assessed every element in the global livestock system.
'The methane that comes from ruminant digestion alone 'is equivalent to adding 2.
8 billion tonnes of carbon dioxide 'to the atmosphere every year.
' Managing the manure produced by farm animals creates another 700 million tonnes.
The carbon stores lost by chopping down forests and degrading habitats also adds 700 million tonnes.
Growing crops to feed animals is responsible for 2.
6 giga tonnes.
Compared with that, the 100 million tonnes released by transporting crops and meat around the world seems almost trivial.
'By adding these and many other factors together, we can estimate 'the total impact of livestock production on man-made greenhouse gas emissions.
' It's clearly been a mammoth task, and the figures have been revised several times, but the latest best estimate is 14.
5% of all the man-made greenhouse gas emissions can be blamed on the animals that we either eat or milk.
'And it's because of this massive environmental impact that 'modern livestock farming has become such a contentious issue.
' Some see industrial agriculture as a miracle.
I see it as a mirage.
The problem with industrial agriculture is it's not just about cows, industrial agriculture is incredibly hungry for oil to produce artificial pesticides and fertilisers to power machines.
It's incredibly thirsty for water to irrigate crops to feed farm animals.
It's madness, it's madness to be feeding those cattle people food.
It's madness to be destroying the Argentinian countryside to feed the factory-farmed animals in Britain and Europe.
Such is the size of the global livestock industry that its carbon footprint is about the same as the contribution made by transport - all the world's cars, trains, boats and planes combined.
So you can see the scale of the problem if you want to be an eco-friendly carnivore, but can you reduce your own personal contribution by choosing the right sort of animal to eat? This is a rodizio, a Brazilian barbecue restaurant.
'It is a temple to meat.
' Rump side of beef? Yes, delicious.
'Great chunks of meat.
' Lamb? Fantastic, yes, please.
'Cooked on skewers and carved at your table.
' Pork loin? Yes, please.
'But which meat should you choose 'if you want to reduce the carbon footprint of your diet?' Yes, please.
So I've got four different plates of meat.
Got some beef, some lamb, some pork and chicken.
Each of them about 100 grams, similar in nutritional value, but the amount of food and energy required to get them here has been very different.
'The first thing you need to know is that animals vary wildly in the efficiency with which they convert food into flesh.
'One way to compare them is by looking at the amount 'of protein they need to eat to produce their meat.
' Let's start with our old friend, the cow.
The cow is a ruminant and its digestion is not very efficient.
'Exact figures vary, depending on 'whether they are fed on grass or grain, 'but on average, cattle need to consume 450 grams of protein 'to produce 100 grams of cooked beef.
' Now, the sheep is also a ruminant, but it takes almost twice as much protein to produce this amount of meat.
Now, the pig is an omnivore, eats pretty well anything and it is much more efficient.
'A pig only needs 110 grams of protein 'to produce 100 grams of pork.
'But top of the list is the chicken, 'which only needs 75 grams of protein in its diet 'to produce 100 grams of meat.
' Now, feed efficiency ratios aren't everything, you also have to take into account the amount of energy that goes in, the amount of gas that these animals produce.
'By adding together all these factors, it is possible to produce 'a single figure for the carbon footprint of each meat.
'Again, the exact results vary between farms and systems, 'but these figures are broadly true 'of the meat we can buy in supermarkets.
'The worst offenders are cattle, 'releasing the equivalent of 16kg of carbon dioxide 'for every kilo of meat produced.
'In at number two is the sheep, with a figure of 13.
' Number three, we have the pig, considerably less, with five kilos, and best of all is chicken.
'On average, the production of a kilo of chicken meat only releases 'the equivalent of 4.
4 kilos of CO2.
'Per kilo, its carbon footprint is about a quarter that of beef.
' So if you're worried about your carbon footprint, then you are obviously better off eating chicken than you are one of the ruminants, like the sheep or the cow.
'Chicken has also become a very cheap source of meat.
'We eat five times more than we did 50 years ago.
'Fried chicken is becoming our takeaway of choice, 'a single shop can sell 600 pieces of chicken a night.
'Which begs a fundamental question.
'Where do all those chickens come from?' Now, the thing is, as you drive through the British countryside, you see cows, you see sheep, but you never, or very rarely, see chickens.
'I'm on my way to find where they are hiding.
' So this is Uphouse Farm and I'm here to meet chicken farmer, Nigel Joyce.
'The reason we don't see most of the chickens we eat 'while they are still alive 'is that they are reared indoors, in sheds like these.
' So this kind of reminds me of going into an operating theatre, putting some over-boots on.
Yes, indeed.
Right Wow! This is enormous, isn't it? I've never seen anything like this before.
There's 54,000 birds in here.
'Intensive chicken farming has had a bad reputation.
'In the UK today, some egg-laying birds are still kept 'in so-called enriched cages.
'But most of the birds raised for meat are kept in barns like this.
' HE SNIFFS And the thing which surprises me is it actually smells very nice.
Yeah.
I mean, I was expecting a terrible sort of ammonia smell or something like that.
Everybody who walks into these sheds always expresses surprise.
The other thing they're surprised about is how settled the birds are, and contented.
No, I was expecting again to see a much more sort of violence going on, lots of pecking.
You know, people expect them to be going up the walls, almost, because they're sort of frightened or something, but it's part and parcel of our job to keep them in a calm and relaxed state.
How many chickens are you growing here on the farm per year? We're doing between sort of 5½ and six million a year.
Wow.
That's big numbers! That sounds huge numbers, but the UK consumer is consuming nearly 19 million a week.
Right, yeah.
You're just one of many.
Yeah, OK.
'To produce chickens in the numbers we consume, 'the whole process has been mechanised.
'In hatcheries similar to this, all around the world, 'billions of eggs are incubated and hatched every week 'and the chicks are processed 'to be delivered to the farms when they are just one day old.
'The industrialisation of meat production 'puts some people off eating meat 'and has driven many others to seek free-range alternatives.
' You can see why.
The day-old chicks that arrive here will spend the remaining five weeks of their short lives in these sheds.
And it is not just the system that has been optimised, the chickens have been bred to grow as quickly and efficiently as possible.
If we compare a modern, so-called broiler chicken with one of its ancestors from the 1950s, you can see how it can grow to almost twice the size in half the time, piling on muscle especially on the breast.
'A dilemma for the ethical carnivore is that, just like the cows 'in America, when it comes to carbon emissions, raising chickens 'this way is more environmentally efficient than free-range farming.
' So, from what I've read, this is pretty much the most efficient way that you can raise meat.
If you're looking at saving the planet, and you want to eat a meat protein, this is probably the only way to do it.
Right.
I think I might put him back down now.
Yeah, he'd be very happy if you did that.
I think he'd be happier.
Off you go, then.
In the last ten years there has been a growth in an academic discipline called life cycle analysis which has been a very effective way of looking at the environmental impact along the whole life cycle of a particular product.
So if you take a chicken, it takes into account the environmental impacts associated with producing the feed, rearing the animals - that's height, lighting, heating, slaughtering them, transporting it until it reaches your dinner table.
And one of the surprising findings of life cycle analysis is that very intensively reared livestock - for example, intensive broiler chickens, have a lower carbon footprint, they're more greenhouse gas-efficient to produce than free-range chickens.
In fact, according to a recent study from Nottingham University, raising chickens indoors like this is the most energy-efficient form of livestock farming.
By that measure, this is the greenest form of meat you can buy.
Well, that wasn't exactly what I was expecting.
I mean, there are lots of legitimate welfare concerns when it comes to intensive farming, but I thought those chickens were remarkably well cared for, and if we really do want to go on eating a billion chickens a year, which is what we're doing at the moment in the UK, then I really can't see much alternative.
Now, at the moment we can just about satisfy the world's lust for meat by more efficient and intensive farming.
But what's going to happen in the future as the population grows and tastes change? 'A look at the pattern of global meat consumption reveals 'the scale of the problem.
America is the most carnivorous country.
On average, every American gets through 120 kilos of meat a year.
'In Britain, like most of Europe, we consume quite a bit less - about 80 kilos a year.
' In Europe and North America, we have hit peak meat.
Consumption of meat has either levelled off or it's declining.
In the developing world, however, consumption of meat is still soaring.
Take the example of China.
Now, in the 1960s, the era of Mao Tse Tung, the Chinese were, on average, eating just 11 grams of meat a day.
That's about four kilos a year.
Now the Chinese are much richer and they're eating 55 kilos a year, mainly pork and chicken.
Now, that is still less than us per head, but there are an awful lot of Chinese, which means that in the last 50 years in China alone, meat demand has increased by an incredible 70 billion kilos a year.
'And this pattern of greater prosperity leading to greater 'meat consumption looks set to be repeated all over 'the developing world.
Coupled with population growth, 'the demand for meat is expected to increase dramatically.
'It's predicted that by 2050 we will have to produce twice as much 'meat as we do now, and that will mean not only many more animals 'but also the crops to feed them.
' Clearly, there is not enough land and resources to be able to do that sustainably.
'We already devote a third of the planet's surface, 'and over 30% of the crops we grow, to raising livestock.
'Even with the most efficient forms of intensive farming, it will be difficult to dramatically increase meat production without 'putting severe strains on the Earth's resources.
Using more land, 'threatening the world's remaining wild habitats and, crucially, 'growing more crops to feed animals that could just as well be fed to humans.
' I think there is increasing recognition that the scale and the growth in livestock production is inherently unsustainable, we can't, we can't do it.
I think that as the scale of the environmental problems we face become more and more apparent that questions of consumption need to be explored.
In a world of nine to ten billion people, we have to think very carefully about how we best use our land.
We have to ask ourselves the question, "Should this land be "used better to produce grains that feed humans directly, or to "produce grains to feed livestock that then less directly feed humans?" One of the inevitable conclusions is that if you want to be a carnivore who cares about the planet, you are going to have to change your meat consumption.
We are also going to have to exploit other forms of farming that put less strain on the planet's resources.
I've come to the Shetland Islands, nearly 150 miles off the coast of Scotland, where they produce one of the most efficient and tasty forms of farmed animal protein in the world.
In the middle of January, it's pretty bleak and barren, but people have been drawn to these islands for over 6,000 years, because of the rich waters that surround them.
'The sea is obviously a source of fish 'but large-scale fishing is just as controversial as livestock 'farming and also has a damaging impact on the environment.
' There is however a farm out there that year after year goes on producing huge amounts of sustainable meaty protein, and it does so with very little energy input.
In fact, all you really need is quite a lot of rope like this.
I've come here to meet Michael Tate who's agreed to brave the conditions to take me to his farm out on the sea loch.
Nice to see you, turned out nice(!) Yeah, welcome and welcome aboard.
OK, thanks.
Just take a hold of the rail.
'This small patch of sheltered water is a mussel farm.
'Hanging below the water are 19km of rope 'covered in hundreds of tonnes of mussels.
We're in among the structure of the mussel farm here where you've got these headline ropes up top and down from there, hanging into the sea, is the dropper ropes.
Is it really as simple as just lowering the ropes in the water and waiting for the mussels to latch on? In effect, yes, you're right.
We hang the mussel ropes, spat collection ropes, into the sea in the spring, the spat hopefully settles onto those ropes.
We'll just have a look at these mussels here now.
These mussels are coming up to be about three years old now.
And ready for harvest.
How many tonnes of mussels can you harvest a year? Our company harvests about 1,000 tonnes of mussels a year.
Wow.
'The great thing about this form of farming is it has a very low 'carbon footprint.
'The mussels spontaneously grow on the ropes with practically no inputs.
'The largest source of energy that goes into farming them 'is the fuel needed to power the harvesting boat, and that small carbon footprint 'is further reduced by the fact the mussels actively soak up carbon 'and use it to build their shells, locking it away from the atmosphere.
' They've had a pretty good clean up, so from being on the ropes to now being ready to sort of process them, we take out the little beards here, so this is what they use to hole on to the ropes, and these are just removed, and that's it - they're ready to eat after that point.
It is wonderfully simple, isn't it? Very, very simple.
So there's about a tonne of mussels in here - incredibly efficiently harvested and very low carbon footprint.
It's about 250 grams of carbon dioxide equivalent per kilo of mussels.
'That makes mussels one of the most efficient forms of farmed animal protein.
'Their carbon footprint per kilo of meat is about ten times less 'than that of chicken and 30 times less than beef or lamb.
' Not only are they eco-friendly, but they are also a healthy source of protein, low in fat, and with high levels of omega-3 fatty acids and vitamin B-12.
'Despite this, most of the mussels 'we produce in Britain are exported to the rest of Europe.
' Rightnice hot mussels, wind blowing loudly outside, let's see what they taste like.
Mm, well, certainly the freshest I've ever had, and even though I say so myself, they are rather well cooked.
Now, the demand for mussels is on the rise.
That may partly be due to the fact they justifiably have this eco-friendly reputation, and that takes a little bit of the pressure off meat production.
Certainly gives me a warm glow knowing how little damage they're doing to the environment.
'So you could improve your own health 'and that of the planet by replacing the occasional meat meal with 'a bowl of mussels.
And though they are never realistically going 'to replace chicken or beef, they are one of a number of alternative 'sources of animal protein that we could use to bolster our diets.
' Fish farming, though controversial, is also energy efficient.
It certainly takes the pressure off wild fish stocks.
In many parts of the world, insects are a staple part of the diet and there's no reason why they shouldn't find their way onto our plates, if only we could overcome the yuck factor.
Further in the future, there is the prospect of growing artificial meat.
Laboratory-grown burgers seem like science fiction, a bit Brave New World, but some people believe they may one day be a serious alternative to farming.
Meat gown in laboratory has, to my mind, a great deal of potential.
It's ten, 15 years away from being marketable, but if we can produce meat protein near market in towns and cities with a fraction of the environmental damage, that's got to be a good thing.
I find it hard to believe that I'm going to be sitting down to a Sunday lunch of lovingly reared laboratory meat any time soon.
But I'm also feeling rather gloomy about the apocalyptic alternatives.
Surely it must be possible to rear meat humanely and in ways which are less destructive to the plant.
Come on, come on.
So I've come to Dorset to see Simon Fairleigh, a farmer, author and environmentalist.
'He has been crunching the numbers and thinks it can be done by 'returning to traditional farming methods.
' Hi, good morning, Simon.
Good morning.
How's she doing? She's all right.
She hasn't got much milk now, it's right at the end of the lactation, she's due to calve in seven weeks.
Right, do you mind if I have a squeeze? I've never milked a cow.
OK.
COW LOWS Very calm.
Ooh, there we go! You kind of imagine it's uncomfortable.
If you grab bits of me and gave it a squeeze like this You should see what the calves are like on her, you know, I mean, don't be afraid.
MICHAEL LAUGHS I think it's because we kind of extrapolate away from our own anatomy.
Very likely.
You're thinking, "No.
" You'll have to get a bit faster than that.
OK, a bit faster.
'The first thing that Simon points out is that we keep 'livestock for reasons beyond their ability to produce meat.
' As ruminants, what they're particularly good at is digesting very fibrous difficult stuff, stuff that we can't eat, like grass, leaves and so forth, and then they're producing dairy, in this case.
A number of other products - meat, leather or wool if it's sheep, draught animals for pulling ploughs and so forth.
Still very important in many parts of the world and, perhaps most importantly of all, they bring in fertility.
Manure? Manure, pretty much 85% of what goes into a cow one end comes out the other, and goes onto the land, and that's a fantastic service.
'And this is the cow's greatest talent, 'they can take land and resources we can't use, like grass, 'and turn it into valuable products that we CAN use.
' A lot of poor land you see round here, for example, is not arable at all, you couldn't use it for growing grain or crops.
This side of the United Kingdom, that's what grows best is grass, that's why we talk about our green and pleasant land.
Ireland is the Emerald Isle cos the grass is just a fantastic crop, and the best way of using it is ruminants, sheep and cows.
It's providing free food, environmentally free food so to speak.
So a kid of win/win situation? Yeah, well, it's been winning and winning for the last 10,000 years, really.
'The price we pay for cattle is the methane they produce, 'but Simon believes when raised in smaller numbers 'they can be an environmentally friendly choice.
'It puts beef firmly back on our menu.
' And it's not just cattle that can provide a source of so-called "free food".
It's thought pigs were first domesticated for their ability to eat our wasted food and turn it into pork.
In the UK today, we throw away 15 million tonnes of food every year, which we could use to feed pigs.
However, it is a contentious issue, because if the swill is not adequately heat-treated, it can transmit disease.
'It is the very last thing this industry needed.
'Official warnings were put in place this morning, 'but this area has been sealed off since Monday.
' In 2001, the foot-and-mouth outbreak was traced to a farm where the pigs had been illegally fed untreated food waste.
It led to the destruction of nearly ten million animals, and the practice was made illegal throughout Europe.
'But environmentalists like Simon think 'we will have to return to feeding pigs with waste if we are to 'produce enough eco-friendly food to feed the planet.
' So how can you eat meat but not wreck the planet? The best way to describe it is probably with a graph.
It's very simple, this axis here is the environmental impact.
This axis here, the amount of meat eaten.
And it's a simple hockey stick graph.
Let's do that quite slowly, and then it steepens quite quickly.
Right.
So the more meat and dairy you eat, the more environmental impact you make.
So there's a sort of crucial amount of meat somewhere roughly around here where it seems to take off.
It takes off, yes.
Up to that point, you can actually eat meat but not have a major environmental impact.
Yes, because this is the point, really, where you start feeding grain to animals, where you start allocating land, for the dedicated purpose of producing meat.
And when you do that, you require not only more land but you also require more water, more chemical fertilisers, pesticides, fossil fuels, et cetera.
Whereas this part, what I call the default livestock part of the graphfor the first part of the curve, for quite a long way, there's very little environmental impact.
Because the meat and dairy that you're consuming is, in a sense, free.
'It's very difficult to calculate how much meat 'we could produce without serious environmental impact.
' But economists have come up with some detailed estimates.
Globally, cattle and sheep grazing purely on grass could produce 40 million tonnes of meat a year.
Pigs and chickens, fed only on food waste could produce another 110 million tonnes.
And feeding animals the residues and by-products of other processes could produce another 40 million tonnes.
In total, it's been suggested we could produce 190 million tonnes of meat each year with a small environmental impact.
'That works out at just less than 40 kilos 'for each person on the planet.
' And where are we on this graph? Well, we're somewhere up about here, with round about 80 kilos of meat consumption a year.
To get it down there, to having really very minimal environmental impact, what sort of numbers are you talking about? Very roughly a half, I mean, it's.
.
Just by boiling this graph, it would take you, yeah, about half.
Very, very roughly.
40 kilos, 40 kilos is still a lot of meat.
It's a little over 100 grams a day.
A bit over.
So it's a burger, it's a respectable amount of meat.
It's a respectable amount of meat, yes.
So, certainly on the basis of this argument, you can see that you can be an ethical carnivore, you can be a carnivore that doesn't impact the planet, but it's only true if we probably quite substantially cut our meat consumption.
Yes.
Yup.
Simon's vision of a sustainable future is idealistic but it's not impossible.
However, for it to come about, two things have to happen, we need to cut down the amount of meat we consume and we need a revolution in the way that our livestock industry is organised.
And without huge pressure, I can't see either of those things happening.
So what should we do? I think the most obvious thing to do is to eat less meat, and there are many alternatives.
What we need to be thinking about is moving away from seeing animal protein as the centre of a meal and exploring a plant-based substitute, plant-based foods as well.
Me personally, I would choose to have a small amount of low-intensity extensive-grazing beef as a very rare treat and the rest of the time either get by with chicken or no meat at all.
'So what meat should we be buying in our weekly shop 'if we want to be ethical, eco-friendly carnivores?' Well, if we want to go on eating lots of meat and the rest of the world wants to join in, then the future is far more intensive farming, particularly on those super-efficient indoor-reared chickens.
'It might come as an unpleasant surprise 'to the environmentally conscious, but intensive farming can be 'the best option when it comes to minimising greenhouse gas emissions.
'However if demand for meat rises as predicted, 'even those intensive methods may become completely unsustainable.
'The alternative is we're going to have to eat far less meat.
'It's impossible to give a completely accurate figure of how much we should eat, 'but if we were to cut our total meat consumption 'to 100 grams per day, about this much, it would 'come close to halving the amount of meat we need to produce.
If you do that, it's good for the planet and also probably better for your health.
So the reality is you can have your steak and eat it, just not very much.
Globally, we consume nearly twice as much as we did 50 years ago.
But our increasing carnivorous cravings come at a price.
This mini meat mountain weighs 80 kilos and it represents the amount of meat the average Briton gets through in a year.
I want to find out how it gets onto our plates and what the environmental impact is.
We already devour 65 billion animals every year.
And that number is predicted to double, again.
The scale and the growth in livestock production is inherently unsustainable.
We can't do it.
If we want to eat meat, is there a way to do so without destroying the planet? Does it matter what kind of meat we eat or how it has been raised? This is the reality, and the reality says this is green.
So what should I be eating if I want to become a more eco-friendly carnivore - chicken or beef? Free-range or intensively farmed? The answers are far from obvious.
Getting to grips with the scale of the livestock industry is a truly sobering task.
Every year across the planet we slaughter and consume an extraordinary number of animals.
300 million cattle.
1.
4 billion pigs.
A billion sheep and goats.
Five million horses, two million camels.
3½ billion ducks and turkeys, and 60 billion chickens.
That's an average of nine animals for every person on the planet.
Beyond the moral considerations, there are serious environmental issues.
The amount of the earth's resources devoted to raising these vast numbers of animals is both controversial and difficult to measure.
Fortunately, the UN Food and Agriculture Organisation has put together some very comprehensive reports on the scale of the livestock industry.
Let's start with an overview.
This, of course, is a map of the Earth.
Now, the area in green, it is grazing land and it accounts for more than a quarter of the entire ice-free landmass of the Earth.
Now, the area in orange is arable land, that is land given over to growing crops.
Now, crops are mainly eaten by humans, but about a third goes to feeding animals.
If you add it all up, then you get an extraordinary figure.
A third of the entire landmass of the earth is given over to animals that we either eat or milk.
That's 70% more land than a century ago, and with meat production set to double in the next few decades, we could rapidly run out of space.
But the trouble with livestock is not just a matter of the land they occupy.
Keeping animals in such huge numbers has other, less obvious effects on the environment.
To find out what they are, I have come to America, where they eat more meat than any other country on Earth.
Come on, ladies, down the hill.
These are the Flint Hills in Kansas.
They were once part of the Wild West.
What do you reckon, Bill? And they are still home to cowboys, cowgirls and, of course, their cows.
Whoa, Bill.
When I'm eating meat, this is how I like to imagine that meat has been raised - in the open air, lots of space, but is this really the best way? If you want to be an ethical carnivore, what sort of meat should you be eating and how should it be raised? Even a farm like this, where the cattle are free to roam and seem in such harmony with the land, has a hidden environmental impact.
The problem comes from within the cattle themselves and it starts with what they eat.
Now, grass is curious stuff.
It's made out of tough fibrous cellulose and most mammals find it completely indigestible.
If I was to chew away and swallow it, then it would pass through my digestive system virtually unchanged and come out the other end, but cows absolutely thrive on this stuff.
A cow can eat around 50 kilos of grass every day and convert it into a kilo or so of muscle, the muscle that we then eat.
It's a neat metabolic trick, but it also has an unfortunate side effect.
Nothing at the moment, but as I get closer I expect to get something.
There we go.
2,876, that was a very high reading.
This is a laser methane detector.
It's not normally used on cows, but used to detect gas escaping from gas pipes.
Anything over 100 parts per million, it makes a bleep.
I am going to see if I can detect methane coming from these cows.
1,700, there is a lot of methane coming out of these cows, and interestingly, it's not really coming out of their back ends, which is what you might expect, but it's from the belching of the cows.
All the time, every moment I'm here, they're producing methane.
4,976 parts per million, that is a lot of methane! One of these cattle has obviously just done a giant belch.
If I got a reading of 1,000 parts per million from a leaking gas pipe, that would be alarming, but cattle churn methane out at an incredible rate.
An adult cow can produce up to 500 litres every single day.
'The cattle aren't at risk of exploding, 'but all that methane has other serious consequences.
' The problem is that methane is an incredibly potent greenhouse gas, 25 times more so than carbon dioxide.
In fact, it's been calculated that the average cow produces the same effect on global warming as a family car.
'Now, cattle and other ruminants have been producing methane 'for millions of years, but it only became a problem 'in the 20th century, and one surprising reason for that 'was an invention that has come to symbolise modern America.
' What can I get for you? Hello, could I get a burger and fries, please? OK.
Anything else for you? No, that's great, thank you.
OK, one with! Now, the hamburger was a technological marvel - cheap, tasty, it was easy to mass-produce.
'The hamburger was an instant success, 'the perfect meal for an increasingly automated convenience culture.
'Originally the burger patties could have been made from any meat, 'but after intense lobbying from the cattle industry, 'an Act of Congress in 1946 stipulated that all burgers should be 100% beef, 'and a diet already rich in meat saw a huge increase in beef consumption.
' There you are, sir.
Great, thank you very much.
Not a problem.
The popularity of the hamburger meant that demand for beef absolutely soared.
By the 1970s, the average American was consuming an incredible 90lbs of beef a year, that is a quarter-pounder every single day.
All that beef meant lots of methane, it also meant that they had to find a way to produce more beef.
'The success of the hamburger played a large part 'in an explosion in the global population of cattle.
'Up from 400 million a century ago to an estimated 1.
5 billion today.
'As a result, methane produced from cattle is now seen 'as a major contributor to climate change.
' About 10% of all human activity in terms of greenhouse gas emissions comes from feeding cows, so are there too many on the planet? Well, if we're trying, really trying to think about moving into a lower emissions world, then the answer has got to be yes.
So if we want to reduce the environmental impact of our diet perhaps we should stop eating beef altogether.
But is there another way? Is it possible to make cattle more environmentally friendly by reducing the amount of methane they emit? 'To find out, scientists have been studying how that methane is produced.
'I've come to the Animal Sciences Department of the University of Nebraska 'to see a remarkable animal experiment 'run by Dr Samoda Fernando.
' Well, that is extraordinary.
I've sort of read about it but I've never seen anything like this before.
He seems quite comfortable he, she? It's a he, it's actually a steer.
OK, so this has sort of been surgically implanted, that's right? Yeah, this is called a fistula or a cannula.
And presumably it's pretty well the only way of studying? Yeah, because this allows actually direct access to what's happening inside the animal and I can actually take this one out.
And.
.
Presumably that's to stop getting infections and things.
Oh, wow.
Yeah.
So I'm looking into one of the stomachs? Yes, you are actually looking to the largest compartment, the rumen.
It can hold 50 to 60 gallons of rumen fluid and it accounts for about 65% of the gastrointestinal tract of the animal.
The rumen is the largest of the four chambers of a cow's stomach and it is through having direct access into that chamber that scientists are better able to study how cattle digest grass and why they produce so much methane.
'I'm assured the animal won't feel a thing.
' Can I stick my hand in? Yeah, absolutely.
OK, ooh, gosh.
Ah, ooh that is odd, that is so strange.
It is incredibly hot.
Really very smelly now.
I'm holding my breath.
That isreally odd, having my hand inside a living, breathing cow like that in its gut.
He doesn't seem to mind in the slightest, does he? No, no.
Hello, are you all right here? So this is partially digested, is that right? Yes.
It still looks like straw, doesn't it? Yes.
So where's all the methane production going on? So the majority of it is actually going on in the rumen, so if you feel some of the methane might be just coming out from here Is that the major gas by-product? What am I smelling at the moment? It should be methane.
This rumen is full of bacteria, viruses and fungi and those microbes are the ones that are actually digesting the hay, or the cellulose that's in the hay.
'When cattle eat grass, they are not just feeding themselves, 'but also the trillions of microbes that live in their rumen.
'It is those microbes that produce all the methane 'but they are also performing a vital service - 'breaking down cellulose into more nutritious molecules 'that the cow can absorb.
' So this great big sort of mixture of microbes is converting the hay into something which the Energy-dense molecules that is absorbed by the animal and used for energy for the animals.
Right.
Some of these microbes that's already in the rumen actually bypass to the small intestines and provide them as microbial cell protein, so they don't have a protein requirement like we would have because the microbes actually become protein, microbial protein for them in the small intestines.
So the cow is actually digesting the microbes as part of its meal? Yeah, in the small intestines, microbial cell protein.
So in a funny way a cow iswell, not exactly a carnivore, but not entirely a herbivore, it's actually living, itself, on living microbes? Yeah.
The cow's ability to harness these microbes' digestive skills to feed itself is a brilliant adaptation and, crucially, it has been shown that you can change the balance of microbes within the rumen and dramatically reduce the amount of methane they produce by simply changing the cow's diet.
This means raising cattle on grass might not be the greenest way of farming them.
So I'm going to see an alternative farming system that some people claim is more eco-friendly.
It was first devised in the 1950s, helping to produce the huge amounts of beef demanded by the hamburger industry, and it is still used to produce the majority of American beef.
I'm going towards a different sort of farm, the sort of farm where a lot of the hamburger meat comes from.
It's charmingly called a CAFO - a Concentrated Animal Feeding Operation - and it's just over here on the left.
This is the Wrangler Feed Yard, just outside Amarillo in Texas.
Its 500-acre site is a temporary home to 50,000 cattle.
They are brought to feed lots like these at about a year-old and are fattened on a carbohydrate and protein-rich diet based on corn.
They stay six months, put on about 300 kilos in weight, then they are shipped off to be slaughtered.
'If you go to America, the chances are that any beef you eat 'will have come from a feed lot like this, 'and similar operations are beginning to appear in the UK.
' Here's the most extraordinary thing I think I've seen for a long time.
Just the scale is awesome.
I mean, really quite awesome.
It is bleak and there's something about them all, eating and staring at you, I'm trying to separate my sort of feelings of, frankly, a little bit of guilt as a meat eater with just the way it's done.
'Seeing this could put you off eating beef altogether.
'Raising cattle in these vast numbers seems to be 'the very antithesis of eco-friendly farming.
'Some feed lots have been criticised for poor welfare standards 'and for polluting the local environment.
'Not surprisingly, Dr Mike Engler, the CEO here thinks 'they deserve a better reputation.
' Hello.
Michael, welcome to Wrangler Feed Yard.
The first thing that strikes you is it is a little bit bleak, it's not a romantic vision, a sort of green vision.
You wouldn't think so, would you? No.
Well, you know, we can get the animal to market weight in less days of their existence than they can on grass, and so we've reduced the total amount of methane emitted.
So if the goal is to produce the most amount of beef with the least amount of resources, this is where you can accomplish part of that solution.
We are part of the solution not the problem.
Are they happier? Looking at them, it's difficult to tell, I have no idea what a happy I mean, to be honest they look neither more nor less happy than most of the ones I see in a field, but.
.
They're herding animals and they don't want to be alone, so what we've given him here in this pen is a herd of animals.
Their behaviour is very similar to an animal's out on range or on pasture.
It doesn't look green, it really doesn't look green.
But you would argue that this method is, oddly enough and paradoxically enough, more green than sticking them out in a field, would you? Absolutely.
One of the things I have a pet peeve about here in the United States, we hear it in politics all the time, perception is reality.
It's not.
It doesn't change reality.
In advertising and in politics, perception is reality, I understand, but in the world where we're trying to produce food for people, this is the reality and the reality says this is green.
Of course, it all depends on what you mean by "green".
The secret to the feed lot's ability to produce more beef in less time, and therefore to reduce their methane emissions, lies in the vast amount of grain they feed the cattle.
Nearly 40% of the corn grown in America is fed to livestock.
To critics, this is a tremendous waste of land and grain, but to Dr Engler and others, it is this diet that is the key to the farm's success.
The main ingredient in the cow's feed is corn, turned into cornflakes, much like we eat.
'But those flakes are also mixed with a number of other ingredients 'into a carefully formulated diet.
' That's a relief, it's very noisy out there, isn't it? Absolutely.
This is what I saw the cows eating earlier, is it? Yes, this is what's in most of the feed box.
When the cows first arrive, we actually start 'em on this ration.
Don't be deceived, though.
It's green because of blue food dye.
What it's actually made from is the by-product, the wet by-product from a high-fructose corn syrup plant.
We also feed a by-product from the ethanol industry which, of course, starts with corn.
This one is the corn gluten feed in a pelleted version.
We feed this for protein.
I nearly forgot, though, we also have liquid fat that we add.
About 2% of the ration would be in this.
Do they also influence the amount of methane that the cow's producing? Absolutely.
It's not quite a reduction to 50% but it is a significant reduction.
OK, so close to 50%.
In addition, he'll gain weight faster on this high-caloric diet, so on the same number of days on this diet, we'll have twice as much weight gain with about half as much methane production.
Right, so that's a kind of win/win situation? Absolutely.
'But there is something that worries me.
'They also feed their cattle growth hormones and antibiotics 'such as Rumensin, which in Europe are banned from the diet of livestock.
' Doesn't that give you pause for thought? No, because there's been no medical reason to ban that use in animal agriculture.
Aren't you worried about feeding resistance or doing something? No, because no-one uses it in human medicine.
You see, nonetheless, it is the one thing that has disturbed me, in a way.
I am just brought up in the tradition you absolutely do not use antibiotics unless you have to.
Well, they're very complementary technologies.
Because, you know, if you're going to go to all this trouble to formulate a scientific diet and you don't avail yourself of the things that have been developed to make the most out of what you've done, then in some cases you've just wasted your money.
OK, that's fairly hardcore.
Yeah.
'The feed lot is not a system that was designed to be eco-friendly.
'But it is a surprising 'and uncomfortable truth that the economic efficiency demanded 'by farms like these can also equate to environmental efficiency.
' Studies show that cows raised this way produce up to 40% less emissions per kilo of meat than grass-fed cattle.
By those measures, this intensive form of farming is more environmentally friendly than raising cattle on the plains.
Now this place is a real paradox.
In many ways it's about as far from a conventional green vision of the future as you can possibly imagine.
Animals in pens, fed corn, antibiotics and hormones.
On the other hand, if you do it this way, then you can get more meat in less time with much lower levels of methane gas production.
So which method is genuinely greener? And this is one of the great problems of trying to be an eco-friendly meat eater.
Different farming systems can be better for different aspects of the environment.
If you want a system which uses a relatively small amount of land or produces a relatively small amount of emissions, or uses a relatively small amount of water, they're all facing in different directions, so there isn't a kind of right answer to what environmental sustainability means.
Does it mean an extensive grazing system where animals are largely living on pasture? Or does it mean an intensive system where you're putting a lot of food into the animals and ending up with a relatively low emissions-per-unit weight? Those two things are both ways of looking at environmental sustainability but they're both quite different.
And this point is reflected around the world.
Wherever we look, we find different farming systems and conditions that raise very different environmental issues.
In Britain and Ireland, we have lots of lush green grass, and well-managed grazing is relatively low impact.
But in other areas, like Sub-Saharan Africa, where grasslands are less fertile, overgrazing risks permanently degrading the land, even turning some areas into desert.
In South America, demand for new pasture has meant the cutting down of millions of hectares of Amazon rainforest.
That in turn has led to a massive loss of wildlife and the release of huge amounts of carbon into the atmosphere.
Elsewhere in Brazil and Argentina, vast areas of natural land are still being ploughed up to create soya plantations, soya that is then exported around the world to feed livestock.
If you had chicken or pork for your Sunday roast, it was probably fed on South American soya.
'Assessing the combined effect of all these factors 'is extraordinarily difficult.
' But the United Nations have had a go, by focusing down on the carbon footprint, the effect of all that activity on man-made greenhouse gas emissions.
'They have assessed every element in the global livestock system.
'The methane that comes from ruminant digestion alone 'is equivalent to adding 2.
8 billion tonnes of carbon dioxide 'to the atmosphere every year.
' Managing the manure produced by farm animals creates another 700 million tonnes.
The carbon stores lost by chopping down forests and degrading habitats also adds 700 million tonnes.
Growing crops to feed animals is responsible for 2.
6 giga tonnes.
Compared with that, the 100 million tonnes released by transporting crops and meat around the world seems almost trivial.
'By adding these and many other factors together, we can estimate 'the total impact of livestock production on man-made greenhouse gas emissions.
' It's clearly been a mammoth task, and the figures have been revised several times, but the latest best estimate is 14.
5% of all the man-made greenhouse gas emissions can be blamed on the animals that we either eat or milk.
'And it's because of this massive environmental impact that 'modern livestock farming has become such a contentious issue.
' Some see industrial agriculture as a miracle.
I see it as a mirage.
The problem with industrial agriculture is it's not just about cows, industrial agriculture is incredibly hungry for oil to produce artificial pesticides and fertilisers to power machines.
It's incredibly thirsty for water to irrigate crops to feed farm animals.
It's madness, it's madness to be feeding those cattle people food.
It's madness to be destroying the Argentinian countryside to feed the factory-farmed animals in Britain and Europe.
Such is the size of the global livestock industry that its carbon footprint is about the same as the contribution made by transport - all the world's cars, trains, boats and planes combined.
So you can see the scale of the problem if you want to be an eco-friendly carnivore, but can you reduce your own personal contribution by choosing the right sort of animal to eat? This is a rodizio, a Brazilian barbecue restaurant.
'It is a temple to meat.
' Rump side of beef? Yes, delicious.
'Great chunks of meat.
' Lamb? Fantastic, yes, please.
'Cooked on skewers and carved at your table.
' Pork loin? Yes, please.
'But which meat should you choose 'if you want to reduce the carbon footprint of your diet?' Yes, please.
So I've got four different plates of meat.
Got some beef, some lamb, some pork and chicken.
Each of them about 100 grams, similar in nutritional value, but the amount of food and energy required to get them here has been very different.
'The first thing you need to know is that animals vary wildly in the efficiency with which they convert food into flesh.
'One way to compare them is by looking at the amount 'of protein they need to eat to produce their meat.
' Let's start with our old friend, the cow.
The cow is a ruminant and its digestion is not very efficient.
'Exact figures vary, depending on 'whether they are fed on grass or grain, 'but on average, cattle need to consume 450 grams of protein 'to produce 100 grams of cooked beef.
' Now, the sheep is also a ruminant, but it takes almost twice as much protein to produce this amount of meat.
Now, the pig is an omnivore, eats pretty well anything and it is much more efficient.
'A pig only needs 110 grams of protein 'to produce 100 grams of pork.
'But top of the list is the chicken, 'which only needs 75 grams of protein in its diet 'to produce 100 grams of meat.
' Now, feed efficiency ratios aren't everything, you also have to take into account the amount of energy that goes in, the amount of gas that these animals produce.
'By adding together all these factors, it is possible to produce 'a single figure for the carbon footprint of each meat.
'Again, the exact results vary between farms and systems, 'but these figures are broadly true 'of the meat we can buy in supermarkets.
'The worst offenders are cattle, 'releasing the equivalent of 16kg of carbon dioxide 'for every kilo of meat produced.
'In at number two is the sheep, with a figure of 13.
' Number three, we have the pig, considerably less, with five kilos, and best of all is chicken.
'On average, the production of a kilo of chicken meat only releases 'the equivalent of 4.
4 kilos of CO2.
'Per kilo, its carbon footprint is about a quarter that of beef.
' So if you're worried about your carbon footprint, then you are obviously better off eating chicken than you are one of the ruminants, like the sheep or the cow.
'Chicken has also become a very cheap source of meat.
'We eat five times more than we did 50 years ago.
'Fried chicken is becoming our takeaway of choice, 'a single shop can sell 600 pieces of chicken a night.
'Which begs a fundamental question.
'Where do all those chickens come from?' Now, the thing is, as you drive through the British countryside, you see cows, you see sheep, but you never, or very rarely, see chickens.
'I'm on my way to find where they are hiding.
' So this is Uphouse Farm and I'm here to meet chicken farmer, Nigel Joyce.
'The reason we don't see most of the chickens we eat 'while they are still alive 'is that they are reared indoors, in sheds like these.
' So this kind of reminds me of going into an operating theatre, putting some over-boots on.
Yes, indeed.
Right Wow! This is enormous, isn't it? I've never seen anything like this before.
There's 54,000 birds in here.
'Intensive chicken farming has had a bad reputation.
'In the UK today, some egg-laying birds are still kept 'in so-called enriched cages.
'But most of the birds raised for meat are kept in barns like this.
' HE SNIFFS And the thing which surprises me is it actually smells very nice.
Yeah.
I mean, I was expecting a terrible sort of ammonia smell or something like that.
Everybody who walks into these sheds always expresses surprise.
The other thing they're surprised about is how settled the birds are, and contented.
No, I was expecting again to see a much more sort of violence going on, lots of pecking.
You know, people expect them to be going up the walls, almost, because they're sort of frightened or something, but it's part and parcel of our job to keep them in a calm and relaxed state.
How many chickens are you growing here on the farm per year? We're doing between sort of 5½ and six million a year.
Wow.
That's big numbers! That sounds huge numbers, but the UK consumer is consuming nearly 19 million a week.
Right, yeah.
You're just one of many.
Yeah, OK.
'To produce chickens in the numbers we consume, 'the whole process has been mechanised.
'In hatcheries similar to this, all around the world, 'billions of eggs are incubated and hatched every week 'and the chicks are processed 'to be delivered to the farms when they are just one day old.
'The industrialisation of meat production 'puts some people off eating meat 'and has driven many others to seek free-range alternatives.
' You can see why.
The day-old chicks that arrive here will spend the remaining five weeks of their short lives in these sheds.
And it is not just the system that has been optimised, the chickens have been bred to grow as quickly and efficiently as possible.
If we compare a modern, so-called broiler chicken with one of its ancestors from the 1950s, you can see how it can grow to almost twice the size in half the time, piling on muscle especially on the breast.
'A dilemma for the ethical carnivore is that, just like the cows 'in America, when it comes to carbon emissions, raising chickens 'this way is more environmentally efficient than free-range farming.
' So, from what I've read, this is pretty much the most efficient way that you can raise meat.
If you're looking at saving the planet, and you want to eat a meat protein, this is probably the only way to do it.
Right.
I think I might put him back down now.
Yeah, he'd be very happy if you did that.
I think he'd be happier.
Off you go, then.
In the last ten years there has been a growth in an academic discipline called life cycle analysis which has been a very effective way of looking at the environmental impact along the whole life cycle of a particular product.
So if you take a chicken, it takes into account the environmental impacts associated with producing the feed, rearing the animals - that's height, lighting, heating, slaughtering them, transporting it until it reaches your dinner table.
And one of the surprising findings of life cycle analysis is that very intensively reared livestock - for example, intensive broiler chickens, have a lower carbon footprint, they're more greenhouse gas-efficient to produce than free-range chickens.
In fact, according to a recent study from Nottingham University, raising chickens indoors like this is the most energy-efficient form of livestock farming.
By that measure, this is the greenest form of meat you can buy.
Well, that wasn't exactly what I was expecting.
I mean, there are lots of legitimate welfare concerns when it comes to intensive farming, but I thought those chickens were remarkably well cared for, and if we really do want to go on eating a billion chickens a year, which is what we're doing at the moment in the UK, then I really can't see much alternative.
Now, at the moment we can just about satisfy the world's lust for meat by more efficient and intensive farming.
But what's going to happen in the future as the population grows and tastes change? 'A look at the pattern of global meat consumption reveals 'the scale of the problem.
America is the most carnivorous country.
On average, every American gets through 120 kilos of meat a year.
'In Britain, like most of Europe, we consume quite a bit less - about 80 kilos a year.
' In Europe and North America, we have hit peak meat.
Consumption of meat has either levelled off or it's declining.
In the developing world, however, consumption of meat is still soaring.
Take the example of China.
Now, in the 1960s, the era of Mao Tse Tung, the Chinese were, on average, eating just 11 grams of meat a day.
That's about four kilos a year.
Now the Chinese are much richer and they're eating 55 kilos a year, mainly pork and chicken.
Now, that is still less than us per head, but there are an awful lot of Chinese, which means that in the last 50 years in China alone, meat demand has increased by an incredible 70 billion kilos a year.
'And this pattern of greater prosperity leading to greater 'meat consumption looks set to be repeated all over 'the developing world.
Coupled with population growth, 'the demand for meat is expected to increase dramatically.
'It's predicted that by 2050 we will have to produce twice as much 'meat as we do now, and that will mean not only many more animals 'but also the crops to feed them.
' Clearly, there is not enough land and resources to be able to do that sustainably.
'We already devote a third of the planet's surface, 'and over 30% of the crops we grow, to raising livestock.
'Even with the most efficient forms of intensive farming, it will be difficult to dramatically increase meat production without 'putting severe strains on the Earth's resources.
Using more land, 'threatening the world's remaining wild habitats and, crucially, 'growing more crops to feed animals that could just as well be fed to humans.
' I think there is increasing recognition that the scale and the growth in livestock production is inherently unsustainable, we can't, we can't do it.
I think that as the scale of the environmental problems we face become more and more apparent that questions of consumption need to be explored.
In a world of nine to ten billion people, we have to think very carefully about how we best use our land.
We have to ask ourselves the question, "Should this land be "used better to produce grains that feed humans directly, or to "produce grains to feed livestock that then less directly feed humans?" One of the inevitable conclusions is that if you want to be a carnivore who cares about the planet, you are going to have to change your meat consumption.
We are also going to have to exploit other forms of farming that put less strain on the planet's resources.
I've come to the Shetland Islands, nearly 150 miles off the coast of Scotland, where they produce one of the most efficient and tasty forms of farmed animal protein in the world.
In the middle of January, it's pretty bleak and barren, but people have been drawn to these islands for over 6,000 years, because of the rich waters that surround them.
'The sea is obviously a source of fish 'but large-scale fishing is just as controversial as livestock 'farming and also has a damaging impact on the environment.
' There is however a farm out there that year after year goes on producing huge amounts of sustainable meaty protein, and it does so with very little energy input.
In fact, all you really need is quite a lot of rope like this.
I've come here to meet Michael Tate who's agreed to brave the conditions to take me to his farm out on the sea loch.
Nice to see you, turned out nice(!) Yeah, welcome and welcome aboard.
OK, thanks.
Just take a hold of the rail.
'This small patch of sheltered water is a mussel farm.
'Hanging below the water are 19km of rope 'covered in hundreds of tonnes of mussels.
We're in among the structure of the mussel farm here where you've got these headline ropes up top and down from there, hanging into the sea, is the dropper ropes.
Is it really as simple as just lowering the ropes in the water and waiting for the mussels to latch on? In effect, yes, you're right.
We hang the mussel ropes, spat collection ropes, into the sea in the spring, the spat hopefully settles onto those ropes.
We'll just have a look at these mussels here now.
These mussels are coming up to be about three years old now.
And ready for harvest.
How many tonnes of mussels can you harvest a year? Our company harvests about 1,000 tonnes of mussels a year.
Wow.
'The great thing about this form of farming is it has a very low 'carbon footprint.
'The mussels spontaneously grow on the ropes with practically no inputs.
'The largest source of energy that goes into farming them 'is the fuel needed to power the harvesting boat, and that small carbon footprint 'is further reduced by the fact the mussels actively soak up carbon 'and use it to build their shells, locking it away from the atmosphere.
' They've had a pretty good clean up, so from being on the ropes to now being ready to sort of process them, we take out the little beards here, so this is what they use to hole on to the ropes, and these are just removed, and that's it - they're ready to eat after that point.
It is wonderfully simple, isn't it? Very, very simple.
So there's about a tonne of mussels in here - incredibly efficiently harvested and very low carbon footprint.
It's about 250 grams of carbon dioxide equivalent per kilo of mussels.
'That makes mussels one of the most efficient forms of farmed animal protein.
'Their carbon footprint per kilo of meat is about ten times less 'than that of chicken and 30 times less than beef or lamb.
' Not only are they eco-friendly, but they are also a healthy source of protein, low in fat, and with high levels of omega-3 fatty acids and vitamin B-12.
'Despite this, most of the mussels 'we produce in Britain are exported to the rest of Europe.
' Rightnice hot mussels, wind blowing loudly outside, let's see what they taste like.
Mm, well, certainly the freshest I've ever had, and even though I say so myself, they are rather well cooked.
Now, the demand for mussels is on the rise.
That may partly be due to the fact they justifiably have this eco-friendly reputation, and that takes a little bit of the pressure off meat production.
Certainly gives me a warm glow knowing how little damage they're doing to the environment.
'So you could improve your own health 'and that of the planet by replacing the occasional meat meal with 'a bowl of mussels.
And though they are never realistically going 'to replace chicken or beef, they are one of a number of alternative 'sources of animal protein that we could use to bolster our diets.
' Fish farming, though controversial, is also energy efficient.
It certainly takes the pressure off wild fish stocks.
In many parts of the world, insects are a staple part of the diet and there's no reason why they shouldn't find their way onto our plates, if only we could overcome the yuck factor.
Further in the future, there is the prospect of growing artificial meat.
Laboratory-grown burgers seem like science fiction, a bit Brave New World, but some people believe they may one day be a serious alternative to farming.
Meat gown in laboratory has, to my mind, a great deal of potential.
It's ten, 15 years away from being marketable, but if we can produce meat protein near market in towns and cities with a fraction of the environmental damage, that's got to be a good thing.
I find it hard to believe that I'm going to be sitting down to a Sunday lunch of lovingly reared laboratory meat any time soon.
But I'm also feeling rather gloomy about the apocalyptic alternatives.
Surely it must be possible to rear meat humanely and in ways which are less destructive to the plant.
Come on, come on.
So I've come to Dorset to see Simon Fairleigh, a farmer, author and environmentalist.
'He has been crunching the numbers and thinks it can be done by 'returning to traditional farming methods.
' Hi, good morning, Simon.
Good morning.
How's she doing? She's all right.
She hasn't got much milk now, it's right at the end of the lactation, she's due to calve in seven weeks.
Right, do you mind if I have a squeeze? I've never milked a cow.
OK.
COW LOWS Very calm.
Ooh, there we go! You kind of imagine it's uncomfortable.
If you grab bits of me and gave it a squeeze like this You should see what the calves are like on her, you know, I mean, don't be afraid.
MICHAEL LAUGHS I think it's because we kind of extrapolate away from our own anatomy.
Very likely.
You're thinking, "No.
" You'll have to get a bit faster than that.
OK, a bit faster.
'The first thing that Simon points out is that we keep 'livestock for reasons beyond their ability to produce meat.
' As ruminants, what they're particularly good at is digesting very fibrous difficult stuff, stuff that we can't eat, like grass, leaves and so forth, and then they're producing dairy, in this case.
A number of other products - meat, leather or wool if it's sheep, draught animals for pulling ploughs and so forth.
Still very important in many parts of the world and, perhaps most importantly of all, they bring in fertility.
Manure? Manure, pretty much 85% of what goes into a cow one end comes out the other, and goes onto the land, and that's a fantastic service.
'And this is the cow's greatest talent, 'they can take land and resources we can't use, like grass, 'and turn it into valuable products that we CAN use.
' A lot of poor land you see round here, for example, is not arable at all, you couldn't use it for growing grain or crops.
This side of the United Kingdom, that's what grows best is grass, that's why we talk about our green and pleasant land.
Ireland is the Emerald Isle cos the grass is just a fantastic crop, and the best way of using it is ruminants, sheep and cows.
It's providing free food, environmentally free food so to speak.
So a kid of win/win situation? Yeah, well, it's been winning and winning for the last 10,000 years, really.
'The price we pay for cattle is the methane they produce, 'but Simon believes when raised in smaller numbers 'they can be an environmentally friendly choice.
'It puts beef firmly back on our menu.
' And it's not just cattle that can provide a source of so-called "free food".
It's thought pigs were first domesticated for their ability to eat our wasted food and turn it into pork.
In the UK today, we throw away 15 million tonnes of food every year, which we could use to feed pigs.
However, it is a contentious issue, because if the swill is not adequately heat-treated, it can transmit disease.
'It is the very last thing this industry needed.
'Official warnings were put in place this morning, 'but this area has been sealed off since Monday.
' In 2001, the foot-and-mouth outbreak was traced to a farm where the pigs had been illegally fed untreated food waste.
It led to the destruction of nearly ten million animals, and the practice was made illegal throughout Europe.
'But environmentalists like Simon think 'we will have to return to feeding pigs with waste if we are to 'produce enough eco-friendly food to feed the planet.
' So how can you eat meat but not wreck the planet? The best way to describe it is probably with a graph.
It's very simple, this axis here is the environmental impact.
This axis here, the amount of meat eaten.
And it's a simple hockey stick graph.
Let's do that quite slowly, and then it steepens quite quickly.
Right.
So the more meat and dairy you eat, the more environmental impact you make.
So there's a sort of crucial amount of meat somewhere roughly around here where it seems to take off.
It takes off, yes.
Up to that point, you can actually eat meat but not have a major environmental impact.
Yes, because this is the point, really, where you start feeding grain to animals, where you start allocating land, for the dedicated purpose of producing meat.
And when you do that, you require not only more land but you also require more water, more chemical fertilisers, pesticides, fossil fuels, et cetera.
Whereas this part, what I call the default livestock part of the graphfor the first part of the curve, for quite a long way, there's very little environmental impact.
Because the meat and dairy that you're consuming is, in a sense, free.
'It's very difficult to calculate how much meat 'we could produce without serious environmental impact.
' But economists have come up with some detailed estimates.
Globally, cattle and sheep grazing purely on grass could produce 40 million tonnes of meat a year.
Pigs and chickens, fed only on food waste could produce another 110 million tonnes.
And feeding animals the residues and by-products of other processes could produce another 40 million tonnes.
In total, it's been suggested we could produce 190 million tonnes of meat each year with a small environmental impact.
'That works out at just less than 40 kilos 'for each person on the planet.
' And where are we on this graph? Well, we're somewhere up about here, with round about 80 kilos of meat consumption a year.
To get it down there, to having really very minimal environmental impact, what sort of numbers are you talking about? Very roughly a half, I mean, it's.
.
Just by boiling this graph, it would take you, yeah, about half.
Very, very roughly.
40 kilos, 40 kilos is still a lot of meat.
It's a little over 100 grams a day.
A bit over.
So it's a burger, it's a respectable amount of meat.
It's a respectable amount of meat, yes.
So, certainly on the basis of this argument, you can see that you can be an ethical carnivore, you can be a carnivore that doesn't impact the planet, but it's only true if we probably quite substantially cut our meat consumption.
Yes.
Yup.
Simon's vision of a sustainable future is idealistic but it's not impossible.
However, for it to come about, two things have to happen, we need to cut down the amount of meat we consume and we need a revolution in the way that our livestock industry is organised.
And without huge pressure, I can't see either of those things happening.
So what should we do? I think the most obvious thing to do is to eat less meat, and there are many alternatives.
What we need to be thinking about is moving away from seeing animal protein as the centre of a meal and exploring a plant-based substitute, plant-based foods as well.
Me personally, I would choose to have a small amount of low-intensity extensive-grazing beef as a very rare treat and the rest of the time either get by with chicken or no meat at all.
'So what meat should we be buying in our weekly shop 'if we want to be ethical, eco-friendly carnivores?' Well, if we want to go on eating lots of meat and the rest of the world wants to join in, then the future is far more intensive farming, particularly on those super-efficient indoor-reared chickens.
'It might come as an unpleasant surprise 'to the environmentally conscious, but intensive farming can be 'the best option when it comes to minimising greenhouse gas emissions.
'However if demand for meat rises as predicted, 'even those intensive methods may become completely unsustainable.
'The alternative is we're going to have to eat far less meat.
'It's impossible to give a completely accurate figure of how much we should eat, 'but if we were to cut our total meat consumption 'to 100 grams per day, about this much, it would 'come close to halving the amount of meat we need to produce.
If you do that, it's good for the planet and also probably better for your health.
So the reality is you can have your steak and eat it, just not very much.