Skip to Main Content
Log in

theWatt Podcast 70

Conversation about the energy requirements of the food we eat with Nigel Winter from the Vegan Society (UK). Hosts: Ben and Stephen

Some show links:

Here's a summary table that I pulled from the report about livestock and it's impact:

Source: Food and Agriculture Organization of the United Nations, "Livestock a major threat to environment", Table 7.1, pg 271

Livestock contributes 18% of the world's greenhouse gas emissions! The report says that this is a bigger contribution than the transport sector.

Here's summary of the report.

Stephen Pilditch: Well , the reason I wanted to see this show was I was quite interested in a quote from Albert Einstein, that nothing will benefit human health and increase the chances for survival of life on Earth as much as the evolution to a vegetarian diet. Now, Nigel, why do you think Albert Einstein would say such a thing?

Nigel Winter: Well, would actually take it a stage further and say that we need to adopt the vegan and organic diet, and the reasons for this are that the consumption of animal products contributes to malnutrition in developing world, water scarcity, pollution, deforestation, species distinction, land degradation, and global warming.

Stephen Pilditch: Wow, that's pretty convincing.

Nigel Winter: Well, Dennis Avery of the Center for Global Food Issues, said the world must create 5 billion vegans in the next several decades or triple its sum put without using more land.

Stephen Pilditch: That's a lot of people we need to convert, Nigel.

Nigel Winter: That’s right, yes, yes. He is talking about it in the context of population growth. At the moment, we got 6.6 billion people on the planet, but it's expected to grow to 9 billion in about 2050.

Stephen Pilditch: Let’s get on to the types of food and how much land and energy and each type of food needs. You’ve got some statistics on that, haven’t you, Nigel?

Nigel Winter: Yes. From one acre of land, you can produce 43 kilos of beef protein or you could produce 470 kilos of soya protein, so more than 10 times as much from one acre of land. A varied vegan diet uses half the amount of land used to produce a typical vegetarian diet and 1/5 of that used for typical European omnivorous diet.

Stephen Pilditch: One of the problems with cows is you need to produce quite a lot of land and you might deforestation and also you need to feed them with soya which could actually be used to feed people.

Nigel Winter: Yeah, there are a few issues here. First of all, converting feed to meat is an inefficient process, say for example, if you give 10 kilos of plant food to cattle, that only produces one kilo of beef protein, so most of the feed is used to maintain the animal’s bodily functions.

Stephen Pilditch: Oh, so a lot of it is lost to heat and all sorts of parts of the cow that can’t be eaten.

Nigel Winter: Yeah, basically keeping the cow alive and then used to make bone, which you are not going to eat. So, it's far more sensible to feed the plant protein directly to people.

Stephen Pilditch: To use as primary food.

Nigel Winter: Yeah. Meat production worldwide has quadrupled in the last 50 years and yet about every five seconds a child dies due to hunger and 840 million people don’t have enough food to eat.

Stephen Pilditch: Yeah. I've realized beef practically is the worst thing you can do, but what about other meats such as chicken, pork, or lamb?

Nigel Winter: Yeah, I mean with one acre of land, you could produce 99 kilos of pork protein, but still bearing in mind 470 kilos of soya protein you could produce 144 kilos of egg protein, so the animal proteins are still a lot lower than the plant proteins from an acre of land. Livestock use 30% of the entire land surface and 33% of global arable land is used to produce the feed for livestock. About 60% of world deforestation is to provide grazing for cattle and as you said, some rainforest declared to grow soya but in fact 80-90% of soya protein is transported around the world to feed livestock. It is mainly used to feed poultry and pigs but 70% of animal feed use imported. It often comes from countries with high levels of malnutrition and between a third and 50% of world grain production is fertilized stock. Some people questions what will happen if whole world goes livid, well, one example is the average vegan eats 15 grams of soya protein per day so even if the whole world is vegan, the amount of soya required would still be far less than is currently produced. I mean current production is about 195 million tons per year and as I said, 80-90% of that soya protein at the moment goes to feed mainly poultry and pigs, but there are some cattle as well.

Stephen Pilditch: In terms of greenhouse gases, the press seems to concentrate most on the transport sector. I was talking to you earlier, Nigel, and you said there are more greenhouse gases for cattle and meat than the whole transport system in the world.

Nigel Winter: Yeah, there's been a very interesting report published only about two weeks ago from the food and agricultural organization called Livestock’s Long Shadow and it says that the livestock sector is responsible for 9% of all human-induced carbon dioxide emissions, 37% of methane and I got a number that methane has 23 times the global warming potential of carbon dioxide and the methane comes from the dodgiest existence of cattle, sheep and goats. Livestock also emits 65% of human-induced nitrous oxide and this has 296 times the global warming potential of CO2 and most of that comes from manure and livestock is also responsible for 64% of ammonia emissions which contribute to acid rain. Now, the important point to bear in mind is that carbon dioxide stays in the atmosphere for about a hundred years, but methane cycles out in about eight years, so if we can reduce methane emissions, we can have a faster effect of cooling the Earth, but as you said it quite rightly that the livestock sector overall produces more greenhouse gases in transport. The actual report of Livestock’s Long Shadow is about 400 pages and is extremely detailed in all the information. Obviously, I can’t quote all the figures off the top of my head on exactly how they've calculated all the figures, but there's a lot of detail in the report.

Stephen Pilditch: Also, fish. If we become vegan, we can’t really eat fish either, can we?

Nigel Winter: No, neither vegetarian or vegan eat fish.

Stephen Pilditch: Oh, okay. Is it very energy intensive? What's the energy calculation for fish?

Nigel Winter: Yeah. I mean there's a very good report published which states that the fishing industry globally burns about 13 billion gallons of fuel a year to catch 18 million tons of fish and that’s 1.2% of global oil production, the equivalent to the amount of oil the whole of the Netherlands use each year.

Ben Kenney: Why does fish requires so much?

Nigel Winter: Because of the fishing vessels and it’s actually increasing because the fishing vessels are having to travel further to catch the fish because the stocks are going down and the amount of energy required to pull up some of these fishing nets is huge.

Stephen Pilditch: How about fish farming? Is that any better?

Nigel Winter: Well, agricultural fish farming is actually growing more rapidly than all other animal food-producing sectors. In the UK, there’s over a thousand fish and shellfish farms and they mainly produce salmon and rainbow trout, but what a lot of people don't realize is for every ton of salmon fish produced, 3 to 4 tons of wild fish are caught to produce feed pellets and in addition to that, the fish are often treated with chemicals because they have sea lice and other diseases and with the waste food and the fish feces can cause environmental damage in the sea-lochs. So, fish farming isn’t an answer for replacing the dwindling fish stocks in the sea.

Stephen Pilditch: Okay. I was reading a good article in the Economist last week and they had a whole section on food production. One thing they argued was that supermarkets cannot often be better than shopping locally. For instance, they have big Lorries. It's an efficient way to transport goods and local shops, you often have to get local people driving to the local shops so it actually produces more food miles by an individual going to the shop. Can you comment on that, Nigel?

Nigel Winter: Yeah. I think this is a good point actually. As well as eating vegan organic food, we also need to eat local seasonal food as much as possible. If possible, we went to the shop by public transport, but that’s not easy if you got have heavy shopping to carry. We could have an organic box of locally produced vegetables delivered once a week. We could try and shop on the way home from work so that we make a special journey. We could order food on the Internet and get it delivered. I mean one Lorry on the search for a delivery route is more efficient than lots of individual cars going out to buy small amounts of food, so yeah, Internet shopping from a supermarket could actually be better than that.

Ben Kenney: But ideally, I mean your definition of something local would be that you could actually walk there and buy your food instead of driving.

Nigel Winter: Absolutely, if that’s possible, that would be much better. Go to a local farmer’s market or farm shops if they’re close to you, but not everyone has that possibility.

Ben Kenney: One issue that we have a lot in Canada right now is we can get, for instance, tomatoes, we can get local tomatoes except all of the big grocery stores, they buy them from California instead of locally.

Stephen Pilditch: Yeah, but you got to be careful there because if you buy local Canadian ones, they might have used natural gas to heat them, you see, because we have that in UK, you know, tomatoes grown in UK, but when you look at the energy balance, it is actually better to import from Spain if they have been heated by natural gas.

Ben Kenney: Really?

Stephen Pilditch: Yeah. That's why it's very key to buy seasonal. Isn't that right, Nigel?

Nigel Winter: Yeah. I mean supermarkets have gotten better on improving their labeling and putting on the country of origin, but it is quite common that you’ll find carrots in the shops that are being grown in Britain, but there are also carrots alongside that have been imported from South Africa, so unless you look at the label carefully, you might not realize that.

Ben Kenney: But do we have a good understanding of how much energy or how much CO2 emissions from farming or from the food cycle come from the transportation of that food? I mean I suppose it depends on where the food is coming from.

Nigel Winter: It's probably not as extreme in this country because we’d be having the tomatoes coming from Spain rather than being grown in Britain greenhouses, so the distance wouldn’t be as great.

Ben Kenney: But you’re saying that it's better just to keep…

Nigel Winter: Yeah, I think that’s the better way to go, you know. If the tomatoes aren’t growing naturally in your area, now with the added energy, then it's better not to eat them at that time of year.

Ben Kenney: Yeah, that makes sense.

Stephen Pilditch: One of the issues is though some people from lower income background is quite hard to afford organic local food because it can sometimes be more expensive, so they end up buying sort of process food that’s cheaper.

Nigel Winter: Yeah. There’s an article in the Economist magazine which said that 1/5 of the energy used in the food chain is consumed on the farm and the rest goes on transport and processing. Now, it’s cheaper to prepare our own meals with fresh ingredients, but people on low incomes often buy a lot of process meals and this costs them more and it also uses more energy to produce and package and transport, but there’s a lot of quick and easy vegan meals, things like vegan chili, vegan shepherd’s pie, vegan curry, vegan risotto, vegan pasta dishes. These are all recipes that are very easy to adapt to fit whatever ingredient you've got available and what's seasonal. I think we need to be teaching cookery and basic nutrition in schools because a lot of people just don’t know how to cook a basic meal.

Stephen Pilditch: Yeah. That’s true in the UK anyway. I'm not sure about the…

Ben Kenney: Well, I'm one example of that.

Nigel Winter: Yes. When you get to a certain level of cooking, someone can just put a heap of ingredients in front of you and you know how to put them together to make a meal and that means you can use whatever is local and whatever is seasonal, but a lot of people will just go out and buy ready meal with loads of packaging because they don’t know how to do that.

Stephen Pilditch: I was reading the Economist again that fertilizer actually can use less land and so is, say, rain forest. Because organic food relies on crop rotation, so you end up using more land because you have to rotate the crops. So, what’s your argument against that?

Nigel Winter: Well, just to retackle a few points I've already said. Firstly, a vegan diet uses 1/5 of the land compared to producing an omnivorous diet, 33% of arable land is used to produce feed for livestock and livestock or any fish converting feed to meat. Now, there is report, which explains the energy usage in European wheat productions and it says that 52% of the energy is used in the production, delivery and application of nitrogen fertilizer, 8% is used in the production, delivery and application of phosphorus and potassium fertilizer, and the remaining 40% is used on other farm inputs and field work. Now, with both artificial fertilizers and animal manure, a lot of the nitrogen and phosphorus can leach into ground water and cause pollution of water supplies. Globally, 142 million tons of fertilizer is used each year and in UK in addition to that, 4.48 billion liters of pesticides are used, so there is all the energy needed to produce those. There’s not enough land in the world to feed everybody on an organic free range meat diet, but we need enough land to feed people on a vegan organic diet, so that’s the key difference.

Ben Kenney: I mean we could just stop building roads and start planting vegetables instead.

Nigel Winter: That’s one of the problems is they are building on a lot of farm lands, which means there’s less and less farm land to use.

Stephen Pilditch: We're also going to have a very big water shortage. I’ve got the New Scientist Magazine here, February 2006, and on the front page it’s got, “It takes 20,000 liters of water to grow one kilo of coffee, it takes 11,000 liters of water to make a quarter pounder, and 5 liters of water to make one kilo of cheese.” What do you think of this statistics, Nigel?

Nigel Winter: We need to be careful quoting these sorts of statistics. There is a lot of variation in the figures that are quoted. I mean that same article in New Scientist quotes in India, it takes one small dairy farmer it requires to pump up 2000 liters of water from underground for every liter of milk he produces. Now, when you think about food production, we need water to feed the crops, the crops are then fed to the livestock, and the livestock also need to drink water, and then water is needed during the killing and the processing of the animals. Now, much of the world's human population growth and agriculture expansion is taking place in water stress regions. The agriculture sector is the largest user of fresh water resources accounting to 70% of water use. So, increasing water scarcity is likely to compromise food production. To give you an specific example of variation in water usage, in Botswana, water used by livestock accounts to 23% of total water use in the country, whereas, in the USA, livestock use just less than 1% of total fresh water. South America, South Asia, and South Saharan, Africa, have the highest demand for water by a livestock. I’ve got another report on water usage and that states that, this is on America, and it states that 77 liters of water is required to produce a kilo of maize, 119 liters of water for a kilo of wheat, 217 liters of water for a kilo of barley, and 3700 liters of water for a kilo of beef. Now, these are average figures for beef production in the USA. Now, in some countries, crops are watered by rainfall, in others tending to be irrigated and water usage in an abattoir varies as well in different countries. Again, coming back to this report of Livestock’s Long Shadow, it states that processing of cattle use 6 to 15 liters of water per kilo of carcass. The poultry processing tends to be more water-intensive than red meat. So, depending where you get the figures from in terms of which country and what method of processing, you can come up with widely varied figures. So, you do need to be a bit careful about what you quote, but we need to bear in mind that more than a billion people lack minimal levels of safe water. It is a serious issue.

Stephen Pilditch: I know in the Middle East, they produce clean water by quite an energy intensive process. They need to pump the water in land and this is going to be quite common throughout the world. Have you got any comments on that then?

Nigel Winter: A lot of people kind of forget something that if you are in a house with water that comes out of a tap that it still needs to be pumped to your tap, so there's energy still used in getting water to ordinary homes. The New Scientist article you referred to also talked about India saying that 2/3 of India’s crops are irrigated with underground water and that needs to pumped up using electric pumps, which is putting a strain on the local energy supplies. It also said they calculated that more water is being pumped up from the boreholes than is actually being replaced by the rains and so there's going to be serious shortages in the future. Again, it takes over five times as much water to feed a meat eater compared with that to feed a vegan.

Stephen Pilditch: So, everything is related really and it all goes to energy as well, isn’t it? You need more water, you need more energy, it's so true.

Nigel Winter: Yes, exactly, but there was a good point in the New Scientist article made though. In India, when it rains hard, most of the water runs off the land, it doesn’t soak in. This can cause soil erosion that some of the farmers are capturing the rain and allowing it to soak slowly into the ground and this has helped keep water levels high in their wells. So, that's kind of a fairly simple thing that they can do.

Stephen Pilditch: I think one of the problems is that poor nations are trying to copy western nations and with world population increasing, this is going to be a problem. Can you talk about the developing world and the growth of their appetite for meat and eggs?

Nigel Winter: Yes. Certainly, that is true. I’ve seen this firsthand I’m living in Africa. Again, we said the population explosion is expected to grow from 6.6 billion to 9 billion by 2050. Many people in the developing countries won’t copy the lifestyle of British and American people and may seem meat-eating as a sign of wealth between 1981 and 2001 and we will join the meat consumption increase by 85% and egg consumption increase by 278%. So, in general at the moment in developing countries, they get about 13% of their calories from animal products and in industrialized countries, we get 28% of our calories from animal products. So, if we encourage developing countries to follow our example and increase livestock production, there’s going to be a huge increase in demand for animal feed and water.

Stephen Pilditch: Right, yeah. There are a lot of problems. Have we got any solutions to help out the developing nations, undeveloped nations?

Nigel Winter: I think there are a couple of farming techniques that can be used. There’s vegan organic farming which uses no animal inputs such as manure or bone meal or artificial fertilizers. Instead, it uses green manures and crop rotation. Commercially in the UK, this is called stock-free farming and there's an association that operates in the global scheme and there are commercial farms in the UK operating to this standard. You can read more about it on their website called There's also a research from America which has developed a farming method called Grow Biointensive. John Jeavons set out to find the smallest amount of land to produce food to feed one person. In a practical test, he showed one person could live off 4000 square feet. That’s about 1/10 of an acre. This is with a vegan diet and it provided all the nutrients with the exception of vitamin B 12, which is obtained from bacteria. He found it is essential to grow the right range of crops and decompost all the waste from the crops and fertility, the soil fertility and soil structure could be maintained and improved. Again, no animal manure or other animal products were used. These methods are now being reproduced in over a hundred countries and on their website, they state that the yields are high in conventional farming, but the energy use is far, far less and that's on The crops are planted much closer than normal, which helps to keep water in the soil and because of the soil structure and nutrients that they developed, there’s less of a problem with weeds and more nutrients get taken up by the plants and not washed into the groundwater, so their methods can actually restore degraded soil. I think these are very valuable techniques.

Stephen Pilditch: I suppose at the moment in the west, we’re having a lot of pressure on our health system, people getting heart disease and are obese and I suppose if they eat a vegan diet would be more healthy, so it would result in less strain on the health system.

Nigel Winter: Yeah. There has been some very good research published recently in the European Journal of Clinical Nutrition. They looked at seven different diets and looked at their overall environmental impact. So, the diets they studied were an omnivorous diet eating a bit of everything using conventional farming methods, omnivorous but organic, vegetarian with conventional farming, vegetarian but organic, vegan with conventional farming, vegan organic, and a typical Italian diet with conventional farming. They considered the effect on human health, the damage to the environment and damage to [unintelligible] such as how much fuel was used to produce the food. The result showed that organic was better than conventional farming, vegan is better than both the vegetarian and omnivorous diets, and the vegan organic is best of all. The report concluded that vegan diets could play an important role in preserving environmental resources and in reducing hunger and malnutrition in poor nations and it said that beef is the single food with greatest impact on the environment, but cheese, fish and milk are also high-impacting foods. The American Dietetic Association says that well-planned vegan diet is appropriate for all stages of the life cycle including during pregnancy, lactation, infancy, childhood, and adolescence. There's a book called "Feeding Your Vegan Infant with Confidence" by Sandra Hood and another book on general vegan nutrition is called "Plant Based Nutrition and Health" by Stephen Walsh. It's important to have an understanding of basic nutrition to have a healthy diet, but I think that’s true whatever you eat, so that’s why we all need to have a basic understanding of nutrition.

Ben Kenney: I’m just wondering actually, why did we start eating meat? I suppose it must have been easier at the time to raise cattle than it was to grow vegetables.

Nigel Winter: Yeah. I think that’s a puzzling question because I mean gorillas are virtually vegan, so, you know, if you look at the different apes why there are some vegetarian or vegan and others have started eating meat, I think that’s a question no one has really answered.

Stephen Pilditch: Well, maybe we could talk a bit about your experience in Africa. If we are going to feed, as we got a lot of starving people, are they actually trying to grow cattle or are they trying to grow vegetables? What are they doing when you were out there working?

Nigel Winter: Certainly, there are people from outside of Africa coming in trying to promote livestock farming.

Stephen Pilditch: Oh right, okay. So, aide organizations, are they actually promoting them to grow cattle or grow vegetables?

Nigel Winter: It's not just any organization. It's some private enterprises as well. Some are setting up businesses out there and encouraging beach production and setting up the abattoirs and then there are aide organizations that are encouraging things like these Christmas gifts of Send a Goat to Africa and Send a Cow to Africa and also setting up poultry rearing in parts of Africa. The local guys that I work with, they basically lived off maize and a few vegetables. Now, I would accept it's not a very good diet and not really well balanced, so it needs to be improved, but they don’t traditionally eat meat, really, because it's not available and it's too expensive for them, but I would say what they need to be doing is encouraging to grow more posies and soya grows very well there and it is a very good nutrient, a wide range of vegetables and also to plant trees with edible fruits and nuts.

Stephen Pilditch: But Africa, actually, I read something pretty horrific. The Ethiopia during their starvation period in the 1980s, were exporting linseed, cottonseed cake and grape seed to the UK and Europe. So, when they were having starvation, they’re actually exporting food.

Nigel Winter: That’s true. As I said earlier, a lot of countries that are suffering malnutrition are actually producing food for livestock in Europe and they could be using that land to grow food themselves, so this is all part of the problem.

Stephen Pilditch: Just a final point on sort of Asia and China and Japan, they are growing areas of meat-eating. They didn’t traditionally eat a lot of beef, but Japan certainly starts to eat a lot more. That’s going to be a problem I suppose?

Nigel Winter: Yeah. It's going to be a problem because there just hasn’t been land available for this sort of growth and the Food and Agriculture Organization states that arable land per person is shrinking. It's 0.38 hectares in 1970, 0.23 hectares in the year 2000, and expected to decline to 0.15 hectares by 2050. The World Resources Institute states that nearly 40% of the world's agricultural land is seriously degraded. There is less and less productive soil per person, so we can’t continue to intensify production on already degraded land. We got to change the farming methods that are going to replenish the soil.

Stephen Pilditch: So, basically, Nigel, just to finish off, what is the world’s choice? What choices do we have to make a sustainable world in terms of land and food?

Nigel Winter: Well, I think just carrying on as we are is not going to feed an increasing population. There's a choice between more intensive livestock farming, more chemicals, more genetically modified food on increasingly degraded land or changing to a vegan organic diet.

Stephen Pilditch: Okay. Ben, do you want to add any more comments?

Ben Kenney: No, that’s great. Do you have any comments on biofuels at all? I mean turning these crops into fuels so that we can put them in our cars and drive places? That’s certainly one of the big things that they’re thinking about doing in the US right now is basically growing corn which requires all this fossil fuel energy to grow and then convert that corn into ethanol fuel so that they can fill their trucks and drive places. I guess that’s how they plan on moving on shipping the Californian tomatoes to Canada.

Nigel Winter: Again, we come back to where is the land going to come from for this. Just last week, there was a report that the price of corn in America had gone up because there are demands of corn to produce ethanol and there is also a demand for corn to feed cattle and because of this conflicting demand, it increased the price of feed to the cattle, so they were questioning whether that's going to increase the price of meat. So, if we got an increasing population, we've got a decreasing amount of land available and if we don’t want to stop using land to produce biofuels and land to produce feed for cattle, where is all this land going to come from?

Stephen Pilditch: Yeah and we're going to have to do more deforestation.

Nigel Winter: Well, that's going to add to the climate change problem.

Stephen Pilditch: Yeah, that's terrible. I was actually out in Brazil and I saw firsthand some deforestation and the local people because they’re not that well educated, they tend to cut all the forest down even to the river and what happens is, is heavy rain and all of the soil gets washed out into the river and obviously that land becomes barren quite quickly and they have to go and deforestation more of the native forest and the soil obviously doesn’t last that long and that’s some of the problems.

Nigel Winter: Yeah. Degradation around the world is a problem generally. The International Food Policy Research Institute predicts that if land loss continues at the current rate, an additional 150 to 360 million hectares could go out production by 2020. So, we're losing land per person due to increasing population, soil degradation and building on farm land. So, all of these different things are having an effect.

Stephen Pilditch: So, this would probably be a high priority than the world transport system.

Nigel Winter: I think the problem is that people are reluctant to change their eating habits and also people working in the livestock sector fear losing their jobs, but people are still going to need to be employed to produce vegan food. Through our, we've been changing demands for different industries. Now, when the personal computer became popular, people lost their jobs making typewriters, but look at how many new jobs have been created in the computer industry. So, I think people need to think more imaginatively about the future.

Ben Kenney: Okay. Well, thank you so much, Nigel, for coming on the show. It’s great to have you.

Nigel Winter: That's a pleasure and thank you for an encouraging debate on this issue. I hope it's going to get people thinking about what food they eat and what effect it has on the wide world.