Animal, Vegetable, or E. O. Wilson

Guest Post by Willis Eschenbach

Buoyed by the equal parts of derision and support I received for writing in “I am So Tired Of Malthus” about how humans are better fed than at any time in history, I am foolishly but bravely venturing once again into the question of how we feed ourselves.

In a book excerpt in the February 2002 Scientific American entitled “The Bottleneck”, the noted ant entomologist Professor Edward O. Wilson put forward the familiar Malthusian argument that humans are about to run out of food. He said that we are currently getting wedged into a “bottleneck” of population versus resources. He warned of the dangers of “exponential growth” in population, and he averred that we will be squeezed mightily before the population levels off.

His solution? In part his solution was that everyone should become a vegivore.

Wilson: “If everyone agreed to become vegetarian, the present 1.4 billion hectares of arable land would support about 10 billion people.

Figure 1. Vegans are not aliens from the star Vega. They are humans who are strict vegivores, as the food chart above shows. They are known for their barbaric habit of boiling and eating the unborn fetuses of rice and wheat. And don’t get me started on what they do to the poor baby carrots, with their so-called … but I digress …



Is this correct? Would we have a net gain in carrying capacity if all the human carnetarians agreed to become vegivores?

Wilson gets his figure of 10 billion people by taking the total amount of the grain that is being fed to animals, and then figuring how many people that grain would feed. In 1999, about 655 billion tons of grain were fed to animals. That’s a lot of grain. At the world average of about 150 kg of grain per person per year, he’s right, that’s an increase of 4 billion more people who would have enough grain. There were 6 billion on the planet in the year 2000, so that makes a total of about 10 billion people.

So up to there, he is correct. But wait. Although he stops the calculation at that point, there’s a few things he is leaving out of the calculation.

First, that’s just grain, which is not enough to keep a person alive. The extra 4 billion people would need additional nuts, seafood, fruits, vegetables, cotton, root crops, and all the other varieties of food and fiber. So the increase would have to be less than 4 billion people.

Second, people have a number of misunderstandings about where animals fit in on the farm. They believe that animals eat lots and lots of food that could be eaten by humans. Their claim is that if we just ate what the animals eat, we could eliminate the inefficiency, and feed many more people than we are feeding now. In other words, their claim is that having animals on the farms reduces the amount of food coming from the farm.

This is what Wilson is repeating here (although he has gone further than others by claiming that this would increase the carrying capacity of the earth by 2/3 again as much as the current population).

I grew up on a ranch where we had both animals (cattle, pigs, chickens) and field crops (hay, alfalfa). I can assure you that anyone who thinks animals reduce available food on the farm is what in my youth we would call a “city slicker”. Farmers around the planet keep animals for meat and milk. What, are farmers all stupid around the planet and only E. O. Wilson and his fellow vegetactivists are smart? Farmers would not keep animals if it were not a net gain.

While in some industrialized countries the cattle get up to 15% of their lifetime nutrition from grain, the vast majority of animals on farms worldwide live on a variety of things that will not or cannot be eaten by humans. Pigs eat garbage, hens eat bugs and grass and kitchen scraps, goats eat leaves, and cows have four stomachs, so they can turn cellulose, which humans cannot eat, into nutritious milk and meat.

If we got rid of all of our chickens worldwide, would we have more food available for humans? Not unless you like bugs and kitchen scraps better than you like eggs. Chickens are the poor woman’s Rumplestiltskin, spinning insects and weeds and melon rinds into golden eggs and tasty meat … I’ll let E. O. Wilson tell her she’s ruining the planet, not me.

If we call the goats down off the steep hillsides where they are grazing around the world, will we be able to put vegetable farms up there? Not unless you can farm sideways without water.

Cattle in the US eat thousands and thousands of tons of cottonseed meal annually, turning it into meat and milk. Would you prefer to eat the cottonseed meal yourself? Sorry, you can’t, it’s mostly cellulose.

The presence of livestock in a mixed farming economy does not decrease the amount of food that a farm can produce. That is a city slicker’s professorial fantasy. Animals increase the amount of food the farm can produce, otherwise farmers wouldn’t have them. Millions of tons of agricultural and processing leftovers, which would otherwise be wasted, are fed to animals. The animals in turn produce milk and eggs and meat, and then go on to enrich the soil through their urine and manure, just like they were perfected to do on the plains of Africa so long ago … what an amazing planet.

Which is why farmers everywhere around the world keep animals — farmers are not dumb, and they haven’t had the benefit of a college education, so they haven’t forgotten that goats eat leaves, pigs eat garbage, cows eat cellulose, and chickens eat bugs. They know the value of chicken manure and pig manure.

With that introduction, let’s see how we might best estimate the change if everyone became vegetarian. We can do it by looking at the land involved. Here’s the numbers: according to the FAO, out of all the land cultivated by humans, about a quarter of the land is used to grow food for animal consumption. This can be further broken down by the type of animal feed grown:

Figure 2. Area of arable land used for human crops, and for animal crops. Image is Van Gogh, “Ploughed Fields”.

Now if we all became vegivores tomorrow, and we converted all that quarter of the cultivated land to growing food and fiber for human use, what is the possible increase in the number of humans?

Looking at the chart, you would think that humans could increase by about a third of the current number. The land used for animals is about a third of the land used for humans. That would be about two billion more people, not the increase of four billion claimed by Wilson. However, the number cannot even be that large, because we have only looked at one side of the equation. We also have to consider the losses involved. By becoming vegivores, we have freed up the 23% of our cropland used to produce animal food, but we have lost the food coming from the animals. Now how much do we have to give back just to maintain the status quo, to make up for our dietary and other losses? These losses include:

•  We would have to replace the loss of the dietary protein provided by the 200 million tons of meat we eat each year, along with 275 million tons of milk, 7 million tons of butter and 47 million tons of eggs. Vegetarians say, “You don’t need animals, you can get enough protein from a vegetarian diet”, which is certainly true.

However, to do it, you need to eat more grains to get this protein, and in a twist of fate, to replace the total amount of meat protein in our diet with protein from grains would require about 50% more grain than we are currently feeding to animals. This is because animals eat many things other than grain, and we need to replace all that lost other-source protein with grain-source protein as well.

So immediately we have to devote about 18% of the total land to replacing lost protein for the existing world population. Subtracting this 18% from our original 23% of freed up land leaves us with only a 5% possible gain. Remember, this is all just to keep the world even, to maintain the world food status quo. We’re not talking at this point of feeding anyone extra. We’re just maintaining the current nutritional supplies of protein for the current population.

• We would also need to replace the amount of fat provided by the aforementioned animal products. While too much fat is a bad thing, dietary fat is an essential necessity of human nutrition.

The weight of dietary fat provided by animals is about a third of the weight of protein provided by animals. In addition, it takes much less land to produce vegetable replacements for the animal fat than for the animal protein. This is because there are vegetable products (oils) which are pure fat, while vegetable products are generally low in protein.

In the event, in order grow the oils to replace animal fat in our diet, we’d have to plant about 3% more  of our arable land to sunflowers or the equivalent. Deducting that from our 5% gain in available land, we are down to a 2% gain.

• Next, the land worldwide would be less productive because in many areas, animal manure and urine is the only fertilizer. We could easily lose more than a couple of percent that way, especially in developing nations. And once we do so, we are at zero gain, meaning we couldn’t add one single person to the world by voluntarily becoming vegivores. But there are several further losses yet.

• There is also a giant hidden loss of food in the change to vegevorianism, as tens of millions of tons of agricultural waste would have to be disposed of, instead of being converted by animals into millions of tons of human food. In many cases (e.g. oilseed residue meal) these wastes are not directly consumable by humans.

• In addition to losing the food animals make from waste, without animals to eat the waste we add the resulting problem of disposal of the agricultural waste, which is expensive in terms of time, energy, and money.

• We’d have to do without leather, hide, hair, horn, wool, and feathers. Especially in the developing world, these products are often extremely important to the health, warmth, clothing, and well-being of the local people, and there often are no local substitutes. This would be a huge cost of foregoing animals. In places where jackets are made of local sheepskins to keep out the frozen wind, explaining to some poor shepherd why he should go vegivore and trade his sheep for soybeans could be a tough sell …

• Finally, about half the land currently used for growing animal food is being used to grow grasses for animals. In practice, this land will mainly be the poorest and steepest of each country’s croplands (or else it would be planted to a field crop), and thus is not likely to be suitable for growing much more than grasses.

All up?

You’d lose by not having animals in the world’s farmyards. I don’t think you’d even come near breaking even — and neither do the farmers all around the world. They know what the numbers have just shown — we can support more people in a planet, a region, a country, or a farm if animals are part of our agricultural and dietary mix.

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Henry chance

I ate great roast beef for dinner. The beef was raised vegetarian. Corn, silage and grass.


No one on any USDA approved, large chicken farm (read egg) serves there chickens scraps.
Additionally, salmon are fed on herring, and dont covert it well, thus eat herring, not salmon.
I agree it is more complex than Wilson states, but it also more complex then you state…


So we have another great philosophical scientist, Professor Edward O. Wilson, trying to impress his peers with what a great thinker he is.

Tom Gray

From the post
Vegetarians say, “You don’t need animals, you can get enough protein from a vegetarian diet”, which is certainly true.
However, to do it, you need to eat more grains to get this protein, and in a twist of fate, to replace the total amount of meat protein in our diet with protein from grains would require about 50% more grain than we are currently feeding to animals
People wouldn’t replace meat protoein with more grain. This is a common problem faced by the many people who cannot eat any or much animal protein due to a health condition.
The best source of protein would be any from of yeast extract. people from the UK are familiar with Marmite which is a spread produced from yeast. it is a far higher source of protein than any animal product. Teriyaki sauce is another familiar product that is based on yeast. If one wanted vegetables that contained protein then one could eat cruciform vegetables such as broccoli, cauliflower etc

Sam Hall

There isn’t anywhere near enough water to convert the millions of acres of ranches in West Texas to cropland.


I really like Vegetarians, because that means there are lots more pork chops for me!!


Brad, herring is OK but salmon is better.


Eating lots of bread, rice and pasta (carbohydrates) makes people fat and is the source of numerous health problems. A lot of the nutrition “truths” (cholesterol, fat, calories, salt…) with which we are bombarded daily by the media rest on nothing or are false.
I recommend the following book to those who want to understand the scientific story of the nutrition vs. health debate.
Gary Taubes: “Good Calories, Bad Calories”
There are a lot of similarities as to the ways inconvenient truths have been established, for both climate and nutrition.


Just think how much cheaper fruit and vegetables would be if we didn’t have to feed all the vegans! That’s enough to feed several million more beef cattle! 8-P

John Campbell

E. O. Wilson – wow – I thought the guy was brighter than that – I have been misinformed. I am not engaging in Ad Hominem argument, and I do not want to hijack this website or post, but I am convinced that the evolutionary past for humans leads to us being omnivores with a strong bias to meat.
Google paleolithic diet if you are interested, but veganism is not what our bodies are designed for in my opinion. I believe that the evidence for the health and utility of veganism is less strong that that in support of AGW. Hey, whatever floats your boat – pass the bacon.
Feeding the world is a real challenge and doing it while promoting health and vigor is more daunting. As the post indicates, animals do a pretty wonderful job of converting food of low or non-nutrition (for us) into tasty and nutritious food for us humans. Early humans weren’t feeding their ravenous brains with huge amounts of primitive grains and veggies – they were using those metabolically expensive brains to hunt and kill animals to eat the high value meat and organs. Poor nutrition was not an option for our ancestors – we can only get away with it now, but the results are obvious even so – obesity and premature aging, decline and the diseases of civilization.
Very good post – E.O. Wilson should stick to insects.


In general, do croplands yielding foods directly for human consumption require more or less energy to cultivate than croplands for animal consumption? Considering grain fields for humans vs. rangeland for cattle, it would seem that it would take more energy and thus more natural resources and humans would have to be devoted to provide that energy.


Ruminant animals are superbly equipped to convert cellulose to protein. This also in poorly arable dry land capable of supporting only grasses which ruminants thrive on. In developing countries, cattle sheep and goat raising is compromised by parasites—if these are controlled, the sky is the limit to what the grasslands can provide for the human population (especially if we could somehow get the CO2 level up to 1000). As has been stated before, less than 0.1% of the earth’s land masses are occupied by humans. I would not quibble with earlier authors that the earth could support greater than 100 billion humans. In the sea, fish convert algae to protein. It would be better if we began to limit and control the top predators, like sharks, whales, and seals so that the herring to tuna and salmon species columns could expand. If not for the fact that dolphins seem to have a perpetual smile on their faces, we wouldn’t have anthropomorphosed them into the inedible food category.
Save a cute little baby Nemo today! Eat a shark steak!
Eat more beefsteak and less soy—reduce the toxic phytoestrogen intake that is wimpifying the human race!
Balance is everything.

Nice logical, step by step rebuttal. I particularly agree with the point that there is a perception that “poor farmers” are uneducated. This could not be furthest from the truth.


Oh, and these are some of the same vegan eco-clowns who have maneuvered the addle-pated politicians into converting corn to ethanol, starving millions.

chris y

Thank you for a very clearly written post, Willis.
After suffering through his 1998 book Consilience; and reading his views on the hypothesized anthropogenic species extinction ongoing now- “As long ago as 1993, Harvard biologist E.O. Wilson estimated that Earth is currently losing something on the order of 30,000 species per year.”; and now this Malthusian garbage disguised as vegetarian carrying capacity of the planet, I have concluded that E. O. Wilson is either incompetent or a self-loathing human-hater. Or both.


If there are no farm animals to feed, there are also no farm animals, such as oxen or water buffalo, to use as farm implements to raise grain. Would he have all the South Asian rice farmers use tractors instead.
Where do the wild animals fit into the equation? How much of the land would be given to them instead of being used to grow the vegan diet?
Like any equation, it’s usually not just a simple substitution of one variable for another.


Even in the harsh conditions of the Viking’s more northern settlement in Greenland up to 100,000 sheep and goats required roughly 400,000,000 kg of hay a year. Gathering that hay was a lot of hard work during a short summer, but in return the sheep and goats provided milk, meat, leather, wool, tallow and lastly dung, which was good for both fertilizer and fuel.
I doubt vegetarian Vikings could have survived the harsh winters.
The people who want to return us to “the good old days” would do well to reserch what life was like back then. (Also they ought reserch problems inherant in cultures where human manure must be used.)

Nice job of explaining things. Sure it is way more complex but what isn’t. The human animal has evolved as an omnivore. It is largely a result of our omnivores nature that humans have been able to adapt to almost every environment nature has provided. Some would say our species is probably the most successful to have ever existed. The appropriate adjective aside, the obvious success of humans can only be a result of being, if not the most, one of the most adaptive species. No pure herbivore or carnivore could possibly as adaptive as an omnivore.

Steve Schapel

Thank you, Willis, I enjoyed reading this account, and I agree with your general tenets.
However, there are a couple of points I think you could expand upon.
First, where I live (New Zealand), the land used to grow grasses for animals is definitely not the poorest and steepest. And I suspect this will be the case in a lot of other places as well.
Second, there is no taking account of the arable land that is used to grow food for animals, where those animals are not themselves for providing food. Racehorses, pets, beasts of burden, and animals kept for other purposes.

John F. Hultquist

“— farmers are not dumb, and they haven’t had the benefit of a college education,”
I’m unable to recall a measure of farmer-dumbness but think it might exhibit a somewhat normal distribution if one exists or is developed. Many of the folks farming with degrees from the “land grant” colleges in the USA and similar institutions world-wide might want to argue the second part of the above premise.
Moral: Colorful writing is not necessarily good writing.

Steve Schapel

By the way, Willis, I also enjoyed your characteristic fiddle with the words carnetarians and vegivores. Cute.

The solution to overpopulation is simple. Charlton Heston figured it out 40 years ago.
Soylent Green!


Wonderful funny story at saturday night. Nicely writen,beside the facts. I’ve had something to laugh.
I mean, eating just grass and nuts, I may have similar stupid ideas as Prof. Wilson has.
The annoying part is, these people are convinced they have to make anybody else as “happy” (=crazy) as they are. No, thanks.

R. de Haan

Great article.
Oil is bad, CO2 is bad, meat is bad…. humans are bad.
In the mean time india is wasting millions of tons of grain.
Instead of distributing this grain among the poorest of the poor they rather let them starve.
An incredible country where the holy cow has more value than a human being and coal is king.


A lot of cattle, sheep and goats are grown on land that is too arid for agriculture. A lot of tilapia are grown in rice paddies. Ducks provide eggs, down, and meat and help control mosquito larva and snails. Chickens provide eggs and help control insects. My chickens eat grain out of horse crap that would otherwise feed rats. Pigs can be used for landclearing, pasture renovation, compost turning, and eating farm and kitchen scraps that would otherwise go to waste.
A lot of folks think that cattle, sheep and goats eat the same things. They don’t, unless they’re starving. Cattle prefer grass, sheep prefer forbs, and goats prefer browse. Pastures shouldn’t be monograzed for optimum production. Grazing different species breaks parasite life cycles as well as making better use of the forage.
I grow sheep, chickens and ducks on swampy clay soil absolutely unsuited for veggie and/or grain production.

Larry Fields

The biggest bottleneck in a pure vegan diet is Vitamin B-12, rather than protein. If we American omnivores didn’t take supplements of any kind, we’d get essentially all of our B-12 from meat and dairy products. Unlike most other water-soluble vitamins, B-12 can be stored in the human body to some extent. If you go 100% vegan–and 100% natural–it’ll take several years for the pernicious anemia to kill you. Not a fun way to go.
That’s why many vegans, who aren’t eager to collect their Darwin Awards prematurely, take B-12 supplements. Or they eat commercial breakfast cereals that have been fortified with B-12.
What about seaweed and fermented soy? My understanding is that these items sometimes test positive for B-12. So what? Sometimes people test positive for illegal drugs that they’ve never taken. The point is that many tests commonly used in analytical chemistry have limitations: interferences, false positives, and false negatives. I’d be more confident in a B-12 positive claim on a plant-source food if it stemmed from two or more independent tests. Until that day, I’d advise caveat emptor on any vegan B-12 claims.
That said, our evolutionary cousins, gorillas–who unlike chimps, are strictly vegetarian in their native habitat–have gotten around the B-12 conundrum in an interesting way: coprophagia. Why? Some bacteria in the large intestine manufacture B-12 from plant-based food. Unfortunately, by then, it’s too late for mammals to absorb this vitamin from the GI tract. Thus for gorillas, some creative recycling is in order.
I’d advise naturalistically-oriented vegetarians, who believe that eating meat and dairy products is equivalent to murder, to give serious consideration to coprophagia. If this posting saves even one innocent human life, it will have been worth the effort.


Kevin says:
September 11, 2010 at 7:55 pm
Yes, but Vegan Soylent Green has little flavor and is full of estrogens and mercury from the curly light bulbs.

I have written a new post on The Bottleneck Problem (E.O. Wilson, Biodiversity and the Species-Area Formula), trying to summarize the history of the lack of use of the scienticific method by ecologists.
Have a look and tell me what you think.


Willis – Great food for thought! For mine its o.k. whichever way you feel comfortable in feeding. As long as its your free choice, or you adapt your lifestyle to suit your choice of the available food supply. However, I reserve the right to refuse compulsory conversion on the whim of either side!!

Willis Eschenbach

John F. Hultquist says:
September 11, 2010 at 7:54 pm

“— farmers are not dumb, and they haven’t had the benefit of a college education,”
I’m unable to recall a measure of farmer-dumbness but think it might exhibit a somewhat normal distribution if one exists or is developed. Many of the folks farming with degrees from the “land grant” colleges in the USA and similar institutions world-wide might want to argue the second part of the above premise.
Moral: Colorful writing is not necessarily good writing.

John, I am writing in response to people around the world who want to claim that if we became vegetarians we could feed more people. In other words, vegetactivists who want to tell farmers that what they are doing is wrong, and how they could feed more people if they just wised up and got rid of the animals …
This, of course, assumes that farmers are too stupid to figure it out for themselves. That’s the idea that I’m objecting to, that a third world farmer who is squeezing every last calorie out of her meagre fields, including meat and milk and eggs and anything else, is somehow too stupid or blind to make the choice that will yield the most food for her kids.


One of those agricultural wastes that animals eat is distiller’s dried grains, the stuff that’s left after fermenting alcohol. I for one am willing to make the sacrifice of eating a steak so that the beer and distilled spirits can keep flowing.

Willis Eschenbach

Steve Schapel says:
September 11, 2010 at 7:55 pm

By the way, Willis, I also enjoyed your characteristic fiddle with the words carnetarians and vegivores. Cute.

Thanks, Steve. It is sometimes a valuable tactic because, as in this case, it dodges the emotional baggage that the original words contain.

In the USA Midwest, the best bottom ground is reserved for crops destined for human consumption as they draw the best prices, the more marginal land grows the livestock feed stuffs, and what cannot be cultivated is left in pasture / hay crops to get some income out of it.
One of the local questions that the farmers all ask is how to get the most income out of things people cannot eat, which has resulted in the pasture / hay answer with multiple animal types, sheep, goats, and cattle and rental for horse grazing areas has dropped off due to the lack of lawful slaughter houses to dispose of the excess stock.
Thank PETA for that, now the residual price for horses is dropping, as the base price of their meat value, has been dropped out of the calculation. Lots of the time you can see ads for free horses, “come pick them up, free to a good home”. As the cost to dry lot feed one, in an urban environment, with out access to open pasture is more than the horse is worth, young and untrained to be ridden.


The execrable Lord Nicholas Stern also believes we all must become vegans.

Christopher Hanley

At least vegans follow their own advice, which is more than you can say for the majority of CAGW hysterics.

David T. Bronzich

John Campbell says:
September 11, 2010 at 7:13 pm
Google paleolithic diet if you are interested, but veganism is not what our bodies are designed for in my opinion. I believe that the evidence for the health and utility of veganism is less strong that that in support of AGW. Hey, whatever floats your boat – pass the bacon.
Very true; and in some modern countries as well. My grandfather was raised with a diet of olives, grapes, goat, chicken, beef, game bird, squid, fish and shell fish. I’m sure that Vegans would tell you that’s a very unhealthy diet, but how many of them will die at 110?

Rhoda R

Larry Fields, you have a vicious mind. I like.

Rattus Norvegicus

Tropic levels? This is the point which you are missing…

Dave F

And, may I point out, that these species would likely be pushed to the verge of extinction if they we ate their food or started using the land they live on to grow food.
Food for thought…

Mike McMillan

I had a couple of vegetarian friends a while back. They had orange skin.

Chris Edwards

Surely with crop rotation you have to leave a section of land allow to let it recover and that, in England, is what grows the grass for the animals to eat, humans are not herbavores (allthough the small brain function assosiated with hebavores is there in vegiterians) so there is a loss for a start, I thought the grain bit is factory farming and not essential.
So far every vegiterian I have met has been a control freak who wants to controll the rest of us, says it all.

Andrew W

I grow beef, even though most of the property is flat enough for arable farming.
I grow beef because I get paid far more for a kg of beef than I would for a kg of grain.
If the property was converted to arable, I’ve no doubt it could feed more people.
I grow about 1000kg/ha (hook wt) of beef a year (grass fed) I understand crops typically grow 4000+kg/ha/of grain a year, but grain is 90% dry matter, beef I think about 15% dry matter, so in terms of feed value, growing grain instead of grass could feed about 20 times as many people per hectare, and that’s being conservative because only about half the carcass weight (hook weight) actually gets to the supermarket shelves.
But I’d still prefer meat in my diet.


Another important point that vegetarians frequently miss is that cattle grazing to take one major example is primarily on range land that is nearly useless for any other purpose. In Central California the piedmont and foothill region along the eastern side of the Great Valley frequently has less than 2 inches of soil over country rock. It can’t be farmed. It is however very good grazing land for cattle and sheep, which is what it supported historically. The bottom lands along the major streams were farmed and some still are, but not far off the stream valleys the hills are dry and waterless all summer.


Also, you want to remember: Caine was a vegetarian. Abel was the herdsman.


D. Patterson

A diet of high calorie meat consumption was necessary for Homo sapiens sapiens to evolve and sustain the present brain mass and corresponding human intelligence and speech. Arbitrarily returning to low calorie non-meat diet comparable to the other primates past and present is a step backwards towards de-evolution and the loss of human intelligence. But you already knew that instinctively…right?


John Campbell says: “…I am convinced that the evolutionary past for humans leads to us being omnivores with a strong bias to meat.”
You cheated, John. You looked at E. O. Wilson’s teeth and found nippers, tearers, and grinders–the hallmarks of an omnivore.


Animals also provide a buffer against crop failure – full or partial. In the case of partial failure, the withered plants can be stored to feed livestock. For instance, corn stalks are baled in drought years.
Livestock are also portable and can be moved to areas with more forage or sold to get food or other things people need.
Both of these create more options for farmers.
One thing that I’ve thought about a lot is that many ecologists do not study humans and their decisions from an ecological perspective. On the one hand, foraging patterns of birds have been reduced to mathematics that predict carrying capacity quite well, and detailed painstaking studies back this up, but on the other hand, the same detailed study of people is not done.
Many claim that civilization is not sustainable when we now know that agriculture has been around for 10,000 years and human society has survived quite a bit. Seems to me that history shows that it is quite sustainable.


Oh, yeah, and BTW, the line at the bottom of the “Vegan Food Pyramid” [source language=”?”][/source] that says “Water 8 to 10 glasses a day…” is more Vegan/New Age/Urban Lore misinformation. Dr. Heinz Valtin, a nephrologist, conducted an exhaustive literature search aimed at finding the original research paper(s) that established this 8 to 10 glass minimum. Result? No such research was found. See the article at:


I am not getting the purpose of this post. You almost acknowledged the existence of such thing as carrying capacity (or at least you mentioned it twice without rejecting the notion) which is a big step forward from the previous post. Yet you proceeded to write a lot of words that really have very little to do with the question of what the long-term carrying capacity of the planet is and whether we’re way past it or not, you were simpply talking about the relative contribution towards increasing carrying capacity that a strictly vegetarian diet vs eating meat could make.
By doing so you entirely missed a very important point that was discussed at length in the previous thread – it doesn’t matter at all how many people we can support now, if the means of supporting them now cannot be sustained in the long-term, which is exactly the case. There is absolutely no way we can produce the amount of grain we’re producing now without oil and fertilizers (what we’re really doing is using soil to convert oil, natural gas and phosphate rocks into food), and the soil will be destroyed in the medium to medium-long term anyway (it already is to a large extent in many of the main agricultural regions of the world). So the whole discussion is moot after you consider that simple fact.
Even then, you simply throw away all of ecology out of the window by focusing on how domestic animals can convert biomass that’s otherwise not accessible to humans into human food. You forget that the goal isn’t to take out as much primary productivity as possible out of the ecosystem for human use in the short term, the goal is to take out only as much as possible without harming the ecosystem. Everything else is overshoot that will catch up with us in a very bad way later. The goats eating plant mass on mountain slopes you mentioned are a perfect example. The goat is probably the single most ecologically destructive domestic animal – the vegetation on those mountain slopes will not last very long if you let goats feed on it, then erosion comes in, whatever marginal soil was there is gone and you end up with no vegetation and no goats.
Unless you do agriculture that uses no non-renewable resources, that closes the nutrient cycle and doesn’t destroy the surrounding ecosystem (it has to be integrated in it in fact), you are guaranteed to overshoot and collapse. Which is exactly what we’re doing. The problem is that such an ecosystem only allows for a much smaller fraction of the primary productivity to be diverted towards humans that currently is (by some estimates, nearly half of the total primary productivity of the planet is in some way diverted to human use, whether it is directly through crops, through domestic animals or through fishing), which is absolutely unsustainable.
You have made a tiny progress since last time, but you still have a very long way to go.