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What would happen if all Americans went vegan?

38 points| dtawfik1 | 8 years ago |sciencemag.org | reply

65 comments

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[+] bmcusick|8 years ago|reply
I'm not a vegan, or interested in becoming one, but this "study" is just stupid. Just look at some of the basic assumptions:

"researcher Mary Beth Hall began by estimating the impact of converting all land now used by the livestock industry to cropland for human food"

Why on earth would you do that? Livestock are much less efficient at using land than crops, in terms of how much land you need to produce a calorie. Furthermore, a HUGE percentage of our current crops are used to feed livestock. Without even Googleing it, the assumption should be that we would not use all pasture land for crop land. The total amount of land under crops might even go down under the vegan scenario, since eating the food directly would be more efficient.

Also:

"Burning the excess waste would add some 2 million tons of carbon to the atmosphere, they estimate."

First off, is burning the most likely way this would be disposed of? Why not compost.

Second, crops are carbon neutral. They take CO2 from the atmosphere when growing, so how can they add CO2 to the atmosphere when burnt?

"Fertilizer demands would also go up while the supply of animal manure dwindled."

Again, only true if the amount of crops increased. I'm doubtful.

The points about nutrition are better made though. Animal products are rich in some minerals and vitamins that are sparse in a vegan diet. Not entirely missing, but sparse. But then that's why I'm not a vegan.

[+] JetSetWilly|8 years ago|reply
Also, not all pasture land is suitable for growing crops. Certainly in my country there's lots of marginal land and hills that sheep are left to wander over that are in no way suitable for growing any crops on. In this way humans can extract calories and protein from land that would otherwise be useless.
[+] qume|8 years ago|reply
If that is really why youre not vegan I recommend the book 'How not to die' by Michael Gregor.

The health benefits of a whole food plant based diet are astonishing, and the whole missing vitamin mineral thing is trivially taken care of.

Becoming vegan will lead to immediate and long term health benefits. And from personal experience its much easier and more fun than you could dare to expect.

[+] icc97|8 years ago|reply
The study clearly takes an extreme view point. I agree with your criticisms, and mostly it seems fairly poor science.

I can see some benefit of looking for the extreme though, it's looking for a theoretical optimum.

I'd have thought they could do studies of land use in India for the most extreme possible switch.

[+] cannonedhamster|8 years ago|reply
Where to start with this study.

* Study authors are tied to dairy farming and, animal and poultry farming.

* America is never going to be a vegan, or even vegetarian nation. There are too many jobs tied up in fattening cattle and pigs to go that route.

* Americans manliness is tied up into how much they kill, it's not going to happen.

* There are some horrific oversights such as the fact that a large portion of our farming is already for animal feed. Something like 800 million people could be fed if we planted different crops instead of animal feed.

* There is literally no reason to go vegan instead of vegetarian for most people. Almost all the ethical reasons behind veganism can be routed around with minimal effort.

* As someone who eats a mostly vegan diet, the dietary concerns for the vast majority of people are nonsensical. Yes, of course there are exceptions to everything, but there are entire countries that are mostly vegan/vegetarian that don't have these issues. B vitamins and calcium? Has his person done zero research? Both are absurdly easy to obtain in vegan form in the local grocery store of most somewhat populated areas right now, if everyone was vegan these would be staple foods.

This is absolutely the worst kind of sensationalized junk science to once again discredit a lifestyle that affects no one negatively.

[+] bunderbunder|8 years ago|reply
I haven't read the paper ($10), but, based on the press release, they seem to be making some very strange assumptions about how things would work out:

...began by estimating the impact of converting all land now used by the livestock industry to cropland for human food. That would increase the amount of agricultural waste—corn stalks, potato waste, and other inedibles now fed to livestock—and eliminate the animals that now eat much of it. Burning the excess waste would add some 2 million tons of carbon to the atmosphere, they estimate. Fertilizer demands would also go up while the supply of animal manure dwindled. That would mean making more artificial fertilizer, adding another 23 million tons of carbon emissions per year.

Converting all the land used by livestock into cropland for human food? That seems highly unlikely, just based on my (admittedly grade school level) understanding of ecology. I'd expect moving humans lower on the food chain to reduce the overall amount of plant matter it takes to sustain them. So Id' expect you could probably let all the pasture land reforest, and then convert a portion of the land used for feed crops to human food, and let the rest reforest as well.

Burning all the by-products also seems drastic. I'm going to assume that an expert in agriculture would have a good reason to not even mention composting. But even without that, and even if other uses couldn't be found, you could at least turn them into a net carbon sink by burying them in a nice anaerobic landfill. And even without that, the apparent that feeding that stuff to cattle makes the carbon somehow disappear is bizarre. The vast majority of that carbon will still end up in the atmosphere, via the animal's lungs.

Their estimate of net fertilizer demands seems like it has just got to be based on some careful selection of the boundaries of the system they're considering. I grew up in corn and soybean country, so, while I'm not a farmer myself, I am well aware that it takes more than just manure to sufficiently fertilize the nation's feed crops. The enormous reduction in artificial fertilizer demand from reduced need for those feed crops has to be included in the formula if you want to get some accurate figures.

[+] merpnderp|8 years ago|reply
I'm gonna go out on a limb and bet the study grossly underestimates how much more fertilizer would be required to turn pasture into cropland, as pasture is normally far less suitable to cropland, and thus is used as pasture.

Not that there is a need to convert very much of that land to cropland - corn and wheat produce far more food per acre than livestock.

Most or all of that land would turn back into wilderness and we'd all die in car wrecks from the millions more deer crossing the roads.

[+] ni-hil|8 years ago|reply
The only thing that article tells me is that if I want to know anything about this I need to read the paper. I think it's an interesting subject and they could have made a good article but this is just lazy reporting.
[+] s0rce|8 years ago|reply
I think you described 90% of science reporting. If you want substance you have to read the (frequently paywalled and expensive) paper.
[+] Simulacra|8 years ago|reply
I think there's an evolutionary reason why we didn't remain vegetarian or vegan. I don't know the science, but I do know plenty of people live healthy lives on meat-eating diets, and do just fine. Questions like this really only lend themselves to hyperbole. There is really nothing a meat-eating person can say that a vegan will agree with, and likely vice-versa. It's a zero-sum argument.
[+] philipkglass|8 years ago|reply
Other summaries of this article have noted that reducing GHG emissions from American agriculture by 28% is equivalent to reducing total American emissions by 2.6%. (Though, as other HN commenters have noted, just converting all land area devoted to animal agriculture to direct production of human-edible foods is unrealistic; I'd expect somewhat larger benefits in a realistic scenario where a lot of that land goes idle. But all agriculture together accounts for only 9% of American emissions to begin with.)

I personally don't eat beef, and have ethical concerns about animal treatment in food production systems, but people whose only source of information is "Cowspiracy" badly overestimate how large a proportion of American GHG emissions stem from animal agriculture.

[+] chasedehan|8 years ago|reply
> Burning the excess waste would add some 2 million tons of carbon to the atmosphere

Hello? This is what composting is for - those materials could be turned back into the land, making for better producing land. This could make some of the pasture land that is no so great into better producing.

[+] ndh2|8 years ago|reply
This similar study by the same authors seems a bit more reasonable.

https://iapreview.ars.usda.gov/research/publications/publica...

> Despite greater total availability of energy, a feasible solution could not be identified, meaning that the yearly nutrient requirements of the U.S. population could not be met under the defined constraints. Deficiencies in vitamins (A, D, E, B12, and choline) and minerals (Ca) were the primary cause of this infeasibility. Although eliminating animals from the food production system may seem advantageous based on surface-level comparisons of system energetics, a more comprehensive analysis of the food production system highlights the unique and essential role of livestock products in the food production system. This suggests that substantial gains in environmental impact could be made by simply reducing daily intake, rather than affecting dramatic shifts in consumption pattern.

Two animal scientists had a silly hypothesis "is it a good idea to remove all farm animals", and proved the answer to be no.

Too bad they don't provide access to these studies. To me it looks like they just left it at that, and didn't investigate any further, e. g. the question of how many farm animals could be removed while still meeting all dietary requirements.

[+] komali2|8 years ago|reply
I wonder if meat cubes will count as vegan when those come about.

I hope so, cause I'd love to go vegan for all the environmental reasons, but god damn do I love meat, and cooking is my primary hobby so I'm not willing to give up all the history of recipes surrounding meat. For now, buying local is my solution.

[+] wccrawford|8 years ago|reply
If we had anything that approximated beef and chicken, I'd go "vegan" right away. I've tried the alternatives and I'm just not impressed yet. I'd even settle for "differently great", and not hold it to the exact taste and texture, but there's just nothing that does it for me like meat does.
[+] Overtonwindow|8 years ago|reply
How can one give up bacon? Should be a philosophical question.
[+] swendoog|8 years ago|reply
> "we don’t currently produce in sufficient quantities to make it a sustainable diet for the entire population"

I wonder what we are missing in our crops that, if grown, would bridge this gap?

[+] dogruck|8 years ago|reply
Personally, I don't find it persuasive or constructive to start a thought experiment with "what would happen if this thing that will never happen actually happens."

Instead, I think you just get divisive click bate. Vegans will click thinking, "damn right!" Non-vegans will likely ignore it, thinking, "okay loony."

I think a stronger argument would lead with a direct fact or point of alarm. For example, "every non-vegan is contributing <blah> to greenhouse gasses."

[+] logfromblammo|8 years ago|reply
How about we also consider some less extreme hypotheticals, such as what might happen if everyone substituted Tenebrio meat for their Bos meat consumption.

I think they taste fine, but the spouse gets super-squicked at just the thought of me eating them. Apparently, it's just fine if the turtle eats them. That's an unfair double-standard right there. We're both opportunistic omnivores, after all.

And the vegan police can't exactly stop me from throwing grain meal in a bucket and raising my own beetles, so the 100% vegan thing won't be happening anyway.

[+] 52-6F-62|8 years ago|reply
This. My first reaction was:

`Severe anemics might start having to carry blood packs? Schedule regular transfusions?`

It's kind of a silly question, regardless. If the whole of America went vegan at once, what would happen to the resulting last generations of overpopulation of meat and dairy cattle? Would their meat be harvested for other purposes or be allowed to rot once they died out?

There are so many variable points to even approach it hypothetically that it just gets ridiculous, and would contribute very little.

[+] ndh2|8 years ago|reply
Did you even read the "article"? You seem to be replying to the headline only.
[+] Overtonwindow|8 years ago|reply
We would likely suffer from mass malnutrition. If you want to see what a country looks like that has gone "all vegan" just look at North Korea. Protein, from animals, is critical for not just survival, but growth and sustainability of the population. Relying on plant-based and artificial sources of protein is a recipe for disaster.
[+] 54mf|8 years ago|reply
This is false and serious FUD. There are a handful of vitamins/minerals that aren't found in meat-free diets (B12 is the big one) but they're all easily covered by fortified foods and/or taking a daily multivitamin. "Protein from animals" is absolutely not critical, and protein is found in all sorts of meatless sources. Nuts, leafy greens, etc.
[+] teilo|8 years ago|reply
> Relying on plant-based and artificial sources of protein is a recipe for disaster.

Protein is not the problem. Never has been. There are plenty of ways to get complete protein on a vegan diet.

But yes, there are often nutritional problems. My daughter tried really really hard to go vegan. She tried for a year and a half, doing all the right things, taking all the right supplements. She had to give it up. She started experiencing syncope (similar to a seizure) when falling asleep. Her LDL levels were too low. Her levels of various hormones were out of whack. Other essential nutrients were also low (we did blood testing to learn all of this). She now eats eggs, fish, and dairy, and takes fish oil. All her issues went away.

Some people have the genetic makeup to do well on a vegan diet. Many people do not, and no amount of supplementation will fix this.

Google for the many stories of ex-vegans whose experiences mirrored my daughter's. It's a difficult thing. I understand that many vegans are vegans for moral reasons, and it's very difficult to face the consequences of one's own genetic makeup. My daughter was angry at first, but has since come to peace with it.

[+] dev_throw|8 years ago|reply
North Korea is impoverished, not vegan. If you eat adequate, balanced meals (not just doritos, oreos and beer), then you will not suffer from malnutrition. Please stop straw-manning the malnutrition argument.
[+] bjoli|8 years ago|reply
Which amino acid is lacking from a vegan diet? The only thing I know is is that eating legumes is good to balance the low lysine value of most grains.
[+] btbuildem|8 years ago|reply
What would happen? 90% of them would go back to non-vegan diat in a relatively short time [1]
[+] komali2|8 years ago|reply
Did you intend to link something? I see the [1] but no link
[+] mangix|8 years ago|reply
What will happen is infant mortality will rise to astronomic proportions and everyone will be a miserable pile of walking gas.

This so called study is meaningless.

[+] komali2|8 years ago|reply
I'm curious about your 2 assertions, because they are new oppositions to veganism I haven't heard before. Where did you learn that veganism causes rising infant mortality, and also that veganism causes an increase in gas?
[+] zodvik|8 years ago|reply
How will infant mortality rise as a result?