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> There is not one shed of science that can suggest with any amount of confidence that eliminating livestock will make a difference with global warming meaningful enough to justify not being able to eat the food that we developed to subsist on.

As long as that gas continues to go into the atmosphere, it's going to keep causing problems for climate change. It accounts for 14.5% of the world's greenhouse gas emissions[1] and a phase out presents a massive opportunity to sequester carbon.

> We show that, even in the absence of any other emission reductions, persistent drops in atmospheric methane and nitrous oxide levels, and slower carbon dioxide accumulation, following a phaseout of livestock production would, through the end of the century, have the same cumulative effect on the warming potential of the atmosphere as a 25 gigaton per year reduction in anthropogenic CO2 emissions, providing half of the net emission reductions necessary to limit warming to 2°C. The magnitude and rapidity of these potential effects should place the reduction or elimination of animal agriculture at the forefront of strategies for averting disastrous climate change.

https://journals.plos.org/climate/article?id=10.1371/journal...

[1] https://www.theguardian.com/environment/2021/sep/07/20-meat-...

Again cows don't emit completely new gas into the atmosphere; all gas they emit originally came from the atmosphere. So their emissions are not in anyway a problem, as it's really just recycled atmosphere.

You'd might argue that they change the composition (eg changing it to methane gas), but methane also breaks down in the stratosphere. Sure it takes like 100+ years to happen, but it's temporary. You can set a population of cows, and keep it steady, and the amount of methane and other greenhouse gases in the atmosphere attributed to the cows won't change after some period of time. Now, growing the population of cows will grow this temporary store of gas, but cows bodies also are carbon sinks themselves which offsets it somewhat. And likewise, as you cite, reducing the population of cows and livestock would decrease their temporary contribution of gas. But this temporary store of methane isn't the root of our problems.

The real problem, is taking carbon from underground, and burning it. For nature to naturally reverse this process, takes millions of years. The only real solution is to stop burning fossil fuels, and/or to reverse the natural process faster somehow (like by repeatedly burying trees and growing new ones).

As long as the methane stays in the atmosphere it does warming. Taking 100+ year to reach equilibrium concentrations still means having massive amounts of methane in the atmosphere doing warming, just at an equilibrium.

Because it breaks faster than CO2 is why we should really reduce the emissions today because it presents us a great opportunity to save more warming effect in the future

> Nevertheless, while methane may have a short atmospheric lifetime, its effects are not ephemeral provided the source of the methane continues to exist. For as long as livestock continue to be farmed, methane continues to exert a warming effect upon the climate.

> As such the argument that since methane’s impacts are temporary, they do not matter, is wrong. Its effects will in practice be permanent, unless ruminant production is halted.

> Methane emissions also increase the risk of us ‘overshooting’ the 1.5°C/2°C target, potentially tipping us into unknown climatic territory, with possibly devastating effects on agriculture, wildlife’s ability to adapt, heat stress in humans and animals, and more

https://www.oxfordmartin.ox.ac.uk/downloads/reports/fcrn_gnc...

We are omnivores, we can subsist on many things, meat being one of them. If you enjoy meat that's one thing, but the "we evolved to eat meat, now give me my steak" mindset is a strange one.

If you put eat in front of a cow, they'll eat it if they're even modestly hungry. Does that mean that they evolved to eat meat? Of course not.

Mad cow disease wouldn't be a thing if this wasn't true.

https://en.wikipedia.org/wiki/Bovine_spongiform_encephalopat...

https://farmhouseguide.com/do-cows-eat-meat/

> If you enjoy meat that's one thing, but the "we evolved to eat meat, now give me my steak" mindset is a strange one.

It's only strange to for those who are unaware of the evidence.

On the other side of the coin from cows, just because we can eat plants, pass undigested cellulose in our stool, and survive does not mean that we either developed to eat plants, need plants, or operate optimally on plants.

The fact that our ancestors ate mostly meat is not controversial and is even backed up by stable isotope testing. The fact that we lack aspects of an herbivorous digestive system is not controversial. Go look for what's called a cecum. By name, we humans have a "cecum" but in name only since that word means "dead end". Our cecum looks nothing like that of any animal that is herbivorous or obligatively omnivorous. That's just one example. At a higher level, we suck at digesting cellulose, and most available plants before agriculture were very fibrous and lacked the flesh of fruits and vegetables you find at a grocery store.

Moreover, meat contains everything we need to survive and function properly to the exclusion of any plant material at all. If you're wondering about things like Vitamin C, well, I don't really want to spend all day going into such specifics, but long story short there's no need for an abundance of Vitamin C on a diet primarily composed of meat and lacking carbohydrates.

So no, it's not just about making excuses to eat tasty meat. You might find that eating meat and not confounding such a diet with carbohydrates and plant material has real benefits.

EDIT: To further address your point about our supposed omnivorism, we are only as omnivorous as we have to scavenge. As I already mentioned, the kinds of edible plants available to most humans before agriculture were not very digestible or energy dense at all, meaning that to eat plants required a significant energy investment given that we didn't always cook our vegetables. Not only was eating plants not nearly as energy efficient as allowing larger animals to digest those plants first, but most plants in nature arguably aren't that tasty.

I'm a forager and have been doing so for well over a decade (long before it was cool), and I have to be honest in that most wild plants don't compare to meat in terms of taste and satiety. The plants that are tasty are usually only around for a short period of the year.

There are a few points to unpack here.

1. Cows are herbivores. They will eat meat in certain situations if you put it in front of them, but it's not good for them. We are not herbivores, we are specifically omnivores.

2. Our ancestors were hunter gatherers, and their diet was by no means mostly meat. In fact, it was only meat when available, which was every few days to weeks.

3. There is evidence that humans are omnivores from both an anatomical and physiological perspective. For example, our teeth are suited for both grinding plant matter and tearing meat, and our intestines are relatively long, which is necessary for digesting plant-based food.

4. Humans can not digest cellulose, this is true. However, heating plant matter breaks down cellulose, so at the very least, ever since we started using fire on food, cellulose is not an issue. Technically, you could even heat grass and eat it, but it wouldn't be very tasty or nutritious.

5. While a diet purely on meat is possible, it's not the best thing for your health. A diet that is high in fat and protein and low in carbohydrates can lead to health problems over time, such as heart disease, stroke, and cancer.

6. Meat is calorically dense, so for hunter gatherers it made a lot of sense to seek this type of food out. In a modern world, this isn't really an issue, we have an absolute overabundance of all types of foodstuff.

> A diet that is high in fat and protein and low in carbohydrates can lead to health problems over time, such as heart disease, stroke, and cancer.

I'm going to need a source for the claim that a diet low in carbohydrates leads to health problems. I'm getting serious correlation/causation vibes from this.

> We are omnivores, we can subsist on many things, meat being one of them.

True, but I personally find it interesting that we have the smallest cecum and shortest digestive tract of the apes. Both of these are more indicative of a carnivorous diet than a herbivorous one.

There is no agreed upon definition of "cecum." The cecum is a pouch-like structure in the lower intestine where the large intestine begins. It is thought to aid in the digestion of plant material, but its exact function is not fully understood. Humans do have a relatively small cecum compared to other apes, but it is not clear if this is due to our diet or our evolutionary history.

There are several possible explanations for why humans might have a relatively small cecum. One possibility is that our diet does not require a large cecum to aid in digestion. Another possibility is that the cecum has shrunk over the course of human evolution as we have adapted to a diet that is less reliant on plant material. Finally, it is also possible that the small size of the human cecum is simply a result of our anatomy and is not related to diet or evolution.

Besides fossil fuel derived fertilizers used for feed, as sibling commenters have mentioned, you’re neglecting the impact animal agriculture has on forests.

2.1 million hectares (5.2 million acres) of tropical forest is destroyed every year to make way for beef herds [1]. That’s 41% of all tropical deforestation (which is where 95% of the deforestation occurs).

This is a disaster both in terms of the vast stores of carbon being released, and the destruction of habitat in the world’s most precious and biodiverse ecosystems.

[1]: https://ourworldindata.org/what-are-drivers-deforestation

As if said impacts are not shared by plant agriculture? Where do you think your vegetables come from? They need vast amount of space to grow, they need to kill animals that would otherwise inhabit the space, they need to spray large quantities of pesticide from above, fertilizer is necessary and fossil fuels are burned in that process, and fossil fuels need to transport the crops.

> 2.1 million hectares (5.2 million acres) of tropical forest is destroyed every year to make way for beef herds [1]. That’s 41% of all tropical deforestation (which is where 95% of the deforestation occurs).

What are the economic incentives to destroy tropical forest? Meat is by no means the only thing that land can be used for, first of all, but there is no requirement that cows be raised on land that was previously tropical forest. Go check out the Great Plains where most of the United States' cows are raised, because you won't find a tropical forest, deforested or not, for thousands of miles. And yet, somehow, meat continues to be produced.

No, I don't want forests to be destroyed, but it's a separate issue. Forests have been destroyed for countless reasons that have nothing to do with meat. Deforestation sucks, but that really isn't a the best reason to conclude that there's a problem with eating meat when deforestation isn't an issue. That is unless you have a problem with the non-forested land that cattle farms occupy, and most people don't because tropical forests are more interesting.

As I have mentioned elsewhere in this thread, if we clean up where we get our energy, these arguments mostly disappear because, regardless of the end product, fossil fuels are currently still being burned. Doesn't matter if you're eating beef or soy.

> As if said impacts are not shared by plant agriculture

Absolutely, and use of pesticides and fossil-fuel-derived fertilizers in crop production and horticulture is also a huge problem.

Fact is though, the same quantities of calories or protein as beef or lamb require vastly more land and energy to produce than plant-based alternatives: roughly 100 times as much [1]. That’s owing both to pastureland and to the fact that half of all the world’s cereal crops are fed to animals.

Granted, livestock raised purely on marginal (i.e. non-arable) pastureland is relatively low impact in terms of carbon emissions. There’s still the factor that carbon dioxide is converted to methane, which in the short-term (that we actually care about) is much more potent in its warming effect.

That model does not represent most animal agriculture, however.

As for tropical deforestation, the United States is one of the chief importers of Brazilian beef [2], so as a country is absolutely implicated in the practice.

You’re right that clearing land for grazing is not the only economic incentive to destroy forest, but equally it cannot be discounted in its contribution to the trend.

[1]: https://ourworldindata.org/land-use-diets

[2]: https://eu.wisfarmer.com/story/news/2022/01/05/brazil-ranks-...

> Whether it's corn or grass that's being fed on, the carbon being belched out by cows comes from the carbon the plants captured from the atmosphere before being eaten.

I think the main problem is that said plants are grown using fossil fuel-derived fertilizers.

Why they don't use cow dungs to fertilize said plants, I don't know. Maybe a farming specialist can enlighten me why chemical fertilizers are so much more abundanly used than animal waste fertilizers.

Another problem is local buildup of carbon or nitrogen. The Netherlands suffers from a nitrogen crisis: an EU court has ruled that the Netherlands' nitrogen emissions are higher than allowed by treaties, and so we must cut emissions. Emissions are caused for a large part by farming activities. These emissions are a problem because the nitrogen in farm waste products originate from a non-local source. So the nitrogen builds up locally and harms nature.

The Dutch government ordered farmers to cut back on their stock. Now farmers are protesting, blocking roads and setting hay balls on fire.

I'm not sure how you can say there's no science to back this up. Livestock are accounted for as contributing nearly 15% of greenhouse gas emissions. And since so much pasture is cleared by razing old growth forest the cost may be even higher. And aside from their primary contribution, livestock place a lot of strain on water resources which are dwindling due to climate change. I'm not anyone has bothered computing the result of a world without livestock because it's so improbable but it would certainly be very significant.

One thing we’re ignoring here is all the fertilizer used to grow animal feed, which is generated from fossil fuels. So it’s not quite all fresh carbon.