> None of those studies take this into account, they all just measure what comes into a cow and what comes out, but no one takes into account the amount of methane produced from the same feed even without cows involved.

Nobody's missing anything. That feed wouldn't have been planted in the first place if it weren't for feeding the cows. And that would translate to less deforestation [1].

[1] https://www.bbc.com/news/science-environment-53438680

That seems wildly misleading? The rainforests that were there before certainly produce methane and other gases as things rot. Total biomass in a rainforest is generally stable - it is not really a sink over any significant timeframes. Plants take sunlight, use the energy from it to rip the oxygen off co2 releasing oxygen as a byproduct, and carbon to build themselves with.

Unless rainforests have an ever increasing layer of carbon (charcoal/coal) building up under them - which they do not - they stabilize with their total carbon intake being roughly the same as carbon released through other means. In most cases this happens (rate decreasing over time, though total carbon storage quantity slowly increases until a wildfire) in less than 100 years after a complete denudation event, most of it happening much sooner than that.

If you want to lock up carbon, you need to take it from the plants and sequester it somewhere natural forces (rot, weathering) won’t break it back down again - like a house, or in a cave, or in a hypoxic environment.

Methane is definitely a significantly more powerful forcing gas than co2, but also breaks down in the atmosphere in a short period of time into co2. Cow fart composition changes also only have a similar local, short term effect.

Short term effects can be helpful, but this only changes some parts of the (closed) cycle.

You only really change the math if you change how things are getting into or out of the overall cycle, which requires long term bonding of carbon to things such as rocks, or burial.

Converting atmospheric co2 (or methane) into plastic that gets buried in a landfill is net negative carbon balance for instance. Making the plastic out of oil products and then putting it in a landfill - net neutral (minus processing energy costs). Burning it for fuel? Contributes fossil carbon into the atmosphere.

>The rainforests that were there before certainly produce methane

Conditions on the forest floor typically facilitate aerobic decomposition which does not release methane. [1]

>If you want to lock up carbon, you need to take it from the plants and sequester it somewhere natural forces (rot, weathering) won’t break it back down again - like a house, or in a cave, or in a hypoxic environment.

Hypoxic environment is exactly the conditions methanogenic bacteria operate in to turn biomass into methane. [2]

> Converting atmospheric co2 (or methane) into plastic that gets buried in a landfill is net negative carbon balance for instance.

Except for the energy needed to convert the molecules, the energy needed to transport plastic to a landfill. Energy production and transportation both are powered by fossil fuels mostly.

[1]http://whatcom.wsu.edu/ag/compost/fundamentals/consideration...

[2]http://solarcities.eu/faq

Then just buy American beef, which is produced without any deforestation.

Is that sarcasm? Pretty much the entire midwest was forest before colonization. Now take a look at Illinois, Indiana, Iowa, Missouri...they're basically one big farm criscrossed by roads, highways, sprinkled with small spinneys of trees, and dotted with cities. Just load up Google Earth, satellite mode, turn off all labels, and zoom out. It's astonishing.

This just isn't true. The Eastern half the US was heavily deforested by colonization, but that's really not true in the midwest. It was prarie.

There are actually a lot of researchers who believe that the Native peoples were keeping the forests back via controlled burns, since grassland is better for hunting and agriculture, and the forests have regrown substantially _since_ most of the indigenous people died via disease.

Go argue with historians, if you like: https://blog.history.in.gov/tag/forestry/

Indiana is the beginning of the Eastern forests. Prairie starts in Illinois and extends over most of the Midwest and runs North/South along the Rockies well into Canada and down to Texas, New Mexico.. nice map: https://en.m.wikipedia.org/wiki/Tallgrass_prairie#/media/Fil...

Like, I'm not saying wikipedia is an infallible source of truth, but I'm not exactly arguing for ancient aliens here:

> In the Eastern Deciduous Forest, frequent fires kept open areas which supported herds of bison. A substantial portion of this forest was extensively burned by agricultural Native Americans. Annual burning created many large oaks and white pines with little understory.[10]

https://en.wikipedia.org/wiki/Pre-Columbian_savannas_of_Nort...

It's not that simple. Not all American beef is raised on native grasses.

Why is native or not native important from a carbon balance perspective? Alfalfa still pulls carbon from the air when it grows.

Corn, people... American cows prominently eat corn.

It is extremely fertilizer and pesticide intensive, and entirely engineered. As pointed out elsewhere in this thread, the fertilizers are also fossil fuel based.

Yeah, this is a bit what I was getting at. But all I know about cattle comes from my family's cattle background in Eastern Montana and the high valleys of the SouthWest corner of the state. In both those regions, many cows are raised in naturally occurring pastures, eating native grasses, save oats which are sown as a cover crop.

However, my impression this is very unique and produces much less pounds of beef per acre than most places. The cattle breeds there are leaner and half wild. I'm hesitant to speak more definitively because I don't know specific statistics on how ranches in other regions differ. My impression is that the difference are substantial.

> ...fertilizers are also fossil fuel based.

True, but these only account for 1% of energy demand[1]. Fertilizer is all about the nitrogen, not the carbon. The carbon for the corn is taken from the atmosphere.

[1] https://www.sciencedirect.com/science/article/abs/pii/S09213...

What I should say is, not all American beef is fed from naturally occurring pasture land. In fact, a good deal of it is not.

At this point, nearly all agricultural land was converted a century ago. The trend now is more towards decreasing total agricultural acreage if anything?

No one in America has slash and burned a forest to feed cattle for a very long time.

Are you accounting for animal feed grown on deforested lands?

Except the beef that isn't from free roaming animals but from mass producing facilities.

So what would grow in that dirt instead? Nothing?

This point relies on the assumption that the cattle are out eating grass (or other plants) which would naturally be growing and rotting without human intervention.

This is kinda not true. Grazing systems supply about 9 percent of the world's production of beef [1]. 80% of the global soybean crop is used to feed livestock [2]. A lot of these soybeans are grown on land that used to be rainforest.

Your comparison shouldn't be cow vs grassland - it should be rainforest vs (cow + soybean + transport + processing).

[1] https://en.wikipedia.org/wiki/Cattle_feeding#Types_of_cattle...

[2] https://en.wikipedia.org/wiki/Soybean

Surely its clear that if the soybeans aren't growing in the field that something else that grows, dies and decomposes would be.

Yeah, and we even have a word for the "something else" that you're describing - its a rainforest.

Something like a forest with large trees that lock up carbon for many years, and a lack of commercial fertilizer (which uses natural gas).

Honestly, I don’t trust the source. What an animal science professor says off the cuff in an interview is something that should be verified with real data.

The question relies on how much carbon ends up in CO2, CH4, and fixed in the soil between use of what would become cattle feed. Carbon is conserved without a doubt, but how much ends up as gas and which gas is important.

Carbon dioxide doesn’t matter because every bit which ends up in the air had to be taken from the air a short time before to build plant matter. Methane matters because it is a much more potent greenhouse gas and how much gets as methane instead of carbon dioxide makes a difference.

I'd like to see an actual study on this. Yeah decomposing grass releases methane, but in the wild does it release as much methane as it would being digested by a cow?

Lets say the carbon in the grass goes into the cow and X% goes through the cow's metabolism and is exhaled as CO2 or becomes part of the cow itself. Y% becomes a part of the cow's manure. Z% is released as methane into the air. The carbon of grass decomposing on the ground will turn some parts as methane into the air, but also some parts into the food chain of smaller creatures, some parts as CO2 into the air, and some parts into the soil itself. Cows and decomposing grass releasing the same amount of methane seems unlikely to me.

That's not to say I think we should eliminate cattle. Well managed grazing actually does amazing things for the health of soil, and can even fight desertification.

The problem is, most weed is produced exclusively for cows, so your argument does not work.

I've got a question that may be stupid. So if you cut the same amount of grass a cow would eat every day and let it rot, then over the course of (say) a year both would release the same amount of methane overall. Do we know if this is the same as if we did nothing to that grass - just let it grow and sit there, without repeatedly cutting it back? Because to me this seems to be what you'd want to compare against.

Only grass decomposed in an anaerobic environment would produce methane. Grass decomposed aerobically would produce CO2 instead.

But methane decomposes into CO2 on a relatively short timescale(12 years?) so surely....it's a wash?

Those couple of years where the carbon is in the form of methane instead of CO2 have a big impact because methane is a much stronger greenhouse gas.

Not a wash. Methane has 85x the impact per unit as co2 which has a half life of 27 years.

Interesting, but still I don't think your comment is very relevant to this. Without cows we could have a forest instead of grass, instead of leaving it to rot. So if the number of cows remains constant you benefit from reducing methane emissions.

But that's an issue with where we feed the cows, isn't it?

For instance - cows are raised on many parts of moorlands in the UK, where they eat only the grass growing there. But if you removed the cows, the moors would be exactly as they are now - they cannot support forests or any other kind of vegetation, because they are basically solid rock with an inch of soil on top. I understand that on the "intensive farming" lots where cows are fed corn/hay specifically grown for them that doesn't really apply - but farmers do absolutely raise cows in such places where it makes no difference - even in the absence of cows or sheep you aren't going to have a forest there.

I understand this isn't potentially isn't helpful, but the problem is very nuanced - some cows are fed in such a way that their methane emissions are a net positive. But I'm also sure there are some where the emissions aren't positive at all, yet it's all bundled into the same "meat causes climate destruction" bandwagon.

I think you're underselling moorlands here. Trees can be planted on moors, and other even more carbon-sinking activity too: "It’s worth remembering that the peatlands of the UK store more carbon than the woodlands of the UK, France and Germany combined!" [0]

[0] https://www.moorsforthefuture.org.uk/our-purpose/habitats-fo...

I don't think they're missing that at all. The cattle in question are eating feed (mainly corn) not grass.

Furthermore the grass in question likely wouldn't "decompose" like what I believe that's describing. It probably depends on where you're physically located, but in the north - grass grows for the duration of the season, until it eventually dries out in the fall to go dormant over the winter. I guess I haven't personally tracked that process but I would be very surprised if it's releasing methane in the same way that freshly cut grass left to decompose (via bacteria) would.

Wouldn’t they make less grass then if it wasn’t used to feed cows as much?

I'm not sure how much this point matters, because the alternative isn't a field of rotting grass. If the land is undeveloped, the alternative is likely some kind of forest. If the land is developed, the alternative is probably cropland. Also to be clear, we're not just talking grass, there's also a massive amount of industrially farmed grains to fatten the them up, which wouldn't have been industrially farmed if it wasn't demanded for feeding cattle. So there's no real equivalence here.

That simply can’t be true in the wild. If that much carbon was released from plants in the wild, we’d never have coal or oil, right? Composting the grass might be the same as cows, but that process doesn’t happen everywhere there’s grass. In the wild, the grass would be trampled and new grass would sprout up to cover it, layers of soil would be generated. But honestly I’m just guessing, but your claim seems so far off the mark.

I’m really glad you asked that! The reason we have coal and oil today is that earlier in Earth’s history microorganisms lacked the enzyme to metabolize cellulose (the most abundant bioorganic material). So until then, it was buried and accumulated as fossil fuels.

Today’s ecosystem can metabolize cellulose, so no more fossil fuel production. Quite literally an unsustainable fuel!

No I understand how it works. But what I’m saying is that the enzymes/bacteria in the wild dont process grass like a cows gut. You need composting to happen vs trampling and burying the grass. But ty!

Coal and oil come from carbon captured during the Carboniferous period, before the evolution of species of bacteria and fungi that could digest the lignin in plants.

Coal and oil formation is not being fed by plant life today. The carbon in plants is recycled rather quickly in to the ecosphere.

Fair. So then I would augment my comment to focus just on soil production in the wild. Not all of the plant debris is being composted. It gets buried too.

IMHO any plant debris that gets buried in the soil is - in the long term - also composted, only its breakdown is slower.

If there is no difference there (I don't know anything about this), doesn't agriculture at least lead to higher rate / volume of grass growth?

But the cows eat the grass a lot faster than it would be rotting right? So wouldn't the speed of the methane entering the atmosphere be faster?

>But the cows eat the grass a lot faster than it would be rotting right?

Not really? Otherwise grass fields would piled up with grass several feet high.

Would there be perhaps less feed grown if cows were supplemented with other feed? If 20% less of the cows' calories come from methane-producing sources, 20% less land/duty cycle is needed for cattle grazing/growing feed, so other things can be grown or don't get cropped as quickly.

Why is this incredibly important? Is there some huge proportion of unused, rotting feed in the world?