[tasty_freeze]

That article seems highly motivated to marginalize the effects of livestock. Quoting a section:

    While methane is 28-times more heat-trapping than carbon dioxide, methane’s lifespan is just a decade, while CO2 — known as a long-life pollutant — remains in the atmosphere for 1000 years.

    After ten years, methane is broken down in a process called hydroxyl oxidation into CO2, entering a carbon cycle which sees the gas absorbed by plants, converted into cellulose, and eaten by livestock.

In the first paragraph, it says methane isn't so bad because it lasts only 10 years, unlike CO2 which lasts 1000 years. In the very next paragraph it says the methane is broken down into CO2 which is then absorbed by plants and recycled. Wait, you just said it lasts 1000 years.

The next two paragraphs say that livestock accounts for 33% of the total methane released and blithely states that it all gets broken down and reused. If no additional animals are introduced, then net release equals net absorption. That is not very insightful -- eventually an equilibrium will be reached. This glosses over the real data that CO2 levels are rising, it is having measurable consequences, and is pushing control loops to new, worse states.

Citing one article written for the "Farm Business" trade publication isn't as conclusive as you seem to state.

[Doji]

There is a certain amount of carbon in the atmosphere, and a certain amount of carbon in the ground.

When you burn oil, you take carbon from the ground and introduce it into the atmosphere. This increases the total amount of carbon resident in the atmosphere.

When you grow plants, you take carbon out of the atmosphere. When you eat it, you release it back into the atmosphere. The total amount of carbon resident in the atmosphere does not change.

Grass grows more vigorously when regularly pruned, for example by a grazing animal. Farms also make a point of planting thing which grow quickly and efficiently. Thus it's reasonable to expect that farming could increase the rate of carbon turnover in the atmosphere, which would create the appearance of increased carbon emissions without a corresponding increase in the amount of carbon resident in the atmosphere.

In practice, farms regularly use synthetic fertilizers. They might cut down trees to clear fields for animals. They use heavy, oil burning equipment. These, and many other practices, actually increase atmospheric carbon, and for that reason should be discouraged. But the cow itself only causes a short lived, fixed increase in atmospheric methane and an increased rate of carbon turnover.

[randomperson_24]

You also have to feed the cows, which requires food. And by normal concensus only 10% of energy is transferred to the next species.

And producing food for cows causes more damage than making same food for humans. (Deforestation, Soy plants, etc emitting more carbon)

[herbst]

This is only true for mass grown meat. A typical Swiss cow spends their summer in die Alps and their winters eating grass from the very same fields.

Most popular meat labels here would not even allow buying external food, if not absolutely necessary.

[johnydays]

--- original: Vast majority of the swiss beef supply is conventionally fed, with imported grain/soya crops.

I was wrong, correction below

[herbst]

Actually 90% of the food is produced IN the country. Instead of soya they use mostly local corn for mass production.

https://schweizerfleisch.ch/herkunft/facts-figures-schweizer...

[johnydays]

I stand corrected, I was looking for official sources but my german is quite bad. Thank you!

[johnydays]

Grass grows more vigorously but also consumes more nutrients when regularly pruned, other plants also "grow more vigorously" e.g get replanted when harvested by humans. This does not seem unique to grass or animal feeding.

Even if it was, grass-fed beef is about 1% of the supply in the US. It has also been shown that grass-fed beef on average causes more environmental degradation than conventionally fed beef, due to the deforestation required to create grazing areas

[GhettoComputers]

Buffalo is a very obvious harm reduction option that would create less harmful externalities but it’s not at all suggested, only lab grown meats and removing all meats from diet.

[Doji]

I never claimed the phenomena was unique to this situation - it's a general phenomena.

Deforestation is a real problem. How do you address this from a policy perspective? If you ban beef, that is only a temporary band-aid on the real problem of deforestation, which both fails to address deforestation properly, and which prevents beneficial uses of livestock such as for reuse of food waste products, grazing of natural grasslands, production of natural fertilizer, etc.

[cjblomqvist]

I've always thought along the same lines. But whatabout methane being 10 times the pollutant?

[Doji]

It's a concern, but fortunately if cattle population stays constant, their portion of the atmospheric resident methane will also remain constant, because methane degradation will keep pace with emissions.

Compare this to cars. Even if the number of cars remains constant, their contribution to the C02 pool grows every day.

So we should avoid increasing cattle population 100x, but we wouldn't want to do that anyway because we'd have nowhere to put them, and I certainly wouldn't support deforestation.

[johnydays]

Projections point to greatly increasing cattle population, unless:

1. Current consumer habits change.

2. Rapidly developing countries decide not to increase the animal proportion in their diet, which has happened in every single culture so far.

[egeozcan]

I think there lies the problem:

> fortunately if cattle population stays constant, their portion of the atmospheric resident methane will also remain constant

I have the impression (as a person uneducated in this topic) that current levels are already too high, and the world population is only going up.

Is there a way to produce more food with lower emissions or should the main target be a steady population? Or both?

I know some people who started eating insects and stopped planning for kids because of this. Me? I'm just confused.

[johnydays]

World population is largely a strayman, it's mostly about rising standards of living. Animal consumption per capita increases drastically as poverty dissipates, and sharply declines as people get educated about health and the environment. It's a race between those two pressures that determines the cattle population. Projections are that it will increase very, very drastically as middle eastern and african countries soon escape the poverty line

[soco]

The methane stays constant because it gets broken down into CO2 which thusly increases.

[WithinReason]

But all that CO₂ was captured from the atmosphere in the first place

[wumpus]

> When you grow plants, you take carbon out of the atmosphere. When you eat it, you release it back into the atmosphere.

So the electricity and diesel that are involved in growing plants come from the atmosphere? That's new to me.

[y4mi]

They didn't say that.

> In practice, farms regularly use synthetic fertilizers. They might cut down trees to clear fields for animals. They use heavy, oil burning equipment. These, and many other practices, actually increase atmospheric carbon, and for that reason should be discouraged.

I cannot say anything wherever cows really are inconsequential wrt the warming effect, but it definitely goes against what's generally said by climate scientists.

[wumpus]

I suppose you could grasp at that straw, but the reality is that grain farms always use diesel and electricity, not just "heavy, oil burning equipment", no matter how much you might think they don't, and that's multiplied by a factor of 10 when you feed that grain to a cow.

[y4mi]

You're clearly misunderstanding what I wrote, which is likely because of my poor phrasing.

To phrase it differently:

Climate scientists generally think that cows are an issue, but I do not have the qualification to judge wherever Dojis claim (that they don't matter) has any truth to it, as I'm not informed enough to form an opinion on the matter.

Doji did not claim that modern agriculture isn't harmful, they just addressed cows specifically.

[dnautics]

I feel like I'm being gaslighted. In advanced physical chemistry we took IR spectroscopy of methane and CO2 and CO2 definitely had much, much more absorption than methane on account of the dipole difference between Carbon and oxygen (IR absorption depends on stretching modes between atoms of different electronegativity, carbon is very close to methane). At the time, it was explained to us young chemistry students that methane was more potent GHG because it lasted in the air longer (CO2 is scrubbed by plants).

Am I missing something? How can methane be a more potent GHG if it has lower IR absorption AND a shorter lifespan?

Edit: found spectra here (not the data that i took, obviously):

https://wattsupwiththat.files.wordpress.com/2014/04/methane_...

CO2 has a big fat band that blows out the absorption at 4.5 um in a region untouched by water (and one that is overwhelmed by water); methane has two spiky bands both of which are partially occluded by water.

[quantum_magpie]

For the most part, the CO2 absorption bands are already saturated -- increasing CO2 concentration has much less effect on transmission spectrum than that for methane.

[agilebodyshoppe]

the greenhouse effect is about internal reflections basically. its the same effect that makes cloth appear darker when its wet even though water is basically colorless. greenhouse gases bend light slightly, making it more likely that a light ray will hit the ground multiple times.

[dnautics]

This is a wrong answer if I've ever heard one.

[agilebodyshoppe]

seems like ive misunderstood this since i was a child. thank you for allowing me to embarrass myself in a safe environment.

[dnautics]

It's ok! Not all of us are atmospheric chemists! I certainly am not one.... Hence my lack of understanding.

[mongol]

Could it be something like how it is distributed in the atmosphere?

[dnautics]

I'm curious and hoping someone can explain it to me

[adrianN]

I'm just guessing: a) We don't have enough water in the atmosphere that the overlap with Methane meaningfully reduces net absorption, b) in the bands Methane absorbs there is more radiation available to absorb than in the CO2 band. If both are true that would explain the bigger effect of Methane.

[tuatoru]

When measured over 100 years, methane has about 21 times the global warming potential of CO2.

When measured over 10 years, it's more like 81 times.

So the "28 times" already allows for the fact that it's mostly only there for 10 years.

https://www.onegreenplanet.org/animalsandnature/methane-vs-c...

[Jensson]

But it means that the meat we eat today just warms the earth for 10 years in the future. Global warming isn't a catastrophe in 10 years, so eating meat today is a non issue. When global warming becomes an issue we can kill all the cows and stop eating meat and that way quickly cool the earth.

[Jensson]

Why was this downvoted? The 28 times figure only applies if you average for when the activity continues for 100 years. Meaning if we stop and most of the warming is in the first 10 years, we'd see a huge global cooling from stopping such a massive effect. This would serve as a great way to quickly reverse global climate change once it gets critical, and once it get critical people can no longer say that it isn't a problem so you'd have the whole world on your side, so not sure why we would waste that opportunity by using it now rather than when the whole world understands the problem?

[anovikov]

No contradiction. It's 28x more heat trapping and turning into CO2, it becomes 1x.