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Comment by ImHereToVote | Hacker News Reader

Can someone explain how lab grown meat releases less greenhouse gasses? Seems like much more energy inefficient than the old fashion way. Are there any figures available that go into the thermodynamics of it all?

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When talking about beef specifically, the problem is that cows produce a disproportionate amount of methane, which is a disproportionately powerful greenhouse gas. If you don't want to give up meat but do want to make a dent in your emissions, even just eating pork or chicken instead is an improvement. There might be ways to reduce the emissions of cows in the future (different feeds, gut biome interventions, bioengineering), but right now these are science fiction.

As for the energy inputs themselves, the notion of grass-fed beef often gets trotted out as a way to make beef more eco-friendly, but in practice this mostly amounts to greenwashing. Most beef is not grass-fed, and most places in the world that raise cows are not suited to pure grass feeding.

And then there's the land use aspect. When we're clearcutting the Amazon in order to satisfy the world's demand for beef, we've fucked up.

> There might be ways to reduce the emissions of cows in the future (different feeds, gut biome interventions, bioengineering), but right now these are science fiction.

I thought there's already research showing that seaweed in the cow's diet drastically reduces methane emissions.

Yes, just 2% of diet as seaweed essentially eliminates methane emissions. But there's no price on methane emissions for the farmer so no incentive to do so.

> cows produce a disproportionate amount of methane, which is a disproportionately powerful greenhouse gas.

Can somebody explain run through these quickly, I'm not sure which parts are wrong and how much they're wrong:

1. the constituents in the methane came from the food the cows eat?

2. the food got it from the atmosphere?

3. cows don't increase methane constantly, rather it's the marginal volume of feed required to sustain every new cow on the planet less the ones slaughtered? I.e. the growth in new supply?

4. Eliminating cows raised for meat would stop the increase in methane due to increase in supply and it would result in a one-off net reduction in atmospheric methane in time proportional to what cows were releasing, assuming the food continues to grow?

5. What happens when the food the cows are no longer eating dies, does anything get released then?

Not my field, so assumptions and simplifications follow. Animal feed mostly grows from absorbing carbon dioxide, not methane. Cows (and other grazing animals) produce net positive methane because their gut microbiota ferment the animal feed, producing methane. So, to keep methane in balance, something in the local grazing biome needs to absorb methane. Otherwise, cows can increase proportional atmospheric methane.

Well yes, but the same grass that these cows eat....would rot and release methane eventually anyway? Is that not correct?

Not quite correct - the grass may rot due to non-methanogenic organisms and/or be eaten by something.

It is correct.

Assuming no fossil fuels provide the carbon, the whole thing is indeed carbon neutral.

However, from a green house gas perspective, plants consume Co2 (moderate green house potential), and either due to rotting or as part of digestion, methane does get produced. Which has a high green house potential. Not in identical proportions to the co2 consumed of course, cows and rotting plants also produce co2.

So think of part of the problem being some co2 being converted into a more problematic green house gas (methane) with a lot of steps in the middle.

Also people being jealous of that tasty steak that is a byproduct of the process.

1/2: Grass turns CO2 and water into sugar and oxygen, cow eats grass and turns sugar and oxygen in to methane and CO2 and more cow.

(Via intermediary step of some of their stomachs being bioreactors filled with bacteria, oh the irony).

3: Sure, but demand is still going up: https://en.wikipedia.org/wiki/File:Beef_production_1961_2021...

4: I'm not sure I follow the question, but methane has an atmospheric lifetime of about 12 years, so it would probably fall, but I'm not sure how much by

5: Some mixture of CO2, methane, and carbon sequestration; at this scale it's worth considering which crops are grown and how they are used precisely to minimise that kind of impact

I wonder if anyone tried to capture methane produced in this way

The idea is that cows, and all the infrastructure around raising them, are a huge source of greenhouse gasses, while just cultivating cow meat eliminates everything not directly related to producing a hamburger. More recent studies [1] cast doubt on that and even suggest as you do that cell-cultured meat may be more environmentally damaging, not less.

[1] https://www.biorxiv.org/content/10.1101/2023.04.21.537778v1....

Can you condense the argument for us? Why can't the supply chain be decarbonised?

One of the main factors: generating the growth media for the cells is by no means carbon-free, and some of the ingredients are very very carbon intensive to produce.

Do you mean energy intensive or carbon intensive?

Carbon intensive. Most of them are agriculturally sourced, and fossil fuels/feedstocks are not likely to be widely replaced in agriculture for several decades, at least.

Nobody talks about the thermodynamics because right now it's terrible (also why the economics is terrible - nobody can get anywhere the $3/kg of chicken breast).

However, theoretically lab grown meat could be a big win on the thermodynamics front, and whoever solves that will have a far easier time getting the economics working too.

I think it's more an issue of resources rather than raw energy. If this can be produced using much less space, locally to consumers, and using clean energy then it's a net gain.

What I'm interested in is where do the raw materials come from? I suppose this needs a number of "ingredients", including proteins, that must be sourced from somewhere.

One of the larger issues is the methane byproduct, i.e. they fart. It isn’t just about energy.

Burps, actually. Even harder to capture if you were going to try.

I think the end goal is control of food production:

1. Introduce artificial meat that only large corporations can make

2. Ban natural meat as artificial alternative exists

3. Jack up the prices and profit

That’s actually super hilarious given the conglomeration that has occurred already anyway.

Turns out you can just skip both the incredible engineering problem of lab grown meat and the incredible political problem of “banning meat” and even people who are apparently paranoid about corporate/government control will just go right along with it.

Most of the meat consumed in the US already comes from a large corporation. 99% of it is factory farmed.

Source: https://ourworldindata.org/how-many-animals-are-factory-farm...

Reality is the opposite with the agriculture and beef lobbies influencing government and cultured meat facing outright bans

however, agriculture and beef lobbies don't demand a ban on small farms and individual cattle raising.

A perpetual goal of all civilization has been control of food production, without which we reliably starve to death.

I mean yeah. You can basically judge political/economic system by how many famines they have.

Yeah, that already happens in the current world with current corporations. You just don't notice because you're too busy consuming.

And I dont mean this in an angry environmentalist way. There are a lot of people who dont pay attention to their current food chain and don't know just how tightly most of the brands are controlled by a select group of companies.

So before jumping to future conspiracies, look at what you're in now:

https://capitaloneshopping.com/blog/11-companies-that-own-ev...

https://xtalks.com/food-industry-by-the-numbers-leading-food...

I eat some of the above foods, so I'm not some anticorporate person.

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