Comment by TollingSteady | Hacker News Reader

Comment by TollingSteady | Hacker News Reader

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I completely agree, natural habitats with native flora and fauna tend to settle into balanced ecosystems. As far as I can tell, that's not what you're arguing for, though, as that is not at all what modern animal agriculture is similar to.

As far as crops, the majority of what we grow is fed to animals. For example, according to the USDA, approximately 70% of U.S. soy is used as animal feed. If you're interested in reducing crop farming, go vegan. (Source: https://www.usda.gov/sites/default/files/documents/coexisten...)

As far as the limited abilities of carbon sequestering, "Grazing management could potentially, and under very generous assumptions, offset between 20-60% of annual average emissions from the grass-fed only sector," meaning that even all grass fed beef is still going to involve horrifying amounts of GHG emissions, completely ignoring the cost/land use that would make it otherwise unfeasible. (Source: https://phys.org/news/2017-10-grazing-livestock-climate-impa...)

Bonus link for more info on ruminants and carbon sequestering: "https://www.cambridge.org/core/journals/animal/article/abs/m..."

Doing regenerative ranching can be net carbon sequestering provided that you model your operation on nature a certain amount. People are doing it successfully.

Another way to be responsible re food is to only buy good grass fed beef. As a bonus cows can make use of grass on land that's too poor for traditional farming.

The source I cite for only 20-60% of GHG emissions being sequestered includes grass-fed beef. It seems like buying grass-fed beef is still environmentally unsustainable.

Your claims don't seem to match any of the evidence I've seen, but I'd be interested in discussing them further if you could provide sources.

As far as poor soil, a) current animal agriculture is mostly making use of usable soil & farmed crops, so this currently seems like a moot point, and b) this gets back to the above issue of being completely unable to scale. Unless you're being careful to only eat meat about once a month, I don't understand how the use of only poor soil is supposed to produce enough meat to feed everyone who would want it.

There are several ways to approach the problem.

One is to look from first principles and analyze how the great plains came to be. It should be obvious that the carbon didn't just sequester itself. Therefore if one were to mimic the roaming herds of bison closely enough (and how close is close enough is up for debate) then it should absolutely be possible to be net sequestering. I'm having trouble finding a good source for this.

There's a guy named Gabe Brown from North Dakota who is consistently increasing the amount of organic matter (and thus carbon) in the soil of his farm. I don't know how you'd interpret his results as anything other than sequestering.

https://www.sandyarrowranch.com/2019-fall-winter-update/

Finally there are places that are trying to study this rigorously as there's huge money to be made if you can offer guilt-free beef. Might that taint their results? Yup, but they might also be right.

https://www.fastcompany.com/90368127/is-it-possible-to-raise... https://www.greenbiz.com/article/how-regenerative-land-and-l...

I'd imagine the Great Plains had a much higher plant:animal ratio than commercial animal agriculture will be able to achieve. Plus the animals involved were native species adapted to the environment, not imported animals bred to maximize meat/milk output. I doubt we'll be able to reach a conclusion about this without more data, though.

Gabe Brown definitely does seem like he's achieving carbon sequestering, which is great! I have no doubt that carbon sequestering exists and is effective — my problem is that it neither matches nor exceeds the carbon output of e.g. cattle. So even with maximally effective carbon sequestering practices, there's still on net large GHG emissions. (See 20-60% figure from above.)

As far as the links you provide, here's the direct quote from the conclusion of the FastCompany site: "...better management techniques can be helpful but not as much as many think, and that the term 'regenerative' is so vague that it risks becoming greenwashing. Another study, from the Food Climate Research Network in the U.K., found that better management of livestock only sequesters carbon under some conditions and even then may be temporary and not necessarily large enough to offset the negative impact of raising the animals."

The second link seems to be marketing copy from General Mills, which as you note I might tend toward being suspicious of. Their sponsored study seems to contradict both the FastCompany site and all the other studies I've read. Definitely something to look more into on my part, though: will update here after reading more thoroughly.

Thank you for the interesting links, and for being willing to engage in good faith.

> my problem is that it neither matches nor exceeds the carbon output of e.g. cattle.

I am having a hard time understanding this concern. If the cattle and grass combo are releasing more carbon than they're sequestering then shouldn't soil carbon be going down?

Conversely if carbon is building up in the soil despite cattle eating grass and presumably incorporating some of the carbon from what they eat into their bodies, where did that carbon coming from besides the atmosphere?

I really cant wrap my brain around the idea that carbon can be building up in the soil while simultaneously cattle grazing operations are a net carbon producer. What am I missing?

Part of the problem when discussing greenhouse gas emissions is that we're not only talking about carbon dioxide, but also all carbon dioxide equivalents.

For example, one molecule of methane (CH4) contains the same amount of carbon [the element] as carbon dioxide (CO2), but is >= 28x more potent as a greenhouse gas than carbon dioxide (https://clear.ucdavis.edu/explainers/why-methane-cattle-warm...).

Therefore, when talking in carbon dioxide equivalents (i.e. making something carbon neutral), my understanding is that for 1kg of methane emitted by cattle, there would need to be ~28kg of carbon dioxide equivalent sequestered by the soil.

Even if cattle produced only CO2, to create a closed carbon cycle, it seems like soil would still be insufficient for carbon sequestering, unless you have massive tracts of land for relatively few cattle. Cattle need a constant input of feed, but it takes time to remove GHGs from the atmosphere.

Your sequestration suggestion should be compared to the most effective non-meat alternative, which is land area effective plant based protein production combined with reforestation of much current pasture https://ourworldindata.org/carbon-opportunity-costs-food

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