It's not carbon neutral if you look at studies that account for more factors. For instance, here's an article with an interview of the researchers in the field talking about how there is no carbon-neutral beef

There’s not been a single study to say that we can have carbon-neutral beef

[...]

We also have to ask how much of the sequestered carbon in these systems is actually due to the cattle. What would happen to the land if it were simply left fallow?

The answer is, depending on the land, and on the kind of grazing, it might sequester even more carbon https://www.washingtonpost.com/food/2022/10/03/beef-soil-carbon-sequestration/

If we look at much more rigorous reviews on the carbon sequestration potential of "regenerative grazing" it's pretty slim. It cannot even sequester enough to counteract just grazing only production which only produces 1g protein/person/day

Ruminants in grazing-only systems emit about 1.32 Gt [...] These are their emissions. The question is, could grazing ruminants also help sequester carbon in soils, and if so to what extent might this compensate? As the following numbers show, the answer is ‘not much’. Global (as opposed to regional or per hectare) assessments of the sequestration potential through grassland management are actually few and far between, but range from about 0.3-0.8 Gt CO 2/yr 301,302,303 with the higher end estimate assuming a strong level of ambition.

https://www.oxfordmartin.ox.ac.uk/downloads/reports/fcrn_gnc_report.pdf

And keep in mind that this doesn't scale very well due to the massive land it requires. Already clearing land for pastures is a large deforester. Trying to even scale to a quarter of beef demand would require using 100% of grassland which would put enormous pressure for further deforestation

We model a nationwide transition [in the US] from grain- to grass-finishing systems using demographics of present-day beef cattle. In order to produce the same quantity of beef as the present-day system, we find that a nationwide shift to exclusively grass-fed beef would require increasing the national cattle herd from 77 to 100 million cattle, an increase of 30%. We also find that the current pastureland grass resource can support only 27% of the current beef supply (27 million cattle), an amount 30% smaller than prior estimates

[…]

If beef consumption is not reduced and is instead satisfied by greater imports of grass-fed beef, a switch to purely grass-fed systems would likely result in higher environmental costs, including higher overall methane emissions. Thus, only reductions in beef consumption can guarantee reductions in the environmental impact of US food systems.

https://iopscience.iop.org/article/10.1088/1748-9326/aad401

[–] VeganSchnitzel@lemmy.world 1 points 1 year ago

Thanks for the thorough write up. Quite impressive for a meme sub :)

[–] PaulL@sh.itjust.works 1 points 1 year ago* (last edited 1 year ago) (1 children)

"And keep in mind that this doesn’t scale very well due to the massive land it requires. Already clearing land for pastures is a large deforester. Trying to even scale to a quarter of beef demand would require using 100% of grassland which would put enormous pressure for further deforestation."

Most deforestation is intended to produce land for crop farming. There is still a lot of agricultural land left that is ideal for grazing, and that cannot be used for growing crops. We may not be able to feed everyone in the world on meat, but we definitely can't do it with plant-based foods alone.

And apart from that issue, there is the matter of protein quality, which is complicated to assess. Most mentions of plant protein are referring to total nitrogen content ("crude protein"), but not all of that comes as amino acids, which is the only form in which nitrogen can be assimilated by the human body.

So mixing and balancing plant protein sources has to be done with a certain amount of skill and care, because if one of the essential amino acids in the mix is deficient, that limits the assimilability of the rest of them.

[–] usernamesAreTricky@lemmy.ml 2 points 1 year ago* (last edited 1 year ago)

Extensive cattle ranching is the number one culprit of deforestation in virtually every Amazon country, and it accounts for 80% of current deforestation

https://wwf.panda.org/discover/knowledge_hub/where_we_work/amazon/amazon_threats/unsustainable_cattle_ranching/

Plant-based food production uses less cropland

The research suggests that it’s possible to feed everyone in the world a nutritious diet on existing croplands, but only if we saw a widespread shift towards plant-based diets.

[...]

If everyone shifted to a plant-based diet we would reduce global land use for agriculture by 75%. This large reduction of agricultural land use would be possible thanks to a reduction in land used for grazing and a smaller need for land to grow crops.

https://ourworldindata.org/land-use-diets

Complete proteins matter doesn't really matter all that much in practice. Things like soy are complete on their own, and things that are technically incomplete proteins like beans can be made complete with rather little like even rice. You don't need to be getting every amino acid in with every meal. If you eat the amino acids at some point in the day, you will be fine