The sheer number of animals that are slaughtered to produce meat for human consumption is absolutely mind-boggling. In addition to the fish, humans killed 72 billion chickens, 3.3 billion ducks, 1.3 billion pigs, over a half-billion geese, turkeys, rabbits, sheep, and goats (each!), over 300 million cattle, and over 70 million rodents for food in 2019 alone [1].
Animal agriculture overall generates more CO2 emissions than every automobile, ship, and airplane on Earth - more carbon than the entire transportation sector. An overwhelming majority of arable land on this planet is used to feed those animals, fated to death from birth, rather than humans - in many developing countries, humans starve while livestock are plumped for slaughter and export. [2]. 75% of historic deforestation in the Amazon, 55% of erosion, 60% of nitrogen pollution, and 44% of anthropogenic methane and nitrous oxide emissions (each) are a direct result of animal agriculture [3].
If you live in the US, like I do, it's not just the animals and the environment that suffer under animal agriculture. It's an open secret that undocumented children are exploited to work in slaughterhouses in this country [4] while politicians are actively rolling back protections for those exploited children [5] to ensure that boneless skinless chicken breasts stay cheap at WalMart.
There is no such thing as sustainable animal agriculture - it is a lie used to greenwash products, to make us feel righteous when we pay for corpses at the grocery store or restaurant. The only sane and ethical response to this devastation is to completely reject the economic exploitation of animals - to adopt a fully vegan philosophy. Of course, this does cause some difficulties in the modern context (especially in the US), but the trouble of learning to cook vegetables and seitan is nothing compared to the harm that animal agriculture causes to billions of humans and non-humans every year. (It also cured my high blood pressure and pre-diabetes in three months, but everyone knows vegetables are good for you :)
[1] https://www.fao.org/faostat/en/#data/QCL (https://web.archive.org/web/20211208184438/https://www.fao.o...) [2] https://www.colorado.edu/ecenter/2022/03/15/it-may-be-uncomf.... [3] https://climatenexus.org/climate-issues/food/animal-agricult... [4] https://www.nbcnews.com/news/us-news/feds-find-100-children-... [5] https://www.axios.com/local/nw-arkansas/2023/03/13/arkansas-...