What kind of proof do you want and I’ll go find it for you how’s that.
i'd like proof of a causal mechanism by which choosing to buy beans has caused meat production to decline. i don't think you can find any such causal mechanism.
what you're presenting is a classic post hoc ergo propter hoc. both of those declined in production following the introduction of color television as well. we can't very well say that color caused a reduced production. in fact, you haven't actually presented any evidence that less asbethos or cigarettes are being produced.
Less animals suffering is a plus too but you could leave it out and still come to the conclusion that there is something behind plant based and partially plant based diets.
this is a nonsequitur. my guess is you have tried plant based diet, and the amount of animal slaughter has only increased:
chart
Given that 80% of all agricultural land is used to feed and raise animals
that's not a given, though. about 93% of all soybeans are used by humans, but about 77% of the cropweight is fed to animals. how can this be reconciled? because we press about 85% of the soybeans for oil, and the byproduct is fed to animals. so we can't say 77% of the land used to grow soybeans is used for animals. 93% is for humans. this myopic focus on distilling all facets of the industry into discrete datapoints fails to understand the system as a whole.
edit:
and it should come as no surprise that poore-nemecek has also infected this link as well.
Eating animals and their secretions requires harming significantly more plants than eating the plants directly because animals need to be fed too,
and they are mostly fed parts of plants that people can't or won't eat. the same field that grows soybeans for human consumption is growing animal feed, it's just different parts of the plant.
i'd like proof of a causal mechanism by which choosing to buy beans has caused meat production to decline. i don't think you can find any such causal mechanism.