[the8472]

for the first two questions refer to https://en.wikipedia.org/wiki/Feed_conversion_ratio

> There are, as far as I know, regions where the soil is only capable of growing pasture, hard to plant trees in.

I assume that those areas would not be sufficient to cover current meat and dairy demands. If they were there wouldn't be any deforestation or soy fields for animal feed. And non-grazed grasslands is still going to release less methane than grazed lands.

[chrisco255]

More than 90% of a beef cow's body weight comes from pasture land grass and hay.

When's the last time the Midwestern plains area of the United States was forest? Before the beef industry, 50-100 million bison roamed the plains. It turns out that ruminants like bison and cows are essential components of a grassland ecosystem.

[markstos]

But killing them for food is not.

[chrisco255]

Yes it is. They are prey animals and they literally evolved to be prey. Incidentally we also killed off most of the major predators around the world so there are few wolves, saber tooth cats, etc to keep population numbers controlled.

[glastra]

Great link, thank you.

Regarding deforestation and so on, I think we must also take into account that "industrialized" non-pastured husbandry (is that the correct term?) is probably cheaper and easier than the greener alternative.

Sadly, it's usually a matter of profits and not a matter of environmental friendliness.