One crazy thing I recently heard that put this into perspective is that Livestock makes up approximately 60% to 62% of the world's total mammal biomass. Combined with humans (approx. 34%–36%), domesticated livestock means humans and their animals constitute roughly 96% of all mammalian biomass on Earth, leaving wild mammals at only about 4%.
I suppose Frontier living doesn't necessitate hunting, but the amount of readily available meat and animal products would have to drop very low.
This is the small solace I take when it comes to climate change reducing arable land - almost all of our crops are grown to supply a luxury product (meat), so if we need to, presumably we could just eat the grains we grow directly, instead of turning them in to animals first.
I suppose Frontier living doesn't necessitate hunting, but the amount of readily available meat and animal products would have to drop very low.