From the context, he appears to be referring strictly to factory farming of animals. From an environmental and ethical position, it’s hard for me to argue against that. I eat meat, but I’m also aware of how awful conditions are on those farms, and just how far definitions of “ethical” are bent in order to define them as ethical. I think that we need to change culture so that people don’t view meat as central to a diet anymore, or eating large quantities of meat as being symbolic of having ‘made’ it
I also think that we likely need some kind of nationalized (maybe even international?) rotation for all crops, because the system that we’re using of heavy fertilization, etc. is depleting our soil badly, resulting in crops with less nutrition than we were getting just 50 years ago. We’re already in the beginning stages of climate collapse, and monoculture is making that significantly worse.