But there are any number of sources you can search up who will claim some kind of stats on this subject. IMO it's impossible to calculate, but it's also obvious that if you eat grains, fruits, vegetables and nuts, it has a lot less cost and environmental impact than eating animals and dairy which requires growing grains to fead those animals (that shit and fart methane, a major greenhouse gas) which are milked or grown to feed humans.

Anyone who will argue against that logic deserves serious questioning