These questions are explored in greater detail in Lustig’s recent Metabolical, which makes a systematic case, although somewhat of a brief one (it's not the mai

These questions are explored in greater detail in Lustig’s recent Metabolical, which makes a systematic case, although somewhat of a brief one (it's not the main point of the book) that heavy greenhouse gas emissions of the bigger greenhouse gases methane and nitrous oxide can be traced back to factory farming, in particular the high methane production comes from feeding our cows a corn-based diet (most of the emissions are burps, not toots) and nitrous oxide emissions are influenced (IIRC) by chemical fertilizers as opposed to traditional manure. (It might have also been that I am mixing things up and the chemical fertilizers create algae blooms which affect greenhouse gases...) The corn etc. is cast as part of a greater addiction to processed food that has been growing, with one of the book’s slogans being ~“it's not what's in the food but what's been done to the food, and that's not on any label.” So in addition to these environment-harming practices you get the health-harming effects of excessive antibiotic usage on livestock, and so now we have to all be on probiotics: that sort of health impact is much more the point of the book. Being a Lustig book of course it calls for limiting consumption of refined and added sugars etc. But it is interesting to also see an evaluation of vegetarianism in regards to whether it improves the climate situation or makes it worse, etc. The biggest kicker for me is, I have a physics background and love back-of-the-envelope calculations. Lustig does a back of the envelope calculation where if we take the estimates of how much of these obesity-related diseases are preventable, multiply by the cost of healthcare to get a rough estimate of how much spending is preventable, it turns out that Big Food’s (extremely generous!) profit margins are only a very tiny amount of what the processed food diet is costing us in healthcare. So the kicker is that in theory we could just ban processed food, keep paying Big Food that profit margin, and free up something like a trillion bucks to do something worthwhile with—if the world worked that way which of course it doesn't. Worth a read if you are into this stuff, but I imagine the bibliography is more important than the main chapter.