JC, you need to go to the westonaprice.org website, and read about the environmental wasteland that would occur if aimals were not kept. Think about it: they can graze where crops CANNOT be grown, and their manure enriches the land.
In fact, "if you wanna be a vegan, you have to kill, kill, kill". Yes, especially if you buy plant-only food from a store, you are responsible for the deaths of millions of animals. Consider combines: they kill countless birds and animals, even deer. That is how grains are harvested--unless you grew your own, cut it by hand, shocked, and then threshed it all by hand.
Now consider how grains are grown: fossil fuels are used for fertilizers, as well as to run all the tractors and combines to plow, plant, fertilise, and harvest. Then more fuel used to process the grain (unless you grind your own with a hand-grinder). Especially consider the high amount of energy needed to get something like corn oil. It is made in a refinery the same way crude is refined. Again, more energy inputs.
Contrast that with raising healthy animals on grass. (We do). We don't even OWN a tractor, much less run one. Yes, we do have to buy hay, which was harvested with fossil fuel, but that is all. When we butcher, we get good old lard and suet; no refineries needed. And our animals' manure goes to enrich our organic garden.
Has anyone stopped to consider that it'd be pretty hard to raise anything organic without manure? Yes, animals usually enrich the soil, whereas plants are soil robbers. If it weren't for our animal friends, the outlook would be bleak indeed. And grass is supposed to be a great carbon-eater, (not that I believe in global warming anyway). But if you do, that also needs to be considered.
I take exception to the notion that "there aren't enough grocery stores" in certain places. C'MON! Food doesn't come from stores! ANYONE, and I mean ANYONE, can grow at least some of their own food.
Yes, tomatoes, as well as other plants, can be grown in window boxes. Read "Square Foot Gardening" and see how little land is needed to grow a garden. Even if there is no window box, one could make an elevated bow as he tells in the book, and use it inside under a grow-light.
The trouble is, most people are too lazy (repeat, lazy) to grow a garden. I grow practically all the plant food we eat in our family of 6, and believe me it is hard work--YOU HAVE TO BE OUT THERE TENDING IT EVERY DAY...but WORTHWHILE.
Until people get rid of the "store" mentality, and start taking responsibility for producing their own, (at least partially) there will continue to be a local-food problem.
As grassfed lamb producers, we really grudge having to take lambs to the auction barn; we'd rather sell them locally to people in the area. But every year, we do end up taking some to the sale barn, because not enough people will but them. They'd rather go to the store, and buy some factory-farm-produced meat, butchered in contaminated slaughterhouses.