First, humans don't generate enough waste to fertilise the crops they need to survive; that's why the Haber-Bosch process was so incredibly revolutionary. Sure,

First, humans don't generate enough waste to fertilise the crops they need to survive; that's why the Haber-Bosch process was so incredibly revolutionary. Sure, nitrogen fixing crops are a thing; crop rotation, there's a lot of ways we've figured out to get more crops grown in less land, and they all have limitations and tradeoffs, and they're all a lot less efficient than just dropping some cheap fertiliser on it. Second, no, small-scale agriculture should not blindly mimic industrial agriculture, but you also don't get any advantages just by being small. Pests want to eat your crops no matter who you are. And yes, of course a backyard veggie garden needs fertiliser. And third, dfferent consumers have different elasticities of demand. Hobbyists doing something for fun often have high elasticities of demand. I mean, obviously; if you were maximally sensitive to price, you'd be buying whatever is on sale at Costco already. :) A friend of mine makes her own cold process soap; they're lovely and high quality, and she has a lot of fun doing it. Even ignoring her time, the cost per bar for her to make them is a couple orders of magnitude higher than store bought. You think she'd stop - or even notice - if one ingredient went up a few cents? Finally: > Bob the farmer has a much closer societal link to joe the fisherman. I can't even begin to imagine how that might be true. We're talking about "hey, what if everyone grew their own potatoes instead of buying them; would that help the planet". But I mean....I don't know any fishermen. I don't even eat fish. And even if I did plant some potatoes in my back yard, I'm not going to suddenly meet a fisherman. And even if I did, I don't see why we'd assume they're an environmental chemist. Seems like he'd probably be pretty busy fishing, maintaining his boat, and (now) growing potatoes, so why would he even know that the fertiliser we're both putting on our potatoes is (eventually, in aggregate) harming the fish? You seem to be envisioning a pleasant world, but none of it really meshes with my understanding of how our world works. But eh, I suppose my arguments sound equally unconvincing to you, so...