You didn't explicitly state this, but I think it's important to highlight: protein != meat. Farming fish is more efficient than farming cows, but it's still more wasteful than having people eat plants directly.
It seems to me that a lot of damage is being done because of the idea that getting enough protein is difficult unless you eat meat. In reality, it's difficult to be protein deficient if you eat 2000+ calories/day.
I'm not advocating that everyone go vegan, but clearly the amount of meat we eat today is unsustainable. I think a good first step to addressing that is some nutrition education, and dispelling the myth that protein = meat.
A plant based diet does not eliminate ecological stress. The requirements for oil and petroleum skyrockets due to the need for nitrates and fereralizers . The only real solution without a ecological impact is reducing world population.
We use land/nitrates/fertilizers to grow crops to feed to cows/pigs/chickens/fish, which convert those plant calories into fewer meat calories. If we ate more plant-based foods, we'd need to grow less, not more.
I understand this is simplistic, as some plants (e.g., iceberg lettuce) provide few calories and are costly to grow. On average, eating from trophic level 1 is more efficient than eating from levels 2 or 3.
It seems to me that a lot of damage is being done because of the idea that getting enough protein is difficult unless you eat meat. In reality, it's difficult to be protein deficient if you eat 2000+ calories/day.
I'm not advocating that everyone go vegan, but clearly the amount of meat we eat today is unsustainable. I think a good first step to addressing that is some nutrition education, and dispelling the myth that protein = meat.