Exactly. It's interesting how Nosu ignores this, and thinks that it's good for the environment if everyone stops eating beef, but not any worse for the environment if everyone becomes vegetarian.
I don't want to speak for him, but I'd say it's not worth responding to because it's an idiotic argument. First of all, I haven't seen anyone here claim that any sort of agriculture on the scale necessary to support the world's human population is without impact. But please let's not pretend that this thread is full of conscientious meat-eaters who only do so because they are oh, so concerned about the impact of nitrogen fertilizers on the Gulf of Mexico.
It's indisputable that the number of calories obtainable per acre of farmland is much, much higher for grain and vegetables than for meat, even leaving aside the animal suffering involved. Are there major ecological issues with the way all food is produced in the world today? Of course. But then I haven't seen anyone claiming otherwise. Have fun with your straw men.