The species would survive the end of faber-Bosch, yes; in some diminished form. But the species would not survive, if for some reason we needed to voluntarily

The species would survive the end of faber-Bosch, yes; in some diminished form. But the species would not survive, if for some reason we needed to voluntarily stop using faber-Bosch in order to do so—it would take some kind of supernatural event to convince everyone, and even then some countries would probably keep doing it.