Even a nuclear war is highly unlikely to eradicate the human species as a whole, the sheer numbers of human beings makes us, as a species, extremely resilient against extinction.
That should not be understood as me saying that we can do whatever we want, not at all. On the contrary, we should do a lot to restore the damage we have done to the earth as fast as possible, or at least reduce the amount of damage we still do to zero if possible.