The human species will not end, we are way to many people for that. Even if 99,9% of people die, the remaining 8 000 000 people are more then enough to allow for stable populations even if those 8 000 000 are spread all over the globe in smaller communities.
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.