We cannot claim that our damage to this planet will reverse before that limit is reached. It might, but we have no basis to say it will.

I just got to this part and that’s a resounding no, even if we dedicated all our resources to it, we couldn’t literally sterilize Earth. I can’t even think of a cosmological event in the next million years that would have this effect.

Earth will be just fine. We will likely be gone by then, but there will be life and it will do just fine. You are seriously lacking knowledge and sense of scale of Earth and the ecosystem and life on a broad scale. Go back to start and try again.