Honestly no one knows if something will or won't happen. Heck, it could happen tomorrow.
This is an often repeated statement that simply is not true. There are many things we can predict with great certainty. Things that can be shown to
not be possible:
1. a new planet in our solar system that enters the orbits of the known planets.
2. the sun using up its hydrogen fuel in the next billion years
3. rapid pole shifts
The unknowns are things like acts of terrorism, human started wars, a small object striking the Earth, or a massive solar flare. But other things can
be shown to be impossible.