The world ends everyday.
However, as a result of the phenomenon described as “Quantum Immortality”, because Earth still exists in a synonymous spacetime stream in a parallel universe, the observer of the doomed Earth in the “first” universe merges with the observer of the extant, unharmed duplicate Earth. In this case the observer is we, Humanity, or more solipsistically, you, You (or me, Me).
The world shall only truly end when every single Earth is destroyed or becomes uninhabitable, depending on your reference, in every synonymous spacetime stream. Alternatively, again solipsistically, the end may arise when every observer is destroyed. Naturally, the end is absolutely certain if the multiverse itself ceases to exist, provided such a thing is possible. Though, I do not see why there could not be parallel multiverses as well. I bet you never thought of that, did you?
I do hope that you can find a way to enjoy eternity.
…discussion continued in Part II…