why using such an unusual word: "cataclysmic"
Wiki leads to this kind of explanation:

[link to en.wikipedia.org]

A doomsday event is a specific plausibly verifiable or hypothetical occurrence which has an exceptionally destructive effect on the human race.[1] The final outcomes of doomsday events may range from a major disruption of human civilization, to the extinction of humanity, to the extinction of all life on the planet Earth, to the destruction of the planet Earth, to the annihilation of the Solar system, to the annihilation of our galaxy or even the entire universe.
From link.

I like that they didn't leave anything out.