Apocalyptic means like the end of the world. Skies the wrong colour, and nothing where a town used to be.
It describes scenes, warnings and predictions, so an apocalyptic sky and apocalyptic warnings about a policy are both standard, and the second use is usually a criticism of exaggeration. The word comes from the Book of Revelation, where an apocalypse originally meant an unveiling rather than a catastrophe, which is a considerable shift. Post-apocalyptic names the whole genre about what happens afterwards.
1adjectiveapocalypticResembling or predicting the end of the world.
“The photographs of the valley were genuinely apocalyptic.”
An apocalypse is an uncovering. Greek apokalyptō meant to reveal or uncover, so the word named a revelation long before it named the disaster being revealed.
Ancient Greek
ἀποκαλυπτικός — revelatory
Latin
apocalypticus
English, today
apocalyptic
Built from
Borrowed from Latin apocalypticus, from Ancient Greek ἀποκαλυπτικός (“revelatory”), from ἀποκάλυψις (“revelation”), from ἀποκαλύπτω (“to reveal, uncover”).
Etymology from Wiktionary, CC BY-SA