Enough about global warming! Let's talk about:
In the 4 issues of this comic, an unnamed, never seen "enemy" was manipulating Earth's environment for unknown reasons (except to kill everyone, I guess). They found ways to cause massive flooding, to spark a massive increase in undersea volcanoes, to generate massive waves of anti-matter...and in this issue, to cause a new ice age:
Our heroes managed to defeat the enemy's machinations--without ever encountering them--by using their sub to create rubble that blocked "the rift"--and by gum, it immediately worked!!
From Voyage To The Deep #2 (1963)