I do like a good disaster movie. I enjoyed this one - The Day the Earth Caught Fire (Pax films, 1961). Free to watch at archive.org:
http://archive.org/details/TheDayTheEarthCaughtFire1961
Probably the calmest disaster movie I've seen, an interesting choice not to focus on heroic scientists or heroic first responders but on one newspaper.
The Day the Earth Caught Fire : Pax Films : Free Download, Borrow, and Streaming : Internet Archive
Title: The Day the Earth Caught FireSummary: When the U.S. and Russia unwittingly test atomic bombs at the same time, it alters the nutation (axis of rotation)...