One of my favorite films is Nausicaä of the Valley of the Wind. So finding this was pretty cool.
If you're wondering what in the world this is and you've never seen the film, it's a reference to a historical event in the film's world where a bunch of giant monster things literally set the world on fire. You can see the only real look at the movie's version of the events around 0:09-0:11 in this (Korean) trailer for the film.
Incidentally, it's my favorite Miyazaki film (admittedly of just two I've actually seen, but the other is the much-hyped Spirited Away) as well as just generally among my favorite films.
Incidentally, the actual purpose of the clip I found is to advertise some kind of museum exhibit... or something. I think. Maybe.