starstar-halfstar-outlinestar-outline(1.5 stars)

If you’re looking for an excellent internalized drama in the guise of a disaster flick, I suggest that you watch “The Midnight Sky” on Netflix.

“Greenland,” on the other hand — a middlebrow, moderate-budget action adventure starring Gerard Butler as a man trying to save his marriage, his son and his life from a disintegrating “planet-killer” comet that is heading straight for Earth — feels like something of a bait-and-switch.

What happened to the guy who played the daring hero of the dumb but fun, CGI-mayhem-heavy “Geostorm”? Here, in a tale that features one scene — on a TV screen! — of Tampa getting flattened, and another featuring a bit of molten debris raining down on a highway clogged with bumper-to-bumper traffic, we’re stuck, for the most part, watching Butler’s John Garrity drive a series of stolen/borrowed vehicles from Atlanta to Canada on his way to convey his estranged wife Allison (Morena Baccarin) and diabetic son (Roger Dale Floyd) to an emergency shelter.

On the side, he makes it clear that he’s trying to atone for infidelity. It’s a bit of a heavier lift than Butler is used to. (Much of “Greenland” features chaotic crowd scenes. The real disaster is how quickly mankind descends into dismaying depravity.)

That’s because, to get the story going, screenwriter Chris Sparling (“Down a Dark Hall”) has come up with a strange idea: To prevent the loss of essential workers necessary to rebuild the world after the comet passes, the U.S. government has selected an elite cadre of professionals — doctors, for example, and structural engineers like John — to be herded off to an underground bunker for preservation. Everyone else? Good luck.

It is uncomfortably reminiscent of current affairs.

This leads to scenes — after each of the three Garritys has been temporarily separated from the others — in which strangers do horrible things to get hold of the protagonists’ wristbands authorizing passage to shelter. Violence. Kidnapping. At least it kicks up the suspense a tiny bit. Shots of screaming mobs at the airport are just anxiety-inducing.

There is one quiet interlude during which the family is reunited at a horse farm belonging to Allison’s father, nicely played by a stoic Scott Glenn — whose character, somewhat bizarrely, is calmly playing cards with friends when we meet him. This, as the world is coming to an end. That’s a bit too stoic.

The interlude gives John the opportunity to emote remorse — aided, throughout the film by flashbacks to happier times — and for Allison to forgive him. That, in a nutshell, is the meat of the film, not the survival of the human race.

It’s small ration, in a story that tries to be nutritious but would have been better served by just admitting what it is and offering up junk food.

PG-13. Available on demand. Contains intense sequences of disaster action, some violence, bloody images and brief strong language. 119 minutes.