This image released by Netflix shows DiCaprio as Dr. Randall Mindy and Jennifer Lawrence as Kate Dibiasky in “Don’t Look Up.” (Niko Tavernise, Netflix via AP/The Minnesota Star Tribune)

"Keep it light, fun," the chipper hosts of a daytime talk show tell Jennifer Lawrence and Leonardo DiCaprio as they prepare to announce that the world is ending in "Don't Look Up."

That disconnect is the movie's main joke. If you've seen "The Big Short" or "Vice," you'll quickly identify "Don't Look Up" as the work of their writer/director, Adam McKay, who has a thing for huge, all-star casts, absurdist humor in tragic situations and hitting us over the head with his message.

The world is told a planet-killing meteor will hit Earth in six months but doesn't want to listen, just like we all seem willing to ignore urgent warnings that climate change dooms our planet.

McKay hits his targets with his crackling, Sorkin-speedy dialogue. The hosts, played by Cate Blanchett and Tyler Perry, are especially interesting since both are more intelligent than they appear but they're so immersed in the put-on-a-happy-face spin their show requires that they can't grasp reality. A stoner played by Timothée Chalamet also shows unexpected dimension. Lawrence's charisma is an asset for a character who is, by design, a downer, and DiCaprio makes sense of what must have been a confusing role on paper, a brilliant scientist who falls under the sway of Blanchett's happy talk.

It's an effective movie but, oddly, not a very funny one. "Don't Look Up" is swift and lively and you can see where McKay wants us to laugh in, for instance, scenes that feature a poll-obsessed president (Meryl Streep) and her dimwitted chief of staff/son (Jonah Hill). But the writing lacks the subtlety of "Dr. Strangelove," a dark comedy to which "Don't Look Up" pays homage, or the satiric punch of the more outrageous "Network."

Unlike those edgier movies, McKay wants to lampoon his characters and make us care about at least some of them, but the script, which has a whiff of Hollywood smugness, can't pull off that tricky balance. Give him credit, though, for a good attempt at doing what may be impossible and for righting the ship in the end.

With world destruction seemingly inevitable, the last scenes of "Don't Look Up" are its best. McKay encourages us to sympathize with even his most odious characters and nails the answer to the inevitable question, "If you knew the world were ending, how would you spend your final moments?"

'Don't Look Up'

*** out of 4 stars

Rated: R for language, graphic nudity and drugs.

Where: In area theaters. On Netflix Dec. 24.