Maybe he’s angry. (His last movie, “10,000 B.C.,” was widely panned.) To judge from the similarity with which he stages the multiple disaster sequences in “2012” — a limo, a camper, a plane, a bigger plane and some really big boats, by turns, race ahead of the impending doom — he seems exhausted. It’s no wonder. Finding newish ways to cram large-scale carnage into a PG-13 package is tricky. You need enough verisimilitude to hook the audience, but not enough to freak it out: the collapsing high-rises have to look real enough to be plausible, as do the itty-bitty computer-generated figures falling from them. Swirling dust and flying debris serve that commercial purpose, not rivers of blood and body pulp.

And so the dust swirls in “2012,” and debris and bodies fly, though at a careful distance. It all looks fairly convincing and also familiar: if you don’t repeatedly flash on Sept. 11, Mr. Emmerich will surely be disappointed. That gives the movie a cheap frisson, though the larger shivers are supplied by the onslaught of pricey special effects, which have grown predictably snazzier since his last cataclysm. Alas, the clich├ęs of the disaster narrative remain in place. To that ruinous end, the larger catastrophe in “2012” functions as both the trigger and backdrop for a soap opera about a fractured family, standing in for the rest of humanity, which heals as the world falls apart. That’s the idea, anyway.

In truth, the central family here is as disposable as the billions of computer-generated humans that soon pile up after disaster hits. Written by Mr. Emmerich and Harald Kloser (they last collaborated on “10,000 B.C.”), “2012” takes its plot points and shifting plates from both science and fiction, and its title from doomsday prophesies, including a myth about the end of days derived from a reading of the Mayan calendar. Though not much is made of the Mayan angle, the most amusing character, a doomsday prophet and radio broadcaster played by Woody Harrelson, seems in hair, beard and interests to have been drawn along the predictive lines of the real author Daniel Pinchbeck (“2012: The Return of Quetzalcoatl”).

Mr. Harrelson looks like he’s actually having the kind of good time stupid movies should provide but that this one roundly fails to deliver. Despite the frenetic action scenes, the movie sags, done in by multiple story lines that undercut one another and by the heaviness of its conceit. Humanity is dying, after all, as the television talking heads keep repeating, and while most of the dead are specks on the screen, Mr. Emmerich occasionally brings you close to the calamity. In one scene a musician (George Segal) calls his estranged son, but the phone is answered by the granddaughter he’s never seen. She’s cute, but then her house shakes and she’s gone, vaporized so that a sob can catch in Mr. Segal’s throat and ours.

There’s no time for real tears in movies of this sort, of course, though there’s plenty of space available for synergistic product placement, as evidenced by the Sony Vaio equipment that fills the government offices where the American president (Danny Glover) stoically stands by. Closer to the ground, another patriarch (John Cusack) plays his part as a divorced dad who will be enlisted for the usual heroics, while Amanda Peet rolls her eyes as his embittered ex. Depending on your tolerance for Mr. Cusack’s mugging, she has traded up or down by landing a plastic surgeon (Tom McCarthy). Completing this family portrait are two irritating children, a preadolescent boy (Liam James) and a younger girl (Morgan Lily).

Chiwetel Ejiofor, as some sort of wizard scientist, gets the chance to say “My. God.” several times in a credible American accent while the less-fortunate Oliver Platt plays a sleazy politician who’s equal parts devil and ham. Thandie Newton shows up as the president’s daughter who, because movies like these subscribe to the Noah’s ark theory of onscreen hookups (two of every kind), becomes an eventual romantic foil for Mr. Ejiofor’s character. Somewhere in the Himalayas a young Tibetan monk (Osric Chau) ponders the mysteries of life as his brother (Chin Han) heads off on a secret mission in China where salvation waits onscreen and, presumably, in that country’s contribution to the movie’s global box-office take.
“2012” is rated PG-13 (Parents strongly cautioned). Old Testament-style destruction served with a smile.

Directed by Roland Emmerich; written by Mr. Emmerich and Harald Kloser; director of photography, Dean Semler; edited by David Brenner and Peter S. Elliot; music by Mr. Kloser and Thomas Wander; visual-effects supervisors, Volker Engel and Marc Weigert; production designer, Barry Chusid; produced by Mr. Kloser, Mark Gordon and Larry Franco; released by Columbia Pictures. Running time: 2 hours 38 minutes.
WITH: John Cusack (Jackson Curtis), Chiwetel Ejiofor (Adrian Helmsley), Amanda Peet (Kate Curtis), Oliver Platt (Carl Anheuser), Thandie Newton (Laura Wilson), Danny Glover (President Thomas Wilson), Woody Harrelson (Charlie Frost), George Segal (Tony Delgatto), Tom McCarthy (Gordon Silberman), Liam James (Noah Curtis), Morgan Lily (Lilly Curtis), Chin Han (Tenzin) and Osric Chau (Nima).