Filmmaker Roland Emmerich (“Godzilla,” “Independence Day”) is up to his usual tricks in “The Day After Tomorrow” — which is to say, pulverizing large chunks of the Western hemisphere. Those Germans and their wacky fetishes.

The difference, this time, is that we really have no one but ourselves to blame. Those tornados whipping through Los Angeles? Self-inflicted. Or maybe they aren't. Honestly, it's hard to say. Emmerich has pumped so much conflicting pseudo-science and karmic irony into the movie — along with his usual kindergarten dialogue and stock characters — that he effectively nullifies his own impassioned warnings of environmental disaster. As globally thinking movie-goers, all we can really do is sit back and enjoy the carnage.

Critics have accused Emmerich of partisan politics in “The Day After Tomorrow.” Gee, ya think? It only takes him 10 minutes or so to unveil a reference to the Kyoto Protocol, which the United States foolishly abandoned, climatologist Jack Hall (Dennis Quaid) reminds the Vice President (Kenneth Welsh). If any further allusions to the current administration need be demonstrated, Emmerich includes a scene where the President (Perry King) is handed a piece of actionable news and immediately turns to his older, crustier second-in-command. "What do you think we should do?" the Prez asks, ever the master delegator.

Initially, no one takes Hall seriously when he predicts an impending Ice Age, much like one that devastated Earth over 10,000 years ago.

Unbeknownst to scientists, global warming has accelerated the process beyond even Hall's predictions, causing the Gulf Stream to cool and the ocean to reach a “critical desalination point.” Right, one of those. All that matters to the layman is that monster twisters are laying waste to Hollywood and a giant tsunami is threatening to deluge New York City. Is it mankind's fault? Emmerich implies as much, but if the same thing happened 10,000 years ago without the benefit of aerosol cans and Lincoln Navigators, why point fingers?

Hall, our putative hero, is pure Cassandra — he knows glaciers and two-week ice storms are coming, but has no remedy other than advising the President to evacuate half the country. The upshot being, “The Day After Tomorrow” is not a stop-it-or-else sort of disaster flick — after the most spectacular calamaties have run their course, the main drama involves Hall's arduous slog through the tundra to rescue his teenage son (Jake Gyllenhaal from “Donnie Darko”), marooned in the ice-bound New York Public Library with his friends. Gyllenhaal is sulky and aloof in the role; pretty classmate (Emmy Rossum from “Mystic River”) notwithstanding, this survival business doesn't seem to push the kid's buttons.

For a time, Emmerich is able to deliver the knotty apocalyptic thrill promised in the trailers. The L.A. tornado scene (produced by f/x production houses Digital Domain and The Orphanage) is eye-poppingly realistic, with the city splintering to pieces under a rueful, charcoal sky.

Other sequences are less moving, including a recurring bit in which the filmmaker uses “super-cooled air” like a swarm of killer bees, chasing the characters through hallways, underground, etc. Oooh, cold air. How will we sleep at night?

Emmerich hitches his hybrid car to human interest subplots to get us through the last hour or so, with minimal success. Mostly, the characters are a banal mob of signifiers borrowed from the Jerry Bruckheimer supply locker, including (but not limited to): The estranged couple (Sela Ward plays Quaid's ex), the teen couple, the homeless guy with the dog, the contrite President and, yes, the kid with cancer. It would be manipulative if it weren't so inept. If Emmerich were more articulate and elegant in his methods, we might have internalized some of that humility which he unleashes on us like a dammed river (in the end, Americans escape the storm by fleeing to Mexico — it doesn't get much more humiliating than that). Preachy and sensationalistic, “The Day After Tomorrow” is akin to a safety lecture from a flunky bureaucrat.

Emmerich's out-of-touch sermon reaches a fever pitch in the final scene when — after the death of billions and the demise of Western civilization as we know it — he has the temerity to offer us the following silver lining: Clean air.

The Day After Tomorrow
Starring: Dennis Quaid, Jake Gyllenhaal, Sela Ward, Emmy Rossum
Rating: PG-13 (intense situations of peril)
Running time: 124 min.
Grade: C