The amount of inanity exceeds the quantity of the special effects in “2012,” and the movie is filled to the brim with them. Writer-director Roland Emmerich (“Independence Day,” “Godzilla,” “The Day After Tomorrow”), whose professional mantra seems to be “When in doubt, blow something up” (preferably a well-known landmark), tries to deliver the ultimate disaster movie, and winds up with something like the ultimate movie disaster. When one character gloomily says, “This is bad, really bad,” you can’t help but agree.

The script is tied to the current obsession with the Mayan calendar, which supposedly ends three years hence and thus predicts a great change, either for good or ill. In Emmerich’s fantasy (cobbled together with Harald Kloser), scientists in 2009 notice a growing instability in the earth’s crust resulting from unprecedented sunspot activity, and determine a looming catastrophe in which the terrestrial surface will shift and doom the entire population. In response, the governments of the earth join together in a secret effort to save a select portion of the planet’s billions of residents, along with species of animals and the greatest human cultural artifacts, when the apocalypse strikes.

Of course, one can’t just play out such a scenario in documentary style; you need to put some flesh-and-blood individuals with whom viewers can identify, and for whom they can root, in jeopardy. So to contrast with the maneuverings of political bigwigs—President Wilson (Danny Glover) and his daughter Laura (Thandie Newton), White House Chief of Staff Carl Anheuser (Oliver Platt) and his chief science advisor Adrian Helmsley (Chiwetel Ejiofor)—Emmerich gives us a slew of ordinary folk. Two are a couple of old duffers (George Segal and Blu Mankuma) who play tunes for cruise ship tours—presumably so that Emmerich can get some peril-at-sea into the mix (“The Poseidon Interjection,” anyone?). But the major audience surrogates are failed author turned limo driver Jackson Curtis (John Cusack), his ex-wife Kate (Amanda Peet) and their kids (Liam James and Morgan Lily), along with her new husband Gordon (Tom McCarthy). And as radio host and prophetic doom-sayer Charlie Frost in the initial reels, there’s a bug-eyed, scenery chewing Woody Harrelson.

A goodly portion of the picture gives us the upper-echelon machinations as the disaster strikes earlier than expected, with the president grieving and his daughter finally brought into the loop, and Anheuser and Helmsley splitting into the boorishly pragmatic and sloppily humanistic camps, respectively. (Anheuser does the Al Haig “I’m in charge here” bit after Wilson chooses not to escape, and certainly his surname is meant to suggest the beer company, and thereby lead to “Bus(c)h.” Of course, you can also see his attitude ultimately reaching back to old mine-shaft guru Dr. Strangelove.) Helmsley, meanwhile, pleads at the end that his ship admit the thousands doomed by the incapacitation of their vessel, giving a rah-rah “do it for humanity” speech that conveniently forgets that all those souls had apparently bought their tickets to safety for a billion dollars each while leaving everybody else behind to perish without much of a thought. Some empathy, some uplift.

One of those billionaire would-be passengers is crude Russian mogul Yuri Karpov (Zlatko Buric), who just happens to be Jackson’s boss; and the Curtis clan (plus Gordon) wind up cadging a ride to China, where the ships await, with him, his obnoxious twin sons, and his trophy mistress. But Yuri drops all of them, save his sons, in the last leg, and they must fend for themselves to get aboard. Rest assured that the outcome follows Oscar Wilde’s dictum about fiction—that the good end happily and the bad unhappily (though I must admit that Gordon’s fate seems undeserved).

But all the “human” action is really beside the point. The sole reason behind a picture like this is the effects, and from a purely technical perspective they’re fine. But they’re definitely overdone. The California reel in the second half-hour, when the Curtis clan is driving or flying past collapsing buildings and freeways, is ludicrously busy. And while it’s obligatory for landmarks to be obliterated in this sort of flick, surely Emmerich could have forsworn repeating the scene of the White House being demolished, which he’d already used in “Independence Day.” (Is it a homage to himself?) Certainly having it smashed by an aircraft carrier on a tidal wave (the John F. Kennedy, no less) isn’t enough to justify it. And what’s with the anti-Catholic bias? Not only do we see the famous Rio Christ statue explode, but a long sequence details how St. Peter’s (particularly the Sistine Chapel) and its entire courtyard are wiped out. No other religion gets such savage treatment. We see the Kaaba at Mecca at one point, for example, but not its destruction; nor is the Wailing Wall touched. What’s up, Roland?

Anyway, even the best disaster effects pale with such endless repetition, especially since in the end Emmerich doesn’t have the guts to go whole hog and have the earth turn into a cinder. Instead we hear that one whole continent has escaped destruction (Africa, of course—how very PC) and that in less than a month the atmosphere has cleared of harmful toxins. So if one goes expecting the globe to do a Krypton, he’s going to be very disappointed, because Emmerich wants it both ways. Yes, the end of the Mayan calendar means great change, but for both good and ill. It’s a cop-out.

Then there’s the unhappy reality that we spend most of the time watching totally cardboard human figures dashing, driving and flying about in an effort to escape the flood, explosion or burst of flame that’s nipping at their heels while reciting dialogue that sounds as though it were lifted from a second-rate comic book. The acting in “2012” is poor across the board—from the overripe posturing of Harrelson, Buric, Segal and Platt to the subdued turns by Ejiofor and Newton, who only seem not to have gotten into the goofy spirit of the thing, and the even gloomier one by Glover, who seems perpetually constipated. The performers you feel sorriest for, though, are McCarthy, a fine director (“The Visitor”) and good comic actor stuck in a thoroughly dumb part, and of course Cusack, whose inherent amiability is called on entirely too often to shoulder the burden. He’s been in brainless action movies before—remember “Con Air”?—but at least there he was in support. Here he must try to carry the picture nearly solo, and he’s frankly not up to it.

It’s true that you can enjoy much of “2012” if you simply choose to take it as an unintentional comedy, in much the same way you had to swallow Irwin Allen’s slew of seventies disaster epics if you’re going to make it through them at all. But the utterly juvenile jokes that Emmerich scatters through this movie (the lowest being when a character says “We’re gonna need a bigger plane”—get it?) suggest that comedy was not his primary goal. To misquote R.E.M., “2012” is the end of the world as we know it, and after suffering through its two-and-a-half hour running-time, I didn’t feel fine, and you probably won’t either.