Earthquakes in London, National Theatre: Cottesloe, London

With plays such as My Child and Cock, Mike Bartlett has made his mark as a laser-sharp minimalist. Now he's been encouraged to "think big", as they say, in Earthquakes in London, a sprawling, three-and-a-quarter-hour, five-act epic that, while set mostly in the present, spans the late Sixties and 2525 as it examines how life is lived under the threat of climate change and impending catastrophe.

"It's Weimar time, it's Cabaret across the world," declares Robert, the maverick scientist, who was quick in the Sixties to spot the danger of carbon emissions, but sold out to the aircraft industry. Now a latter-day prophet of doom, he has been a disastrous father to the three women whose fortunes form the focus of a piece that sometimes reminded me of Angels in America with its multiple perspectives and fantastical intimations of apocalypse.

The oldest daughter, Sarah (Lia Williams), is a Lib Dem minister in a coalition government who is striving to put a stop to airport expansion. The youngest, 19-year-old Jasmine (Jessica Raine), is all ripped tights and hedonistic rebellion. Pregnant and desperately unsure whether it is ethical to bring a child into such a perilously uncertain world, Anne Madeley's Freya has a moving imaginary encounter with her teenage daughter-to-be. Seeming to justify her mother's foreboding, this apparition's profession of pessimistic pointlessness is in sharp contrast, though, to the promise and air of purpose in the girl that we objectively witness in the final scene.

Rupert Goold's staging of the piece (a co-production between Headlong and the National) characteristically goes for broke in its flair and flamboyance. An orange S-shaped catwalk snakes through the punters, some of whom sit by it on swivel-chairs, transforming the Cottesloe into a phantasmagorical vision of a louche, moneyed bar and powerfully evoking a society bent on distracting itself from the truth through decadent excess.

The overkill extends at times, though, to the script. The fifth act is a case of not knowing when to stop, as Bartlett intercuts the affecting tentative reconciliation of the family at a birth-and-death with an irritatingly fanciful futuristic scene in which Freya, aroused after cryogenic suspension, pines to return to the past to deliver her earthquake-interrupted message to the planet. The intermittent outbreaks of song-and-dance can feel a bit too close for comfort to Enron (also directed by Goold) in the calculatedly cheerful cheek with which they offset gathering darkness.

What's impressive about the piece is its mix of zeitgeist-capturing ambition and irreverent refusal to lapse into tidy-minded preaching. For example, I liked the way in which Freya's husband, rightly horrified at his father-in-law's doom-mongering advice to her, is a just a touch compromised in this stand by the fact that he is himself the grumpy author of a stocking-filler called Fifty Shit Things about Britain. If not as theatrically penetrating, for my taste, as the best of Bartlett's miniatures, Earthquakes in London still scores highly on the Richter scale. Paul Taylor

To 22 September (020 7452 3000)