He had aliens zap the Big Apple in Independence Day, and a latter-day Godzilla stomp it to mush. Now mayhem meister Emmerich floods the place with a tidal wave, then freezes it over for an encore. Thus is banished any inkling that 9/11 might have affected Hollywood's appetite for childlike destruction. But there's also a serious agenda beyond the usual CGI fiesta, since these rising sea levels and glacial temperatures result from melting polar ice caps altering the ocean currents, an unavoidable by-product of global warming. Sure, the compacted time frame here is gleeful nonsense, but it's solidly founded on environmentalists' credible warnings, allowing the movie to trash the Northern Hemisphere in the noble cause of eco-awareness. Connoisseurs of disaster-movie tack will be relieved to know their favourite elements remain intact, from slumming performers (boffin Holm turns ashen upon the realisation he's facing a snowy demise with only half a bottle of single malt), to dumb macho heroics (scientist Quaid's too late to save the world, so he'll make do with rescuing son Gyllenhaal from iced-in Manhattan), and the regulation child leukaemia 'victim in peril'. True, genuine excitement's in short supply, but the notion that it'll take the onset of a new Ice Age to alter US government environmental policy adds a properly cautionary note to one's enjoyment of the cheese.