Hot air.... not only is it responsible for the climatic chaos that turns half the planet into an ice pack, it accounts for most of the script too.

But that's no matter, because The Day After Tomorrow delivers exactly what we've come to expect from a summer blockbuster - and then some.

It all starts when the world won't listen to climatologist Jack Hall (Quaid, in set-jawed Harrison Ford mode).

He predicts that another ice age is imminent, but when fellow scientist Terry Rapson (Holm) calls with ominous news, even he is surprised that it has come this soon.

Before you can say "It's a bit parky out there", gigantic storm systems virtually obliterate the northern hemisphere: Tokyo is battered by hailstones the size of tennis balls, LA is levelled by twisters and New York floods before the whole lot freezes.

As all this is going on, Jack's son Sam (Gyllenhaal) holes up in New York's public library with a handful of people who paid heed to his warnings against braving the storms.

Then, despite his own advice, Jack makes a mystifying and probably suicidal bid to rescue his boy...

From the ominous opening scenario, through a deluge of spectacular set-pieces to the wonderfully ludicrous acts of human heroism, this is eco-preachy entertainment of the highest order.

So the story is nothing new, although Emmerich and his co-writer throw in a few nice moments of irony while hammering home their message - such as the beleaguered US government wiping out Third World debt as its warmth-seeking citizens clamour to get into Mexico.

But with tornadoes raging, tidal waves rising, supertankers sailing through Manhattan and ice taking over the world, this isn't about the script.

An apocalyptic mix of the laudable and the laughable, TDAT certainly gives the audience its money's worth.

Elliot Noble