I must be close to having seen every English-language movie in the genre, as well as its disaster, dystopian and post-apocalyptic sub-genres. I've even ploughed through dozens of zombie flicks, ridiculous though they are (I Am Legend and 28 Days Later excepted).

The themes these films explore are endless. Sometimes, the catastrophe is nothing more than a backdrop for the usual celluloid fodder of romance, vengeance, an improbable triumph or plain old gore. Yet the apocalypses or societal breakdowns depicted in art tend to reflect the fears of the time. The earlier dystopian tales of last century often centred on class struggle and authoritarianism (think Metropolis, 1984 or, more recently, V for Vendetta). World War II and the atomic age spawned a still-growing collection of post-holocaust survivalist stories (On the Beach, The Day After, The Road). The space race encouraged the alien-invasion genre (Invasion of the Body Snatchers, The Thing), just as the computer age stoked old fears of machines turning on their masters (2001: A Space Odyssey, The Terminator, A.I. Artificial Intelligence).

There are plenty of other causes of these fictional crises: pandemics (see the BBC's brilliant TV series Survivors), mass infertility (Children of Men), an ebbing sun (Sunshine), solar flares (Hell), natural disasters, asteroid impacts, divine judgment (Left Behind: The Movie, for a laugh) and even the gradual dumbing-down of mankind (Idiocracy, for many laughs).

Most are wildly implausible, not that that makes them any less fun (see the gaudy nonsense of 2012, based on the Mayan prophecy that the world will end this year). But critiquing the ''reality'' of this fantasy genre misses the point. I indulge in these films to escape my everyday worries. When watching them, I worry instead about how I'll hide or defend my family from scavenging bandits in the future post-apocalyptic wasteland of northern Canberra. (As I know nothing about guns or cars, and noting again my lack of a vegie patch, I've accepted that we're pretty much goners.)

You may have noticed a gap in this short summary: films that are based on the dominant fear of our time. A handful of science-fiction movies exist which tell of a world devastated by climate change, but they make up a tiny proportion of the genre. There was the expensive 1995 flop, Waterworld, which told of a near-totally submerged planet with no ice caps. In contrast, 2004's The Day After Tomorrow, an extreme portrayal of the Earth passing a climate tipping point, was a box-office smash. In the usual Hollywood style, the story's science was fudged to compress the action (events that would take decades unfolded over a couple of weeks). For some reason, this infuriated many viewers. Newspapers and politicians angrily decried the film as propaganda and inaccurate. Sci-fi fans like me wondered why they took it so seriously; how on earth would they react if they ever saw, say, Independence Day?

But that's the rub with climate change: the public discussions about it have never made much sense. Each debate descends into hateful rhetoric; even escapist fiction is viewed through an ideological prism. As scientists become more certain of climate change, and more confident of their predictions, the community becomes less willing to act. Lowy Institute polls show that more than two in three Australians believed global warming was a ''serious and pressing problem'' six years ago. Today, despite stronger evidence that change has already taken place, and at a faster rate than earlier models forecast, just over one in three Australians hold that view.

This week, United States researchers announced that the shrinking Arctic ice sheet was almost the smallest size on record. It says much about the prevailing public mood that few newspapers even reported the study. I guess we were all too busy seething with indignation at the carbon price, which is so minute it won't change anyone's lifestyle anyway.

It's little wonder filmmakers ignore the only likely apocalypse of our time; we've made it clear we don't want to know about it. Nor would these movies make for riveting viewing, in any event. The pending crisis will be so gradual that we'll be able to continue to deny it. Even my children will probably live mostly comfortable lives, though any grandchildren I may have won't. We'll cop worsening droughts and storms, but we'll survive. Climate change won't destroy our society; it'll just make it slowly poorer.

The scientist and economist who heads the United Nations' climate panel, Rajendra Pachauri, is not prone to hyperbole. Yet five years back, he gave a stark warning that was out of character: ''If there's no action before 2012, that's too late. What we do in the next two to three years will determine our future.''

We weren't listening. We're still not. We're too absorbed in our escapist fantasies to deal with the dull but real doom on our doorstep.

Markus Mannheim edits The Public Sector Informant. Send your tips to aps6@canberratimes.com.au