Last night I watched Life After People, an apocalyptic docudrama with a twist. The scenario is that suddenly all humans disappear from the face of the planet. What happens next?

• After a couple of days, all the lights go out.

• After a couple of weeks, the streets are wild with feral dogs.

• After a couple of months, underground tunnels start to flood.

• After a couple of years, roads are disappearing beneath the undergrowth.

• After twenty years, buildings start to collapse.

• After two hundred years, cities are effectively raised to the ground.

• Once you get into time spans of over two thousand years, any traces of human life start to disappear for good.

I took the film to be a modern-day myth. For one thing, the forensic science deployed in telling the tale served the drama more than, say, predictive accuracy. There was no mention of plastics, for example, perhaps because plastics don't do anything very much even over the longest time spans it considered. Or there was speculation about cats growing webs like flying squirrels so that they could leap between buildings in Manhattan, except that I suspect any such evolutionary developments would take far, far longer.

It was a moral tale, of course, one of the earth returning to its natural state after the unnatural activities of humans had ceased. Once more, the seas would teem with fish, forests would cover the land, refined materials like iron would return to the minerals from whence they came. Note the choice of details, precisely reflecting current anxieties about over-fishing, deforestation and climate change, and the need to recycle.

Personally, I don't have a problem with that. Our relationship with the world around us needs far more than just rationality to be a good one. If the programme served to inculcate a few moments of piety towards the planet on bank holiday sofas, then all well and good.

On the other hand, it could have been taken in the opposite way, a kind of consolation that even when humankind does its very worst, nature recovers, so we might as well carry on regardless. (Some scenes were taken from Chernobyl where humankind's worst was done: only twenty years on, trees have returned aplenty, and there's more wildlife in the locality now than in surrounding habitats.) Others might find the implicit misanthropy annoying, as when scientists confessed to feeling comfort in the thought that if we disappeared today most of nature would be glad to see us go.

But that's another reason why the programme can be read as a successful, popularizing myth. It speaks and yet there is no controlling its interpretation.