Like you, I'm a completely selfish bastard who doesn't give three figs about future generations. I want to use my kettle whenever I want, as often as I please. So what if it's murdering the ice caps? What have polar bears ever done for us anyway? Name one good album by a polar bear. You can't. They don't understand that respect is earned, not given. Take a long, hard look at the next polar bear you come across. Note how it makes no effort to engage you in conversation. Ask to borrow its coat. Not a chance unless you kill it with a breezeblock or something. Check out the size of its belly: someone could do with shifting a few pounds, that's for damn sure. Endangered? Enfattered, more like.

Blah blah Clarkson blah. We're screwed, of course. Humankind will happily swerve the planet into climatic meltdown for the sake of heating a few patios. Everyone knows this, we're just hoping we can ignore our way out of it, like a passenger staring fixedly at the in-flight entertainment system on a flight where all four engines have failed. Still, if you're in the mood for a novel take on just how screwed we all are, tune in to Bang Goes The Theory: Human Power Station (Thu, 8pm, BBC1), a programme which manages to be both a characteristic chunk of breezy mainstream BBC edutainment and a violently discouraging portent of impending ruin. The presenters smile as they deliver one piece of bad news after another: it's a bit like being repeatedly punched in the face by a Butlins Redcoat.

The idea is a simple one, and pretty boring on the face of it. They've plonked an average suburban family in a house and asked them to behave as though it's a normal day. Unbeknown to said family, the house's entire supply of electricity is being generated by a room full of human volunteers in a giant warehouse next door; 80 of them, all sitting on bikes. If mum switches the telly on, 20 of them have to start pedalling. If dad has a shower at the same time, 40 more have to join in. And if one of the kids simultaneously decides to microwave an Action Man, it's all hands to the pump (or rather feet to the pedals).

Hanging on the wall in front of the cyclists is a big screen displaying a continual live feed from the house, which is a nice device because it means the knackered pedallers gasp with horror and desperately call for more people to leap in the saddle and help each time a family member approaches, say, the dishwasher. This is where the fun comes in: it's basically like an episode of Big Brother with a sternly philanthropic sense of purpose and a curious emphasis on household appliances.

The interplay between the oblivious onscreen family and the anonymous army generating their power reminded me of The Numbskulls, the vintage Beezer comic strip depicting tiny and often bemused workers toiling inside a man's brain. The main difference is that the Numbskulls weren't perpetually hammering away on exercise bikes, pissing litres of sweat through every pore. The room in which the "human power station" is housed must reek like a submariner's bunk bed on National Underwater Thermostat-Tinkering Day.

As a frightening visual illustration of just how much energy we consume in an average day, it largely succeeds. But as an hour of TV entertainment, it's slightly less convincing. About halfway in you'll probably fancy a break. I left the show running for a bit, wandered into the kitchen and boiled a kettle, thereby killing eight more polar bears. Like I said at the start, we're all screwed. My advice: buy shares in penguin coffins today. And get used to the way the human power station works, because the Chinese will probably be forcing us all to take part in something similar in 10 years' time, as an eco-friendly means of keeping their mass prisons illuminated. Happy Christmas.

Buy Charlie's new book The Hell Of It All for £8.99 (rrp £12.99). Visit guardianbooks.co.uk or call 0845-6064232