There's always a few little hints at first. I was in Tesco's the other day, and there was no filter coffee on the shelf. None. Just a couple of jars of that vile instant dried sludge they lay on for the disadvantaged. It was just the little Express Tesco near me, not the big one, but still.

Now we've all seen disaster films, so I expect you're thinking the same thing I'm thinking, namely that's how it begins. There has to be a minor mishap or two at the beginning, just to set the scene. They're usually trivial in themselves, but when you put them together an ominous pattern emerges. Unexplained tremors in the suburbs of San Francisco. Ice sheets cracking under Dennis Quaid's feet. Electrical problems in a new tower in San Francisco (San Francisco again. Such a terribly dangerous place, yet gay people thrive there. God must really love them).

I think that's what's happening in the real world. Minor mishaps. At first.

Mark my words, the mishaps may start small, but they escalate fast. This week there's no decent coffee. Next week there might not be any cakes, and that's it for elevenses.

Other meals could go the same way. Foot and mouth would take down the steak houses, and there wouldn't be much call for chip shops if potato blight cut down the nation's tubers.

Suppose the farming malaise spread to other key sectors, like oil or football. City centres would be gridlocked as cars ran out of petrol. Staple goods would be even more expensive. Previously reliable players like Lee Johnson would start to make basic defensive errors. Believe me, it might happen.

Farms, factories and takeaways are repossessed (no more pusillanimous conditional tenses now, I'm hitting my stride). Ministers resign. Gary Johnson gets a new job at Rovers, and takes all our best players with him. Demagogues take over the streets, as Abu Hamza and Martin Amis duke it out for control of the Finchley Park crack trade. London burns, and being by the river somehow fails to help.

A sign appears outside the Ivy - Meat Curry, £5 a bowl. Only the A-List can afford to pay. Fern Britton waits tables for scraps, but Judy Finnegan's got none to spare, and somehow Bill Oddie's got owl feathers caught in his beard.

By now we're into the final stages. Famine, plague, religion. The seas rise, comets appear from nowhere and the last boy kills the last girl in a fight over the last gnawed bone.

A pessimistic vision, you might think, particularly as it turned out they'd moved the coffee to a different shelf. How little you understand.