EVERY SATURDAY MORNING I go round the house turning off lights, putting the tops back on children’s pens and wondering if I can recycle my jeans for one more day.

I wouldn’t dream of filling the whole kettle to make a cup of tea. And if my wife isn’t about and I think I can get away with it, I tweak the thermostat down a notch or two. I smoke roll-ups rather than ready-mades because, as everyone knows, roll-ups are the healthy, environmentally friendly option and the other ones kill you.

I can’t abide excess packaging, partly because I shop by bicycle and buy as much food as will fit in my rucksack. I’ve been known to leave a small heap of it at the checkout, stripping off outer layers of Cellophane, plastic and cardboard, amalgamating items, transferring products out of their original casing into my own containers, getting funny looks from the check-out girl. I’ll take Carr’s water biscuits out of their box and leave that behind. If berries have been sparsely packed, I’ll rationalise two plastic cartons into one. Once I dispensed with the outer Weetabix box. The white-plastic wrapped inners slid in nicely, one in each side pocket. And if I ever bought After Eights, which I don’t, I’d dump all those individual sachets, because they’re really silly.

If I examine my motives honestly, I find that none of them has much to do with saving the planet. I recycle because I like the sense of order and achievement that comes with fulfilling small domestic routines.

I boil the right amount of water because it’s quicker. I ride a bike because it is the most efficient way to travel around London and, while I may not burn any petrol, the bike burns plenty of calories. Every ten miles another sandwich dies. If such selfish motives still produce the desired ecological outcome, then no worries. In fact, you might say, human nature being what it is, the only way to promote mass greenism is via such an appeal to enlightened self-interest. But what happens when the self-interest isn’t enlightened? What happens when actual self-denial is required?

The best example I can think of is berries. I’m very keen on all forms of berries, your straw, your rasp, your blue. I like the taste, they’re good for you and I can (just about, with swingeing economies elsewhere in the family budget) afford them. In the summer, there’s no problem.

In the winter, two green imperatives come into conflict. One is the desire for me and my family to eat healthy food. Blueberries in particular, if the propaganda is to be believed, will help my children to live fulfilling, Nobel prize-winning lives until they’re about 150. My heart sings with every single one I can get inside them. The other imperative relies on a concept I’ve only recently become aware of: food miles.

Food miles — the distance each food has travelled to your plate, with all the energy consumption and emissions that implies — appeals to the O-level geography student in me. Last Saturday I bought blackberries from Mexico, raspberries from Spain, blueberries from Chile and strawberries from Israel.

Gathering all this deeply unseasonal food in East London comes at a price, namely about £12 and what, 12,000 miles?

More, probably. To indulge my desire for year-round soft fruit, chunks of ice cap are crashing into the sea. The trouble is, and I know if everyone thought this way, catastrophe awaits, but the food miles argument is asking me to forgo a tiny and yet tangible personal good in the present to avert an admittedly huge and yet only fuzzily potential public disaster in the future.

I just don’t think I’ve got either the discipline or the imagination to act on that basis. I need the decision taken out of my hands. And the best way to do that is to price me out of the market for exotic produce in midwinter. It strikes me that £12 for two punnets of blueberries, two of raspberries, one of strawberries and one of blackberries is not a great deal considering that they have come halfway round the world.

Now, I’m a free trade kind of guy. I don’t see why I should support blueberry farmers in Kent in July, and penalise blueberry farmers in Chile in February. I don’t want a tariff, but I do want a huge tax increase on aviation fuel. Turn this stuff back into a luxury item reflecting its true cost and see just what price I’m prepared to pay. I’d be interested to find out.

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