Having filled my small one-litre family car with biodiesel, I drive the four miles to my local supermarket.

There, I collect a trolley and trawl the aisles on the weekly shop. I take time seeking out goods that have been 100 per cent ethically traded or products that have been produced using only 100 per cent organic methods of farming.

Sweet potatoes grown by struggling peasants on the foothills of the Andes, yoghurt made by one-parent families in the small hill villages of Bhutan, baby beetroots harvested by poverty-stricken smallholders from the Russian steppes.

I take even more time buying non-food items. Shampoos and bubble baths made from plant extracts that haven't so much as a hint of any man-made additive, face cream with extract of lanolin from the coats of Mongolian yaks.

Shark-friendly tuna, alpine meadow-reared beef, wind-farmed washing powder.

I also have to be aware of what not to buy, avoiding wine from parts of South America like the plague, because of its record on child labour, and completely snubbing certain bags of noodles which originate from areas of China with appalling human rights abuses.

The shop takes about five hours, by which time, the car has usually attracted a £60 parking ticket. I am glad to see the back of it, as I park at home and stuff the kids into the two little tent-like carriages attached to my bike.

Weaving and winding dangerously along, I manoeuvre the elongated bike along the busy dual carriageway, wrinkling my nose up at the hideous, gas-guzzling four-wheel drives that tear past, their owners completely oblivious to the destruction they are wreaking on the polar ice cap.

I arrive at the fortnightly eco-fair held at a local farming-friendly farm, and scour the stalls for a new dress for my daughter. An hour later, and we still haven't found anything in natural, rough-hewn hessian with a hemp trim.

Still, she cheers up when we head off to book a holiday. We can't fly - too big a carbon footprint there. I spend two hours on Google searching for eco-holidays, where we can spend a week with like-minded people in an organic, biodegradable setting.

That night, after a filling supper of nut roast and vanilla seed pods, I spend an hour making sure that all the low-energy lightbulbs are turned off. The light in the hallway - the one with a greenish haze that makes it look like the entrance to a Thai brothel - is the last one I check before heading upstairs for a bath in recycled rainwater from the butt beside the garage, and a long sleep between reconditioned Egyptian cotton sheets.

It's easy being green.