When I was a kid, we didn't have plastic bags. Carried bags were brown paper with cord-like handles which hurt your fingers if you bought something heavy.

Fine, when the weather was dry but by the time my mother sent me to go fetch three lots of fish and chips and a big bottle of sarsaparilla in the pouring rain it became a soggy mess which ripped from the handles.

"I only bought that yesterday!" Mum said, as though it was my fault that investment had bottomed out, with no praise for hugging the contents to safety and no sympathy for the chippy smell which hung around for ages on my coat.

Next time I insisted on a "proper shopping bag," but the adult-sized heavy old thing threatened to pull my arm out of its socket and dragged along the pavement if I weakened.

Then, eighth wonder of the world, now we have plastic carrier bags which are light, waterproof and free, often brightly coloured with an advert for the shop or store. True, they can cut into your hands and sometimes break, but who cares - throw it away and get another one.

I knew vaguely that they're manufactured by the petrochemical industry and I can recommend the internet for inspiring a headache on the subject. Worldwide production, estimated at between 4 and 5 TRILLION plastic bags a year. That's 4,000,000,000,000,000,000 or 5,000,000,000,000,000,000.

I had been shocked by the figure of 17,000,000,000 (that's 17 billion) plastic carrier bags used in Britain every year, which could become a mountain-sized pile in landfill or litter the country and might take between 5 to 400 years to break down. Don't you just love these estimates! Even biodegradable bags needs exposure to sun and weather to decay in their promised time and they won't get that buried under tonnes of rubbish. I always reuse plastic bags - but refusing them might be better.

How much oil will manufacturing 17 billion bags use up?

I'll leave that headache to you.

By Lesley Banks.