At first sight this appears no contest, does it? Not if you're environmentally minded, anyway. Plastic bags can take ages to break down (unless of course they're filled with tins of dog food, in which case they've been known to break down in about three minutes and the tins end up on my foot. Ouch!) In fairness the Co-op have tried out bio-degradable bags, which are supposed to start rotting away within about a year or so, but these are paper thin and very flimsy.

So the answer would seem to be paper bags, wouldn't it? At least until the rain starts up here (probably this coming week) in which case the bag will start biodegrading rapidly before you get home.

Well, there's another reason I'm beginning to distrust paper bags in spite of their green credentials. Last week we bought a large mug in STarbucks, all nicely packed in a brown paper bag with handles. Then we checked the small print. 'Made in Germany'. And flown to South Wales and heaven only knows where else!

Am I going mad or something? There must be places in Wales that can make such bags for the local market - what sort of carbon footprint has been saved by importing paper bags from Germany?

Well, I've got the answer. I'm going to make my own. THere's a nice length of canvas in my garage that should do the job nicely....

I live on the side of a mountain, and from my kitchen window I can just make out the top of an ancient cairn of stones. Since early times, mountains have been venerated, held sacred. Not just in Wales or even northern Europe, but all over the world. But whereas my mountain is virtually unknown outside the immediate vicinity, some are quite famous.

Take Mauna Loa in Hawaii. Although its slopes rise very gradually, its summit is actually 56,000 ft above its base – that makes my little mountain above my kitchen window minute by comparison. But only is this a mountain by anyone’s standards it is also a volcano, and a very active one at that. In fact, some claim it is the most active volcano in the world. Thousands of visitors go to see it each year.

Now I know the saying goes, ‘Take only photographs, leave only footprints’ but people being what they are, some decide to take home a small souvenir, usually a small piece of stone from the lava slopes. There’s plenty lying about and nobody seems to notice.

Until, that is, the tourists return home. A number have reported a spate of ‘bad luck’ accidents, and become convinced that the stones they collected as harmless souvenirs are in some way cursed. Some have mailed the stones back to the Volcanoes National Park (home of Mauna Loa) and then reported no more troubles after that.

The belief seems quite widespread, too and apparently the National Park Service reports regular deliveries of packages containing stones that have been taken from the volcanoes slopes and which their new owners are only too eager to return.

I think stones can certainly ‘pick up’ on certain energies and may often be the cause or means of transmitting certain hauntings and psychic phenomena. Quite what is being transmitted at Mauna Loa I’ve no idea. One thing’s for sure, I wouldn’t go and remove stones from the cairn on my mountainside.