Hardly a day goes by when I don't get the feeling that there's something to say on matters to do with carbon emissions and the environment. This is the Blog in which I'll sometimes say it to the world. And it would be interesting to see what other people say in response. It'll also be a forum for exchanging ideas on how to tread lightly on the planet and avoid supporting exploitation and corrupt practices. Here we go...

Sunday, 16 September 2007

Natural Refrigeration

For our holiday in Greece this year we spent some idyllic days at a place called Sangarada, on the Pelion peninsular. Sangarada is actually a collection of four villages suspended below the road on a steep hillside several thousand feet above the sea. Wonderful springs of water gush out of the side of the hill and tumble down the steep gullies, which are wooded with dense deciduous woodland and criss crossed by ancient paved paths.
Our village was called Agia Paraskevi, after its church. Beside the Church was the Plateia, and in the Plateia was a Plane Tree. Not just any plane tree. A plane tree like this:

The trunk of this tree is wide enough that you could stand ten or eleven people in front of it, across the diameter. The tree is thought to be the oldest in Europe, possibly 1500 years old. In this picture you can see someone standing in the fork of the tree...

and in this picture you can one of the branches, propped up by a stone pillar...



On the last day we were there it was rather more chilly than other days, because there had been a thunder storm in the night. We came back after a walk and went to sit at the café under the Plane tree by the church, for a drink. It soon became apparent that the place under the tree was not just cool and shady, it was like a fridge.
Well, of course it would be like a fridge, because what a tree does is fetch water up from underground and evaporate it through its leaves. And that's how a fridge works, because in order to get the water to evaporate it takes heat from the area below which is then cooled in the process. In this case, no doubt, a good deal of extra water was being evaporated —all the water that was still lying in drops on the leaves and branches after the storm. But it made us realise that sitting under a tree is cool on a hot day, not just because it's shady, but because it's actually doing some additional refrigeration work.

Since the invention of electric refrigerators I think we've rather forgotten about the effectiveness of natural refrigeration. It's not clear to me that we need to run our fridges at all most of the year. A cupboard in a shady place outside the back door, covered with a wet cloth, would be at least as good if not better.

And you know those pictures of people carrying their lunch in a red spotted handkerchief tied to a stick carried over the shoulder? (Pigling Bland has the lunch in a spotted handkerchief but I can't find a picture of the stick anywhere....). Well, the secret is that you make the cloth damp, and it keeps your lunch moist and also chilled. And you carry it hung from a stick so it doesn't make your hands cold and wet, and it gets maximum evaporation. Clever, no? I recommend it. There's no good need for a cool box...
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