I stumbled across a fabulous website on graphic representation by David McCandless, and got thoroughly distracted for an hour or so. Being a bit of an eco geek, one caught my eye about how much CO2 is produced by different things, many of which are day to day items http://visualization.geblogs.com/visualization/co2/
Like a gawker at a road accident, I hunted out the worst excesses, turns out that a night in a (high carbon) hotel produces 60kg of CO2, equal to 600 plastic shopping bags. Inevitably I teetered on the edge of a slight sense of eco doom. Everything seems to produce endless amounts of CO2, except plastic bags, which have other less endearing features.
Eventually I found some good news, a good hot bath is totally carbon zero, if you heat the water with solar thermal panels. Which in Spain is great news – there’s no sun shortage here in Andalucia.
On a similar theme, swimming in the sea, which is also solar heated, assuming you live close by and don’t have to drive an hour to it like I do.
It also turns out that an apple from your garden is carbon zero too. Living in the Spanish campo as I do, I don’t have many apples, but my garden is stuffed with oranges, olives, walnuts, plums, almonds, loquats, tamarillos, cherries, lemons, and all sorts of other weird and wonderful things. Its a bit cheap to list a rack of them, so I’ll count that as one.
By definition, a net carbon zero house is, well, carbon zero. Easy enough in Spain where you can easily produce more energy with solar and wind than you use over the year, assuming its a low energy house in the first place.
I suppose if we are being picky it all depends. Did you fertilize the tree with nitrate fertilizers, which are quite carbon intense, or did you drive in your Hummer to pick up a bucket of goat manure to plant the tree. Then there’s the embodied energy in the spade used to plant the tree. Such picky-ness aside, lets assume the best about our garden apple. What about the embodied energy in the solar hot water panels, and the materials to build the house?
It’s all quite true, in its essence everything uses some amount of energy, somewhere along the way. Yet clearly a solar heated bath uses a heap less energy than a normal bath, according to the infographic between 500g and 2,600g less. There’s embodied energy in both, so the reduction is a clear reduction. The saving in CO2 will eventually pay back the embodied energy, sooner or later. If you’re interested in this you will love this talk by Catherine Mohr:
She builds a low energy house and makes all those difficult calculations, and faces the purist dilemma with good information and clear reasoning.
Author: Philip Gilmore