Saturday, 4 August 2012

How bad are bananas?

I have to admit, I don't actually like bananas. But I've just bought a book called "How bad are bananas? (the carbon footprint of everything)". And it contains far more than just musings on bendy-shaped yellow fruit.

Bananas galore!
Image: Martin Wiesheu
The author, Mike Berners-Lee, meausres carbon footprints for a living. While it's not an exact science, he does at least explain how he arrived at his figures, and is very careful with some of his results that contradict popular wisdom.

I even found the answers to the hand drier versus paper towel debate and the fruit juice dilemma :
  • Using two paper towels is equivalent to using an electric hand drier. Surprisingly, there is no difference in the energy used, even though the paper towels are usually transported by truck. So if you can get away with using a single paper towel, that's the more environmentally friendly option. However, even this is trumped by a cyclonic hand drier, like the Dyson Airblade, which wins hands down.
  • Fresh juice seems to beat concentrated juice. Oranges are usually transported by boat, which is fairly efficient. However, creating fruit juice concentrate uses lots of energy. So despite the fact that concentrates are made to reduce the volume and weight of the juice, so it can be transported more easily, it doesn't translate into less energy being used overall. It just means that a single boat can carry more.
I found some other surprising facts about transportation that I hadn't considered. For example, a bottle of wine imported from New Zealand to the UK could have a lower carbon footprint than one from Italy. Products from within Europe tend to be transported by road, whereas the New Zealand wine will arrive on a boat. So even though Italy is closer to the UK, it's the mode of transport that makes the biggest difference. The concept of "food miles" is beginning to look a bit suspect to me now.

By the way, the same logic applies to bananas too. They may come from far away, but they usually arrive by boat.

Which begs the question, why don't we ship more freight by sea and waterway?

Photo by Martin Wiesheu, CC-BY-SA licence, obtained via

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