Stephen Rees's blog

Thoughts about the relationships between transport and the urban area it serves

Archive for November 5th, 2007


with one comment

George Monbiot in the Guardian continues his campaign against biofuels. They are an easy option for western governments, since they allow their voters to keep on driving but seem to reduce greenhouse gas emissions. I say “seem to” since the calculations seem to ignore the math of full cycle cost and only look direct cost. So, for example, it would appear that although we know that the use of nitrogen fertilisers releases nitrous oxide – a much more powerful greenhouse gas than carbon dioxide – this emissions are not included in the evealuation. Not only that but it turns out to be much harder to ensure that there are not knock on effects. We may not like palm oil for our biofuels, but that does not mean the oil we do take to make our diesel is not replaced by palm oil.

Anyway, he is a much better writer than I am so I hope you click the link and find out what he has to say.

But just to give this some Canadian content, the federal government has mandated 5% ethanol of all our gasoline. And that will almost certainly come mostly from corn, or possibly other food grains, since that technology is well known and understood. In theory you could make ethanol from other plant material – like woodwaste or wheat stalks – but so far that has not been proved commercial. And from what I understand it actually takes more energy to produce and distribute ethanol than you get out of it. And that is before you take the fertiliser into account.

Written by Stephen Rees

November 5, 2007 at 4:46 pm