It did not take long for biofuels to turn from one of the darlings of the environmental movement to the bugbear.

As recently as 2004, green groups such as Friends of the Earth were calling for an expansion of biofuels to make road transport greener. Biofuels, derived from plants, are carbon-neutral over their lifetime – the plants absorb carbon dioxide from the atmosphere as they grow, which is released back into the atmosphere as they are burned. This makes them one of the few “clean” alternatives to petrol as a transport fuel.