Here in Norfolk the flavour-of-the-month is maize cultivation for biofuel. There's a huge storage facility for the stuff fairly near us, and I understand the idea is to ferment it to produce methane. The tractors pulling great truckloads of chopped-up maize are everywhere in late summer, and production of grain such as barley and wheat seems to have fallen out of favour. Could this craze for methane-production be a contributing cause of the methane increase?