Twenty per cent of our corn is now sold for use as ethanol, blended into gasoline.
Over the last year wholesale corn prices have roughly doubled.
Food companies are warning that high corn prices will feed through to everyone’s grocery bills.
The price of agricultural land has started to rise.
The use of ethanol is government subsidized.
This trade-off between greener fuels and higher food prices is one of several difficult issues thrown up by the rapid development of the biofuels industry.
The world has already witnessed the absurdity of virgin rainforests in Asia being torn down to make way for palm oil plantations.
Palm oil, like corn, has become hugely profitable because of demand from biofuel producers.
But the environmental benefits of the biofuels are outweighed by the loss of the rainforests.
Biofuels can make a contribution to reducing greenhouse gas emissions.
But the processes by which they are produced need to be kept under constant review to make sure that they do not have perverse consequences.
And that includes forcing up the price of essential foods.