Be sure not to miss George Monboit's latest, thought-provoking rant against biofuels. Here's bit of it as posted on his blog:
An Agricultural Crime Against Humanity, George Monbiot, from the Guardian Nov 6: Biofuels could kill more people than the Iraq war. … In principle, burning biofuels merely releases the carbon they accumulated when they were growing. Even when you take into account the energy costs of harvesting, refining and transporting the fuel, they produce less net carbon than petroleum products. The law the British government passed a fortnight ago - by 2010, 5% of our road transport fuel must come from crops - will, it claims, save between 700,000 and 800,000 tonnes of carbon a year. It derives this figure by framing the question carefully. If you count only the immediate carbon costs of planting and processing biofuels, they appear to reduce greenhouse gases. When you look at the total impacts, you find that they cause more warming than petroleum.
A recent study by the Nobel laureate Paul Crutzen shows that the official estimates have ignored the contribution of nitrogen fertilisers. They generate a greenhouse gas - nitrous oxide - which is 296 times as powerful as CO2. These emissions alone ensure that ethanol from maize causes between 0.9 and 1.5 times as much warming as petrol, while rapeseed oil (the source of over 80% of the world's biodiesel) generates 1-1.7 times the impact of diesel. This is before you account for the changes in land use.
A paper published in Science three months ago suggests that protecting uncultivated land saves, over 30 years, between two and nine times the carbon emissions you might avoid by ploughing it and planting biofuels. Last year the research group LMC International estimated that if the British and European target of a 5% contribution from biofuels were to be adopted by the rest of the world, the global acreage of cultivated land would expand by 15%. That means the end of most tropical forests. It might also cause runaway climate change. … (footnotes omitted here)