It used to be a matter of good intentions gone awry. Now it is plain fraud. The governments using biofuel to tackle global warming know that it causes more harm than good. But they plough on regardless. In theory, fuelsmade from plants can reduce the amount of carbon dioxide emitted by cars and trucks. Plants absorb carbon as they grow — it is released again when the fuel is burned. By encouraging oil companies to switch from fossil plants to living ones, governments on both sides of the Atlantic claim to be “decarbonising” our transport networks.

In the UK’s budget this month, finance minister Gordon Brown announced that he would extend the tax rebate for biofuels until 2010. From next year all suppliers in the United Kingdom will have to ensure that 2.5% of the fuel they sell is made from plants. By 2050, the government hopes that 33% of our fuel will come from crops. Last month George Bush announced that he would quintuple the US target for biofuels: by 2017 they should be supplying 24% of the nation’s transport fuel.

So what’s wrong with these programmes? Only that they are a formula for environmental and humanitarian disaster. Biofuels would set up a competition for food between cars and people. The people would necessarily lose: those who can afford to drive are richer than those who are in danger of starvation. It would also lead to the destruction of rainforests and other important habitats.

Since the beginning of last year, the price of maize has doubled. The price of wheat has also reached a 10-year high, while global stockpiles of both grains have reached 25-year lows. Already there have been food riots and reports that the poor are feeling the strain all over the world. According to the United Nations food and agriculture organisation, the main reason is the demand for ethanol: the alcohol used for motor fuel, which can be made from maize and wheat. Farmers will respond to better prices by planting more, but it is not clear that they can overtake the booming demand for biofuel. Even if they do, they will catch up only by ploughing virgin habitat.

Already we know that biofuel is worse than petroleum. The UN has just published a report suggesting that 98% of the natural rainforest in Indonesia will be degraded or gone by 2022. Just five years ago, the same agencies predicted that this wouldn’t happen until 2032. But they reckoned without the planting of palm oil to turn into biodiesel for the European market. This is now the main cause of deforestation there and it is likely soon to become responsible for the extinction of the orangutan in the wild. But it gets worse. As the forests are burned, both the trees and the peat they sit on are turned into carbon dioxide. Biodiesel from palm oil causes 10 times as much climate change as ordinary diesel.

We need a moratorium on all targets and incentives for biofuels, until a second generation of fuels can be produced for less than it costs to make fuel from palm oil or sugar cane. Even then, the targets should be set low and increased only cautiously. I suggest a five-year freeze. This would require a huge campaign. Encouraged by government policy, vast investments are now being made by farmers and chemical companies. Stopping them requires one heck of a battle. But it has to be fought. — The Guardian