Roland Clift, professor of environmental technology and a member of the Defra (Department for Environment, Food and Rural Affairs) advisory council has said, "Biodiesel is a complete scam because in the tropics the growing demand is causing forests to be burnt to make way for palm oil and similar crops."He is expected to tell a seminar Thursday that use of bio-fuels is likely to increase greenhouse gas emissions.
Clift's comments will amount to a direct challenge to Secretary of State for Environment David Miliband who has published a strategy promoting bio-fuels. It coincides with a surge of anger among environmentalists over the weak pledges on climate change that emerged from last week's G8 summit. The audience on Thursday will also include Howard Dalton, Miliband's chief scientist at Defra, who is expected to speak in defense of bio-fuels.
Clift said: "We calculate that the land will need to grow bio-diesel crops for 70-300 years to compensate for the CO2 emitted in forest destruction." Clift will also condemn plans to produce British bio-diesel from rapeseed, pointing to research showing the crop generates copious amounts of nitrous oxide - an even more powerful global warming gas than CO2 The attack comes as the government increases its support for bio-fuels.
Next year it will introduce a requirement for 3% of all fuel sold on UK forecourts to come from a renewable source.
Across the EU the renewable transport fuels obligation will increase this to 5% by 2010, with the British government pushing for a target of 10%.
Miliband wants British farming to diversify into bio-fuels. "It is an important part of our vision for a diversified farming sector," he said in a recent speech. The UK Biomass Strategy published last month is, however, also critical of turning crops into transport fuels, pointing out that this is the least efficient way of using them. It says that it is most efficient simply to burn them.
Clift is not the only government science adviser calling for a rethink on biofuels. Roger Kemp, who advises the Department for Transport on energy use in transport, told a conference last week that using bio-fuels in transport would have no impact on cutting emissions.
In his submission to the Institute of Engineering and Technology's climate change committee he warned that Britain produced 200m tonnes of CO2 a year in transport emissions. On current trends that will double by 2045 - whereas the government has pledged to reduce transport emissions to around 90m tons by that date.
"We would need to plant a land area twice the size of Britain to get enough bio-fuel crops to halve our emissions," said Kemp, professor of engineering at Lancaster University. "The numbers simply do not add up." Kemp and Clift point out that the surging global interest in biofuels derives from a "false belief" among politicians that there must be a technical solution to climate change.
Kemp said: "Underlying all this is the assumption that we have to preserve the mobility and freedom to travel that we now enjoy at all costs. "However, when you look at the science of climate change it is clear there are no such simple solutions. Humanity has to accept that." A similar message was this weekend emerging from environmentalists as they denounced the G8 industrialised nations for failing to take action on climate change at last week's summit.
Tony Juniper, director of Friends of the Earth, accused the G8 of being little more than a "talking shop". He said: "The G8 has a record of putting the short term interests of rich countries before those of the environment and developing countries and this year was no exception." Bio-fuels come from plants: bio-ethanol from sugars and starches, bio-diesel mainly from rapeseed and palm oil. They are blended with normal fuels, making up about 5% of the product.
The carbon in bio-fuels comes from the atmosphere so when they burn that carbon is simply rereleased and there is no increase, the ethanol lobby believes. But critics notge that bio-fuel crops take land from growing food and create pressure for deforestation. Burning forests generates vast amounts of CO2.