The Brown government has turned unenthusiastic on biofuels, with new Transport minister Andrew Adonis proposing that quotas for biosourced ingredients in ordinary motor fuel be moved back by some years.
"Everyone agrees that to tackle climate change we must develop new and cleaner fuels. But we are clear that biofuels will only have a role to play in this if they are sustainably produced," said Adonis, as he opened a public consultation on rolling back the deadline for five per cent renewable content in UK petrol and diesel from 2011 to 2014.
The suggested slowing of the UK rush to biofuels follows government research this year by Professor Ed Gallagher of the Renewable Fuels Agency. The Gallagher Review said that biofuels had a lot of potential to reduce overall carbon emissions, but sounded a note of caution on sources and possible unintended impacts on food prices and deforestation.
At present, the most commonly available kind of biofuel is ethanol made from food crops. This has gained some momentum owing to Western farm subsidies and agricultural lobbying, providing it with a powerful political constituency. At present, crops are made into ethanol using energy- and carbon-intensive processes driven by coal or gas, but biofuel advocates say that in future the process could be self-powered, using some of its own products to drive itself.
However, most authoritative analysis suggests that there is insufficient cropland in existence to both feed the human race and power a meaningful fraction of its transport - even less so as Third-World countries industrialise and achieve higher living standards, and still less if the energy needed to turn crops into fuel must also come from biofuels.
Thus, crop-based biofuels are often now seen as directly contributing to high food prices - and resulting hardship and starvation among the world's poor. The appetite they create for new farmland is also seen as a factor in the destruction of rainforests.
As a result, the quest is now on to find "sustainable" biofuels, perhaps made from plants which will grow in otherwise unused places - deserts, say, or algaes farmed on the surface of the sea. But for now, possibly-sustainable biofuels form only a tiny fraction of total production. Even naughty crop biofuels aren't yet being used to any large degree.
Finding sustainable, OK-to-use biofuels is perhaps most important to the aviation industry. Road transport could use alternative technologies in the post-fossil future: electric vehicles, hydrogen or what-have-you. But the technical challenges of such methods would be enormously greater for aircraft.
In addition to the consultation on slowing down quotas published today - which will be followed by legislation unless everyone rises up and demands more ethanol right now - the gov also announced a further £6m for research into sustainable fuels by the Carbon Trust quango.
Tom Delay, Chief Carbon Trust, added: "This funding will help in the urgent search for low carbon and sustainable alternatives to oil by accelerating the development of two advanced technologies; pyrolysis-based conversion and algae as a sustainable feedstock."
Pyrolysis is intended to make the conversion of wastes into fuel more efficient and less carbon-intensive. More details on the planned research are available from the Carbon Trust here.
Similar arguments on the pros and cons of biofuels are going on in Europe.®