The UK has scaled back its plans to introduce biofuels after a government-commissioned report warned of their wider social and environmental impacts.

The government will now review its renewable transport fuel obligation, which required suppliers to ensure 5 per cent of all their fuel comes from renewable sources by 2010. That is now likely to be pushed back to at least 2013 as part of a 'more cautious approach' to biofuels.

The report, by Ed Gallagher, chair of the UK Renewable Fuels Agency, confirms concerns over the indirect effects of the growing biofuels industry - including rising food prices, and the risk of increasing rather than reducing greenhouse gas emissions.

'Our review makes clear that the risks of negative impacts from biofuels are real and significant, but it also lays out a path for a truly sustainable biofuels industry in the future,' Gallagher says.

In particular, Gallagher stresses the importance of avoiding land-use change that releases large amounts of carbon into the atmosphere. Ploughing up grassland and forest releases carbon previously trapped within the plants and the soil, which can take years to offset by growing the biofuel.

While it may take only 3 years to recover the carbon released when converting Brazilian grassland to grow sugarcane for bioethanol, converting US forestland to grow soya for biodiesel could take up to 481 years to offset. Gallagher calls for biofuel support to exclude feedstock cultivation with a carbon payback of longer than 10 years.

The report also says more incentives are needed to encourage R&D on advanced technologies that could deliver higher greenhouse gas savings, and calls for government policies to include a specific obligation on transport fuel suppliers to supply biofuels achieving a high level of greenhouse gas saving, possibly up to 75 per cent. New policies should also make use of waste feedstocks for fuels where possible.

The report was broadly welcomed by Clare Wenner, head of transport biofuels at the Renewable Energy Association, the industry body representing UK renewable energy producers. 'There are good and bad biofuels and the UK industry is 100 per cent committed to producing good biofuels,' she said. 'However, no progress will be made unless there is investment in production and research. The Government needs to give consistent, reliable and long-term targets. The Gallagher proposals do not do this.'

Manisha Lalloo. Additional reporting by James Mitchell Crow

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