Biofuels bonanza facing 'crash'

Mr Steiner warns that Indonesia palm oil may never be sustainable

The biofuels bonanza will crash unless producers can guarantee their crops have been produced responsibly, the UN's environment agency chief has said.

Achim Steiner of the UN Environment Programme (Unep) said there was an urgent need for standards to make sure rainforests weren't being destroyed.

Biofuel makers also had to show their products did not produce more CO2 than they negated, he told BBC News.

Critics say biofuels will lead to food shortages and destroy rainforests.

They point to the destruction of Indonesia's peat swamps as an example of biofuel folly.

The swamps are one the richest stores of carbon on the planet and they are being burned to produce palm oil.

Mr Steiner implied that because of Indonesia's inability to police its land use, biofuels from palm oil grown by the nation might never be deemed to be sustainable.

But he said some biofuels could be considered sustainable. He highlighted ethanol production in Brazil, and a dry land crop called jatropha, which is resistant to pests and droughts.