Don't take my word for it - read the EUs "Directive of the European Parliament and of the Council on the promotion of the use of energy from renewable sources"- it explicitly states that the rationale for the biofuels mandate is climate change.
As the Independent said in November 2005:
"At last, some refreshing signs of intelligent thinking on climate change are coming out of Whitehall. The Environment minister, Elliot Morley, reveals today in an interview with this newspaper that the Government is drawing up plans to impose a ‘biofuel obligation’ on oil companies... This has the potential to be the biggest green innovation in the British petrol market since the introduction of unleaded petrol…"
