A fuel derived from organic material.
Biofuels are typically made using oils extracted from energy crops such as palm oil, sugar cane, corn and rape seed. However, so-called second generation biofuels are capable of producing fuels from non-food based crops, including grases, algaes and waste organic matter.
Supporters of biofuels argue that the fact that plants soak up carbon dioxide as they grow means that they can deliver deep cuts in carbon emissions compared to fossil fuels, while avoiding the need for investment in new low carbon vehicle technologies.
However, critics have warned that the widespread use of biofuel can contribute to deforestation, drought and food shortages as demand for energy crops increases pressure on agricultural land.