For related articles and more information, please visit OCA’s Environment and Climate Resource Center page and our Organic Transitions page.

Liquid biofuels are often touted as a partial solution to oil scarcity and climate change. But what are the realistic prospects?

There are, essentially, two types of liquid biofuel: ethanol and biodiesel. The former, produced from crops such as maize, sugar cane, sugar beet and grain sorghum, can be blended with conventional petrol in small ratios and used in existing internal combustion engines, or used in higher concentrations in modified engines. Biodiesel can be made from various oil- bearing crops, including soya beans, palm, canola and sunflower seeds. Biodiesel can be blended with conventional diesel or used alone in diesel engines.

Last year, biofuels comprised about 3% of global road transport fuels.

The US has been the world’s leading biofuel producer since 2006, when it overtook Brazil. According to BP’s data- base, in 2011 the US produced an average of 567 000 bbl/d of ethanol distilled from maize – almost half the world’s biofuel output. This ethanol industry was artificially stimulated by generous federal government subsidies. These expired at the end of last year, and the industry is now taking huge strain, especially as maize prices soar.

Brazil began developing its ethanol industry in the 1970s in response to the oil shocks. Since 1976, there has been a mandatory blending percentage for ethanol in petrol fuels, varying from 10% initially to a high of 25% in 2007. Brazil remains the second-largest biofuel producer, with 22% of the world total, averaging 265 000 bbl/d of ethanol produced from sugar cane in 2011.

The European Union was in third place, with 195 000 bbl/d, comprising mainly biodiesel, and also boosted by subsidies and blending quotas. China managed just 2.2% of global biofuels, while Africa’s production was negligible.