Biodiesel has been championed as a means of reducing our carbon dioxide emissions. However, like many emerging ‘green’ technologies, the environmental impacts or benefits depend largely on how it is produced, in particular, where the feedstock comes from.
Biodiesel made from used cooking oil has the least emissions, as you are using what would otherwise be a waste product. Making biodiesel from a purpose grown crop causes some emissions; from the tractor that seeded and harvested the crop, the truck that carted it, processing, fertilisers and pesticides, etc. All considered though, it still stacks up very well compared to fossil fuels.
But what if a rain forest has to be cleared to make room for the oil crop? Not only do we lose the biodiversity, we also lose the CO2 locked up in the soil and the trees. When the forest is burned in the process of clearing, even greater amounts of CO2 are released into the atmosphere compared to using fossil diesel.
Unfortunately, the oil palm grows very well where tropical rainforest used to. Palm oil yields are also the best of any oil crop. For many years, the Indonesia and Malaysian territories of Sumatra and Borneo have been clear fell logged and burned to make room for palm oil to be used in cooking and cosmetics. New demand for biofuels (spurred by mandates in over 30 countries) has greatly increased the demand for palm oil, accelerating the rate of rainforest destruction in Sumatra and Borneo. Similarly, in Brazil, demand for land on which to grow soy is accelerating the rate of clear felling in the Amazon and Cerrado. Biodiesel is only a sustainable fuel if the feedstock is produced sustainably. The UN has named rainforest clearing to produce biodiesel as responsible for 4/5 of the emissions in Indonesia – the 3rd largest climate culprit.
Smoke from agricultural and forest fires burning on Sumatra (left) and Borneo (right) in late September and early October 2006 blanketed a wide region with smoke that interrupted air and highway travel and pushed air quality to unhealthy levels. This image from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite on October 1, 2006, shows places where MODIS detected actively burning fires marked in red. Smoke spreads in a gray-white pall to the north. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of the MODIS Rapid Response team.