Friday, 4 January 2008

Measuring the True Costs of Biofuels


It is generally assumed that the replacing of finite, carbon dioxide-generating fossil hydrocarbons by biofuels can be nothing but beneficial. In deed, the EU proposes that 10% of transport fuel should be derived from such sources by 2020. A paper in Science Today by Scharlemann and Laurance (http://www.sciencemag.org/cgi/content/full/319/5859/43) points out that the 'true costs' of biofuels should take into account their full impact on the environment (including reducing the land devoted to forests and farmland, their effects on biodiversity, hydrological functioning and soil protection etc) in addition to the amount of greenhouse gas that they emit when they are burned. This is essentially a method developed by Rainer Zah of Switzerland's Empa Research Institute (http://www.empa.ch/plugin/template/empa/3/*/---/l=2). Twenty-six biofuels were studied using the Swiss method and, of these, 21 produced at least 30% less CO2 gas when burned than did gasoline. Of these, however, 12 had a total environmental impact that was greater than using fossil fuels. These included the 'economically-significant fuels' of ethanol from corn (USA), ethanol from sugar cane (Brazil) and diesel from Palm oil (Malaysia). Biofuels from recycled cooking oil of using ethanol derived from grass or wood were superior to using fossil fuels. Scharlemann and Laurance also pointed out that government initiatives have led to some 'perverse' outcomes such as farmers in the US being given incentives to switch from growing soya beans to growing corn for biofuels. This has driven up the price of soya and has actually encouraged farmers in Brazil to encroach further into the Amazonian rainforest and tropical savannas to produce more soya (used to fatten cattle etc). We have already noted the conflict between Palm oil generation in Malaysia and attempts to conserve the Orangutan. It does seem to be the case that planners will have to be a bit more sophisticated before advocating all biofuels as an answer to our energy problems.

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