About to weeks back, on May 22nd, 2008, Belgian Minister of Mobility (Van Brempt) decided to abandon all biodiesel use in public bus transport of “De Lijn”, because biofuels’ sustainability is not clearly proven and because biofuels’ part in current food price crisis. Although Van Brempt herself implemented the mixing of 3% biodiesel mix in public busses in 2005, with which she claimed to play a ’frontrunner’s role’, she now calls for fixed sustainability criteria and certification. This, as only one of many examples of growing, let us call it, precaution on biofuels.
Biofuels clearly have to meet two minimal requirements: (a) it should be renewable and (b) is should have lower negative envrionmental impact than the current fossil alternative (Janulis 2004). In both requirements land use and land use change play an important role. Impacts on (regional) water balance and soil (and maybe vegetation and biodiversity) might hamper the renewable character of land use based biofuels, while removal of vegetation, in favor of biofuel production, influences their overall environmental impact (even on global warming potential, as pointed out by Fargione et al. 2008, but also on (regional) biodiversity, downstream water availability, etc.).(Also see the Nick Wigginton ‘Acknowledging the elephant in the room with biofuels’.)
Land use and land use change have been and are often overlooked in environmental impact assessments of products’ or functions’ creation (like in life cycle assessment – LCA). While the carbon debt repayment time concept of Fargione et al. shows that, in some situations, it takes a biofuel several (human) generations’ time to repay the initial carbon investment caused by the land use change.
So, if biofuels show not to be able to fulfill one of the main aims of their usage (cutting CO2 emissions) I think we have to use the principle of precaution. We indeed need a good framework to assess biofuels’ sustainability, but therefore we need a good way to assess system state impacts of land use based or agricultural production systems. This is not easy, because several impacts play on different spatial and temporal scales (local, regional, global biodiversity, regional water availability, global emissions, …), and also tend to be quite site specific.
Nice post! It is going to be very interesting to hear an expert opinion on biofuels, given the conflicting coverage in the media – decreased greenhouse gases vs. increased food prices. I’ve seen the latter argument framed as “people are starving while we run our Hummers on the food they can’t afford”. It’s definitely one of the subjects of the moment.
I’d like to see figures on what would happen if all used chip shop oil found its way into the diesel chain.
In a good old Landcruiser BJ70, you can put filtered chip oil straight into the tank, provided it is not too cold outside.
As for the food-for-fuel issue – I found the omnipresent vitamin A fortified vegetable oil (USAID, not to be sold or exchanged) a comforting backup fuel in Ethiopia. A 5 liter can could keep your engine running for 50 km.
In a good old Landcruiser BJ70, you can put filtered chip oil straight into the tank, provided it is not too cold outside.
apparently you can in most diesel engines. Oil, after all, is oil. You have to watch it though – with certain engines the seals tend to dissolve.