When it is assumed that straw should be returned to a large extent to soils, the in­put of fossil fuels in the life cycle of bioethanol from European wheat is such that, whatever the allocation between ethanol and co-products [DDG(S) and glycerol], there is a rather small margin between the fossil-fuel-based energetic input and en­ergetic output of the life cycle (vonBlottnitz and Curran 2007; Reijnders and Huij­bregts 2007). This limited advantage regarding the emission of greenhouse gases for bioethanol is, however, well exceeded by the average emissions N2O and CO2 from conventionally tilled soils on which wheat is grown, whatever the allocation cho­sen (Crutzen et al. 20007; Reijnders and Huijbregts 2007). When indirect effects on land use are also factored in, ethanol from European wheat does worse than fossil gasoline, whatever the choices regarding allocation (Fritsche 2007; Reijnders and Huijbregts 2007).

Example 3: Palm Oil

Palm oil has been proposed for use as a heavy-duty transport fuel in warm climates (Prateepchaikul and Apichato 2003). It may also be used in electricity production and after transesterification as biodiesel in cars (Reijnders and Huijbregts 2008a). In the case of palm oil, there is, both in monetary and physical terms, one major mar­ketable output of production (palm oil) and one minor one: palm kernel cake (which may be used as animal feed). For the establishment of oil palm plantations, a variety of land use changes is possible, and the effects thereof canbe distributed overtime in different ways (Reijnders and Huijbregts 2008a; Wicke et al. 2009). It turns out that when the plantation is on mineral soil and native forest is cleared, palm oil will do worse than diesel based on mineral oil unless the changes in C content of the ecosys­tem are distributed over a long time span (Reijnders and Huijbregts 2008a; Wicke et al. 2009). When the plantation is on peaty soil, palm oil does much worse regard­ing the emission of carbonaceous greenhouse gases and N2O than diesel based on mineral oil (Danielsen et al. 2008; Fargione et al. 2008; Reijnders and Huijbregts 2008a; Wicke et al. 2009). On the other hand, when a palm oil plantation is estab­lished on abandoned mineral soils, palm oil will do much better than fossil diesel (Germer and Sauerborn 2007; Wicke et al. 2009).