Transport Biofuels Derived from Perennials

Lignocellulosic biomass produced in a way that does not significantly change C sequestration in ecosystems will do better than fossil fuels in electricity produc­tion (see Fig. 4.2). Biodiesel made from palm oil may well be inferior to biodiesel when forests are cleared to grow oil palms (Danielsen et al. 2008; Fargione et al. 2008; Reijnders and Huijbregts 2008a). The same will hold for coconut biodiesel (contrasting the conclusion of Tan et al. 2004). But the opposite will hold when palms are established on abandoned agricultural land where there is currently little sequestration of C, provided that cultivation does not lead to lowering of soil carbon stocks (e. g. Germer and Sauerborn 2007). When, under market conditions, perennial grasses, short rotation woody perennials and herbaceous species such as Miscanthus are used in industrialized countries as lignocellulosic biomass for the production of Fischer-Tropsch diesel or ethanol, it would seem likely that there will be a large indirect effect on land use involving clearance of natural vegetation (Searchinger et al. 2008). In this case, it is doubtful whether lignocellulosic biofuels will much outperform fossil fuels regarding life cycle greenhouse gas emissions (see also the last row of Table 4.2).