There was a strong positive correlation between biogas yield and the potential reduction in fossil depletion (FD) impacts, an
indicator of the finiteness of fossil fuel supply. For example, biogas yield from Base LS-1 was 135% higher compared to Base LS (66.3 m3 t1), therefore, FD impacts reduced by approximately 70% in Base LS-1 compared to Base LS (18.76 kg oil-eq) (Table 2) (Pöschl et al., 2010).