So what else affects biofuels’ emissions? Indirect variables of indirect land-use change

There are factors other than what has been described in detail so far that need to be taken into account to allow accurate GHG emissions estimation from biofuels. As mentioned in an earlier post, this includes taking into account whether the biofuel has useful by-products, such as the high-protein material left after bioethanol production, which can be used as animal feed. Matthews et al. (2011) found that it is realistic to increase ethanol output by up to 3 times compared to the present and still avoid the often-expected indirect emissions from having to convert more natural land to agriculture. Such an increase in bioethanol production is said to easily meet the biofuel demand of the US, for example, expected by 2016 (Matthews et al., 2011). Other useful byproducts include materials which can be utilized in plastics and pharmaceuticals manufacture and yeast for human consumption.

Other indirect determinants of GHG emissions from biofuel production include case-specific electricity generating pathways. In Brazil, for instance, 85% of electricity was generated by hydropower in 2009, which is likely to significantly decrease GHG emissions from production (Matthews et al., 2011).

The information in this post therefore adds to the fact that there is great variation in the emissions from biofuels and that the amount of GHG savings or emissions from biofuels should not be generalized.