The total quantification of biofuel greenhouse gas (GHG) emissions is controversial. Many studies that seek to estimate the advantages of biofuels neglect to include vital factors in their calculations, most notably land-change, and relay skewed results to the public and bioenergy aficionados. As discussed in class when analyzing the Searchinger et al paper, the diversion of cropland to cultivate bioenergy feedstocks is one of the biggest problems at hand because of its resulting interference in carbon sequestration and overall increase in GHG emissions. One of the ways feedstock farmers are coping with this is to plant crops as efficiently as possible, and one way to do that is to use as much of the bioenergy crop as possible. Based on both the water footprint, the volume of freshwater used to produce goods, calculated in the Gerbens-Leenes et al. paper and the biofuel emissions per unit area cropland calculated in the Campbell et al. paper, bioelectricity trumps cellulosic ethanol other biofuels and biodiesels. Bioelectricity maximizes land-use efficiency in that entire feedstock biomass may be used in its production. Alternatively fuels, such as cellulosic ethanol, only utilize the starch and oil fraction of the crops resulting in much larger waste and a less efficient use of land. Factors including type of feedstock, climate and agricultural practices must be considered when reading both article but both clearly draw the same conclusions about land-use efficiency and bioelectricity.
Bio-electricity: better land-use emissions?