The climate benefit of Swedish ethanol: Present and prospective performance
Review article, 2012
Biofuels are introduced in the transportation sector as a means to reduce the sector'ns greenhouse gas (GHG) emissions. European and other national and global standardization schemes for biofuels also include certain minimum GHG emission reduction among the requirements to be met. Assessments of the GHG performance of biofuels are complex due to the complexities of physical, chemical, and biological conversion processes, feedstock diversity, and variability in site-specific environmental conditions. Differences may also arise in analytical approaches, including in how direct and indirect land use change is accounted for. Current production of first-generation ethanol in Sweden, based on wheat, causes relatively low GHG emissions, whereas a future expansion may cause increased emissions from changes in land use and less optimal utilization of by-products. Such negative impacts may be avoided by an introduction and expansion of second-generation ethanol based on lignocellulosic feedstock (e.g., straw, short rotation coppice, and forest residues), which eventually could become the major feedstock in ethanol production. This transition to low, indirect impact ethanol systems creates an opening for a significant expansion of ethanol in the transport sector without compromising the sizeable climate benefits and sustainable resource exploitation.