Energy balance & greenhouse gas emissions of biofuels from a life cycle perspective

Abstract

Policies and targets for biofuels have been set in several countries around the globe. The main drivers for the setting of such policies are potential contributions to energy security, climate change mitigation and rural development. However, there is ongoing and intense debate over whether biofuels are really capable of meeting these expectations. In particular, the sustain- ability profile of biofuels has been recently questioned by several researchers (e.g. Doornbosch and Steenblik 2007; Fargione et al. 2008; Searchinger et al. 2008). The most frequently cited issues of concern include direct and indirect land use impacts, carbon stock decreases, water depletion and pollution, biodiversity loss, and air quality degradation. In addition to these environmental problems, critics point to potential economic and social conflicts deriving from energy/food source compe- tition. As a consequence, policies supporting biofuels are currently being challenged.