Multi-scale integrated assessment of soybean biodiesel in Brazil

Developing counties are often believed to have excellent conditions for biofuel production, however studies aimed at assessing the sustainability of large scale biofuel programs have generally focused on a few variables related to one scientific domain and one scale. Contrary to this approach, this paper analyzes soybean biodiesel in Brazil using a parallel biophysical and economic assessment at different scales. A Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism (MuSIASEM) approach is applied as a scenario analysis tool. A soybean biodiesel energy balance for the specific conditions of Brazil is included and the energy ratio turns out to be 1.09. This means that the energy delivered is higher than the energy invested, however the net energy is very low. The economic impacts are analyzed through input-output analysis. The results show that soybean biodiesel increases energy consumption per hour of work without a corresponding increase in economic labor productivity. Consequently the already low energy efficiency of Brazilian production could get worse. Although Brazil has large expanses of land, the substitution of 20% fossil diesel (i.e. just 3.3% of the country's primary energy consumption) with fully renewable biodiesel might destroy protected areas and forests and increase the GHGs emitted. (C) 2011 Elsevier B.V. All rights reserved.