The environmental impact of bioenergy carriers can be determined with the help of life cycle analysis. The present study shows that bioenergy carriers offer some clear ecological advantages over fossil fuels, such as conserving fossil energy resources or reducing the greenhouse effect, but they also have some definite disadvantages-in particular regarding certain airborne pollutants-when the overall life cycle is considered. The paper first discusses the methodological approach for conducting a Life Cycle Analysis (LCA) for biofuels; this approach is then used for a case study of Rape Methyl Ester (RME) compared with diesel fuel. The same approach is then applied for some bioenergy routes discussed currently in Germany. For the different bioenergy routes the results of the LCA for Energy, CO2 equivalents, N2O emissions, SO2 equivalents, SO2 emissions and NOx emissions are given and discussed. (C) 1997 Elsevier Science Ltd.