Can biofuels replace fossil energy fuels? A multi-scale integrated analysis based on the concept of societal and ecosystem metabolism : Part 1 - Giampietro, Mario (Istituto Nazionale di Ricerca per gli Alimenti e la Nutrizione Via Ardeatina) ; Mayumi, Kozo (The University of Tokushima) ; Ramos Martín, Jesús (IFF Social Ecology)