Is the expansion of sugarcane over pasturelands a sustainable strategy for Brazil's bioenergy industry?

Highlights: • In Brazil, most of the recent sugarcane expansion has been placed over extensive pastures. • Pasture (PA) to sugarcane (SG) transitions affects key ecosystem services (ES). • Except for Maintenance of biodiversity, this land use change improve the ESs evaluated. • As result, PA-SG transitions would increase the sustainability by 78% in south-central Brazil. • Our index provides a sensitive and science-based approach for sustainability assessments. -- Abstract: Biofuels are fundamental for meeting societal energy needs within the next few decades, but the sustainability of large-scale land use conversions to supply feedstock crops remains unclear. Quantitative data documenting how biofuel crop expansion will affect ecosystem services (ES) is needed to develop sustainable energy policies. Using pairwise comparisons of published and novel environmental, social and economic indicators, we quantitatively assessed the provision of critical ES related to key aspects of the sustainability of pasture-to-sugarcane transitions in Brazil. We found that with the exception of maintaining biodiversity, conversion of pasturelands to sugarcane fields enhanced many ES. Based on the Sustainability index, aimed to capture changes on key sustainability aspects by considering multiple ES and properly integrating them, we concluded that pasture to sugarcane transitions would increase the sustainability by 78% in south-central Brazil. Our results provide science-based empirical evidence that the expansion of sugarcane into degraded pasturelands is a suitable strategy to enhance Brazil's biomass feedstock supplies for producing bioenergy. Moreover, facing the complex and multidimensional concept of sustainability, our study also illustrates the importance of considering holistically land use change effects rather than individual ESs when establishing sustainable land management practices and bioenergy policies.