Microalgal biofuel production systems: environmental aspects and impacts on biodiversity

Abstract

If humanity aims to avoid further biodiversity losses and environmental degradation, future energy demands must be met through the use of more sustainable energy production systems. Biofuels have been proposed as a more sustainable alternative for energy production as, under several cultivation conditions, they reduce greenhouse gas emissions and facilitate carbon recycling over much shorter time frames than fossil fuels. However, several environmental impacts have been linked to biofuel production, particularly when their cultivation competes with food production and biodiverse lands.Microalgal production systems may become a more sustainable option for the production of biofuels, as a result of their high yields per unit area, their potential to use different types of water (freshwater, brackish water, and seawater), their non-dependence on arable lands, and their potential to use wastewater and CO2 from industries. This project evaluates the several potential environmental impacts of microalgal liquid biofuel production systems compared to first generation biofuels (i.e., food crops such as maize, sugarcane, soybeans, and oil palm), with a focus on vertebrate biodiversity. Additionally, it identifies cost-effective areas for siting microalgal production farms globally, in which profitability is maximized and direct competition with food production and biodiverse areas is minimized. Finally, it evaluates how novel and more sustainable biofuel production systems can be implemented in order to gradually replace less sustainable biofuel production systems, which include those based on food crops.This work improves the understanding of the potential synergies and trade-offs between microalgal biofuel production, agricultural production, and biodiversity conservation at global and regional scales. Furthermore, it provides a framework for identifying best areas for siting microalgal biofuel production farms globally based on targets in energy demands. Microalgal biofuel production systems can help humankind achieve ambitious targets in energy production with lower environmental impacts than first generation biofuels, mainly in terms of reduced land-use changes within high-value agricultural areas and biodiverse lands.