Abstract
Biofuel production is a key strategy for reducing CO2 emissions globally and is expected to increase substantially in the coming decades, particularly in tropical developing countries. The adoption of sustainable biofuel production technologies that do not place large demands on agricultural or forested lands, has the potential to make a substantial contribution to decreasing greenhouse gas emissions while reducing biodiversity losses and degradation of native ecosystems resulting from high demand for land. With their high productivity per unit area and ability to grow on non-arable lands, microalgal biofuel production systems could become a major sustainable alternative to biofuel production from food crops (first-generation biofuels). However, the potential impacts of microalgal biofuels on food production, biodiversity, and carbon storage, compared to other biofuel production alternatives, are largely unknown. In the present study, the most suitable areas for siting microalgae production farms to fulfill 30% of future transport energy demands were determined within four Neotropical countries with high population densities and high importance for agricultural expansion and biodiversity conservation globally (Colombia, Ecuador, Panama, and Venezuela). These results were contrasted with the best areas for siting oil palm and sugarcane crops to fulfill the same target in future transport energy demands. Microalgal production systems offer the most sustainable alternative for future biofuel production within the Neotropics. Meeting 30% of future transport energy demands with microalgal biofuels reduced land area requirements by at least 52% compared to oil palm and sugarcane. Furthermore, microalgal biofuel production reduced direct competition with agricultural lands, biodiverse areas, and carbon-rich systems within countries, with little overlap with the biodiverse and carbon-rich rainforests. This study can guide decision making towards the identification and adoption of more sustainable biofuel production alternatives in the Neotropics, helping in avoiding unnecessary environmental impacts from biofuel expansion in the region.
Highlights
Renewable energy sources have strong potential to replace fossil fuels and meet future energy demands (Jacobson and Delucchi 2011, IEA 2017, Obama 2017), thereby mitigating global warming and its negative socioeconomic and environmental impacts (Pecl et al 2017, Nunez et al 2019)
Meeting 30% of future transport energy demands with microalgal biofuels reduced land area requirements by at least 52% compared to oil palm and sugarcane
This led to the development of eight models on best microalgal biofuel production areas based on two microalgal cultivation scenarios within each of the four countries, and the development of eight models on best oil palm and sugarcane biofuel production areas based on the cultivation of these two biofuel feedstocks within each country
Summary
Renewable energy sources have strong potential to replace fossil fuels and meet future energy demands (Jacobson and Delucchi 2011, IEA 2017, Obama 2017), thereby mitigating global warming and its negative socioeconomic and environmental impacts (Pecl et al 2017, Nunez et al 2019). Biofuel production is currently based on food crops (i.e. first-generation biofuels) that compete with suitable land for agriculture (Lambin and Meyfroidt 2011). This drives direct and indirect land-use changes, often in biodiverse areas (Immerzeel et al 2014, Correa et al 2017). The expansion of first-generation biofuels is likely to exacerbate competition with food production within the tropics (Smith et al 2014, Correa et al 2019a) and trigger biodiversity losses and CO2 emissions as forests and savannas are replaced (Searchinger et al 2015, Elshout et al 2019)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
