The goals of ensuring energy, water, food, and climate security can often conflict. Microalgae (algae) are being pursued as a feedstock for both food and fuels—primarily due to algae's high areal yield and ability to grow on non-arable land, thus avoiding common bioenergy-food tradeoffs. However, algal cultivation requires significant energy inputs that may limit potential emission reductions. We examine the tradeoffs associated with producing fuel and food from algae at the energy–food–water–climate nexus. We use the GCAM integrated assessment model to demonstrate that algal food production can promote reductions in land-use change emissions through the offset of conventional agriculture. However, fuel production, either via co-production of algal food and fuel or complete biomass conversion to fuel, is necessary to ensure long-term emission reductions, due to the high energy costs of cultivation. Cultivation of salt–water algae for food products may lead to substantial freshwater savings; but, nutrients for algae cultivation will need to be sourced from waste streams to ensure sustainability. By reducing the land demand of food production, while simultaneously enhancing food and energy security, algae can further enable the development of terrestrial bioenergy technologies including those utilizing carbon capture and storage. Our results demonstrate that large-scale algae research and commercialization efforts should focus on developing both food and energy products to achieve environmental goals.
Center for Integration of Science & Industry, Bentley University, Waltham MA, 02452, USA;Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY, 14853, USA;Department of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA;College of Agriculture, Forestry & Natural Resource Management, University of Hawai’i Hilo, USA, USA;Department of Civil and Environmental Engineering, Bucknell University, Lewisburg PA, 17837, USA;Cinglas Ltd., Chester, UK;College of Agriculture, Forestry & Natural Resource Management, University of Hawai’i Hilo, USA, USA;B&D Engineering and Consulting LLC, 7419 State Hwy 789, Lander, WY, 82520, USA;Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA;College of Agriculture, Forestry & Natural Resource Management, University of Hawai’i Hilo, USA, USA;Department of Biological & Environmental Engineering, Cornell University, Ithaca, NY, 14853, USA;Duke University Marine Laboratory, Nichols School of the Environment, Duke University, Beaufort, NC, 28516, USA;Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY, 14853, USA
Recommended Citation:
Michael J Walsh,Léda Gerber Van Doren,Deborah L Sills,et al. Algal food and fuel coproduction can mitigate greenhouse gas emissions while improving land and water-use efficiency[J]. Environmental Research Letters,2016-01-01,11(11)