cientists affiliated with the Marine Algal Industrialization Consortium have published a research article demonstrating the potential of using microalgae to significantly mitigate greenhouse gas emissions if used as a source of food. Leading the study was Michael J. Walsh, a research fellow in Bentley University’s Center for Integration of Science and Industry, in Waltham, Massachusetts, who holds a doctorate in biological and environmental engineering. The study’s findings highlighted that algal food and fuel coproduction can mitigate greenhouse gas emissions while improving land and water-use efficiency.
The study investigates the use of algal biomass for the production of food or energy products. Recent products such as Soylent protein shake and Thrive culinary oil have brought algal food to the mainstream. However, compared to conventional agricultural crops, algal biomass can be cultivated on non-arable lands, at higher yields and using seawater.
The paper shows that the substitution of conventional crops with algae can significantly reduce the impact of current agricultural practices through:
- Avoiding deforestation and promoting afforestation
- Enabling emissions reductions from some of the hardest to mitigate emissions sources (deforestation and agriculture)
- Saving significant amounts of freshwater water by displacing water-hungry crops
- Enhancing food security by decoupling food production from at-risk agricultural regions
Using algae for energy can still reduce emissions but does not yield the benefits associated with offsetting conventional agriculture. “Thinking about algae as a food product opens new paths for achieving a number of sustainable development goals that are out of reach for algal biofuels,” says Dr. Walsh, the lead author on the paper.
The study also examines some of the negative tradeoffs of an algal food economy. For example, algae require large, unsustainable inputs of chemical fertilizer. However, this demand may create markets for novel technologies such as carbon capture and storage and nutrient recapture from wastewater.
Dr. Walsh notes that if researchers can overcome these challenges we may see broader benefits. “Algae food holds the potential to open up a significant amount of land to other uses. With the benefit of available land, we can implement more emission reduction technologies such as bioenergy carbon capture and storage (BECCS),” he says. This matters because according to the 5th Assessment Report of the Intergovernmental Panel on Climate Change, if our ability to mitigate emissions through BECCS technology is limited, it’s likely many climate change models will not be able to limit warming to below 2 degrees Celsius (the known target for globally impactful temperature reduction).
Dr. Walsh’s work builds on and is supported by the Marine Algal Industrialization Consortium, a group that has received over $20M in DOE & USDA funding and has conducted numerous algal cultivation experiments and animal feed trials. The Consortium has recently published a Commentary in Oceanography summarizing its research for a more general audience titled Marine Microalgae: Climate, Energy, and Food Security from the Sea and a blog post summarizing this study.