In scenarios of nuclear war or significant volcanic eruptions, the presence of black carbon in the atmosphere could lead to a nuclear winter, drastically affecting global food supplies with a potential temperature drop of up to 10 degrees Celsius. Recognizing the severity of such a catastrophe, an international team of researchers, including CC&E’s Cheryl Harrison, explored a potential solution for maintaining food security amidst such challenges – seaweed.
Harrison, an assistant professor in the Department of Oceanography & Coastal Sciences and Center for Computation and Technology, collaborated with researchers from the Alliance to Feed the Earth in Disasters (ALLFED), the University of Canterbury, and the University of the Philippines Diliman Marine Institute. Together, they investigated whether seaweed production during events like nuclear winter or volcanic eruptions, which reduce sunlight, could counterbalance agricultural losses on land.
The researchers discovered that seaweed exhibits remarkable resilience. Utilizing models based on the seaweed plant Gracilaria tikvahiae combined with nuclear winter climate data, they found that the plant thrives even in conditions that would render traditional agriculture and fisheries unfeasible. Their findings were published in the journal “Earth’s Future.”
“Alternative food sources like seaweed will be critical for global and regional food security after sunlight reduction scenarios, such as nuclear war and large volcanic eruptions,” emphasized Harrison. “It’s only a matter of time before the latter happens, so we need to be ready. Because the ocean does not cool down as rapidly as land, marine aquaculture is a very good option.”
Harrison also highlighted potential seaweed aquaculture sites, naming both the Gulf of Mexico and the Eastern seaboard of the United States as potentially productive locations. These farms can scale relatively quickly and are projected to meet a substantial portion of the global food application demand within about a year.
While some farmed seaweed may be directly consumed by humans, the majority could contribute indirectly to food stocks by serving as animal feed or biofuels.
Investing in seaweed aquaculture offers near-term advantages, such as mitigating eutrophication and acting as a carbon sink, potentially reducing methane emissions if used as cattle feedstock.
The researchers recommend that nations proactively invest in global seaweed farming to enhance global food security and prevent mass starvation in the face of disasters, according to David Denkenberger of the University of Canterbury, an expert in food resilience.
Seaweed aquaculture is already underway in the Philippines, where low-tech seaweed farming is commonly implemented. This research was featured by the European Geosciences Union at their conference this year (https://blogs.egu.eu/geolog/2023/05/17/seaweed-an-unlikely-but-promising-food-solution-in-nuclear-winter/).