Seaweed as a resilient food solution in nuclear winter

Abstract

<p>Abrupt sunlight reduction scenarios such as a nuclear winter, an asteroid impact or an eruption of a supervolcano would decimate agriculture as it is practised today. We therefore need resilient food sources for such an event. One promising candidate is seaweed, as it can grow quickly in a wide range of environmental conditions. To explore the feasibility of seaweed in a nuclear winter, we simulate the growth of seaweed on a global scale using an empirical model based on <em>Gracilaria tikvahiae</em> forced by nuclear winter climate simulations. We assess how quickly global seaweed production could be scaled to provide a significant fraction of global food demand. We find seaweed can be grown in tropical oceans, even in nuclear winter. The simulated growth is high enough to allow a scale up to an equivalent of 70 % of the global human caloric demand, while only using a small fraction of the global ocean area. The results also show that the growth of seaweed increases with the severity of the nuclear war, as more nutrients become available due to upwelling. This means that seaweed has the potential to be a viable resilient food source for abrupt sunlight reduction scenarios. </p>

The Fragile State of Industrial Agriculture: Estimating Crop Yield Reductions in a Global Catastrophic Infrastructure Loss Scenario

“…By incorporating more precise and comprehensive datasets into this analysis, its accuracy could be improved. Exploring resilient food options that could serve as viable alternatives to conventional food production in the event of global catastrophic infrastructure loss. For instance, seaweed, which has demonstrated promise following other global catastrophes, [ 47 ] may also prove beneficial in this context due to its ability to thrive in low‐tech cultivation. Also, leaf protein concentrate can be produced at the community scale.…”

“…For sun-blocking scenarios like a supervolcanic eruption this includes the exploration and preparation of resilient foods such as single-cell protein from natural gas, [43] hydrogen, [44] sugar from wood, [45] greenhouses, [46] or seaweed. [47] More traditional resilience measures include food storage, diversification of agricultural practices, crop insurance, or regulations of the agricultural market. [1,15] Most of these solutions, however, depend on industrial infrastructure in one way or another or assume that only a smaller subsection of global food production is impacted.…”

Seaweed as a Resilient Food Solution After a Nuclear War

“…• Nuclear winter ocean data: Jehn et al (2023b). helped with the initial scoping of the project by running some of the ocean model data through his growth model and providing said growth model to the project, but passed away in 2021.…”

“…For a detailed description of the factors see Figures S10-S14 in Supporting Information S1. The code (Jehn et al, 2023a) and data (Jehn et al, 2023b) for the growth model can be found at the corresponding repositories. We excluded the self-shading factor in our adaptation of the growth model and only looked at it in the scale-up model, as it is more relevant for continuous harvesting and less so for assessing if seaweed can grow after nuclear war at all.…”

“…The code repositories also contain instructions for installing and using the models. Python code for the Seaweed Growth Model: Jehn et al. (2023a). Python code for the Seaweed Scale‐Up Model: Jehn and Dingal (2023).…”