Seaweed as a Resilient Food Solution After a Nuclear War

Abrupt sunlight reduction scenarios such as a nuclear winter caused by the burning of cities in a nuclear war, an asteroid/comet impact or an eruption of a large volcano inject large amounts of particles in the atmosphere, which limit sunlight. This could decimate agriculture as it is practiced 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 after nuclear war, we simulate the growth of seaweed on a global scale using an empirical model based on Gracilaria tikvahiae 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 after nuclear war. The simulated growth is high enough to allow a scale up to an equivalent of 45% of the global human food demand (spread among food, animal feed, and biofuels) in around 9-14 months, while only using a small fraction of the global ocean area. The main limiting factor being the speed at which new seaweed farms can be built. The results also show that the growth of seaweed increases with the severity of the nuclear war, as more nutrients become available due to increased vertical mixing. This means that seaweed has the potential to be a viable resilient food source for abrupt sunlight reduction scenarios. An abrupt sunlight reduction scenario like nuclear winter could reduce sunlight and harm agriculture. Seaweed is a promising food source for such events because it can grow quickly in many conditions. We studied the growth of seaweed globally using a model based on one type of seaweed, and found that it could provide an equivalent of up to 45% of the world's food in 9-14 months. The main challenge is building new seaweed farms quickly enough. The growth of seaweed actually increases after a nuclear war, because more nutrients become available in the ocean. This means seaweed has the potential to be a reliable food source in case of abrupt sunlight reduction. Abrupt sunlight reduction from events such as nuclear war or volcanic eruptions can affect agricultureSeaweed is a promising resilient food source due to its ability to grow quickly in a range of conditionsA global simulation shows that seaweed could provide a significant contribution to global food security in 9-14 months