Seaweed Farming—The Cure for Climate Change?
“Macro-algae forests have the potential to replace fossil fuel energy, while removing 53 billion tons of CO2 per year from the atmosphere.”
Do you know the seaweed in your sushi rolls can help mitigate climate change and its negative impacts?
The carbon dioxide (CO2) in the atmosphere has reached the highest level ever recorded. The high levels of CO2 are leading to the growing global temperature and increasingly vulnerable marine ecosystems.
However, an analysis indicates by using 9% of the world’s ocean surface to farm macroalgae (seaweed), we can substitute biomethane from seaweed for fossil fuel whilst reducing the amount of CO2 to pre-industrial levels.
In addition to serving as biofuel and carbon sinks, seaweed can also address issues associated with marine and food systems. The multifunctional feature makes it the perfect cure for climate change.
Let’s take a closer look at the magical power of seaweed.
When seaweed is in the ocean, …
Ocean covers 71% of the earth’s surface, absorbing great amounts of CO2 and heat from the atmosphere. It’s doing a great job of reducing global temperature but at the expense of becoming warmer and sourer.
Seaweeds—the fast-growing, long-life span oceanic plants—are good at capturing and storing carbon. According to a study, seaweed contributes 50% of carbon trapped in sea floor. A great fraction of that carbon can stay in the ocean for probably centuries.
Through photosynthesis, seaweeds absorb carbon, nitrogen and other excessive nutrients to generate new biomass (the material used for energy production) and produce oxygen. Therefore, seaweeds not only serve as carbon sinks but also heal the marine ecosystem by ameliorating acidification and providing habitats for marine animals.
When seaweed is in our daily life, …
Do you know why Japanese have a long-life expectancy? One explanation is that they integrate seaweed into their daily diet. Besides sushi rolls, they have created various seaweed recipes.
The explanation is reasonable in some way. Edible seaweeds contain all kinds of nutrients, like antioxidants, proteins, minerals, vitamins, and fatty acids. Studies show having red, brown, and green seaweeds can help us reduce blood pressure, and prevent cancers, obesity and diabetes.
Moreover, no land, freshwater, or fertilizer are needed for seaweed farming. That is to say using seaweed for food can save resources as well as CO2.
Seaweed is good fertiliser or animal feed for farmers. As the fertiliser, it supports plants’ uptake of nutrients and assist them in prevention of soil-related diseases.
As the animal feed, it can help reduce methane gas (the major component of greenhouse gas emissions from agriculture sector) produced by cows. According to a research, putting a small amount of dried seaweed into a cow’s diet can help reduce up to 99% of methane gas produced by the cow.
For energy sector, there has been growing interest in using seaweed as biofuel. Research claims that many species of seaweed are high in carbohydrate content and low in lignin content, which make it perfect for producing bioethanol. Compared with soybeans and corn (which are widely used for ethanol production), seaweed is not only more productive but also land-saving.
The reality of seaweed farming
Even though non-profit, businesses and development organisations have recognised the diverse benefits of seaweed, the development of seaweed aquaculture is quite limited.
Up to now, most of seaweed products come from coasts of Asian countries, like China, Indonesia, South Korea, and Japan. That explains we can hardly buy local seaweed in Australia.
To use seaweed to tackle climate change, policymakers need to develop more policies to motivate people to farm seaweed and expand it. As consumers, we can spread these messages and start turning seaweed into everyday food.