by Sofie Castelein, Universiteit Utrecht
Seaweed absorbs CO2 five times faster than trees and can provide us with food, energy and biodiversity when farmed. It could therefore play a huge role in transforming our carbon-emitting economy into a carbon-absorbing one.
Scientists say that in order to reduce climate change, we will have to decrease greenhouse gas emissions and draw three gigatons of CO2 out of the atmosphere every year. This challenge got researchers thinking of some ingenious carbon filtering technologies, like the Orca plant externe linkin Iceland. However, they do not (yet) compare to the multi-potent climate solution of seaweed farms. Or so Prof. Tim Flannery externe link, the scientific advisor of the by Utrecht University sponsored Climate Cleanup externe link, tells us.
In Asia, seaweed farms are already a billion-dollar business. Most of the time these farms are combined with the growth of fish and shellfish, a term called ocean permaculture. This works so well because seaweed deacidifies the ocean by absorbing carbon, making the local environment ideal for growing marine protein.
Prof. Tim Flannery says that if we could cover 9% of the ocean in these ocean permacultures, we would restore the carbon in the atmosphere to pre-industrial levels. As an added benefit, the ocean permacultures would be able to feed 10 billion people 200 kg of high protein yearly, deacidify the oceans and increase biodiversity. We can achieve all of this, without using valuable resources or acres of agricultural land.
The reason why seaweed can absorb so much CO2 is because it is incredibly energy efficient. An astounding 98% of the sun’s energy is stored into biomass. The result is that seaweed is able to grow a meter per day and store five times more carbon than any plant on land.
Aside from the carbon storing abilities of seaweed, it is also a very versatile product. Seaweed is used in high quality pharmaceutical and cosmetic products. It can also be manufactured into biofuel and bioplastics. However, the most direct function is to serve as food for humans and livestock.
Seaweed is highly nutritious, even more so than vegetables grown on land. It is rich in fibre, protein, vitamins and minerals which also makes it an excellent alternative for meat. Although seaweed is a regular side-dish in Japan, it has yet to make a big impact on the diet of the rest of the world.
The systemic advantages of cultivating seaweed are overwhelming, it is therefore not surprising that we start to see an increase in seaweed products in our own stores. Seaweed bacon strips, cheese crisps, salads, wraps, tapenades, powders and herbs.
What these farms currently need is worldwide support. Eating seaweed should also be normalized in western cultures. New recipes incorporating seaweed into western dishes appear daily on the internet. You could encourage the seaweed market by buying the seaweed products from the store. By trying them, not only will you help save the planet, you will also have a tasty, healthy snack.
