When you think of plans to save the world from climate change, you think of the usual projects, such as solar energy, wind farms and reducing plastic waste. However, there is a new environmental saviour: seaweed. This organism is an essential part of the ocean, providing nursery habitats for fisheries while also being a major food source for all species. But more recently, it has been a vital tool in environmental efforts.

A seaweed farm the size of Croatia

A new initiative called Seafields has plans to start testing a farm of floating sargassum (a variety of brown seaweed) to harness the ‘wondrous properties’ of the marine algae. The field will need to be huge to be effective and John Auckland, the initiative’s founder, has plans for it to be the size of Croatia, at a mind-blowing 55,000km² of seaweed. This floating farm will draw in enough carbon dioxide (CO₂) to combat the dangerous emissions creating climate change. This idea is built on evidence that simply reducing emissions is not enough, and that carbon capture is necessary.

The sargassum farm will have pipes attached that connect the seaweed to the nutrient-rich deep waters, allowing the algae to grow. It is expected to double its biomass every ten days. It will then rotate in the Pacific Ocean currents, also known as the gyres, while broadly remaining in place, meaning the mass of foul-smelling seaweed will never be washed up on shore.

This initiative is the latest step in the global carbon capture industry, which has significant growth potential. According to McKinsey , the voluntary carbon market surpassed $1bn last year and is predicted to rise to $100bn by 2050. Seaweed has the potential to be one of the main sources for carbon capture, with nearly two-thirds of all oxygen on earth produced in the oceans by seaweed, which stores around 175 million tonnes each year.

Could seaweed eventually replace plastic?

Seaweed is being used to save the world in many ways, with new and innovative uses being tested every day. One example of this is seaweed fibres being used as a raw material in paper and packaging products, replacing single-use plastics with more sustainable goods. Global packaging company DS Smith said that it sees the use of seaweed ‘as a real game changer for our customers, who increasingly want products that are easy to recycle and have a minimal impact on the environment’.

Another increasingly popular use of seaweed as a plastic substitute is in the manufacture of surfboards, as only 45kg of seaweed is needed to create a board. According to Surfers Against Sewage, an estimated one million plastic surfboards are manufactured worldwide every year, which results in large amounts of waste and the use of many poisonous byproducts. Seaweed would solve these problems while also increasing sustainability.

Will it work?

Overall, this looks like a great initiative with the potential to solve an existential crisis facing Earth. Seaweed has long been discussed as a method of capturing CO₂—one that is more efficient than trees and vegetation while also not using up valuable land space. It will also provide further employment in the agriculture industry in remote and often poor areas around the world.

Concerns exist, however, especially regarding the Seafields project, with critics highlighting the rush to monetise CO₂ capture ideas and the risk of overselling technologies that will ultimately fall short. Despite these, there is no doubt that this is a definite step in the right direction, and advances on this front must continue.