Can seaweed save the climate?
No, but it comes with different potential that deserves more research, new study says
- Researchers look closer at the argument that seaweed can act as “ocean forests” and thus help sequestrating carbon
- They warn that seaweed farming should not be seen as a quick fix for the climate
- Seaweed can help reduce emissions by replacing food that have larger environmental footprints
WEEDS OF CHANGE: The idea that seaweed can help reduce carbon emissions should not be rejected altogether, but it comes with several shortcomings. This is the conclusion from a study recently published in Reviews in Fisheries Science & Aquaculture.
Centre researchers Max Troell and Patrik Henriksson, together with colleagues from Sweden, Chile and Canada have looked closer at the argument that seaweed can act as “ocean forests” and thus help sequestrating carbon.
They warn that seaweed farming should not be seen as a quick fix for the climate. Doing so may lead to several misdirected investments and shift focus away from further research on needed societal transformation, viable carbon sequestration methods and more substantial benefits related to for instance food production.
Even if seaweeds can play a role in reducing the carbon released from food systems and other activities, they have limited potential to sequester carbon dioxide on a large scale.
Max Troell, lead author
A major shortcoming relates to the idea that carbon in seaweed biomass could constitute a carbon sink simultaneously while simultaneously be consumed as food by humans or feed by animals. Consumed seaweed biomass will instead enter the fast carbon cycle and be released back to the atmosphere rather quickly.
Suggestions for sinking of seaweed biomass to the deep sea comes with several uncertainties related to feasibility, economics, ecosystem impacts and ethics, according to the authors. Instead, seaweed can potentially help reduce emissions in other ways, for instance by replacing food that have larger environmental footprints.
Seaweeds are an attractive source of nutritious biomass because they can be grown without additional freshwater, land, and fertilizers, but consumer acceptance, bioavailability and high iodine content make their potential role in global diets uncertain.
“Both wild and farmed seaweeds could potentially play a larger role in our diets as they can provide important nutrients with limited environmental burdens” says Patrik Henriksson.
More research needed
Other decarbonization efforts such as seaweed bioenergy production or reducing methane emissions from ruminants by including certain seaweeds in their feed have potential, but more research is needed.
“There is still a need to understand to which extent diverse seaweed farming systems capture and sequester carbon, which emissions that arise from different farming and processing activities” Troell and his co-authors conclude.
M. Troell, P. J. G. Henriksson, A. H. Buschmann, T. Chopin & S. Quahe. 2022. Farming the Ocean – Seaweeds as a Quick Fix for the Climate?, Reviews in Fisheries Science & Aquaculture, DOI: 10.1080/23308249.2022.2048792
News & events
General news | 2024-02-29
Johan Rockström awarded the Tyler Prize
Johan Rockström, professor and former director at Stockholm Resilience Centre at Stockholm University, now leading the University of Potsdam Institute for Climate Research, has received the world's top environmental prize.
Research news | 2024-02-20
Having good neighbours and few top predators make predatory fish populations more resilient
A regime shift is gradually spreading through the archipelagos of the Swedish Baltic Sea coast, where shallow bays, previously dominated by pike and perch have one by one become dominated by one of their prey species, the three-spined stickleback.
Research news | 2024-02-08
Eating new plant-based foods can be good for the environment, your health and your economy
Replacing animal-source foods with plant-based alternatives or whole foods decreases environmental impact, meets nutrition recommendations, and can be cost-competitive with the current average Swedish diet
Research news | 2024-01-29
Bird AI and sailing drones – green game changers for marine ecosystems
Groups of guillemots on an island in the Baltic Sea have unknowingly inspired how marine research can be done. Two AI-powered research projects can change how to monitor marine ecosystems – and potentially manage them in real-time
Research news | 2024-01-24
Centralised social networks can hinder innovation by making decision-making too similar
Social systems where influence is centred around one or two individuals can lead to pack mentality and groupthink in farming communities
Research news | 2024-01-23
Planetary Commons: Fostering global cooperation to safeguard critical Earth system functions
We should look at tipping elements of the Earth system as global commons, argue researchers in a new paper published in the journal Proceedings of the National Academy of Sciences