Seaweed Revolution - RSA Journal - RSA

Seaweed revolution

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  • Picture of Vincent Doumeizel
    Vincent Doumeizel
    Senior Adviser for Oceans to the UN Global Compact & Director at the Lloyd’s Register Foundation
  • Environment
  • Health and wellbeing

Marine flora can help to reduce world hunger, pollution, the impact of climate change, disease, biodiversity loss and social inequality. What would the world look like if we fully exploited its potential?

Seaweed, undoubtedly the world’s greatest untapped resource, has been largely spurned by our society. Often misunderstood and seen as a form of pollution, the climate emergency and global population growth are now pushing us to reconsider this overlooked treasure.

The fact is that these species of marine algae offer an endless source of innovation and concrete solutions that could help us address some of the major challenges facing our generation. If we learn how to grow it sustainably, seaweed could feed people, replace plastic, decarbonise the economy, cool the atmosphere, clean up the oceans, rebuild marine ecosystems and reduce social injustice.

An essential pillar of life on earth, seaweed reproduces quickly and can grow dozens of metres in a few days without needing food, fresh water or pesticides. If we want to rebuild ecosystems instead of destroying them, seaweed is an excellent place to start.

Turning hope into reality

I was invited onto a radio programme recently and the journalist asked the speakers to sum up seaweed in one word. The oceanographer sitting next to me thought for a moment, and then chose a simple word: ‘hope’.

To what extent can seaweed represent a new hope for the world of tomorrow? Each of us holds part of the answer. It is our joint responsibility to turn hope into reality. To dream of a world where the economy’s only aim is to repair ecosystems and improve social justice is perhaps utopian but, throughout history, the ‘utopians’ have made many advances that seemed far-fetched to their contemporaries.

Over the past 70 years, utopians developed food systems that have dramatically reduced the number of people dying of hunger. Utopians have also fought to achieve higher literacy rates, gender equality, greater tolerance of minorities, the establishment of democratic regimes in half of the world’s countries and a historic reduction in the number of armed conflicts.

We owe a great deal to those who have chased these utopias. So let’s all become ocean utopians for a moment and ask ourselves: what would the world be like in 2050 if we fully integrated seaweed, and the ecosystem it supports, into the way the world functions?

Imagining success

It’s New Year’s Eve 2050, and seaweed features on most dinner menus. We are now aware of the benefits of seaweed, both for the environment and for our health. Our eating habits, respect for the environment and knowledge of our bodies have changed enormously. Seaweed is also trendy among young people, who have increasingly turned towards a plant-based diet.

If, in the 1950s, rock music, western films and Hollywood gave us American burgers and sodas, since the 2020s Japanese manga, Chinese soft power and K-pop have sprinkled seaweed onto our plates. Lacto-fermentation makes the taste of seaweed more accessible to the western public. This fermentation also makes it possible to avoid systematically drying it, which is an energy-consuming process.

To meet the growing demand, seaweed cultivation has expanded massively in our utopian world. Efforts have been made to facilitate access to cultivation areas and to accelerate the distribution of offshore concessions. At the same time, the rapid development of offshore wind farms has increased opportunities for cultivation in areas previously untouched by production.

Investments at the global level have accelerated since the UN Framework Convention on Climate Change introduced carbon offset mechanisms linked to seaweed. This recognition and promotion of the role of seaweed for the environment has facilitated access to funding, with many young entrepreneurs investing in the seaweed industry.

International standards have been rapidly adapted through traceability systems and a standardisation effort on the part of international institutions. All this progress has received firm support since the creation in 2028 of UN-Oceans, the first UN agency for the collective management of the high seas.

In India and Africa, seaweed cultivation allows for greater food sovereignty, which reduces nutritional deficiencies and dependence on international aid. Algaculture has its own curriculum in universities, while ambitious training programmes for coastal communities have anticipated the disappearance of non-artisanal fisheries and reoriented people towards aquaculture using seaweed.


In the east of Africa, coastal countries have developed new species while integrating other animal or shellfish crops. A large global movement called ‘She-weed’ has also emerged on the African continent, using this new industry to fight against old patriarchal models of aquaculture and fishing. Active on the latest forms of social media, this virtual community brings together women from all over the world.

The Indian government has made it compulsory for aquaculture production to incorporate seaweed to limit waste runoffs and reduce negative effects on the environment. Further north, global warming and ice melt have opened up production in Siberia, Alaska, Greenland and Canada. The rapid development of sectors in these areas attracted new populations and marked the beginning of the ‘Cold Blue Rush’ in our imagined future.

Thanks to the contribution of seaweed and integrated aquaculture products, food insecurity has been drastically reduced. In addition, the use of seaweed protein extracts in animal feed, instead of genetically modified soybean meal from Brazil, has been a major factor in halting the deforestation of the Amazon. More generally, seaweed cultivation, together with the strong development of vegetarian diets, has freed up land for less intensive livestock and other crops.

The profit margins on the sale of edible seaweed also improve the sophistication of biorefineries for transforming certain seaweeds into by-products. Marine plants are used as natural fibres in textiles and are gradually replacing cotton, which requires a large quantity of water and pesticides. Seaweed extracts are also helping to replace plastics.

Cutting cancer rates

Research into algal microbiology has become cutting-edge, with pharmaceutical companies increasingly incorporating seaweed compounds into the manufacture of medicines. This new capacity has been accompanied by advances in nanotechnology and immunotherapy. Thus, since the 2040s, a drop in cancer rates has been observed as preventive and curative treatments based on seaweed increase in efficacy.

By effectively stimulating animals’ immune systems and growth, seaweed enabled a 90% reduction in the use of veterinary antibiotics between 2020 and 2040. This decrease explains why, against all expectations, antibiotic resistance declined over the same period. Thus, the antibiotic molecules of 2020 are still efficient today.

In addition, by 2042, the combined action of fermented and non-fermented seaweed almost completely eliminated methane emissions from ruminants worldwide. Moreover, the huge invisible fields of seaweed along coastlines are now able to absorb and store large amounts of carbon. These two factors contributed to slowing down global warming and to achieving the commitments made at COP32, where the Paris Agreement was revised.

Thanks to tidal energy, submerged machines were created in the 2030s, replicating the movements of seaweed in the water to produce energy. Later, in 2043, UN-Oceans decided to turn some seaweed farms into gigantic carbon pumps designed to sequester carbon at the bottom of the oceans, hoping to actively cool the atmosphere.

These advances, combined with other carbon austerity measures, have helped to avert the climate catastrophe that was heralded since the beginning of the century. In recent years, there has even been a slight decrease in the level of greenhouse gases in the atmosphere, which would indicate a cooling in the coming years.

The fight for seaweed is an intergenerational commitment to hope and optimism

Circular agriculture

The phosphate crisis of the mid-2030s, which began following a depletion of mineral resources and could have led to global famines, was largely resolved by pollutant-recycling systems. Growing these crops, which are capable of recovering phosphate compounds from fertilisers at sea and reusing them, has enabled the creation of a regenerative and circular agriculture between land and sea.

Most recently, the increased sophistication of techniques using iodine from seaweed, combined with the launch of tropospheric drones and nanotechnology to seed clouds, has increased our understanding of the water cycle. It is therefore now possible to transport rainwater to desert regions. The emergence of new arable land, coupled with increasing ocean resources, makes it possible to sustainably feed a growing and ageing population that is less prone to disease.

So, in less than 30 years, humans have succeeded in mastering the complete cycle of the three major essential compounds: water, carbon and phosphate. For the first time in our history, we have managed to feed our entire population properly. And the best is yet to come…

A feasible future?

This projection may be fiction, but it is feasible. Idealistic for some, or nightmarish for others, it is within the limits of what is possible with current scientific advances. The most uncertain part is our common desire to implement this integration of the oceans to help solve the major challenges of our generation.

No doubt there will be sceptics who will see this imagined future as a bizarre flight of fancy. But while it may be impossible to predict the future of humanity, it is easy to recount its past. Life originated in the ocean billions of years ago and only very recently began to evolve outside the water. Our connection to the sea is unique and timeless. As a condition of life on Earth, our relationship with this immense expanse could decide the future of civilisations.

An ocean view fills us with serenity. Seeing the sea, swimming in it, immersing oneself in seawater and sunshine is a joy. The human body is essentially made up of water. The ocean is not part of our environment, we are part of the ocean’s environment.

As a father of three, I cannot bring myself to watch those already being called ‘Generation Covid’ experience the predicted extinction of our species. This fight for seaweed is an intergenerational commitment to hope and optimism.

But we are feeding our children with fear when we should be providing them with solutions and a source of optimism. There is hope. The research into seaweed and the projects that have been launched, both locally and globally, hold great promise for the future. It is a future where world hunger, pollution, certain diseases, climate change, loss of biodiversity, social inequality and impoverishment will be reduced.

By reconnecting with living things and collaborating with the marine prodigies with which we share our origins, we can bring about an ecological, geopolitical, medical, energetic, social and humanist revolution.

The seaweed revolution.

Vincent Doumeizel is Senior Adviser on the Oceans to the UN Global Compact and Director of the Food Programme at the Lloyd’s Register Foundation. This article has been excerpted and adapted for the RSA from his recent book, The Seaweed Revolution, translated by Charlotte Coombe

This article first appeared in RSA Journal Issue 3 2023.

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  • Inspiring article which I missed in June. Fresh strand line seaweeds gathered carefully have surprised me as a quick and effective domestic compost accelerator. Large Kelp pieces are best avoided.

  • One must never forget the contribution to seaweed cultivation of the eminent female scientist "Mother of the Sea" Kathleen Mary Drew-Baker - see .

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