Underneath the rocking blues of the ocean’s
surface lie forests of green. Gently flowing in the currents, these organisms are the trees of the
ocean. Stunning groves rise up from the depths and shelter thousands of species from the vast void of
the sea. But for us humans, these organisms are so much more, they’re food, animal feed, protection
from storms, a livelihood, and a possible solution to pulling years of fossil fuel emissions out of
the atmosphere. These wonders are none other than seaweed. And today we’ll discover why these plants
(that are not actually plants) may be the key to unlocking a new way of farming that could be an
essential tool to building a zero-carbon world. This video is sponsored by CuriosityStream, which now comes with Nebula for free when you
sign up using the link in the description. The Basics of Seaweed Farming
[Clip of seaweed hype] Over the last decade, entrepreneurs, fisherfolk,
and thought leaders have latched onto the promise of seaweed farming with at times fanatical
exuberance. [Play another clip]. Nonprofits like Greenwave, and for profit entities
like Sea6 Energy, have emerged to encourage and fuel a seaweed farming boom in the United
States, and more broadly the Americas and Europe. What they claim is, on the surface, extremely
promising: a thriving seaweed farming system that supports the livelihoods of thousands of
coastal communities, restores ocean habitats, and for many, the most important bit, sequesters
millions of tons of carbon out of the atmosphere. This is the promise of the nascent “Blue Carbon”
industry. We’ll get into whether seaweed farming lives up to this hype in a little bit, but before
we do that, what do seaweed farms actually look like on the ground? Luckily countries like China
and Indonesia have been farming seaweed for almost 1700 years, so we can already see what this blue
carbon aquaculture looks like at scale. Most seaweed farming looks like plots of coastal waters
with lines of kelp or suitable seaweed species growing vertically down from lines strung across
the surface of the water. Some seaweed varieties can grow as fast as two feet per day, and when
fully grown, are then harvested by boat, processed on land and broken down into numerous materials
that run the gamut from dried seaweed flakes, to animal feed, to agar for thickening, and even
biofuels and bioplastics. In 2019, the world produced 35.7 million metric tonnes of seaweed,
with China and Indonesia responsible for 84.61% of that production. Needless to say, imperial
core countries like the United States are chomping at the bit to fill their coastal waters
with seaweed farms, especially considering their benefits. But can these macroalgae actually
fulfill their host of proposed promises? The Promise of Seaweed: Seaweed farming is growing in popularity across
the world for a myriad of reasons. Some farmers grow them to serve demand for edible seaweed in
a wide range of dishes like sushi, while others grow them for animal feed– supposedly aiding the
health of livestock guts and drastically reducing the methane emissions of meat as a result. Still
others are spurred on by seaweed’s potential to sequester substantial amounts of carbon in
ocean sediments and the deep sea. It’s here, with carbon sequestration, that we’ll begin
to unpack the benefits of seaweed groves. Looking at wild seaweed, which is an umbrella
term for thousands of species of large algae, scientists have discovered their immense capacity
to draw carbon dioxide out of the atmosphere and lock it back into the earth or deep ocean.
One research paper estimates that macroalgae sequester roughly 173 teragrams of carbon per
year globally. To put that in perspective, that's the equivalent of sequestering the emissions of
8.65 million people living in the United States each year. The authors claim that the high end of
this carbon sequestration estimate would be enough to outpace the carbon capture rates of mangroves,
seagrassses, and salt marshes combined. Looking towards seaweed aquaculture, this paper
claims that a square kilometer of seaweed farm could sequester 1,500 tons of CO2 every year,
which would be like reversing the footprint of 300 people living in China or 75 people living in the
U.S. To be clear this is still a rough estimate of carbon removal. The body of research and recording
is in its infancy, so it’s hard to get exact numbers on how much carbon wild and domesticated
seaweed is actually capturing. That being said, there are a host of other benefits that seaweed
provides to coastal ecosystems. Seaweed farms, when introduced have provided rich habitats for
sea life, deacidified their surrounding waters, created storm and flood resilient coast lines
by buffering wave energy, as well as provided oxygen-rich oases in oxygen deprived zones. These
are all exciting prospects. Along the Chinese coast, for example, seaweed farms introduced
near dead zones successfully mitigated deadly toxic algal blooms and reintroduced needed oxygen
back into the ecosystem. While farms off the coast of Costa Rica noticed that the cultivated seaweed
“rapidly attracted biodiversity.” But part of the reason seaweed aquaculture is so appealing is
that it requires few inputs and seaweed grows incredibly fast. You don’t need fertilizer,
herbicides, or pesticides, and the seaweed mostly takes care of itself. Which means
that an ocean farm is comparably easier to start and maintain than its on-land cousin.
In short, seaweed farming, if done right, could potentially sequester
millions of metric tons of carbon, all the while repairing ecosystems and providing
buffer zones for coastal communities. But emphasis on “if done right” and “potentially”
because our knowledge of the effects of seaweed farming on carbon sequestration as
well as habitat restoration is still growing. The Perils of Seaweed:
A quick google search of seaweed farming reveals a lot about the excitement over the
potential of this carbon sequestration powerhouse. Articles like this, or this, feel like 19th
century gold rush promoters of the American West. That much hype raises alarm bells for me.
Especially considering this recent scientific paper that has called into question seaweed’s
potential for carbon sequestration. It points out that previous studies have failed to account for
the contribution of the influx of organic material and plankton that wash into wild seaweed groves
providing extra food for sea life and ultimately leading to significantly more carbon dioxide
emissions. The paper claims that as a result, wild seaweed forests might actually be a net
source of carbon. I use this paper not to discount seaweed sequestration wholesale, but merely to
demonstrate that the research on these practices are extremely new and evolving. We are still in
the midst of parsing out exactly how wild seaweed and seaweed farming contributes to our ecosystems.
To be clear, many scientists in the field have found the research promising, but we have to
be careful how we treat and implement these types of natural sequestration solutions. If it’s
used as just another carbon offset scheme–letting the fossil fuel industry continue generating
emissions with impunity–then seaweed farming could be a dangerous proposition, especially
because we aren’t clear how much seaweed farming sequesters. Expanding seaweed farming then, should
not be viewed as an excuse to continue fossil fueled capitalism, it is instead an exciting
tool in a wide ranging toolkit that should be used for the struggle to build a zero carbon world
free of fossil fuels and capitalist extraction. A World of Seaweed:
Seaweed could unlock a whole new mode of agriculture that would tie humans back
to the earth and the sea, but to do so, seaweed farming must not just be seen as another
novelty for a startup to automate. Seaweed farming is a piece of an amazingly complex web of
low-carbon, carbon negative, and justice oriented actions and ideas that we must integrate to build
a better world. Because, at the end of the day, even if seaweed farms expand to pepper the
world’s coastlines and drawdown millions of tons of carbon from the atmosphere, it will
not be enough. Yes, it will certainly help, but if we continue to grow our emissions footprint
as our capitalist system is currently doing right now, the sequestration of seaweed farming will
be trying to fill an ever widening hole. So, the natural carbon capture mechanisms of seaweed
farming have to be combined with political tendencies, justice oriented ecosocialist
degrowth that seek a contraction of production in the imperial core and an expansion of
well-being for the periphery. Seaweed farming might be a small piece of an exciting new future,
but that future has already begun to take shape in the seaweed harvested along the coastlines
of the world. With each harvest of seaweed we’re bringing food to our plates while repairing
the harm of centuries of environmental damage. But what kinds of seaweed farms are springing
up across global coastlines? Are they small or massive industrial plots? How is the
current seaweed boom being managed and where is all of that seaweed going? Those are some of
the questions I answer in the bonus section to this video I’ve uploaded on Nebula all about the
current state of American and European seaweed farming. If you haven’t heard by now, Nebula is a
streaming service a group of creators and I built that is ad-free and creator focused. So the bonus
content for this video replaces this ad because there aren’t any ads on Nebula. And you’ll not
only see a lot of extended editions, exclusive videos and ad free content over on Nebula from me,
but also from channels like Second Thought, who has a wonderful Nebula exclusive video exploring
the history, ideology, and contemporary resurgence of fascism, it’s amazing and I highly recommend
a watch. At its core, Nebula allows viewers to support creators directly so they don’t have to
worry about the pesky YouTube algorithm. Nebula is awesome but it’s now made even better
with our partnership with CuriosityStream. CuriosityStream is the go-to streaming platform
for thousands of top-tier documentaries, like the ocean episode of Dream of the Future,
which dives beautiful technologies and solutions to problems like overfishing and maritime
transport And because CuriosityStream loves supporting educational creators we worked out a
deal where if you sign up with the link below, not only do you get access to
CuriosityStream, but you'll also get Nebula for FREE. And this is not a trial, you'll have
Nebula as long as you're a CuriosityStream member. What’s even better is that CuriosityStream has a
special deal for my viewers until this Tuesday: 42% off their annual plan - that's a
little under a dollar a month for BOTH CuriosityStream and Nebula. By signing up, you
not only directly support Our Changing Climate, but you gain access to thousands of documentaries
and exclusive videos from your favorite creators So if you want to support both Our Changing
Climate and hundreds of other educational content creators go to CuriosityStream.com/OCC or
click the link in the description and sign up for CuriosityStream and Nebula for
just $11.79 per year, that's 42% off. Thanks so much for watching all the way
to the end! If you’ve already signed up for CuriosityStream you can also support
me by becoming an Our Changing Climate Patron. Just pledging one dollar a month allows
me the flexibility to keep making more videos like this. Thanks again for watching
and I’ll see you in two weeks.
