You're looking at a climate hero.
Food, fertilizer, plastic – this green machine can do it all.
"We're on the verge of a revolution."
It even sucks CO2 out of the atmosphere and reduces the methane in cow burps.
Oh, and you have it to thank for all life on Earth. So what are you looking at?
It's algae. 3.5 billion years old, and we're only just figuring out its potential.
It all started long, long ago. The Earth was a hot soup, full of toxic chemicals.
No animals, no plants.
Blue-green algae, or cyanobacteria, changed all that.
"Cyanobacteria are essentially one of the most fascinating
groups of organisms there are. They're really fascinating."
This is Moritz Koch,
a microbiologist who studies
this particular type of algae.
"The fact that we are nowadays living in a world which has oxygen
in the atmosphere is mostly due to the so-called
Great Oxygenation Event, which is when about a couple of billion years ago,
cyanobacteria started producing oxygen
and thereby created the world we live in today."
Cyanobacteria are what are called microalgae – very small.
Macroalgae on the other hand, is what washes up on the beach,
and what many call seaweed.
"Algae are actually like the plants in the ocean,
and so they do the same process as plants do on land,
which is photosynthesis. So they take up CO2 and they convert it using sunlight."
This is Mar Fernández-Méndez.
She's a marine ecologist
studying how algae capture carbon
and impact the whole marine food chain.
"When an algae uses up that carbon from the ocean,
then the ocean immediately absorbs carbon from the atmosphere
because it's in constant equilibrium.
So if you remove something it needs to get equilibrated with the atmosphere again."
Ocean algae absorb one quarter to a third of global CO2 emissions every year.
But all algae do this even if they aren't in the ocean,
so no matter what it's used for, growing algae captures CO2.
And humans have been using algae for thousands of years.
Indigenous peoples from the Americas to East Asia
are the original seaweed farmers.
Seaweed was even mentioned in the oldest known Japanese poetry.
From Ireland, a type called Irish moss
is used worldwide as the food additive carrageenan.
Algae also helped people there survive the Great Famine of the 1840s.
Today, algae aquaculture is most well-developed in Asia,
where it makes up a large part of the cuisine.
It can also be in toothpaste, cosmetics, and medication.
Growing algae for these products captures CO2,
but greenhouse gas reduction is not the main aim.
That is about to change, because using algae as animal feed, fertilizer,
and bioplastic also diverts emissions from polluting industries.
Its impact is effectively doubled. Let's talk about plastic.
Some algae naturally contain and produce a bioplastic called PHB.
It can replace polypropylene, the second most widely used traditional plastic.
In this landmark paper,
Moritz and other researchers modified blue-green microalgae,
or cyanobacteria, to produce more of it.
"Using some metabolic engineering techniques,
we were able to increase this amount from 10 percent to more than 80 percent.
So we really created almost like true bioplastic bacteria,
which consisted mostly out of bioplastic."
PHB disintegrates under normal household compost conditions,
and releases no pollutants into the environment, unlike other bioplastics.
And we already have the infrastructure to produce it.
"You could essentially already use the existing technology
for producing different cyanobacteria,
not just for food consumption like Spirulina
but also for the production of bioplastics, for example."
Aquaculture technology can also be used to grow macroalgae.
One type has a truly amazing property:
When Asparagopsis taxiformis is added to animal feed,
it reduces methane from livestock by up to 82 percent.
Methane is produced in the stomach of livestock during digestion,
which the animals then release.
Compounds in this seaweed
appear to stop the gas from forming in the first place.
Startup Symbrosia is in the media spotlight
for producing algae feed for livestock.
But questions remain as to scalability,
partly because this algae needs to be farmed.
In some cases, however, the algae is already there.
Like sargassum a perfect example of too much of a good thing.
Its home is the Sargasso Sea,
which accounts for 7% of the CO2 absorbed by all the oceans.
But due to global warming and pollution, sargassum is growing out of control.
Huge amounts are washing up yearly in the Caribbean and Gulf of Mexico.
In 2018, the bloom weighed over 20 million tonnes.
Normally the algae would disintegrate, but now it's washing up on shore.
Besides smelling horrendous, it contaminates the water,
killing off animals and destroying coral.
"At this quantity, these mats of sargassum are basically death stars."
Jorge Vega Matos
works at C-Combinator,
a company that focuses
on using sargassum blooms to make climate-friendly products.
One promising use is fertilizer, something that dates back to the Roman empire.
Now it's being synthesized into extracts for large-scale use.
"We're able to turn it into different compounds that are applied foliarly,
so on the plant itself as a spray, that can be applied directly into the land,
either in liquid form or also in little granules."
Nutrients in the fertilizer enrich the soil
and induce processes in the plant that protect against pathogens.
The result is more fruits, and plants more resistant to stress and disease.
But the most direct way to use algae is also the simplest:
pure CO2 sequestration.
Algae naturally falls to the ocean floor when it dies.
There it stores its captured CO2.
We can speed up this process.
"If we want to enhance the amount of carbon that is actually sequestered,
by this sargassum in this example, then we would actively need to bail it,
compress it and actively sink it."
This means adding weights or using a pump
to send it to the bottom of the ocean.
A recent study found that global agricultural emissions could be offset
by using two percent of the ocean to farm and sink seaweed.
So why haven't we been doing this already?
The most widely farmed macroalgae, kelp, only grows attached to something.
Some kelp farms are making headlines for sinking algae,
but on a large scale it would require a lot of infrastructure.
Here's where sargassum comes in.
"If you have a macroalgae that can grow everywhere floating in the ocean
like phytoplankton does but can sequester that carbon with a way higher efficiency
than phytoplankton, then you have a winner.
And that's sargassum."
The technology to collect sargassum is already in use in affected areas,
like Mexico.
And people from a seaweed startup in the UK to the Mexican government
are working on making it more efficient.
"This is not just something that people like me,
you know, biology should be looking at.
This is something that the whole society should be looking at."
The missing piece is funding.
So with the growing attention on algae farming as a climate solution,
incentives to support CO2 capture need to be ramped up as well.
It's time to expect more than just seaweed snacks.
Mmmm. Carbon capture never tasted so good. If you liked this video, tell us.
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