https://www.youtube.com/watch?v=n-bVnKPMhyc&t=560s

Here is the transcript;

This is my story of finding an ocean of hope in a world on fire. 

The Droughts,   floods,    and fires    raging through countries, desertification, the end of coral reefs, tens of millions of climate refugees, rampant diseases, untold human suffering, water wars. As a young climate scientist I’ve had many nights buried under climate fatalism.

Yes, there are lots of young people, like me, scientists, entrepreneurs, activists, all stepping up around the world demanding change. But as fast as I grasp at that hope, logic and fear kicks in.

Emissions are going up, we are tracking to blow past 1.5 degrees, full pace, catastrophic, runaway climate change has begun. Your not supposed to drop F bombs at COP so I’ll say it seems like we are pretty screwed.

My way of coping has been, trying to find the most scalable solution possible. I come from a skinny country surrounded by ocean and from a family of free divers. With a childhood spent under or on the water, it was natural I looked to find this scale in our oceans. The ocean covers 70% of our planet, holds 50x more carbon than the atmosphere and provides us one in every second breath. Take a moment, to breath in the ocean.

As I finished my undergrad I found Blue Carbon. These are coastal ecosystems like mangroves, saltmarshes and seagrasses. These ecosystems not only bury carbon at rates faster than tropical rainforests but they also buffer from storms, support critical biodiversity, boost fisheries and stop excess nutrients choking up our coasts. Actually, these ecosystems created the fossil fuels that we use today.

Restoring and protecting these ecosystems is critical and can be done all around the world to account for 3% of global emissions by 2030. Sounds like something I can fight for. But while that is big, I wanted to find something bigger. Seaweed occupies a larger area than all coastal blue carbon ecosystems combined.  And, is the fastest growing organism on the planet. Half a meter a day which is unbelievable !  We can get more seaweed biomass per hectare than anything on the planet without the need freshwater or nutrients.  So I turned to seaweed as a climate change solution for my PhD and became known as the weird seaweed guy to my friends over the last few years.

Like many ecosystems, Seaweed forests have been collapsing around the world, up to 95% for some kelp forests in Tasmania.  Restoration of these kelp forests is critical from a biodiversity and social perspective – but seaweed grows on rocks, and doesn’t bury carbon in sediments. And while seaweed grows really fast, is also breaks down really fast with a lot of that carbon returning to the atmosphere, seaweed is sequestering carbon when we restore it, but its really tricky to measure out how much.   

Seaweed farming is also sequestering some carbon, it is a huge industry in south east asia and is expanding around the globe. Seaweed farming is great, it reduces acidification, takes up nutrients, boosts biodiversity and is a great low carbon product. For example seaweed bioplastics, fertilisers, or pharmaceuticals.  But that seaweed is being used for products where most of the carbon ends up getting back into the atmosphere..

For my honours project I had a go at building these bamboo and hemp pyramids, that would float out to sea where they would grow seaweed on them and then eventually sink sending that carbon to the deep ocean. And while it could work in theory, through my PhD I found there were too many challenges, like the fact that seaweed outcompetes phytoplankton for their nutrients. So while seaweed fixes lots of carbon, it makes phytoplankton fix less.

So seaweed is pretty cool, and seaweed restoration and farming are important, but I wanted to go bigger. Now there is this concept called the iron hypothesis. It says that the reason there is not a lot of life out in the middle of the ocean, away from the coasts, is because of a lack of iron. So researchers in the early 2,000s tested the iron hypothesis by fertilizing the ocean with small concentrations of iron. They were right, It created massive phytoplankton blooms fixing huge amounts of carbon for not much work. The problem was the phytoplankton didn’t really sink, they just degraded and the carbon got back to the atmosphere. It didn’t work.

But this got me excited, this is the type of thing we need for low cost at scale carbon removal. The solution has got to be in the open ocean.

And recently other researchers have been looking at the same thing. But instead of Iron they have been looking at other minerals, like aluminum and silica. These are specifically used by diatoms, phytoplankton with hard silicate shells. These phytoplankton are heavy, and sink faster. So perhaps we could use different concentrations of these minerals to create big phytoplankton blooms that sink.  

But crushing up these minerals as rocks and spreading it as dust doesn’t work that well for phytoplankton.  Phytoplankton can’t take in a whole bit of iron dust, they need the individual iron molecules. Which is very expensive, too expensive.

Then I heard about this other thing, and bear with me cause it’s a mouthful – electrochemical alkalinity enhancement. Basically you electrocute seawater to make it less acidic, this in turn sequesters more carbon in the ocean. There are a few startups working on this at the moment, and it looks promising. But the problem is they have to take the acid out of the seawater, which can be turned into other products, but this means the seawater has to be pumped through machines on land. It’s a good solution, but requires a lot of energy.  

I kept getting my hopes up, I heard of other carbon removal solutions like upwelling deep nutrient rich water or marine cloud seeding, but for one reason or another the science, the scale was falling short.

Then recently I heard a new solution– a new type of electrochemistry. One that uses metal anodes as the conduit for the reaction. This could both increase alkalinity, sequestering carbon but instead of creating an acid byproduct it would release trace minerals like aluminum into the ocean. These trace minerals would be small enough to be used by phytoplankton, and so would create more carbon sequestration as the byproduct. Win win.

This solution would lower ocean acidification, and require relatively little energy or material use. And while the research on this has barely begun, and many questions are still to be answered, I’ve finally let myself feel a bit of genuine hope on this one.  It seems like something that can scale, and for the first time I’ve landed on a solution where the light, the hope hasn’t gone out.  

A lot of you will be thinking, this stuff sounds a lot like geoengineering, deliberate interventions in the earth system to combat climate change. And your right, that’s what it would be. This scares a lot of people, rightly so, and elicits a lot of opinions.

For me its pretty simple, we have to do absolutely everything. We are now mid fall, not teetering on the edge,    Apathy and denial pushed us … we have no parachute we are free falling into climate chaos…  We’ve lost the privilege now of sugarcoating the reality of the situation. 

And while this new type of electrochemistry has me excited and hopeful finally. There is not just one solution. We have to restore our coastal ecosystems, build back our seaweed forests and coral reefs. And then yes use the lowest cost, lowest impact methods to pull as much carbon out of the air as we can.

We need policymakers to be ready for marine carbon removal that happens in international waters. We need investors to back our oceans. But most of all, most of all we need to put a mask on and go for a swim in the salt. See the rubbish choking the fish and beaches, and see the spectacular life that despite all we have done, still lives on. It’s the sense of wonder and adventure from the ocean and science that has pushed me to seek out these solutions and we need everyone else to fall in love with the ocean too. Because when you love something, you never give up hope that you can save it.