A massive amount of seaweed known as the Great Atlantic Sargassum Belt is growing as a response to climate change. To date, it has expanded to a width twice that of the United States.
When sargassum reaches the coast, it causes human health problems, destroys ecosystems, and wipes out tourism, usually in communities that don’t have the resources to combat the issue.
So, what can we do to prevent these destructive seaweed blobs from reaching coastal regions and remove carbon dioxide from the atmosphere in the process?
Patricia Estridge and Mike Allen serve as CEO and Chief Science Officer, respectively, at Seaweed Generation, a startup using robotics and seaweed to fight climate change.
On this episode of Reversing Climate Change, Patricia and Mike join Ross, Siobhan, and Asa to explain how their technology, a Pac-Man meets Roomba meets WALL-E style robot, collects seaweed and sinks it in the deep sea.
Patricia and Mike discuss Seaweed Generation’s pilot project with Antigua, describing the advantage their process may have over other methods of carbon removal and how they’ve been received by the community there.
Listen in for insight around the growing acceptance of open-systems pathways for carbon removal and learn how you can get involved in helping Seaweed Generation tackle the sargassum problem around the world.
More from the show
Ad-free episodes and other benefits come with a paid subscription.
Carbon Removal Newsroom, the news show that ran alongside this one, is over. Its episodes are still up, on the feed Climate Workers Anonymous now uses.
Carbon Removal Memes is still going.
Resources
Carbon Removal Memes on Twitter
A Small Place by Jamaica Kincaid
‘Leveling the Playing Field for Open-System Carbon Removal’ by Dai Ellis & John Sanchez
‘Quantification Uncertainty and Discounting’ by Dai Ellis & John Sanchez
Patricia’s Interview with Mike on the Seaweed Generation Podcast
Full Transcript
Ross Kenyon: You’re listening to the Reversing Climate Change podcast, by the team at Nori, the carbon removal marketplace. This is a show about the innovators and entrepreneurs developing solutions to climate change. Hello, and welcome to the Reversing Climate Change podcast with Nori. I’m Ross Kenyon, and I’m one of the co-founders of Nori, which is a carbon removal marketplace based in Seattle. Today I have with me Asa Kamer, the producer of Carbon Removal Newsroom, our sister podcast, which is an amazing weekly — bi-weekly — news panelist kind of show with all the latest in carbon removal. Is that fair to say?
Asa Kamer: Well, it’s three times a month, so there’s not really a good shorthand word for that.
Ross Kenyon: Yeah. Is there a tri-monthly? Yeah, tri-monthly. A tri-monthly show. And you guys should check it out — the world’s best tri-monthly carbon removal podcast. People will be so curious about what that even means, they’ll have to Google it, and shazam. We also have Siobhan Montoya Lavender from Thanks a Ton, and also Nori’s Lab, which — if you follow Carbon Removal Memes on Twitter — Siobhan and Asa both work on that. A couple of you don’t follow. Why do you not like to laugh at carbon removal? Do you not like to laugh, or do you lightly chuckle and then scroll past, or not laugh at all? I’m excited to doom-scroll some memes now.
Also with us today we have Mike Allen, who is the Chief Science Officer, and Patty Estridge, who is the CEO, of a wonderful new startup called Seaweed Generation. They’re going to be talking to us today about their project, and about how we’re going to use the power of seaweed in the ocean to reverse climate change. Welcome!
Patricia Estridge: Thanks for having us. Good to be here.
Mike Allen: Great to be here. Yeah.
Ross Kenyon: So I’m a big fan of your technology, and I particularly like how you described it as a Pac-Man-style robot that eats seaweed. So what does that mean for our audience? What is this technology you developed, and why do you see its potential?
Patricia Estridge: I think that’s a good opener. So I describe it usually as a Pac-Man meets a Roomba. It’s kind of a big Pac-Man-like mouth, but it does the function of a Roomba in the ocean for these stinky seaweed blobs that we’ve seen coming through in the central Atlantic region, called sargassum. Anything to add, Mike? Is that a succinct synopsis?
Mike Allen: It’s great, and obvious. But I don’t like the Pac-Man analogy. I like WALL-E, if I think of a lovable robot. So we’ve been more like the WALL-E idea, where we collect the seaweed and then put it in the deep sea. You just need to make it cute.
Patricia Estridge: Mike likes this technology cute — googly eyes and lovable. I think a lot of what we’re doing, you really have to involve the public, and to get the public to connect to what you’re doing you have to really make it engaging. So it’s not just about having a successful technology, it’s about telling our story as well.
Ross Kenyon: Which public do you mean — just general environmentally concerned people, or locals where you’re doing this activity?
Mike Allen: Both. Yeah, both. I think you’ve got to engage with the local communities that we’re helping out, but ultimately this is a global problem, and we need to engage with a global community. So having things that people can understand, and our processes being very, very simple, is very important in how we explain that. And you can explain it to a child as well as an adult, so that’s really important for us.
Ross Kenyon: Yeah, let’s zoom out for just a minute and tell the audience: what is the virtue of sinking seaweed? For those who maybe have heard of Running Tide or other companies — maybe they haven’t — what is the virtue, for carbon dioxide removal, of sinking seaweed?
Patricia Estridge: So in this case there are a couple of virtues, I suppose. The first is that carbon dioxide removal, as we know — and probably most people who are listening to this know — would need to get to a very, very huge amount every year, around 10 billion tons by 2050 of additional removal from the atmosphere. So carbon dioxide coming out of the atmosphere and going somewhere that isn’t the atmosphere anymore. And for that, seaweed and using the oceans could be incredibly scalable. That’s a massive number. So if you’re looking for something that’s going to get to that point of one, two, three, maybe more gigatons a year, then seaweed biomass in the ocean is one of the things that can be really scalable.
And at the same time, we have this enormous, massive amount of seaweed which is growing naturally, as a response to climate change, in the central Atlantic, in an area called the Great Atlantic Sargassum Belt. It’s now being talked about as the seaweed blob, which is twice the width of America at the moment. Mike, is that right?
Mike Allen: I think about 5,000 miles, yeah. It’s absolutely ginormous. And it’s happening because of climate change, because of fertilizer runoff, soil runoff, sewage runoff, and different changes that we’re seeing in the global ecosystem. And that sargassum is coming in to the coast on a massive, massive scale. It’s rotting, creating an anoxic zone, dumping out a whole bunch of arsenic, because it’s really good at absorbing arsenic as it’s growing.
Patricia Estridge: And that is a really, really good candidate for us to stop that from happening, and to conduct carbon dioxide removal with our WALL-E-meets-Roomba-meets-Pac-Man, which we actually call the AlgaRay. Our prototype is Alfie. So Alfie the AlgaRay is going to grow up and learn how to intercept and sink this stinky seaweed before it can get to the coast and cause problems. And through doing that, we can learn a lot about what the parameters of carbon dioxide removal with seaweed more broadly could be.
Mike Allen: As the scientist, I need to say: it’s not stinky when we intercept it. It only gets stinky when it starts rotting, and then it really, really stinks. When it’s out in the open ocean, it’s wonderful. Seaweed is beautifully healthy. The problem is when it goes coastal, it becomes a problem. So stopping it from getting to the rotting bit — it’s glorious, beautiful seaweed.
Ross Kenyon: Given the magnitude of this blob — I’m not actually sure if it’s WALL-E-sized, or Pac-Man-sized, given that it’s a little digital representation — how could that possibly make a dent in such an enormous blob? How many WALL-Es do there need to be?
Patricia Estridge: We’re starting out with our current one. Alfie is 2 meters by 5 meters, about half a meter deep. When he grows up, he will be a pretty large, maybe less cute version: he’s going to be around 10 meters by 4 meters and 1.5 meters deep, and will take about 16 tons of sargassum every time it does a drop. And it’ll be able to do that around 26 times an hour or so, at around 25 percent capacity rate. It will be able to remove around 8,000 tons of carbon dioxide a year — think 80,000 tons of sargassum. So to clean up everything that there is in the central Atlantic region, you’d need around 1,000 of them.
I don’t think you’d want to go that big that fast. What we’re trying to do is learn about carbon dioxide removal with seaweed and stop the coastal damage at this current stage. The challenge is massive, but by breaking it down a little blob at a time, we can meet the challenge, I hope.
Ross Kenyon: We should write a children’s book: Alfie and the blob.
Asa Kamer: Yeah, content marketing idea.
Ross Kenyon: Yeah, I love marketing ideas that are intentionally old school. I’m always like, can we send someone a fruit basket? I always want to do videos like that. A serialized comic book is a very clever idea that appeals to me. Total tangent, though: I read Wide Sargasso Sea in high school, when I read Jane Eyre, and since then this is the first time I’ve heard anyone talk about sargassum. So what even happens to the coast if you just left this blob to run wild?
Mike Allen: The Sargasso Sea is a great topic to bring up here, because it’s the only sea that’s actually defined but has no land boundaries. It’s actually just a mass of water that’s kind of circulating around. Its base is stable. It’s a beautiful area, full of wildlife. But what we’re talking about with the Great Atlantic Sargassum Belt is seaweed that has probably come out of that and then has seeded an entirely new region of the ocean.
And as Patty said earlier, with ocean acidification and the warming of the oceans, as well as all that nutrient runoff, we’re now fueling seaweed growth in different areas. So it’s going from the west coast of Africa, it’s growing all the way across the Atlantic, and then it’s sweeping into the Gulf of Mexico, and then it’s hitting the land, and that’s where it’s causing a problem. Because the Sargasso Sea possibly moves around, but ultimately it stays in the same place. This stuff is moving across, and when it hits the coast, that’s when you get all your problems.
Asa Kamer: Yeah, so I was actually just recently down in the Yucatán Peninsula, in Quintana Roo, and it was sargassum city. I talked to some friends about it — a friend of mine owns an apartment down there and invited us down — and he was saying how much money the hotels and the government are spending to clean up the sargassum. I found one statistic that says it’s costing about a million US dollars for offshore sargassum barriers, and that they can run up to 100 dollars per linear foot. And then there are also hotels that are spending thousands of dollars daily, if not weekly, just to hire people to shovel sargassum off the beaches.
They’re also doing clever things like undercutting beaches, so that there’s a shelf that catches the sargassum and there’s a strip of clean beach, because it really is just flooding these beaches. And to Mike’s point, it might not be smelly in the ocean, where it’s beautiful and it’s a great habitat, but on the beach it is rotting, and it does not smell good.
Mike Allen: You’ve got a health impact there, with those noxious gases coming off, to humans. But I mean, probably the bigger impact is on the coastal erosion. As you’re removing it, you’re also smothering coral reefs, you’re causing massive anoxic zones. As it rots, all those nutrients go back in, and then it fuels microbial growth. It’s an absolutely horrible situation.
Asa Kamer: Yeah, yeah, it really is. And so there’s all sorts of people trying to use barges and shoveling, or whatever they can, to get this out. It seems like a real opportunity for potentially multiple revenue streams. We talk a lot about CDR needing multiple revenue streams, and I’m sure somebody would want to at least help you, but more likely pay you to clean this stuff up for them. Have you found that to be the case?
Mike Allen: Yeah, I worked quite a few years trying to find some value in the sargassum biomass, trying to convert it into fuels, fertilizers, feeds, things like that. The problem, as Patty alluded to earlier, is a lot of heavy metals in it make it very difficult to do anything like that. There are lots of really cool entrepreneurs out there trying to do something valuable with it, making it into tourist items and things like that, and bricks to make houses. The problem is, with millions and millions of tons turning up in different locations, you can’t control where it’s going to go, when it’s going to go — there are so many variables.
So to create a sustainable industrial process is very, very challenging with this biomass, because it’s so uncontrollable, and when it is there, it kind of overwhelms you. So it’s feast and famine, really, which is really difficult to create sustainable industries around. So that’s why with our approach, intercepting it offshore, it’s always going to be there and you can track it from space. So you sort of get rid of all those variables.
Patricia Estridge: Yeah, I mean, to some extent — or we can work with the variables that it offers us. I think, to go back to the multiple revenue stream question, there’s definitely potential there. At the moment we’re more in the realm of fielding invitations to go and participate and test and do pilots in different areas, and we’re quite often mindful that this is another climate change disaster that’s hitting these nations, and not all of them have the money to do anything about it — very few of them do.
So a lot of our modeling is around revenue sharing with nations who are looking at trying to do something about this, trying to unleash or leverage their blue economies where they have them. I would say we’re certainly of the mind that there could be a secondary revenue stream, but we’re very conscious of things like climate justice. A lot of these places have actually just abandoned the coasts that are being inundated with sargassum, and a lot of that tourism has been shut down. The Mexican region that you were in is certainly one of them that is actually kind of engaging with it, spending a lot of money and fighting back, and trying to do things like dig away parts of their beach, which is probably going to cause a ton of erosion over time.
So we haven’t found a one-size-fits-all kind of model at the moment. We’re engaging with stakeholders and seeing what kinds of appetites there are. Largely speaking, we’re talking to countries that don’t have the money to put into it. But you could imagine in the future there being something like a tourist tax, especially where it’s carbon credits staying within a country, and that tying in with the country’s footprint. That kind of approach might work, I think, in the future, but it might be a bit early.
It’s a bit early for us to say, “This is definitely what the carbon dioxide removal piece looks like, this is what the tourism piece looks like,” and then figuring out where the carbon credits and additionalities and exactly what activity lies where ends up being. We’re very focused on that carbon dioxide removal angle, because we think there’s just so much potential in the sargassum itself to learn, and then also in seaweed more broadly for carbon dioxide removal on a much larger scale.
Mike Allen: It’s really interesting what you said about the costs as well of cleanup, because we tried to get a grip on this a few years back and it’s really difficult to get accurate numbers, because everyone who’s involved in the industries having to remove this seaweed is downplaying the problem. Because if you say that you’re spending this amount on removing all this seaweed, yeah, it’s not just cost, but you’re actually raising awareness of the problem. So people are actually downplaying the problem. There’s very little media, social media, on sargassum. When COVID hit, for example, because tourists weren’t traveling, the problem went away. Now it’s back with a vengeance, as the whole world has reopened, really. So it’s really interesting to try and get a grip on it.
And at the same time, if you look at the people who are trying to help out on the beaches, saying, “I removed X number of tons,” people take a lot of pride in that. So they say, “Well, maybe instead of removing one truckload, I removed ten truckloads,” just to show that they’re really, really helping. So getting accurate numbers on the cost is really, really challenging.
Ross Kenyon: So it seems like it has an advantage over other carbon removal methods, because the environmental justice component of this seems pretty straightforward. I can imagine for other types of carbon removal, the siting has a potential neo-colonial concern. People are worried about people coming in and changing the demographics or economy in some sort of damaging or just unwelcome way. And this seems like it’s actually solving a problem for people who are most impacted, and thus is able — unless you [unclear] — to sidestep a lot of these concerns and actually be involved in addressing them, rather than just being neutral. It seems like potentially even a straightforward positive. Is this an accurate read?
Patricia Estridge: We think so. I mean, it’s definitely [unclear] a little bit. But yeah, yes.
Asa Kamer: Doing their PR for them.
Patricia Estridge: Yeah, so we definitely see this. And one of the reasons why we decided to do this was because of the terrible side effects that it’s causing. And Mike’s been working in this, like you said, for like nine years now.
Mike Allen: Yeah, and I think throughout my research career it’s been trying to make cleanup operations pay for themselves, and actually, especially in the areas where local governments can’t afford the cleanup operations, the problems are allowed to fester. So this is a culmination of about 20 years of work.
Patricia Estridge: Yeah. He’s a good guy. But yeah, I mean, it’s definitely one of those problems that you look at and you say, this is horrible. It isn’t necessarily an enormous problem when it’s out there — it is significantly less diverse than the Sargasso Sea, so you can see there is one primary species which is winning, an invasive species, I suppose, which means that it’s not quite as much of a vibrant habitat. But when it comes in to the coasts, it’s causing human health problems, it’s causing complete destruction of ecosystems, it’s destroying tourism. It is even so bad in some places that the fishing boats can’t get out into the sea. So the knock-on effects it’s having can be really tremendous.
And that’s in the last year or so. It’s become something that I look at and go, oh my goodness, this is very anxiety-inducing, in the way that general climate change can be.
Mike Allen: Yeah, it’s not great when it comes in very, very large amounts, and it’s doing so on an increasingly regular basis.
Ross Kenyon: I really love what you said about the justice components here, because as is common with climate change and the effects of climate change, a lot of these coastal communities that have contributed the least are bearing the worst brunt of climate change. And as you point out, this is being caused by runoff and fertilizers largely from the Amazon, as my understanding is, and from Brazil’s deforestation projects. And yet here it is impacting small island nations. Speak to us a little bit about this pilot you have going. Is it with Antigua?
Patricia Estridge: Yeah, we’re going to Antigua next month — or Alfie’s going to Antigua next month, and it’ll take some time to get there. So we’re starting in May to do our first full robot trials of interception and sinking, and to start baselining data of the areas where we’ll hopefully be doing the sinking longer-term.
Mike Allen: Yeah, I absolutely — like you say, a lot of these small island nations are being terribly, terribly impacted in an increasingly consistent way. If you go down a bit further south to Barbados and [unclear], which are lovely places, the sargassum is coming in almost all year now. You can see it on the satellite, kind of swirling around and not really going away, which it used to do when the problem first started in 2011.
Patricia Estridge: So we’re very hopeful that the pilot will go very well and that we’ll be able to demonstrate that we can intercept and sink in a consistent and efficient way with Alfie. And then we’d like to open up the opportunity for other areas to host pilots, especially because for us the purpose of doing a pilot is to learn as quickly as we can. So if we can run more of them in different places, that means that we can have more consistent and ongoing learning happening. Whereas if we’ve got one place, we have to wait for the sargassum to come at the right time and then go and learn as much as we can as quickly as possible. So yeah, we hope to expand to more areas quite quickly.
Asa Kamer: This is so in line with so many of the conversations we’ve been having about carbon removal, where you guys sound relatively confident about the technology and you’re developing this really interesting project, and it comes down to the business model innovations, and the social acceptability, and the climate justice and who’s-responsible elements, that it sounds like — I mean, you didn’t say this directly, but they are also incredibly difficult knots that you’re working on. So it just tracks with all we’ve been talking about, where there’s obviously, I’m sure, technological challenges, but there are these other bigger questions of how to even fund it and how it can even exist, that are maybe even more complicated.
Patricia Estridge: Yeah, absolutely. I mean, I think that’s been — but we can sort of talk about this broadly. There’s been a shift, I think, in the last few months really, from direct air capture and closed-system carbon dioxide removal being the most popular, probably because they’re the most measurable and you can account for every molecule. And what we’re looking at is really a very open system, which is completely the other end of the spectrum, which felt like, for a bit, it wasn’t being pushed forward as much as the closed-system approaches. And I think now we’re starting to see some traction and some momentum in the direction of people accepting that if we’re going to get to this very large amount of carbon dioxide removal, we do have to start to explore open systems — and that we must do that very thoughtfully.
You know, in our case, I think with biomass sinking in the oceans, albeit a problematic one, which should be beneficial overall because it’s causing so much damage on the coast, we still need to make sure that we’re getting buy-in, that we’re properly explaining what we’re doing, and that we’re most importantly proving what we’re doing, and then tracking it, and making sure that what we think is going to happen in the deep ocean, and what we think the effects of it are going to be — which we think are very minimal, or we wouldn’t be doing this — are indeed the case. So there’s lots and lots of measurement, verification, reporting, monitoring involved in our plans.
And we also hope that a lot of those findings will be quite clear, and secondly, that we will disseminate them quite widely. Because, like you say, it’s not just does a technology work and can we remove carbon this way, but also, is it acceptable? How do people socially view it? And in a sense, really just trying to move forward thoughtfully and be in a position where people feel like they can trust us. But probably most importantly, being able to move the whole industry forward at the same time, because we’re not going to be the only people in the world that do this.
The last thing this industry needs is someone kind of running out there, sticking a flag in the ground and going, I’m gonna go and do this, and then everyone goes, oh, wait a minute, that doesn’t seem like a great idea. So what we’re really trying to do is bring people on the journey with us and be as open as possible. And, hand on heart, if this turns out to not be a great idea, I think it’s a thing that we shouldn’t do. And I hope that a future generation will turn around and say, actually, we tried it, and we don’t think it’s a great idea, but we can use these things for these other things instead. So that’s kind of where we start, I suppose. We’re trying to be quite pragmatic about it, I suppose, from two different angles.
Ross Kenyon: How’s the reception been from people who live in Antigua? I read a book years ago — maybe you know her, Jamaica Kincaid; she wrote a book called A Small Place. She’s an Antiguan writer, but quite critical of the tourist trade and off-islander involvement. And then also, how has the reception been in the carbon removal community? I know seaweed sinking, biomass sinking, has had its share of headwinds. Is this something that you’ve seen as well?
Patricia Estridge: Answering these two questions might take the rest of the show, so I can just hang out here. From the perspective of the Antiguan people that we have interacted with — Mike, correct me if you think this is not quite right — I would say there is generally quite an open-mindedness about people being able to come in and contribute to helping with some of the problems that they’re having on the island. They are very positive, very open in general to bringing in new technologies, but they certainly want to be at the center of it. They want to create an economy that will benefit Antigua, and they want to be able to use their ocean space in a way that will be good for their future, and I think that’s absolutely fair.
So we’re kind of doing pilots and we’re developing a technology, and they are our partners — well, they will be our partners in this. This is a massive problem in these island nations, but as we’re talking here, it’s a massive opportunity as well, and the key thing is that it’s an opportunity for the island nations, not just Seaweed Generation. Our journey will be doing it together.
Mike Allen: And a big part of what we’re doing, in my role, is the education side of things, and developing citizen science programs, and developing a whole seaweed bioeconomy across the region. Because once the sargassum is gone — ideally in 20, 30, 40 years we’ll have removed so much of the sargassum that it’ll be manageable — then we’ve got perfect ground for growing seaweed, but the seaweeds that we want, in a controlled manner. So to do that, we need the local community. So we need to be working together, and that’s really important to what we’re doing.
Patricia Estridge: Yeah, absolutely, I second that for sure. And I think there’s a lot of excitement. If you think about the way that these island nations tend to be set up, they’re quite small, with massive amounts of water. And the only thing that’s been done economically speaking — or the biggest thing that’s been done economically speaking — with those waters is fish, which is at the moment under quite a lot of stress, and the fish stocks are quite low. And the second is tourism and travel.
Ross Kenyon: Like Trinidad — like, big on oil, like there’s some oil production happening too.
Patricia Estridge: Yeah. Yeah, there’s a bit of oil, and sort of mining in the ocean space — not so much in Antigua, but in some areas there are. Now, if there’s an opportunity to start doing carbon dioxide removal, growing seaweed biomass, expanding that blue economy, that’s quite exciting to a lot of these places, and will likely, like Mike says, make up a big part of what they’re able to do in the future, and what we would like to help develop the technology to do.
And then the second, very meaty question. Two main buckets of carbon dioxide removal thinking, I suppose, and it actually maps quite simply to the closed versus open system techniques that I alluded to before. There are people in the industry who much prefer closed-loop systems, and very, very measurable — where’s this molecule going from here to there — and being able to say without a shadow of a doubt that this is happening. And then there are people who appreciate on a more broad scale that we need to do this on a massive scale, and that every approach really does need to be explored, and we’re too early to be able to throw out approaches.
And people who sort of step back and look at the problem are saying, 10 billion tons is an awful lot, how are we going to do that? Well, look, the system has been doing a pretty good job of that for an awfully long time already. And people who think that way are much more comfortable and excited about the approach that we’re taking, especially because really what we’re trying to do is learn about seaweed biomass sinking, and what does that mean. So I think more people are starting to become comfortable with the idea of open systems, and I’d expect — or we hope — that that will continue, at least to the point where we can start getting data and reporting back on our findings.
Ross Kenyon: I think people are okay with it as long as it isn’t participating in carbon accounting strictly, so companies are emitting fossil tons that we can measure and there’s an indeterminate amount going through an open system and we don’t really fully understand. But I find when you relax the standard of, okay, we’re doing a ton-per-ton carbon accounting negation scheme for balancing our carbon budget, I think the enthusiasm goes up a fair amount also. I love that Dai Ellis and John Sanchez piece that just came out on — yeah, we’re coming for you, as Christophe used to say. We should do an episode on that.
I hope that’s true. I know there’s a tendency to really want to know exactly what’s happening, and it makes sense, it’s an honorable impulse, but it’s also pretty limiting, and it boxes us into a tack that, while easy to measure, may not be the most effective way to go in all cases. It’s a case of, as the expression goes — it’s from Measure What Matters — it’s like, the thing that you can measure, you will optimize for and you will max out. It’s like the kill ratio in Vietnam: it didn’t actually translate into whether or not the US was winning. It was just, how many bodies are there on the ground after a battle, and then it turns out many of them had weapons on them, it turns out they were all VC. Every single person who died was VC — of course that was not true, but it was easy to measure, and so it gets maximized, and that was the most relevant thing.
Asa Kamer: And let’s go back to WALL-E. Sometimes we talk about how to distinguish ourselves from all the other climate podcasts out there, and I don’t think you’re getting carbon accounting to Vietnam War comparisons on many other podcasts. So, you know: really great guests, stay for Ross’s historical analogies.
Well, I’m a little curious. Mike, you said you’ve been working on this for 20 years, and so it’s pretty clear that this is your passion project, this is your area of focus. How did you rope Patty in, or did she rope you in, or how did that all come about?
Mike Allen: So, like I said, I’ve been working on this concept for 20-odd years now. [unclear] Patty asked me to do a podcast, which is now somewhere on YouTube, and we had a chat about seaweed, and I was telling her — I can’t remember exactly. Do you want to paraphrase it?
Patricia Estridge: I could paraphrase. So, we didn’t get this on video then — our second conversation was when we did the podcast — but he basically told me I was totally mental. Why would you want to grow more seaweed? Because I wanted to start with cultivation. When there’s this huge problem, go and look at this problem and find me something to do with it. So I did.
Mike Allen: So I think, coming at it from — for me it’s from sargassum, that I need to put into a product, a physical product, and I’ve been trying to make that work for ages. I just couldn’t make it work. Then Patty sort of wandered along into my world and just said, carbon dioxide removal. And I was like, oh my God, that’s a thing. And then it’s a bit like WALL-E. And so together we came at it from very, very different points of view, and it was — yeah, it was just a match made in heaven, and here we are now, discussing it on this podcast.
Siobhan Montoya Lavender: Yeah, I’m really excited that there is this concept of taking an existing problem and bringing in carbon dioxide removal. Because obviously we already have the existing problem of too many parts per million of CO2 in the atmosphere, right? That exists. But so many solutions that we’re looking at are focused on getting those molecules out of the atmosphere and storing them, in the biosphere or the lithosphere, somewhere away from the atmosphere. But you’re almost coming from the sargassum problem, and then the CO2 removal is almost like the co-benefit. It almost seems like the primary thing is getting rid of the sargassum, and the CO2 becomes the co-benefit. Ross, you were going to say something.
Ross Kenyon: Is there anything else like that, where carbon removal is the co-benefit? Is there any other case? I guess maybe regenerative ag, something kind of like that too. Is there anything?
Mike Allen: Well, biochar has existed for more than the carbon removal. With biochar it’s similar, and burying biomass. But we’re actually very similar to biochar, but much more intelligent.
Ross Kenyon: That’s the title. That’s the title.
Mike Allen: Essentially, with biochar you take biomass and you char it, so it’s biologically unavailable, and then you store it — but essentially in a very biologically available area, which is why you have to char it. Whereas we’re storing it in the deep ocean, which is not available to the surface cycle, so we don’t have to char it. So we don’t have any of those energetic costs of charring it. So effectively it’s much more simple and effective in terms of carbon capture.
Patricia Estridge: So yeah, it’s definitely very efficient. I think it’s sort of a solar-powered automated robot without having to actually really process anything, so the LCA is pretty good.
Ross Kenyon: We haven’t gotten — I mean, I’m sure folks can look at your website, but just the short version of how it works? I mean, it’s a robot that sinks seaweed, but what are the steps? How does it get it? I don’t even really quite know. Do you want to take that one?
Mike Allen: Yeah, I’ll take that one. The robot takes the seaweed which is floating on the surface of the water, collects it, and then it takes it down to about 200 meters down, just in a vertical translocation. And at that point the pressure of the water compresses the seaweed so it can no longer float. Just like if a diver was taken from the surface and put 200 meters down, they’ll feel that compression on their head. The seaweed is compacted, the air in it is compacted, and it basically sinks down. And we do that in areas of around 4,000 meters deep, so the seaweed goes to the very, very deep ocean.
And if you think about that distance, four kilometers from the top of the water there — basically, once that material is down there, it can’t move to the top again. So it’s effectively removed from the surface cycle. So it’s a very, very simple process. There’s no biological or chemical processing; it’s just a physical translocation, and we let physics do the rest. And it’s essentially mimicking the biological pump, which is nature’s way of storing carbon anyway. That’s why the deep oceans have about 37 trillion tons of carbon, which is far more than anywhere else on the planet.
Ross Kenyon: So then, what mechanism pushes it down to the 200 meters? Is it gravity? It comes into the robot, and then something — what pushes it? How does that work?
Mike Allen: The robot goes down.
Ross Kenyon: Oh, okay. Okay, that’s what I wasn’t getting.
Mike Allen: So at about 35 meters, the balance between floating sargassum and sinking sargassum occurs. We take it to 200 to make sure, and release it from there, and then the robot goes back to the surface to do the same again — to do that four times an hour, 12 hours a day, just slowly nibbling away, WALL-E style, Pac-Man Roomba style.
Patricia Estridge: Another thing that the AlgaRay does is it films every one of those drop events and gathers data for it. So we take that data and give it as proof, as one of our MRV points, for people who are purchasing carbon dioxide removal. We think reporting back the data is a really important part of it.
Ross Kenyon: And what about cost? The robot sounds expensive. Talking about cost now, what are your projected hopes and dreams for future costs — which is how I would frame it to any CDR company. What are your hopes and dreams for the future cost?
Patricia Estridge: Our hopes and dreams. So at the moment we’re selling tons for about $350 or $250, and that’s across the first three years of vintage — which I still just can’t get over; I love that we call them vintages. We’re projecting with the larger version of Alfie that we’ll be able to bring the costs down below $100 a ton, and pretty quickly. And that’s mostly due to the fact that it’s just so reusable. Everything we’re building is reused over and over and over again. There’s nothing else being dropped into the ocean apart from the sargassum, and then everything is solar powered, so there aren’t really fuel costs ongoing. So the largest cost we have is maintenance, as we keep going with the robots.
We are projecting that we’ll be able to produce them for around 100,000 to 150,000 dollars per robot, and they’ll be removing around 8,000 tons of carbon per year. So at $100 a ton, the sort of return rate on that is quite short. That’s our hope and dream, so we’ll see if that actually turns into reality. The current version of Alfie, we’ve produced for thirty thousand dollars, so that’s pretty cost-effective.
Ross Kenyon: What are the regulatory rules and regimes you have to contend with to run these? I just know it’s very complicated with ocean stuff. Is it the London Protocol mostly, or what else are you looking at?
Patricia Estridge: Well, we’re working in exclusive economic zones of countries, so we’re within the jurisdiction of — in the pilot case — Antigua and Barbuda. And the vast majority of the Caribbean gets well below the thousand meters of depth, which is the kind of deep ocean delineation we’re trying to optimize for, which just means longer-term carbon dioxide removal. But for the most part we’ll be working with countries who are having a problem with sargassum in their exclusive economic zone, to deal with the problem, at least for the foreseeable future. That’s the plan.
Ross Kenyon: There’s this organization or company — I’m not sure — called The Ocean Cleanup, and they’ve gotten a lot of press. They collect the garbage in the Pacific garbage gyre. I just kind of feel like there’s some parallel there. Are you guys aware of what they do? Have you looked at their technology? I’m just kind of not knowing much about the space; I’m just curious what you think of that.
Mike Allen: It’s really interesting what they do. But their problem — it’s not biomass that they’re intercepting, it’s basically a plastic product. So whereas we can just sink it in situ because it’s a natural biomass, they unfortunately have to take it out of the ocean and take it away and either recycle it or make it into expensive products that people can wear, visors and things, and thereby subsidize the process. So it’s similar on the surface, quite literally, but it’s a very, very different process that we’re actually doing.
But I think it’s great that people are starting to put profile on the ocean and the cleanup. And the more care that’s put into restoring the ocean environment, the better the world will be. Seventy percent of the planet is covered in water, so we need to start taking care of it. And the more people there are that are active, the better.
Ross Kenyon: How can people get in touch with you if people want to get involved, or if people want to support you? What are your immediate needs that you want to put out to our audience?
Patricia Estridge: Well, that’s a good question. We’re always looking to talk to more countries and states and, honestly, local governments that are having issues with it. So if anybody’s in Mexico, Belize, Florida, probably Louisiana fairly soon, or any of the Caribbean nations, please get in touch — the contacts are on our website. And then we’d love to chat to scientists, anyone who’s out there thinking about doing some ocean research but who wants to come and do some deep ocean observations on our pilot site — that’d be awesome. And anyone who wants to buy carbon dioxide removal: we are here. We’re doing small pre-sales to help pay for the pilots and the next couple of years of testing, and that kind of stuff. So yeah, please get in touch.
Ross Kenyon: Well, thanks so much for listening. I hope you had a great time with us learning about seaweed. We really don’t cover ocean stuff and seaweed stuff nearly enough; there’s a lot of interesting work happening over there. Send this to a friend — it helps get the word out. Give us a great rating and review on Apple Podcasts or Spotify; that also helps us quite a lot. And thanks so much for listening. Have a lovely day.
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