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Home » Dr Shaun Fitzgerald OBE – Can Kelp Forests Capture a billion tonnes of carbon?

Dr Shaun Fitzgerald OBE – Can Kelp Forests Capture a billion tonnes of carbon?

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Shaun Fitzgerald

Director of Centre for Climate Repair at Cambridge University. Speaks and writes regularly about climate change & the need for repairing the climate.

Dr Shaun Fitzgerald OBE, Director of the Centre for Climate Repair in Cambridge, discusses new research to build resilient and scaleable kelp growing platforms, asking the key question: can kelp forests capture and store a billion tonnes of carbon?

Listen to the discussion audio on all podcast channels.

ClimateGenn

Can give us a definition and an overview of what an offshore kelp platform is, and why you’re researching this area at all?

Dr Shaun Fitzgerald OBE  

Well, offshore kelp is really what I mean by the growing of kelp in the surface waters of the deeper ocean, and specifically with the target that some of that kelp, when at the end of it sort of useful productive time as part of a plant it sloughs off and takes carbon, therefore, in a macro algae form down to the deeper ocean. So once it’s below the surface waters of the deep ocean, once it gets into that deep layer. The idea is that that then hangs around for a very long time, hundreds, perhaps 1000s of years, certainly hundreds of years. So the area that we’re looking at is how can we get more kelp to grow and get it into the, into the deep water. That’s what we mean.

ClimateGenn  

Okay, this is particularly focused on carbon sequestration, blue carbon, that’s the objective here?

Dr Shaun Fitzgerald OBE  

It is the objective of the Center for Climate repair. But as always, we’re looking at how we might develop schemes which have got co-benefits. So the idea of a platform is that not all of the kelp necessarily needs to be just for carbon sequestration. Some of it can be used for supporting local economies. So supporting, for example, food being exported to other countries, for cattle feed and things like this or being used for other products, or actually their own food. But so that can help effectively pay for the platform, and therefore as a co-benefit, it’s the carbon sequestration. So depending on which lens, you’re looking at this problem, it could be that the CO benefits carbon sequestration, or the CO benefit is actually supporting local economies.

ClimateGenn  

Okay. Where is the platform located or to be located? And why have you chosen a specific place?

Dr Shaun Fitzgerald OBE  

Well, the first project that we are involved with from a research point of view, is the off the coast of Namibia. The reason that we’re starting there is that it is an upwelling zone and therefore is already a bountiful supply of nutrients because when kelp grows and is either harvested or sloughs off, and it goes into the deep ocean, it doesn’t just take down carbon, it takes down nutrients as well. So we’ve got to think very carefully about the nutrient balance. So we’re starting off in areas that are upwelling and we want you to make sure that as a result of growing kelp it is additive in terms of carbon sequestration because if you’ve got nutrients available, in the right balance, phytoplankton, for example, can grow. Then depending on what happens to that phytoplankton, if that gets into the deep ocean, then growing kelp in its place isn’t additive but if that phytoplankton is eaten by other creatures, and then released back into the environment through the activities of organisms, and it doesn’t make it to the deep ocean, whereas the kelp does, then it truly is additive. So the first area we’re looking at is these areas of natural upwelling. But that is not the end game, the end game is to look at places where we can actually use the platforms in areas that aren’t necessarily upwelling zones. And then to think really carefully about how we ensure that they’ve got the appropriate nutrient provision.

ClimateGenn  

From everything you’ve just said, what are the risks that something could go wrong? Is it just a quite benign risk overall? Or is there something that could upset the ecosystem?

Dr Shaun Fitzgerald OBE  

Well, it’s a very important question, Nick, and anything that you do in the natural world, I think it would be wrong to say they’re benign. No, we are very concerned, to learn as much as we can and to go an appropriate pace where we learn by incremental not by revolution, and one of the big challenges that we’ve got is growing something in an environment that wouldn’t grow there naturally. So that’s what these platforms do, they allow the kelp to grab onto something and then for it to grow in the surface waters of the deep ocean anew. Those platforms are providing this structure. But we are concerned about the rate at which you grow kelp. So if you grow kelp faster than the rate at which nutrients can be provided, then effectively what you’re doing is starving that region of the ocean, and therefore other organisms that might want to use those nutrients and are no longer able to do so. So we think really carefully about this issue of nutrient provision. And that’s the risk that we are acutely aware of and trying to devise schemes whereby that risk can either be removed, or it’s certainly minimized.

ClimateGenn  

How do you monitor it, and also, who are you working with? I believe this is a collaborative effort.

Dr Shaun Fitzgerald OBE  

So there’s a group for the first project, which is in the upwelling zone with Kelp Forest Foundation, and Kelp Blue. The idea is to clearly measure the amount of kelp that’s being grown, then also to take samples within the water, before and after the deployment of a raft to try and get the kelp to grow, and look at the chemical imbalances. 

Where we’re really interested in is looking at other places where they aren’t in upwelling zones and the concerns about nutrient provision. Ultimately, what we’re looking at is how might you get more nutrients to be provided to the surface waters of the deep ocean, and there are two big ideas that have come about. 

The first is more of an engineering approach, where you use solar power or wind-powered pump, to go and bring some of the deeper water, which is more nutrient-rich, so richer in nutrients, up to the surface waters. When you look at the numbers that are going to be involved, it is quite a lot of water to move, because effectively, what we’re asking is to increase the degree of mixing between the deep waters and the surface waters. 

A more revolutionary kind of idea is where the kelp platform itself might actually sink and go take the kelp to the nutrient-rich waters. So the idea is if you can get the kelp platform to traverse through the several 100 meters of the surface waters of the ocean at night when the kelp isn’t growing as much because it photosynthesises and therefore at night, it’s not photosynthesising. If you get it into the deep waters for long enough, then the question is, can the kelp act like a sponge, take in the nutrients, and then the following day, bring it back out, into the photic zone and allow it to grow? 

So that’s the second big idea and the real benefit of that scheme is that one of the other risks that you have with growing kelp platform is that if you have a hurricane or a typhoon coming through, it can actually destroy the surface platforms. Whereas if you take it 10’s of meters down, it’s then back in the safety of the water, away from the hurricane. 

So this might be the way to provide resilience to these to these platforms, against these terrible weather conditions, but also provide the way of getting kelp to have enough nutrients and therefore not risking depletion of nutrients in the surface waters and minimising the risks.

ClimateGenn  

Okay, sounds quite ingenious. You’ve mentioned that it’s at the ideas stage. So status-wise, where are you?

Dr Shaun Fitzgerald OBE  

The work in Cambridge is at the moment focused on modeling. There is a team in the Department of Applied Mathematics and Theoretical Physics, led by Professor John Taylor. He is building a team there on the modeling of, not just kelp but of the oceans in nutrients. So it’s got implications also for other schemes such as marine biomass regeneration. 

Although we’ve started off thinking about the challenges and opportunities to do with kelp by working very closely with the folks at the Kelp Forest Foundation and Kelp Blue, because modeling in and of itself, teaches so much, but you’ve got to ground the models in reality and give them enough data so that actually you’ve got a model that is filling in the gaps. 

A model is not there, just to tell you everything. The idea is that you want to use experimental data. This is field-scale experiments with data. There will be some lab experiments that will be done as well but to ground the model in data and then use the model to fill in the gaps and maybe extrapolate a bit further. That’s the joy of working with experimentalists.

ClimateGenn  

Have you got an estimated time when you might be deploying one of these field studies?

Dr Shaun Fitzgerald OBE  

Well, the field studies are started already. The Kelp Forest Foundation, has started getting the raft built, just off the coast of Namibia, and they’ve started growing the kelp but these are baby steps. So we’ve got a long way to go but it is really, really exciting.

ClimateGenn  

Okay, and what about these ideas of moving up and down through the water column?

Dr Shaun Fitzgerald OBE  

So that one is at the idea stage rather than the experimental stage, but it is something I’m really keen to develop further because adjusting the buoyancy of the kelp platform, the big question is by how much would you, for example, need to expand a chamber in order to change the overall density of the platform sufficiently that it would then sink or rise? 

So we’ve got these big questions first to figure out what are the changes that you need and how are you going to power that because you won’t need, for example, as much power as bringing water from the deep up to the surface waters day in, day out, with solar power, wind-powered turbine with batteries on board, but you are still going to need some energy in order to change the buoyancy We think it’s going to involve rather less energy. As I mentioned before, we’ve got this lovely other co-benefit of making it more resilient against severe weather events.

ClimateGenn  

If you get positive results, and things are going well, what sort of scalability do you see on this? What is the end game impact that you’re really excited about?

Dr Shaun Fitzgerald OBE  

From a climate point of view, at the Center for Climate Repair, we’re not really interested in tinkering at the edges, we are interested in greenhouse gas removal approaches, that when scaled up and deployed on a global scale, get you to something like a gigaton, or more than a gigaton, of carbon dioxide per year being sequestered. 

At the moment it is big numbers. We are emitting something like 40 Gigaton of carbon dioxide per year and at the moment, it’s not going down. The rate of growth appears to have slowed down, but it’s still going in the wrong direction. So, it’s 40 gigatons and there isn’t one silver bullet, that’s going to take the whole 40 that we’re aware of, and therefore we need to choose the approaches, but you know, lots of very little things add up to a little thing. We’re interested in the gigaton scale. And initial estimates are that if you did this, and covered a reasonable, few percent of the ocean, you start to get some pretty interesting numbers.

ClimateGenn  

So you reckon that ultimately there are a billion tonnes plus of sequestration in this?

Dr Shaun Fitzgerald OBE  

There is the potential, Nick. As I said, it’s still at the research stage and therefore, you know, we need to be careful on the risk side, we need to be careful about overstating as well, but we wouldn’t be doing this if we didn’t think it had significant potential.

ClimateGenn  

Okay. And you mentioned global emissions just now as we move towards COP27, and on the back of what many regard as a pretty failed and flawed process, what do you think the successes are that we can really look for in this approaching COP and, given that it’s is based in Africa, it’s been seen as a vulnerable Nations COP, do you think there are successes we can look for?

Dr Shaun Fitzgerald OBE  

So certainly in the northern hemisphere, over the last two years, the increased severity of these severe weather events, has just brought it closer to home. People are realising that we are just not equipped to cope with the impacts of very hot summers. Similarly, when it comes to the winter, we’re not going to be able to cope with lots of flooding and things like this. So we’ve got to get a lot more serious about doing the fundamental thing of grappling with the root cause and it is about emissions reduction, Nick. 

So what I would really really hope for out of COP27 is an increased desire and commitment for people and nations to just stop building out coal-fired power stations, for example, and let’s not muck around by thinking we’re solving it by just moving to gas. We’re gonna go much harder than that. 

The dash for gas, look at what that’s done in terms of the challenge regarding lack of resilience, security of supply, that language in terms of just it’s all too centralised, not distributed enough. Whereas things like solar power, wind power, yes, they’re more volatile in some ways but politically, they’re far less volatile. Therefore, when you go and look at what you really mean by security of supply, then, in fact, some of these alternative schemes, wind and solar being the two that are first in my mind, that are carbon-free. We’ve got to do so much more with these and increase our investment in this significantly now. 

That’s what I would really like to see, and supporting developing nations, so they don’t make the same mistakes that, frankly, we have. We are not covered in glory. Those of us who are the modern developed nations! We’ve got to help other countries not tread in our footsteps, but do things differently. Because they could do far better than we have.

ClimateGenn  

We’re always talking about this space that we’re operating in and this will be very much the case with you at the Center for Climate Repair, you always have to assume that you have the space to operate in. But things are accelerating, and it’s getting scarier out there, do you think with the concurrent and continual impacts around the world that we are starting to lose that front foot response, and we’re starting to be pushed onto the back foot in responding to these challenges?

Dr Shaun Fitzgerald OBE  

I don’t think it is a back foot. I do think our approach at the Center for Climate Repair, we have a three-pronged attack: The first is to reduce emissions. The second is to then remove greenhouse gases, hence the kelp, and the third one is to actually worry a lot about the timescales that are involved in sorting out the first two R’s. So our third R is to refreeze the Arctic. 

This does mean doing things that can actually reduce the amount of the sun’s energy coming into the earth, so reflect some of the sun’s rays. Now, this term that some people have used in the past, geoengineering, is not welcomed by many people, and it certainly hasn’t been welcomed by the funding agencies or the national funding agencies, 

I think things are changing, Nick, what we need as an absolute minimum, and as an absolute priority, is to develop our understanding of those sorts of approaches, very quickly, because this could be what we have to resort to, in order to buy us time to get the planet in order on reducing emissions, removing greenhouse gases. 

So this area, if anything, as a result of the lack of progress on the first two R’s, has raised the importance of getting on with research at the moment, for this third R of refreezing the Arctic, or reflecting some of the sun’s radiation. I see that as absolutely critical because the research might teach us why that’s such a terrible idea. It could do, or, it could say, ‘this is how you should do it if you’re going to do it at all, but it’s not for the scientists to decide whether it should be used. That is a decision for the wider society at large.

Dr Shaun Fitzgerald OBE – Twitter: @DrSDFitzgerald

Dr Shaun Fitzgerald OBE on developing Kelp for CO2 Capture

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