Dr. Michael W. Beck, professor at the University of California Santa Cruz, coauthored a new paper in Scientific Reports entitled, "The Global Flood Protection Benefits of Mangroves". Today we dig into how mangroves work against flooding, their carbon sequestration potential, how to quantify their financial benefit, and how that helps make them legible to financial systems.
Full Transcript
Ross Kenyon: Hey everyone! We are doing that podcast thing now and launching a Patreon. You can find it at patreon.com slash noripodcasts. There are various tiers with different types of goodies available. Do you want to receive a special newsletter digest of what Norinauts are reading that week? Be a part of a Nori book club? Get special access to Nori events? Go take a look at patreon.com slash noripodcasts for what we’re offering. And in that spirit of being lean in that startup kind of way that, you know, we like to do, this list of goodies is subject to change and we’d very much like your feedback.
Is there something that you’d really like to see but it isn’t listed here? Honest feedback does a lot to help us shape what we offer to you. You can send an email to podcast. nori.com or fill out our podcast survey anonymously in our newsletter, which you can find at nori.com slash subscribe. Hello and welcome to Carbon Removal Newsroom. I’m Ross Kenyon. I’m the lead strategist at the Nori Carbon Removal Marketplace. Today I have with me Dr. Michael W. Beck, professor at University of California, Santa Cruz, and co-author of The Global Flood Protection Benefits of Mangroves in Scientific Reports.
So thank you for being here, Mike.
Michael Beck: Glad to be here, Ross. Thank you.
Ross Kenyon: Yeah, it’s my pleasure. One of my colleagues sent me a summation of this paper that you co-authored, and it was in phys.org’s Research Shows Mangrove Conservation Can Pay for Itself in Flood Protection, which, you know, that’s a title that will get our attention. So I just want to dive into this. We haven’t done nearly as much content about mangroves and blue carbon as we should. So what broadly is happening in the science of mangroves? What is moving currently?
Michael Beck: Ross, if you don’t mind my saying, let me start by saying, well, thanks for being on the show or inviting me on the show. And we’re working on mangroves on a couple of different fronts. The primary work that we’re doing is looking at the These are what are also their climate adaptation benefits to people. So that’s a really big focus of my group in the Coastal Resilience Lab. We do collaborate. We collaborate quite a bit with others who are working on some of these blue carbon benefits, as you say, that is the carbon mitigation benefits.
So we’ve been helping them as well to value some of those benefits, but our real expertise is in valuing these adaptation benefits.
Ross Kenyon: Indeed. And what are the adaptation benefits of mangroves? I guess people in general, when they speak about mangroves, they tend to get really excited because there are so many benefits to preserving or even restoring mangroves. So what adaptation benefits might there be?
Michael Beck: Yep. So the principal adaptation benefits that we’re looking at are what is their value in reducing flooding? And that’s flooding from storms and even in some cases from tsunamis. So obviously coastal risks. So, we are putting more people and we’ve been trying to put a really rigorous value on what that coastal protection is. So that is how important are keeping your mangroves in place for reducing waves from storms and reducing that storm surge and thereby reducing the amount of flooding and erosion. And we’ve been doing that at very many levels in our team, from very site-based levels to national levels, like in the Philippines and Jamaica, but then also globally, which is what the news is.
New study shows where we do really rigorous engineering and economic modeling to understand the benefits of mangroves. And we show that every year mangroves reduce the costs of flooding by $65 billion. And that’s a reduction in flooding to more than 15 million people. Again, every year around the world, 59 countries around the world.
Ross Kenyon: Well, how much would it cost to do mangrove conservation in those areas such that it is paying for itself? Is it pretty much equivalent to the benefit that it provides monetarily or is it disparate?
Michael Beck: Well, first of all, it’s not surprising to know that there’s a lot of variation in these benefits all around the world. So in places where mangroves are right in the middle of storm belts, where storms come and We mapped all of these benefits. We are doing this level. Every kilometer, using industry standard models from engineering and insurance, every kilometer we estimate this flooding and that’s for 700,000 kilometers. And across all of those 700,000 kilometers, you do find a lot of variation in those benefits, again, just because of variation in where mangroves, people, property, species.
Storms all occur together. And so in some sections, we summarize our results into 20-kilometer coastal study units. That makes it just a lot easier to be able to visualize the results. But in many of those, just in a 20-kilometer section, there will be $100 million of benefit every year in flood risk reduction. So that’s a huge amount in these sections of coastline. Mangrove restoration, depending upon where you are in the world, can vary from costing somewhere around $20,000 to $30,000 per hectare the Caribbean. To maybe $2,000 to $4,000 per hectare if you’re in Southeast Asia.
And so when you’re talking about offering hundreds of millions of dollars in protections on coastlines for thousands to tens of thousands of dollars in upfront costs for restoration, well, you’re receiving benefits that are, you know, in some places 10 to 1 in terms of benefit to cost ratios.
Ross Kenyon: Wow. Okay. That’s good to know about the differences depending on geography and density and all of that. A bit of a basic question, Mike, which is when I think about a mangrove, I’m thinking about trees that are in standing water on the coast. So maybe this is brackish water. That’s a mix of saltwater and freshwater. Maybe it’s just even in saltwater. Maybe it’s only in freshwater. So there’s that. But then also when I’m thinking about flooding coming in, I’m thinking about why a mangrove might help. Does it just slow the rate at which this water is inundating?
Does it do something else? I’m asking this because one, I don’t know, but I imagine some listeners out there have heard a lot about mangroves, but maybe this basic question has eluded them as it has made.
Michael Beck: Yep. Well, first of all, you know, you’ve got to write in terms of where mangroves occur. So mangroves occur in intertidal environments in saltwater. So that’s where they really dominate. And They’re in mainly tropical areas. So basically in our temperate areas, you know, like say on the U. S. East Coast, you have marshes in that intertidal saltwater habitat. And then about midway down Florida, Florida Coast, they start to give way to mangroves. So those two types of species, groups of species, occupy that kind of same niche as it were, one in temperate, one in tropical environments.
Wetlands work in very similar ways, although, as I’ll explain, mangroves work even better than marshes in terms of reducing flooding. And that’s because the way that they work is that, first off, they provide almost... I mean, if you’ve ever tried to walk through a mangrove forest, like a dense mangrove forest, it is nearly impossible. And that’s not just because of the mud. I mean, if you’ve ever, I mean, that mud is actually the carbon benefit altogether. All the accumulated sediment underneath those mangroves is where all of that carbon is stored.
It’s impossible to get through them because of that, but also because it’s this huge tangle of roots and stems and trunks and things. That creates a wall for incoming surge. So when you have an incoming surge, a big, essentially you can think of it as a bulb of water, like as if you were pushing in your bathtub and you’re pushing that big ball of water. So, in the first instance, it’s holding back a lot of water that would otherwise flood onto land. And then as some of that water passes through, it’s also got waves associated with it.
And the mangroves are actually helping to, let’s say, back down those waves. So they’re working on both waves and surfaces. And that’s exactly what salt marshes do on the East Coast or other temperate areas all around the world. But of course, mangroves can grow bigger and in many ways even denser than marshes. So they can work on really quite substantial surge and flooding.
Ross Kenyon: Great. Thank you for explaining that. You mentioned carbon, and we’ll get to that in a little bit. But first, I’m wondering, specifically for adaptation benefits and protecting coastlands from inundation or from storms, who might be funding mangrove conservation and restoration? What’s happening now? Are any new players entering the scene? How are people thinking about this currently?
Michael Beck: Yep. That’s a very, very important question and one that we’re working on a lot with many groups of folks. But the real key to all of the kind of new partnerships that I’m going to describe is being able to rigorize. That is, put people and dollar values in ways that follow industry standards. Because once we can do that, then we can open up a whole variety of new funding and policies. So for example, we’re working with folks like So, after the hurricanes in 2017, for example, there was nearly $100 billion appropriated for recovery.
That is going to end up recovering gray infrastructure, including gray defenses like seawalls and dikes, because in order to access that funding, you have to be able to prove that you can offer... And that’s what we can now do with mangroves. So we’re working to help. And in the same way, we’re working with insurance companies and we’re coming up and ensuring, making sure, rather, that mangroves are considered in some of their risk models so that they get accounted for in terms of the benefits that they’re providing. And in parallel with some work in coral reefs, we’re coming up with actually some new insurances themselves.
So I’m going to give you an example from the coral reef off of Mexico, but it’s one that we’re now looking to apply into mangroves as well. And that is, there is a new insurance policy for the reef off of the coasts of Cancun and South. That recognizes the value of that reef for reducing flooding to the Mexican people and to the hotels that drive the economy along that coastline. So if a storm damages that reef, there is now an opportunity to receive an insurance payout to rebuild that reef for the protections that it offers.
Ross Kenyon: Wow. And the fulcrum that this happened around was because they were able to effectively price the value of the ecosystem service that this reef was providing to these hotels and the people who lived in the area.
Michael Beck: Exactly. That’s exactly it, Ross.
Ross Kenyon: Wow. How do you do such a thing? Because people are sometimes critical of placing prices on something like a coral reef. Shouldn’t we just value this inherently? But I guess if you’re not doing that, then policy and commerce just doesn’t recognize it. So you’ve effectively translated the value into something that entities can understand beyond just the biophilia or some such.
Michael Beck: Yeah, well, indeed, before I became a research professor here at UC Santa Cruz, I was for 20 years the lead marine scientist at the Nature Conservancy. So I fully believe in protecting these habitats forever. For their intrinsic value, because they’re amazing, they’re beautiful, they’re supporting species and biodiversity, in addition now to the services that we can value from them. So again, that’s what... What I believe, but I also understand why decision makers are in tough spots and they need to protect people and they need to show that they’re protecting those folks.
And in order to do that, we really did need to vote. Value them in some of the same terms to essentially bring these additional stakeholders to the table, which is really critical. I want to say a very important part of the approach that we took in all of this is that Many ecologists and conservationists kind of develop their own models about these services and benefits, and then they take them to the insurance companies or the World Bank or FEMA and say, hey, look at the models we developed about their values and benefits.
You should accept these because they’re really, really important. Instead, the approach that we took was we went with some engineering collaborators and others, went to these institutions like the insurers and the World Bank and said, hey, What models do you use to value flood risk reduction and adaptation benefits? So that when the results are all done, they’re actually yours. They’re not something that you have to accept all of our models in the first place to do. And this was critically important in the much more rapid acceptance of these kinds of values into decision making.
Ross Kenyon: That does seem very important, and I can see why that would appeal to them, you know, accepting their priors and then running with it. Yeah, you can skip that entire fight over the models. Very clever. I can see why you have had success with this.
Michael Beck: You have to sit there. You have to understand fully their models. You have to go, OK, what are the different ways we can fit? This isn’t maybe the way if I was just designing it from scratch I would have done. But again, when you when you come out the back end of all of that work, then they understand exactly what happened.
Ross Kenyon: Great. Thanks for explaining. I find that very compelling. How does this interact with the carbon value of mangroves? Does that stack on top? Are people still working on the financing? And then just broadly, if you happen to know, Mike, what is the potential for mangroves to pull carbon dioxide out of the atmosphere and store them in some way, if you can give us some back of the envelope estimate of this?
Michael Beck: And again, I’ll preface this, Ross, with, you know, I do a bit of work on carbon mitigation with mangroves there. That is my greatest area of expertise, but I do know quite a bit, I hope, to inform. And a couple of... A couple of things that are important here and which tie these mitigation and adaptation benefits together is that, well, there is a lot of work on pricing these carbon sequestration benefits from forests. And then mangroves in particular. And so there is a very active marketplace for that. And because there’s that active marketplace and there are now increasingly well-developed standards for measuring carbon saturation.
We’re now working with some groups to develop parallel standards for accounting for what we will call their resilience benefits, these flood risk reduction benefits that can parallel the standards for these mitigation benefits. And the way that mangroves really work in carbon mitigation and why they’re really so important for this benefit is that The carbon that’s being sequestered is not just in the trunks of the trees. That’s where you kind of, when you’re talking about forests, you’re typically talking about all of this carbon being sequestered in the trunks. They’re also extraordinary.
We’re extraordinarily good at essentially accumulating sediments underneath the mangrove. So trapping all of these sediments that are coming down from rivers and all of the leaf litter coming out of the trees. That’s all carbon being piled up and stored very rapidly in mangrove environments. Mangroves are incredibly good at building land, and that building land is carbon being sequestered as well as then offering additional flood risk reduction benefits.
Ross Kenyon: Wow. Do you have a sense of the scale or what we might anticipate from, I imagine if there are additional ways of financializing and encouraging mangrove conservation and restoration that more than just the carbon benefit financing this, we might just see mangroves overall expanding and being more protected. So do you have any sense of like how many gigatons are being stored there or might be stored in the future? Is this just too far outside of your ken?
Michael Beck: Yeah, I wouldn’t be able to give you the very best answer on what the gigatons potential is, I’m afraid. What I can say is that there is a lot of increasing awareness of the value. And in part, because of that, you’ve seen a lot of slowing of mangrove loss and then a lot of... Very successful restoration efforts around the globe. And so that’s saying that people are really, I mean, just even at a broad level, before you get into the exact dollar values, that they’re recognizing some of these values. And now by being able to really tie some dollar values to that, both on the sequestration and on this flood risk reduction side, we can open up new markets and really, I hope and I actually truly believe, really expand mangrove habitats around the world.
Ross Kenyon: Wow. Well, where can people learn more if they want to dive into this topic?
Michael Beck: Well, they can learn a lot from our website. It’s coastalresilience. ucsc. edu. And from there, you can find some of our papers, some of the maps and tools that we provide for exploring these results, and even some of our op-eds and blogs.
Ross Kenyon: Great. And the paper and the article that I referenced at the beginning the show are also in the show notes if you’d like to follow up. Dr. Beck, thank you so much for being here.
Michael Beck: Ross, really appreciate the opportunity.
Ross Kenyon: It’s my pleasure. Well, thank you so much for listening. If you like the show, please rate and review it in Apple Podcasts and or Stitcher. It really helps us a lot to get this content to a wider audience. If you think what we’re doing is useful, interesting, fun, hopefully all three, we’d certainly appreciate your rating and review. You can keep up We are also now on Patreon at patreon.com slash Nori Podcasts if you’d like more content, engagement, and community. And thank you so much for your support.
