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The future of coastal erosion

Studying the chemical secrets locked in coastal rocks, a geoscientist says we can know what coastlines looked like long ago and understand where they are headed tomorrow.
Geological coastal cliffs
How are modern rates of coastline retreat different from the past? | Stocksy/Blue Collectors

Guest Jane Willenbring is a geoscientist who studies accelerating coastal erosion. The challenge lies not in understanding why coasts are receding today, but in determining what they looked like a thousand years ago to know how much they’ve changed — a secret revealed in coastal rocks through isotopes shaped by cosmic radiation. But measurement is only one part of the equation, she says. We must now think about erosion’s impact on humans, Willenbring tells host Russ Altman on this episode of Stanford Engineering’s The Future of Everything podcast.

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[00:00:00] Jane Willenbring: Because we can tell people this is the amount that the coastline is going to retreat over the next, you know, decade, two decades, 50 years, 100 years. And so, if we have to invoke something like managed retreat where people actually are moved away from the coastline where railroads are moved away from the coastline. That is something where we can actually give people advanced notice, which you'd think would be a good thing.[00:00:30]

[00:00:34] Russ Altman: This is Stanford Engineering's The Future of Everything and I'm your host Russ Saltman. If you enjoy the podcast, please follow or subscribe to it wherever you listen to podcasts. Today, Jane Willenbring will tell us about Coastal Erosion. Why it's happening and what it means for our future. It's the future of coastal erosion.

Before we jump into this episode, a reminder to please rate and review the podcast. It'll help our audience grow [00:01:00] and it'll help us improve.

So we all know that sea level is rising, and we all know that one of the big consequences of that is loss of coastline. How does the coast even form? And then how does it degrade and why does it matter? Well, the impacts on infrastructure and on human life and societal impact is quite non-trivial.

And today we have Professor Jane Willenbring from Stanford University to tell us about it. She's a professor of [00:01:30] Earth and Planetary Sciences and Earth system Science at Stanford University, and she's an expert on landscape and coastal erosion.

So Jane, One of your interests, of course, is coastal erosion. Uh, and to start, what are the processes that lead to the buildup or the breakdown of coastal areas?

[00:01:50] Jane Willenbring: Yeah, so one of the really important things, and one of the things that I really love about studying the coastal environment is that it's [00:02:00] incredibly dynamic. And so if we think about coastlines, we think about places that are changing all the time. And so in California in particular, some of the processes that are going on are obviously wave action.

We also have, um, uh, pronounced wave action, especially when there are storms. Um, and we also have things like water flow through coastal cliffs that can impact, um, [00:02:30] when cliffs fail on the coastline. Um, Of course we have buildup and loss of sand that happens seasonally, especially in some seasons when we have big storms.

Um, and so one of the, uh, we can think about it from a perspective of how the ocean is impacting the cliffs, but then also the nature of the cliffs themselves. What they're made of, how steep they are? You know, if there's been any kind of, um, seismic activity like [00:03:00] earthquakes or faults or, um, any kind of jointing or anything like that in the cliffs themselves.

[00:03:06] Russ Altman: So when I've, uh, just living life and being at the, I grew up on the East coast. I now live on the west coast. I've watched coasts, you know, from a distance and I don't see a lot. It always seems like things are kind of receding. But is it true that like the coasts everywhere are always receding or you made a brief mention of buildup, like what leads to actually the addition of Coast or is there [00:03:30] anything that leads to the addition of Coast?

[00:03:32] Jane Willenbring: Yeah, I mean in places, especially by river mouths. We get the buildup of coastal material right now. It like your observations were very astute.

[00:03:43] Russ Altman: Thank you.

[00:03:43] Jane Willenbring: Because right now we're in a period of sea level rise. And so in periods of sea level rise, you know, on the east coast we have the drowning of estuaries or estuaries and we have, um, a lot of waves that are closer [00:04:00] to the cliffs in, on the west coast where we have actively uplifting, uh, land surfaces. And so it does, your perception is correct. It does seem like we're losing coasts in a lot of places. And, uh, In other places like where the river mouths and deltas, for example, we also have, um, buildup of land.

[00:04:20] Russ Altman: Gotcha. Okay, good. So, uh, and I haven't spent as much time by rivers, so that's interesting that I have a totally kind of biased sample. So I know that, you know, you're an [00:04:30] engineer, uh, and one of the things you do is, uh, innovate in the area of measuring this erosion because, you know, as we always say, you can't intervene in anything if you can't measure it. Uh, so tell me a little bit about your measurement technologies and what are the challenges of like understanding how things change. I don't even know if it's day-to-day, month to month, or eon to eon and I suspect you're interested in all of the above.

[00:04:56] Jane Willenbring: Yeah, so I'm actually trained as a scientist. Um, so [00:05:00] my perspective is maybe a little longer term than the average coastal engineer. Um, and so there are folks who are doing a lot of monitoring of coastal environments that, uh, use lidar, which is um, kind of like a laser level if you are familiar with that carpenter tool. But, um, actually.

[00:05:22] Russ Altman: I think they're using them in self-driving cars as well.

[00:05:25] Jane Willenbring: Yeah, exactly. Yes, exactly. And so, um, you can use [00:05:30] those, uh, that technology that is actually from satellite data to understand over the period of monitoring how cliffs evolve and change. You can also go out there and just look. So those are things that happen over a short period of time.

So my role as a, um, geomorphologist, who is someone who I like to say is studies the science of scenery, is someone who will go out and kind [00:06:00] of look over a longer term. So we can look over hundreds of years, even before, um, people were really monitoring and measuring the coastal environment or millennia.

[00:06:11] Russ Altman: Yes.

[00:06:11] Jane Willenbring: To figure out how different the modern rates of retreat are from the past, like kind of natural baseline rates of retreat.

[00:06:21] Russ Altman: Great. So tell me how you do that, because obviously we didn't have GPS a hundred years ago, so you don't have any. And we didn't even have photography 200 years ago, say, [00:06:30] and so obviously you need to, you have a problem of setting the baseline and then looking for the delta, the change. Delta. Good word. Uh, so, um, tell me a little bit about how you can make such measurements over these time periods.

[00:06:44] Jane Willenbring: Yeah. So we use kind of, uh, what I like to think of as a bit of a fancy technique called cosmo isotopes. So isotopes are variants of different elements that have different amounts, different masses, and some of those isotopes that we can [00:07:00] extract and measure are formed only through the interaction with cosmic radiation. Which sounds sort of like a sci-fi novel...

[00:07:09] Russ Altman: Right.

[00:07:09] Jane Willenbring: Something out of Fantastic Four.

[00:07:11] Russ Altman: Right. It definitely does. Cosmic rays are gonna help you measure the coast.

[00:07:15] Jane Willenbring: Yes, that's right. Um, so those cosmic rays produce certain isotopes that are only produced in that way. And then we can take a rock sample, for example, from a coastal platform, think like a tide [00:07:30] pool.

[00:07:30] Russ Altman: Mm-hmm.

[00:07:31] Jane Willenbring: And we can figure out how long something has been exposed to cosmic radiation at the Earth's surface and then we can calculate a rate. So if we have a sort of a long shore platform that extends into the ocean, you know, maybe 300 feet or so. We can take samples all along there and figure out how long those different parts have been exposed to these cosmic rays, and that gives us a rate.

[00:07:57] Russ Altman: Does this also, could this involve [00:08:00] going into an archeological situation and kind of get finding layers of rock that are not currently being exposed, but you see evidence that they were exposed and then you can kind of say, okay, something must have happened to move this rock off the coast, you know, into the ground.

[00:08:16] Jane Willenbring: Yeah. So some places you have more of an archeological record of settlements that have been there in the past, um, and are now in a different place. People are usually setting up shop [00:08:30] near water sources.

[00:08:31] Russ Altman: Right, right.

[00:08:31] Jane Willenbring: Or, you know, near sources where they can launch a boat or something like that and so it's really common. To have a settlement that's near a coastline and now that settlement was abandoned because that coastline is no longer in that particular place. And so that is one way that a lot of people measure such things. And, um, it's been a long history of like figuring out what people have done [00:09:00] in the context of, you know, environmental change. Because we've, as a species, we've really been very good at adapting to differences in, you know, the environment and the landscape around us.

[00:09:11] Russ Altman: Right, right. Okay, great.

So, um, okay, so I know, so, okay. That was very helpful 'cause now we kind of see what you're measuring and that you can get these exposures. I had, while you were describing this, it occurred to me that this must be extremely complex because as you know, better than I, uh, it's not just the erosion that's [00:09:30] happening. There are plate tectonics and there are earthquakes, and there are things like that. So I'm guessing that you have to deconvolute lots of processes in order to isolate the impact of these things on the coast versus things moved because of an earthquake or because of other things. Is that true?

[00:09:49] Jane Willenbring: Yeah, that's exactly right. So in some places in the world, um, we have to kind of think about relative sea level. So sometimes sea level seems to [00:10:00] actually be going down in certain places, even though globally sea level is rising.

[00:10:06] Russ Altman: Right.

[00:10:06] Jane Willenbring: Um, and that's because the land surface is being pushed up by tectonic forces. And that's one of the things that happens, especially along the California and west coast of the United States and Alaska.

[00:10:18] Russ Altman: So Great, great. So, so I know that one of the things you're passionate about is studying the impacts of. It's not just how the erosion happens and how fast it's happening, but also the impacts both on humans [00:10:30] and on, as you said, you study the landscape.

So, um, let's get to humans second, but first tell me about what are the impacts on the infrastructure and on the actual coast. Like what are we seeing and what catches your attention and makes you either concerned or excited or whatever the right, uh, verb would be?

[00:10:49] Jane Willenbring: Yeah, I mean, if you think, if you kinda invoke sort of a coastal environment in your mind, you probably think of like a home perched on top of a cliff, um, that looks [00:11:00] like it's gonna fall into the ocean. And so of course, that's concerning because that person is gonna lose their home but then we also have things like, um, you know, lots of different kinds of infrastructure. We have roads and railroads, you know, the coaster line in Southern California goes right up alongside the, um, the beach.

[00:11:23] Russ Altman: It's spectacular.

[00:11:24] Jane Willenbring: Maybe, maybe a couple meters away. Um, we have, um, [00:11:30] the Diablo Canyon nuclear power plant that is nestled, right.

[00:11:35] Russ Altman: I only laugh because I dunno what else to do.

[00:11:38] Jane Willenbring: I know, I know. It's really, uh, bizarre and, um, maybe not a great idea. But we also have, you know, like, water treatment plants and military installations and so, airports.

And so there are all kinds of different reasons to be concerned about this. Um, and so that's one of the things that I think is [00:12:00] really important and interesting is just like there are so many people who are stakeholders and if you fix one thing in one place, which is kind of the engineer approach. You ruin something in another place. And so it really takes kind of a holistic, um, view in order to figure out how to solve some of these problems from a policy perspective.

[00:12:21] Russ Altman: So as a scientist who's pursuing knowledge about the fundamental processes that are leading to this, I can't imagine that you're not kind of [00:12:30] sucked into the policy and the planning aspects of this are you, do you have people from say California or from Florida calling you up saying, we need help. And if they are calling you, what are the questions that they're asking?

[00:12:43] Jane Willenbring: Yeah, so I think it intersects with policy in the sense that we can really tell how, you know, if we were thinking about erosion of landscapes, especially coastal landscapes, these happen very fast. And , um, people can see this [00:13:00] happening. But then it doesn't happen in some ways fast enough from a policy perspective for, you know, someone in their term of office to actually make like really unpopular decisions because probably in four years, maybe not too much will happen.

[00:13:17] Russ Altman: Right.

[00:13:17] Jane Willenbring: Maybe something. And so we have these sort of episodic events where something will happen and then not nothing for another five years, and then something else will happen. And so this is not ideal [00:13:30] from a policy perspective. People want something that is going to happen for sure. And so the long-term view I think is really important in that sense because we can tell people this is the amount that the coastline is going to retreat over the next, you know, decade, two decades, 50 years. 100 years. And so if we have to invoke something like managed retreat, Where people actually are [00:14:00] moved away from the coastline where railroads are moved away from the coastline. That is something where we can actually give people advanced notice, which you'd think would be a good thing.

[00:14:10] Russ Altman: Right.

[00:14:10] Jane Willenbring: Sometimes it's totally ignored, but in an ideal world, we could actually like, um, influence some future planning.

[00:14:18] Russ Altman: Are you seeing, uh, policymakers and public leadership open to your projections, or is it still. Uh, an issue of even getting them to pay attention?

[00:14:28] Jane Willenbring: Yeah, I mean, there [00:14:30] have been some wins so recently, um, in Southern California around Del Mar, that's where this Coaster Line, um, that's one of the busiest Amtrak lines, um, in the country. Um, they've actually invested $300 million to move it away from the coastline so it doesn't completely fall into the ocean. So that was a huge amount of money to be spent. You know, probably they wouldn't have had to spend so much if this had been, you know, decided [00:15:00] upon years ago.

Um, now it's kind of an emergency rush job because it was, you know, every now and then it's closed down because of.

[00:15:09] Russ Altman: Ya.

[00:15:09] Jane Willenbring: Um, because of a bluff failure, um, and this also costs, you know, human lives, um, in 2019, 3 people died, um, because of bluff erosion in around Encinitas.

[00:15:22] Russ Altman: So, uh, I'm interested, I know this is a little bit in the weeds, but is the solution not to build a bridge and to like, just leave the [00:15:30] tracks where they are but support them in another way versus, uh, moving them?

And it sounds like in this case, they're gonna move them. Is building the bridge ever a good option or is that just, uh, delaying the, what's going to happen eventually which is the water is simply too deep and you can't get structural stability.

[00:15:49] Jane Willenbring: I think it's problematic to build a bridge because a lot of times when you build a bridge, you're also kind of hardening the infrastructure around the bridge so the bridge doesn't [00:16:00] collapse.

[00:16:00] Russ Altman: Right.

[00:16:00] Jane Willenbring: And anytime you do that to this dynamic environment, you're really gonna affect some of the, you know, kind of up coast and down coast areas and how they accumulate sand and so you can really, um, make your neighbors angry by doing such a thing.

[00:16:18] Russ Altman: Great. So in the last few seconds for this segment, before we take a break, I have to ask you, in one of your papers you refer to landscape unzipping and I just needed to ask what that is?

[00:16:29] Jane Willenbring: Oh. [00:16:30] So, um, if you imagine a sort of like a plateau, sometimes streams are cutting through that plateau and the way that they cut through it is they start at the bottom. And then they create more of a valley as they move upstream.

[00:16:48] Russ Altman: Okay.

[00:16:48] Jane Willenbring: And so that, that is the unzipping of that landscape.

[00:16:52] Russ Altman: I see. And you get multiple, I actually know this, I think I know this phenomenon from the west coast of California where you see these, um, [00:17:00] these, yeah, uh, these. They look like rivers that are coming down from the hills but they are creating all of these lines through the, um, through the bluffs and through the cliffs.

[00:17:10] Jane Willenbring: Yeah, exactly. And that's another way, like that's separate from the coastal erosion but that's another thing, you know that can impact homes on some of these high plateaus.

[00:17:22] Russ Altman: This is The Future of Everything with Russ Altman. More with Jane Willenbring, next.[00:17:30]

Welcome back to The Future of Everything. This is Russ Altman and I'm speaking with Professor Jane Willenbring from Stanford University.

In the last segment, Jane told us about coastal erosion, how she measures it and what we do about it.

In this segment, she'll tell us about the different ways in which sea level rise is impacting the coast, and also some of the human impacts.

In this segment Jane, I wanted to ask you about sea level rise. You made a couple of references to it be before but [00:18:00] it's something that we're all seeing. We literally get updates in the news every week or month about how things are going. People are working very hard to try to stem sea level rise. What is the ways, what are the ways in which sea level rise is impacting our coasts?

[00:18:15] Jane Willenbring: Yeah, so sea level rise is problematic. And of course, you know, um, depending on where you are, the rate of sea level rise is gonna be different depending on what the land surface is doing. But generally it's about an eighth, an inch a year these days. Um, and one [00:18:30] of the things people really worry about is that, you know, we're gonna have some kind of episodic. Um, kind of catastrophic loss of ice masses, which is gonna increase that rate, um, in a big way in lots of places around the world. And the kind of intuitive way that sea level rise impacts coastlines is that you can imagine that the, uh, water level as it increases. You're gonna flood a lot [00:19:00] of the sandy areas, which actually protects coastlines. And then you're gonna have those waves that are closer to whatever coastal cliff is gonna be around there. And so that's really problematic on the west coast.

On the east coast, you are familiar probably with like submergence and how things are gonna flood. And so that's really one way that we have, uh, the impact of sea level rise on the east coast where we don't have such, uh, dramatic topography right at the [00:19:30] coastline.

[00:19:30] Russ Altman: Right. So in addition to the flooding is the other, are there other patterns of damage that are perhaps not appreciated that we should be on the lookout for? I don't know if there's changes in the shape or of the coast or, um, the way in which the coast articulates, uh, with the ocean. I'm just wondering if flooding is number one and what's number two?

[00:19:53] Jane Willenbring: Yeah, so flooding of the coastlines is a big one. And then again, like anytime you have [00:20:00] some of your water level higher, you're able to move offshore a lot of the sandy material. That again, like protects those coastlines, so they've found like the wider the beach, the lower the rate of erosion of the coastal cliffs on the west coast, and so those beach environments are really some of the best defenses against, um, coastal erosion. And so if you're eroding those beaches, not only do you not get a nice [00:20:30] beach to go to, I'm sure you like to go to the beach during

[00:20:33] Russ Altman: Yes, I do. I do.

[00:20:34] Jane Willenbring: Yes, everyone does. So it's also a huge thing for a lot of, um, local economies...

[00:20:39] Russ Altman: Yes.

[00:20:39] Jane Willenbring: ...is just, you know, having that beach environment. And so we're really thinking about like, oh, in the future. Are we not gonna have any beaches like that just sounds horrible to me.

[00:20:48] Russ Altman: So when a ,so, you know, I do go to the beaches around, uh, here in California and I see these big cliffs, you know, 20- 30 feet of like, basically sand. When they collapse, [00:21:00] do they create a new beach and give us a little bit of time before the next collapse gonna happen?

Because I would imagine that mass kind of forms a little bit of a, you know, a little bit of a sandbar that then gives us sometime before we have to wait about the next collapse. So is that the natural cycle or is it much more complicated than that?

[00:21:20] Jane Willenbring: Yes, that is actually like one of the ways in which we're like naturally replenish beaches. And so that's why when people are, you know, really worried about their home [00:21:30] and they artificially harden the coastline using concrete.

[00:21:33] Russ Altman: Right.

[00:21:34] Jane Willenbring: Or a bunch of boulders and um, things like that, you're actually removing that source of sand. So you have to think about, you know, um, if someone were to do that, should they pay some kind of like sand tax or something?

[00:21:50] Russ Altman: Right.

[00:21:50] Jane Willenbring: You know, 'cause they're really ruining the presence of the beach for other people.

[00:21:54] Russ Altman: Right.

[00:21:54] Jane Willenbring: And so you're right though, that is one way that we protect that [00:22:00] particular coastline is just in that little apron of material.

[00:22:03] Russ Altman: Yes.

[00:22:03] Jane Willenbring: That and that's why it's so episodic too.

[00:22:05] Russ Altman: Yes.

[00:22:05] Jane Willenbring: Sometimes after you get a big beach failure and collapse, then it's hard to erode that particular spot and then you'll erode either up coast or down coast of that area.

[00:22:17] Russ Altman: So in the last five minutes, I wanted to talk about another area that I know you're interested in, which is, we talked about the infrastructure impacts. But there are human and social impacts of these coastal erosion. What are the ones that get your attention [00:22:30] and what are people doing about them?

[00:22:32] Jane Willenbring: Yeah, I mean, you know, if, again, if you invoke like that idea in California of like who is living on the coastline, you think like, well, not a big deal. This is probably the vacation home or something, you know.

[00:22:45] Russ Altman: Right, right.

[00:22:46] Jane Willenbring: Some of those fancy houses, like some of 'em are hard to feel.

[00:22:49] Russ Altman: Sorry, it's hard to feel exactly. I mean, I don't want to be heartless, but sometimes it's not your number one sympathy target.

[00:22:55] Jane Willenbring: No, no, of course not. But there are a lot of communities where [00:23:00] it is not a really wealthy person that lives there. And there are a lot of places where, you know, even just the highway, you know, passes through a place. And so it affects a lot of people who really need to get to work to go to their jobs.

[00:23:15] Russ Altman: Yes.

[00:23:15] Jane Willenbring: And of course, in, for example, Alaska, there are a lot of, um, indigenous people whose villages are right near the coastline. And so, you know, the current way is that the federal government will like, actively move [00:23:30] people inland, um, when they're at risk of their village going into the ocean. Um, and those rates of cliff retreat and coastal retreat are, you know, 30 meters a year sometimes. I mean, really, really fast.

[00:23:44] Russ Altman: Oh, that's a big, that's big. So it's not just

[00:23:46] Jane Willenbring: That is huge. Yes. And so, um, so there are a lot of just displacement that are gonna happen and for whatever reason, people just do not have the appetite or the stomach to think about, you know, their [00:24:00] homes and their places are very important to them. And, you know, it's a beautiful place to live. And so, um, there are a lot of really fraught conversations that we're gonna have to have about who gets to build along the coastline and what happens to people who are already there and where should they go.

[00:24:16] Russ Altman: Yes. And I'm sure that there's complex legal issues about like what happens to your land if it gets. Especially if the government prematurely, like it's not underwater yet, but the government is telling you this is happening, and you're looking [00:24:30] at your land thinking, why are you doing this to me? Uh, and it's the same thing about the kinetics of how fast this happens and when people are willing to face the reality. Um, and I made the joke about the rich people. But it's probable that just because of the numbers that probably, it might be, my guess would be that there would be many, uh, low income people who would, many more low income people displaced by this than the high income people.

Because they just have one house and a lot of land. But in [00:25:00] villages and things and we saw what happened in Maui with, with the fires. That's thousands of people who just live there. Um, just having their life and they're not particularly wealthy. Um, So, um, how about, are there health implications to all of this?

[00:25:16] Jane Willenbring: Yeah, I mean, there's the active physical threat of actually being crushed by a collapsing cliff.

[00:25:23] Russ Altman: Yes.

[00:25:23] Jane Willenbring: Um, which I'm laughing about because it sounds horrible and awful, not because I think it's funny. Um, but then there's also a [00:25:30] lot of, um, You know, thinking about water treatment plants and if there is a storm surge, for example, or if that water treatment plant, you know, has a, you know, one decade lifetime because of coastal erosion, that's really gonna affect a lot of people.

And it also creates, you know, um, a lot of uncertainty about, you know, if we have to go to desalinization plants. Um, what [00:26:00] that is going to look like, where those would go. And so, as always, a lot of these problems are, you know, have fingers in lots of different areas that affect human health.

[00:26:10] Russ Altman: So, and the final thing I wanna ask you again, just out of curiosity is, sometimes we see people planting plants in order to protect the coast. Like they say, we're gonna put in these plants, they're gonna help provide a barrier. You see this especially along rivers but also I think at the ocean. Uh, what is the role of vegetation? Or is that not a big enough hammer to [00:26:30] kind of stop any of these big processes?

[00:26:34] Jane Willenbring: Yeah, so a lot of, um, the early efforts to really use, especially invasive plants, um, people have tried to plant bamboo where it didn't belong, ice plant in Southern California is really common. That has actually been, um, a negative...

[00:26:51] Russ Altman: Ah.

[00:26:52] Jane Willenbring: ...in terms of how coasts respond. Um, it creates like a lot of buildup of sediment and not a [00:27:00] slow, um, a slow erosion of that surface. Um, and then it kind of like is a capacitor where it fails all at once after...

[00:27:09] Russ Altman: Ah.

[00:27:10] Jane Willenbring: ...that happens. And so that's probably not a great thing. Native plants are probably a better choice. There's a lot of interest in, you know, how we could use kelp, for example, to not harden the coastline necessarily, but to soften the waves.

[00:27:25] Russ Altman: Ah.

[00:27:25] Jane Willenbring: Which ultimately probably would not really help in the long [00:27:30] term. But it might kind of delay some of these, um, big storm effect.

[00:27:34] Russ Altman: Oh, it's such a nice idea. They see all of those kelp and they're just like buffering the waves and making them a little bit less powerful. Uh, and then I suppose there's nothing to do on the side of a cliff. There's nothing to grow there that's gonna stop it from falling.

[00:27:49] Jane Willenbring: No, not really. There's like some little, like, what are, they are called biofilms. They're kind of like an algae.

[00:27:55] Russ Altman: Yes.

[00:27:55] Jane Willenbring: That actually kind of, um, help to stabilize [00:28:00] some of the

[00:28:00] Russ Altman: Oh, that's interesting.

[00:28:01] Jane Willenbring: Um, and then another thing that comes up a lot in Southern California and Northern California is when people have like lawns on top of the cliff and so they'll usually irrigate and that adds water...

[00:28:16] Russ Altman: Yes.

[00:28:16] Jane Willenbring: ...to the system. And anytime you're adding water to the system, it creates less rain that you need in order to cause a failure. So there are some human impacts that are related to like how people use the land [00:28:30] on the surface.

[00:28:31] Russ Altman: I see and we would prefer for them not to be watering the lawns too much.

[00:28:35] Jane Willenbring: Yeah, exactly. Yeah. 'cause to get those super green lawns and like, especially probably seen, you know, like, um, golf courses right there.

[00:28:44] Russ Altman: Yes, yes.

[00:28:45] Jane Willenbring: Um, also bad as you might imagine.

[00:28:47] Russ Altman: Yes.

Thanks to Jane Willenbring, that was the future of coastal erosion. You have been listening to The Future of Everything with Russ Altman. If you enjoyed the podcast, please consider subscribing or following it so you'll [00:29:00] receive news of the new episodes and you'll never be surprised by the future of anything.

Maybe tell your friends about the podcast too and definitely rate and review it. We have more than 200 episodes in the back catalog, you might go check out some of those, which are still evergreen and good.

You can connect with me on Twitter @RBAltman and follow Stanford Engineering @StanfordENG. You can also now follow me on threads @Russ, R U S S , B as in [00:29:30] boy, Altman, @RussBAltman, all one word.