Climate Change and Implications for Disasters in the United States

Examples from the Arctic, Caribbean, Northeast, and Gulf States

Published Jun 10, 2022

by Abbie Tingstad, Susan A. Resetar, Jordan R. Fischbach, Jessie Riposo

Climate change is contributing to more frequent and more severe disasters. In this video, three climate researchers from the RAND Corporation discuss climate change and risks for disasters in the United States. They focus on several regions: the Arctic, the Caribbean, the Northeast, and the Gulf states. They examine how climate effects and hazards are affecting communities in the region, ongoing adaptation activities and achievements in addressing these hazards, and remaining needs and opportunities.

This February 2022 event was presented by the Disaster Management & Resilience (DMR) program (formerly the "Disaster Research and Analysis Program"), part of the RAND Homeland Security Operational Analysis Center (HSOAC). The DMR webinar series was created to increase understanding in how disaster policies can affect the ability of communities to respond to and recover from disasters.


Jessie Riposo

Thank you, everyone, for joining us this afternoon, and welcome to the Disaster Research and Analysis Program's webinar on climate change. The webinar series was created to help increase understanding in how disaster policies can affect the ability of communities to prepare for, respond to, and recover from disasters. I'm Jessie Riposo, the director of the Disaster Research and Analysis Program, and I'll be moderating our session today. Please pose your questions in the question box, and I will ask them at the appropriate time.

Today, three experts will be discussing climate change risks affecting populations in the Arctic, the Caribbean, and the Gulf States. They will discuss ongoing adaptation activities and achievements in addressing these hazards and the remaining needs and opportunities in these regions. We'll have three speakers.

Abbie Tingstad is the associate director of the Engineering and Applied Sciences Department and a codirector of the Climate Resilience Center. She is also a senior physical scientist at the RAND Corporation, and her research focuses on issues related to strategy and planning in defense and homeland security and for the environment.

We also have Sue Resetar, who is a senior operations researcher with over 25 years of public policy research at the RAND Corporation. She's been working in the areas of strategic planning, natural and cultural resources, environmental policy, disaster management and recovery, and the intersection of these topics with climate change. She has worked closely with clients in the Department of Defense, Department of Homeland Security, the White House Office of Science Technology Policy, the Environmental Protection Agency, and the Department of Energy.

And we have Jordan Fischbach, who is the director of planning and policy research at the Water Institute of the Gulf and an adjunct policy researcher at the RAND Corporation. Before joining the Water Institute, Jordan was the codirector of the RAND Climate Resilience Center, a senior policy researcher at the RAND Corporation, and an affiliate faculty member at the Pardee RAND Graduate School. He also served as the quality assurance manager for the Homeland Security Operational Analysis Center between 2018 and 2020, and since 2010 has led research focused on climate adaptation, urban resilience, water resources management, coastal planning, and post-disaster recovery.

So with that, I will turn it over to our first speaker, Abbie.

Abbie Tingstad

Thank you so much for having me today, and welcome, everyone. It's my pleasure to speak with you today about climate and disasters in the Arctic—although I should note that, although it is my pleasure to speak with you today, this is not particularly a pleasant topic. But it's very— it's great to have this kind of a community discussion about important topics such as this. Before I do so, though, I'm going to step back just for a moment and to talk more generally about climate, climate change, the influence that these have on the occurrence of disasters, and how they also affect response and recovery. Next slide, please.

What I want to emphasize here is that not only are there multiple ways in which a changing climate influences the occurrence of disasters and where they occur and how severe they are, climate and climate change also influence how difficult it can be to respond and recover from these disasters. So on this first of two slides here, I wanted to emphasize some of the different ways in which climate both creates or contributes to the problem of the disasters that affect local communities around the world and certainly around the U.S. So just some examples here. I wanted to highlight many of the different climate change–related effects that are important. For example, you see here that warming oceans and atmosphere can increase the wind speed of some storms. Also that increasing temperatures fuel larger numbers of high-intensity storms due to increased evaporation of water vapor into the atmosphere. Also, intensifying temperatures and evaporation drive and complicate drought through impacts on water demand and supply.

I think in the news we often hear about how climate change may be increasing the frequency and intensity of storms, especially with a very powerful hurricane season recently, for example. But it's important to note that climate change also [inaudible] all sorts of disasters, including ones that are [inaudible] over time, such as drought, which affects many parts of the U.S. Something that is very pertinent, of course, to the Arctic, which I'll be speaking about shortly, is the issue of melting glaciers. Which, when ice melts on land, it can directly lead to rising sea levels around the world. As some people have previously joked that this is one of the reasons why— this, among others, is one of the reasons why climate change in the Arctic doesn't just stay in the Arctic, it contributes to impacts all over the world. Rising sea levels are also associated, perhaps in a smaller measure, with thermally expanding oceans as well. And naturally, sea level rise is important because it creates vulnerabilities in coastal areas, it increases the impacts that things like storm surges or tsunamis can have, and the like.

And then finally, I'd like to highlight that climate change has a troubling feature, which is that the more climate change that the globe experiences, the more climate change it can create through feedback systems. And one of these feedback systems that I want to highlight here is very pertinent again to the Arctic, because the less snow and ice that the world has in the Arctic region means that less solar energy is reflected back into space. So warming then begets additional warming. And again, this is a way in which the Arctic region and how it experiences climate change does affect the rest of the world, very importantly.

But moving from how climate in some cases can increase the frequency of disasters or their intensity or simply just their effects by kind of weakening the soils or the coastlines or infrastructure, other [inaudible] that are impacted by the disaster. Next slide, please. We also see that these same factors can really complicate the ability to respond and recover. And I highlight a few different ways that this is true here. So, for example, mobile and fixed infrastructure can be impacted, of course, by severe storms, for example, which is not only a part of the disaster, but then also really can delay the recovery. And we often see this where, if the storm hits a certain location, even if aid is available and people are available to come and help, there's no workable airport or no workable port, no workable roads, in order for them to arrive and start delivering this. And so, in that sense, climate-impacted disasters are a bit of a whammy. Physical access, clearly, also to people in areas in need can really be inhibited.

Oftentimes we see more of a systems-level impact of these climate-related or climate-fueled or somehow -impacted disasters, in that it's not just the fact that the storm hit, it's also that, say, the ground became even more destabilized due to intense rains causing or triggering landslides and things like this. So you can see multiple sorts of impacts across the physical system as a result of, in some cases, you know, a short-term disaster like a storm combined with, say, longer-term problems that are somehow linked to climate but are more slowly moving so that you have these longer-term, weakened soil combined with a storm and then landsliding in addition to the storm itself and perhaps some additional coastal erosion, storm surges, and things like this. Flooding. So lots of things compounding, and many of these also complicate the ability to respond and recover.

I wanted to highlight, too, that there's also can be issues with the readiness of personnel who are trying to help with the response and recovery. And we should think about, for example, the impacts of extreme heat on their ability to help and [inaudible] for example, are really waterlogged. And these people who are trying to help respond and recover can clearly also have their own lives at risk and trying to do so from drowning.

And then finally, I should add that from perhaps a more policy or resource management perspective, when climate-fueled disasters can have the potential to spread over large areas—I already mentioned this kind of systems problem that there can be when there are disasters related to or fueled by climate change. The issue then is, of course, when they are widespread and there are multiple kinds of problems that have happened, resource management can be problematic and so priorities have to be given to one area or another. And there may not be enough resources immediately available to help some other areas that may have been affected. So a lot of— [inaudible] for climate to not only instigate or help fuel disasters, but also for climate-related effects to help impede effective response and recovery.

So now that we've set the stage, I will—before I turn it over to my colleagues—I will discuss some examples from the Arctic region, specifically Alaska with the Arctic region in context there, because the Arctic has been impacted by climate change very rapidly, very intensely, more so than the rest of the world, in fact. And as such—next slide, please—the Arctic has been, if you will, a bit of a canary in the coal mine for us around the world to understand how disasters as a result of climate change might look in the future and what some of the complications will be to respond and recover from those.

So one thing I wanted to highlight here is that in Alaska—Alaska has its own sort of challenges and flavors of climate-induced or -associated disasters. But in many ways, at a macro level, these might look very similar to those elsewhere, in the United States at least. So we have— we see landslides and severe storms, not unfamiliar to the places that Susan and Jordan will be talking about as well. And, of course, coastal erosion and environmental contamination, wildfires, and the like. So in this sense, Alaska faces some similar—I'm putting this natural in quotations—"natural" disasters as other places.

But—next slide, please—one of the unique aspects is that when we think about responding and recovering in an Arctic environment, this is often different and in some cases more difficult than elsewhere in the U.S. And here are some of the particular reasons why. So in Alaska, as well as other Arctic places, you have permafrost, which is— basically, it's frozen ground. And in a lot of places, there's seasonally frozen ground. So it will melt and thaw and melt. And what this causes is—because water is changing form, essentially—what this causes is ground movement. And in some places, the melting season can result in a lot of ground instability. And just by virtue of the fact that the permafrost is melting and thawing means that, for example, roads that are built on top of permafrost are not very stable, and they will shift and they will crack. Buildings that are top of permafrost that ends up melting and thawing—or just melting in some cases due to climate change—will end up with cracks along the foundation, and in some of the circumstances will collapse entirely. So the operating on unstable ground is really important and really a consideration that must be thought of when responding in these high-latitude environments like Alaska.

I will say also that in the Arctic, there are also people who frequently rely on ice roads. And those are, of course, only available in the coldest months of the year. And because of this—because of climate change—the ice road season is decreasing in length. So this becomes a real logistical problem. And if we can imagine, you know, trying to help a community that has experienced a disaster that may only be accessible by ice road or by air on a very small landing strip, this makes a massive, you know, evacuation or bringing in of medical supplies and other things very, very difficult, not to mention rebuilding activities and things like this.

I find sometimes that people forget, too, that at high latitudes you have severe limitations on daylight for several months of the year. And in the pictures that you see here, although it is daylight, we have to bear in mind that this is for a handful—if that—hours per day, and that is the sunniest it gets. If there is the sun even peeking out, because there can be severe weather during these times of year where the sun will never show behind the clouds. And operating under those kinds of daylight conditions—I mean, sure, you can use headlamps, and people do, of course—but it becomes very difficult, not only just from not being able to see anything, but if you can imagine the needs for specialized equipment. This is why people who live in, you know, very dark winter places wear a lot of reflective gear, so cars driving around don't hit them. And also just the psychological impacts. You may be aware that people in very high-latitude communities can often suffer from depression and anxiety during these winter months. And even those who don't—you know, I've had the fortune of living in a place that is very high latitude, and you are just sleepy all the time. It feels like you should just be in bed. So, again, an issue that we might not think about immediately, but definitely can complicate responding to disasters.

In the Arctic—and Alaska is totally included in this—there are vast distances, limited infrastructure, including communications, available. So any of the resources that we might imagine ourselves having across the majority of the lower 48, in many parts of Alaska are simply not available or just sparingly available or somehow otherwise difficult to obtain. And the same is true when we think about how severe environment impacts performance of both humans and technology. In the photo you see here, you see those pumps are entirely frozen over. Those don't work in the Arctic the way that you think that they they should in the lower 48. So Alaskans contend with having to deal, certainly, with winterizing vehicles, and in the summertime dealing with very muddy areas, dealing with things freezing, wires and batteries not working. Other things that would not be regular things that many of the lower 48 states in disaster situations would have to contend with. Next slide, please.

So to conclude here, I wanted to point out that we can look to Alaska and the Arctic in general to really think about the scale of future disasters and the corresponding scale of future response that may be required. And one thing that we are learning from communities such as Kiruna, Sweden and Kivalina, Alaska, is that these communities are contending with major environmental and climate-related changes. These are two places where communities are being moved. Whole communities are being moved. Some of them are very small, but there are many of them, and some of them are actually a little bit bigger. Like you can see Kiruna, with 20,000 people, you know, is not considered a big city by any stretch. But if we think about how far north it is, it is a relatively large community there. And having to be moved is a big deal. And so more and more [people] in Alaska are having to contend with questions of whether climate and other issues are going to lead to depopulation and/or having the community be moved. Where is the funding going to come with that? And importantly, there are also major equity issues here. So in the North, as in other areas, we have a lot of important indigenous communities, and— that conduct subsistence living activities. And in so doing, you know, as they say, as they report, no hand in the issues related to climate change. However, they are some of the very first communities to be impacted by it, including having to leave places that they have inhabited for hundreds of years in some cases. So a lot of equity issues also built into some of these questions. And with that, I will turn it over to Susan. Thanks for having me.

Susan A. Resetar

Hi. Good afternoon. So, I am going to be covering the Caribbean, focusing on Puerto Rico and the U.S. Virgin Islands. Next slide, please. Before I dive in, I just want to note that— because I'm talking about the Caribbean, but I'm recognizing that Puerto Rico and the U.S. Virgin Islands are very different places. They have very different histories and physical characteristics and different populations. Puerto Rico, for example, has almost three and a quarter million people on the island that has a range of industries, from manufacturing to insurance and finance and tourism. Whereas the Virgin Islands has less than 90,000 people that are spread across three different islands, three major islands. Each of those islands has their own personalities. St. John has a large national park covering the area. St. Thomas is home to the capital. And St. Croix, which is a little larger than the other two, has more agricultural activity. And in the Virgin Islands, tourism is a major sector of the economy. So these are very different places. So while I talk about climate change in broad brushes, we want to understand that those effects and the consequences are different across the region.

But there are some commonalities. This region is ecologically rich, and it's considered a biodiversity hotspot that has a lot of endemic species, which means that this is the only place in the world that these species exist. And so the natural resources in the area are— they are under stress, but they provide what we call ecosystem services, which contribute to improved air quality, water quality, sedimentation and pollution control, erosion control, and a host of others. I won't talk a lot about that, but I do want to point that out. And by virtue of the fact that they're small islands, they have unique vulnerabilities to climate change. They're remote; they're over a thousand miles from Miami and the mainland. And that complicates and increases the cost of logistical challenges for supplies and support. They also are pretty reliant on imports for basic necessities ranging from food and fuel to other products. They're highly dependent on local freshwater sources. And then lastly, they have a proportionally greater coastline, right? So any kind of exposure to climate change effects will be proportionately larger on the islands. The region has also experienced—both Virgin Islands and Puerto Rico—has experienced outmigration. According to the 2020 census, Puerto Rico's population has dropped by about 12% from 2010, and Virgin Islands' population has dropped about 18% since 2010. So this creates many issues, not the least of which are workforce challenges.

And then finally, I just want to note out I will be talking about some of the climate projections on this. But in this region, it's a little bit— there's a little bit more uncertainty about some of these projections than in other parts of the United States. And that has a lot to do with their size and how the modeling is performed, as well as the availability of historical data. So just want to put that so people understand that there is still uncertainty about some of these projections. Okay, next slide, please.

So the primary climate indicator is air temperature. And this slide is taken from the Fourth National Climate Assessment, and it's based on internationally accepted scenarios and modeling standards. And it's showing, with the orange line, the historic trends and average annual temperature in the region, and then the projections out to the end of the century for what's considered a lower case, lower-emissions scenario and a higher scenario. So you will notice that the average temperature has already been increasing in the region. It could increase over the 1950 to the 2005 baseline, which is the standard baseline used in these models, by up to nine degrees Fahrenheit. That's for a high-emissions scenario, but that's kind of the range that people are talking about. Temperature increases in this region are higher than the global average, and it's uneven across the region. San Juan was already experiencing higher warming, greater warming than the rest of the island. And some of that is due to what we call the "urban island effect," which is, you know, when you have an urbanized area, there's not so much vegetation. There's a lot of heat that's dissipated from human activities. The building materials themselves will affect the heat in the urban area. So that's being experienced here in Puerto Rico. So as the temperature increases, there's obviously—well, not maybe obviously, but—the number of hotter days will increase. They're seeing nights, projecting nights to be increasing. And all of this has some fairly obvious consequences for energy use, human health, and ecosystem services as some of these natural resources are stressed. Next slide, please.

Related to the increasing atmospheric temperature, our ocean temperatures are increasing. We're also experiencing acidification. And these are factors that stress this marine life, which is really important to the community, to the culture, as well as to basic necessities, fisheries, coastal protection, and so forth. And as the sea level rises, it amplifies those effects that Abbie had mentioned in her brief. And so because of this proportionately higher coastline of exposure, this is very concerning for the islands. And they've been monitoring erosions along the coastline. And the rate of erosion has been increasing in the last decade or so.

You know, what are the consequences of this? Well, in Puerto Rico, at least, approximately 60% of the population lives in coastal municipalities. So they have that exposure. And with the population is the infrastructure and cultural heritage sites. So there's a lot of really important assets, if you will, near the coast that are potentially exposed. The Virgin Islands is similar, although some of the islands are well above sea level, so there's maybe not quite as much infrastructure along the coast, but the capital is really only a few feet above sea level. So there are some really significant places where sea level rise and erosion is of concern there as well. Next slide.

So I wanted to show you what happens when you build too close to the coast and there's a lot of erosion. Building so close to the water disrupts natural processes that actually kind of replenish some of the beach. Beaches are not stable. Sediment accretes and erodes throughout the year. Researcher— scientists in Puerto Rico noticed that sediment will rotate around the island. And so, any kind of physical structure will disrupt those processes, which again has that feedback loop: if they're not able to replenish the materials, then the beach will not be able to absorb some of those storm surges or wave action and protect the infrastructure. So there's sort of a feedback loop there as well. And sometimes the sediment comes back. It did come back in Rincón; I'm not familiar with exactly how much. But sometimes it doesn't. So that's concerning. Next slide.

I'm going to spend a little bit of time on this one. So, in terms of modeling rainfall, or projecting rainfall in the future, it is pretty challenging in this region because of the variability in rainfall. In Puerto Rico alone, certain parts of the island might experience 40 inches of rain a year. Other parts might experience 200 inches of rain. Virgin Islands, not quite so dramatic, but there's still variability across the islands. So, because of that, and because of more limited data and the fine scale that the modeling has to occur, it's especially problematic for the Virgin Islands. There's not as much certainty around projections of precipitation in the area. However, generally, precipitation is expected to decline in the future and occur in fewer but larger events. I just happened to notice that last weekend Puerto Rico experienced a heavy rainfall that closed about a dozen schools and led to some landslides. So, these kinds of events may become more frequent as the climate is changing. Drought periods are projected to increase, and the region is already not immune to drought. During the 2015 time period, water actually had to be rationed and there was some severe consequences to agriculture and the economy as a result.

In a summary here, both Puerto Rico and the Virgin Islands are highly reliant on surface water sources for their freshwater, and that means that they need a consistent rainfall. Puerto Rico maintains several major water storage reservoirs, and in the Virgin Islands, households have their own cistern systems. So as the hotter temperatures increase the demand for water, as the reduction in annual rainfall decreases the supply of water, these heavy rainfall events can drive sediment and other pollution into the storage reservoirs and streams and guts. And these periods of droughts will be more frequent. And I also didn't mention, but sea level rise can impact some of the— can cause saltwater intrusion into the coastal aquifers, which will also affect freshwater availability. So these— all of these trends are compounded by existing management and infrastructure issues in the region. So, you know, the region is highly vulnerable to losing their water supply. And Professor Guannel from the University of Virgin Island calls this a "silent emergency." And so I think that's very concerning when you think about the future trends of climate change. Okay, next slide.

Another example from Maria that I want to present is what happened when the heavy rains that Maria dropped on Puerto Rico. So, Maria triggered over 40,000 landslides in the mountain region of Puerto Rico. And this was the highest-recorded ever number of landslides for that kind of, that size of an area ever recorded in the world, so far as I know, according to a recitation. It also was the highest amount of— the most— largest rainfall event ever recorded in Puerto Rico.

So what does that mean? Well, you know, the house on the left that I took a picture of, it just basically, you know, toppled from its foundation. And you could see where the road was kind of damaged when the slope failed. And then the map on the left was prepared by Dr. Stephen Hughes at the University of Puerto Rico. And each red dot, which admittedly is a little hard to see, notes where a landslide occurred. So he used satellite imagery data to identify all of the locations of the landslides. And then the USDA did some fieldwork and used his data to estimate the sediment loadings that were released as a result of Maria in the Dos Bocas watershed, which is a key watershed for supplying water to San Juan. It has a key water storage reservoir in the watershed. And they estimated—and granted, this was a quick estimate just after the hurricane occurred—that 23 million cubic meters of sediment was released as a result of these landslides. And that's equivalent to about the volume of about 22 Empire State Buildings. So this is concerning. This is concerning because, besides the obvious safety threats to life and infrastructure, landslides are the main source of sediment that is already reducing limited water storage capacity of the island. And there's been some simulations that have shown Puerto Rico could be in a permanent water supply deficit as early as 2025. So, you know, the time is now to kind of figure this out. And we also saw in Maria that the sediment and the pollution it carried, you know, stressed the marine environment, stressed these mangroves and seagrasses and corals that also help reduce coastal erosion. And then, also, there's water quality concerns for the island's population here. So— and the last point of the slide is that, you know, these record-setting events also suggest that there should be a relook at the design set standards for critical water infrastructure. So I just want to point that out as well. Next slide.

I'm probably one of the only people who goes to these beautiful islands and takes photos of garbage dumps. But here we are. I think it's probably not something that most people think about when they think about climate change. But what we found, what we learned in Maria and Irma and I'm sure others knew this long before that, but hurricanes do generate a lot of debris, a lot of construction and demolition waste and other solid wastes that have to be contended with. This debris and the waste can block access and slow response and recovery. It contributes to flooding. Obviously, as these dumpsites leach pollutants into the environment, that threatens human health as well as ecosystem health. We saw an experience where some of these large piles of debris and waste were a fire and safety hazard. There are recurrent fires of the St. Croix landfill, that's actually shut down the airport because of visibility issues. So— and along with those are some serious environmental justice issues. So, again, as storms increase in intensity, you know, these are important issues to get ahead of. I think there's, we saw that—excuse me—the conflicting priorities for how to manage waste by these storms was really contentious at times in both Puerto Rico and the Virgin Islands. So it's a challenging problem there because of the remoteness. But there are options. There are opportunities exist. Next slide.

So what does this all mean? Well, I summarized it on the slide. I'm not going to go point by point. But I do want to end by saying, you know, the vulnerabilities to climate change—potential exposures to climate change—are exacerbated by a lot of the ongoing challenges of managing land use, urbanization, habitat loss, and so forth. And, you know, these challenges, these vulnerabilities, do reduce human and ecological systems, do reduce the ability to recover quickly after an extreme event. And then finally, while climate is another global issue, but the effects and the risk mitigations are very local. So as we think about recovery from extreme events and climate adaptation in general, it's critical to consider what local priorities are and how to pursue strategies that are locally sustainable and how to pursue strategies that maintain the sense of place in these beautiful and culturally rich islands. And with that, I will pass the baton to Jordan.

Jordan R. Fischbach

Thanks, Sue. All right. So, I want to talk a bit about the Gulf states. I'm cognizant of the time, so I'm going to be a little bit more brief on the impact side, because Abbie and Susan have already described many of those that I'll amplify here. And I'm also going to focus in on some adaptation examples, really, at the statewide scale. All right, next slide.

As we've already discussed to some extent, you know, coastal communities across the nation are facing increasing risk from climate change. So we've talked a lot about rising sea levels already and the connected loss of wetlands and other coastal features. Also about the change in the frequency of coastal storms in particular, as well as higher-intensity rainfall events, which I'll come back to. And as we've discussed in our previous panelists, all of this is amplified by just the amount of people and the amount of assets that we have concentrated, and increasingly concentrated, in our coastal counties and parishes. So this is something that— where we see the impacts of climate change coming together with increasing population and economic growth over time, leading to serious risk in terms of loss of life, property damage, and disruption from coastal events. Next slide.

I'm going to talk about Louisiana, which is a place that I work quite regularly. I have been working there for almost 15 years, and Louisiana is mentioned along with the Arctic and Alaska as sort of the other canary in the coal mine when it comes to climate impacts, particularly for coastal communities. So Louisiana's obviously been dealing with these major hurricanes and other flood disasters for decades. And we experienced that, of course, this past year with Hurricane Ida making landfall in Louisiana. But really, for the state, 2005 and the hurricane, both the hurricane season that included Hurricane Katrina and Rita, really spurred the state into action at this point in time. So that point really changed the structure of state government when it came to managing the coast and developed a new organization in the governor's office to promote comprehensive long-term master planning and bring together the goals of coastal restoration and hurricane risk reduction for the first time. Just to give you a sense for Louisiana, just a handful of storms around the 2010s—Katrina, Rita, Gustav, and Ike—were about $150 billion of damage. And the estimates for Ida back in 2021, last year, was $75 billion. So it's already moved into the top ten list. Next slide.

Louisiana obviously faces major challenges when it comes to sea level rise and its presence on the coast and hurricanes, but also has massive challenges from coastal erosion and land loss. So, due to a combination of rising sea levels as well as sinking or subsiding coastal land and human management of the Mississippi River, the state has lost near about 2,000 square miles of land since the early 20th century. So that's about, like, metropolitan Los Angeles about four times over, for a sense of scale. And this loss continues. So all of these areas you see in red here are estimates of that historical loss from 1927 up to the present day. Next slide.

And in supporting Louisiana and its future planning, myself, along with a number of other scientists who've worked with the state for quite some time, have developed estimates looking forward at how these trends might continue and how the biophysical system itself might change when faced with continued land subsidence and sea level rise. So, looking at different scenarios over time, when we look out over 50 years—these estimates were done back in 2017—we're looking at upwards of 2,000 additional square miles of land loss based on the model estimates. So all the areas you see in red here are areas where you could see additional land loss or land converting to open water. And the green is the little segments that are actually land gain happening in this coastal environment. Next slide.

And this really extends, of course, to flood risk as well. So, in support of Louisiana's master planning, we've also developed some estimates of future flood risk taking into account climate change and these other key trends. So here's an estimate of the 1% annual chance, or 100-year, flood depth for Louisiana that we had developed in 2017, again, in that middle scenario. And you can see that, just, dramatic flood risk, many areas facing over 15 feet of flood depth at the 100-year level, and it extends really far inland in terms of where you'd see significant flood impacts. We're actually currently conducting the analysis to support Louisiana's next phase of master planning, and these estimates, unfortunately, are going up relative to what we saw in 2017. Next slide.

What Louisiana did after 2005 was develop this new office, which is now called the Coastal Protection and Restoration Authority, and mandate that that office develop a 50-year master plan and update that plan on a regular basis. So the first plan—the first of these sort of comprehensive plans—was developed in 2012. 2017 was the first major update to that. And this included a really significant effort towards integrated systems modeling to develop the kinds of maps I showed you previously and understand how the biophysical conditions and the human systems— how these sort of cascading impacts over time might happen. And particularly looking at these long-term trends as well as looking at, you know, discrete hurricanes and disasters. And this also included, with substantial work by myself and other RAND colleagues, a planning framework to sort through a number of different projects intended to support coastal restoration and flood risk reduction to develop the right set that would help to promote the state's goals, reduce flood risk, and achieve what would be a more sustainable coast. Next slide.

Just to give you some sense of what this looks like, when we went through this whole exercise of looking coastwide and looking at a series of different types of land building or restoration projects, if you look at the projects that are in there, they could gain about 802 square miles of land under this median scenario. Now, note that that is less than the 2,000 square miles of land I mentioned previously. So this actually still would indicate land loss over time. And it would build essentially a different coast, a different coastline. So this would not look like the coasts that Louisiana has had in the past. But the goal is to reach something that looks more like equilibrium and build land in key areas and help to keep that ecosystem intact and then have that cascade over into the benefits to human communities, both the benefits from those ecosystems themselves as well as the benefits with respect to the risk reduction and buffering that those ecosystems can provide. Next slide.

And when it comes to flood risk, we saw similar gains, although, again, not an elimination of flood risk, but a reduction. So, those estimates: we estimated about two and a half billion dollars of flood damage in terms of expected annual damage, or that average annual loss, every year under current conditions. But then when you look out at these future scenarios, that increased to over $5 billion 25 years out and over $12 billion 50 years out, again, in kind of this middle scenario. With the projects that were proposed for the master plan in place, that does not go to zero, but was basically stabilized over time and a much less dramatic— or, a reduction in that flood risk by year 25 and a much less dramatic increase over time. So, you see $2.2 billion of flood risk instead of five—over five—in year 25, and then it comes down substantially in that year 50 number. So again, these projects are intended for risk reduction. These things include, you know, levees and other hard protection features, but also significant investments in nonstructural features such as home elevations, structure flood proofing, and structure acquisition. Next slide.

This master plan process, which I'm just sort of touching upon here, really highlights to me the kinds of transformative changes that we need to think about with respect to climate change. It looked at a wide range of projects at a really big spatial scale across the entire state coastline. It was a very comprehensive effort when it came to the analysis and the science that was included in here and obviously had a very considerable component that included local leaders, stakeholders, and other key leaders in the overall planning process. So this included many, many people and lots of input. This is something that is iterative and updated over time and, as I mentioned, is going to be updated for the next master plan, which will be the 2023 Coastal Master Plan. And then, interestingly in a state like Louisiana, the 2012 and then the 2017 Coastal Master Plans were both passed easily by the legislature, the state legislature. So this is something that really has very, very broad support across the state. Even if the politics might be different around the specific drivers, there is much more agreement around the need for transformative adaptation and these major investments in resilience.

And I should also note here, before we move on, that this pattern has actually been picked up by a number of other states. So, the state of Texas has developed a coastal resilience plan. The Commonwealth of Virginia just developed its own coastal resilience plan for the first time. And I know the state of North Carolina is in the process of working towards its first flood resilience blueprint. So this kind of transformative scale of work at the state level is something that other coastal states are picking up and running with. And one of the major advantages to that— of this, of course, is, you know, Louisiana does not have the $50 billion and did not when it prospectively developed this plan in 2012. But this is the kind of plan that is intended to inform a series of investments over time. And obviously, there have been many disasters that have happened in Louisiana since 2012 and even since 2005. But the goal of a plan like this is to direct those various funding streams at the state level and at the federal level towards a common plan that will achieve these kinds of transformative adaptation outcomes. All right, next slide.

I want to briefly also touch on inland and rainfall flood risk. So, we mentioned it previously, so I'll just touch upon this briefly, that we already see— this is, these are estimates from the Fourth National Climate Assessment back in 2017. Looking at historical statistics on the left hand side of this plot, we've seen an increase in the five-year maximum daily precipitation. So, if you look at kind of an extreme level of precipitation, we've seen in the northeast, it's a 27% increase. In the southeast, it's more like a 16% increase across that region. And even if you look at the, essentially, the wettest storm of the year—this 99th percentile here on the right—you see increases that are actually over 50% in the northeast and closer to 25%. And this is just a historical. And we are expecting to see more of this, and actually an acceleration of this, with future climate—at future climate change—and seeing a real increase in the number of these heavy rainfall events. Next slide.

As those of you from FEMA who are on the call today know, Louisiana is very heavily mapped into the federal floodplain. So it has over 26,000 square miles of land mapped into the special flood hazard area, which is actually over half of the state. So, in addition to that coastal flood risk, which you can see here, there are massive portions of the state of Louisiana that are mapped in, as you know, riverine or fluvial, flood risk in other areas. And so they also face significant risk when it comes to river flooding as well as heavy rainfall flooding. Next slide.

Now, this one isn't remembered as much outside of outside of Louisiana. But in 2016, there were a series of major rainfall events that led to massive flooding in both March and August. So across Louisiana, this affected about 145,000 structures were damaged and about 7 trillion gallons of rain—which is a number I can't even begin to fathom—that's actually more than Katrina and Hurricane Isaac combined—dropped. And these massive events—and you can see the scale of what these affected. The March storms were really statewide, whereas the August storms were more focused a little bit closer to the coast and in the Baton Rouge area, but still very, very significant in terms of the widespread impact.

In response to this—next slide—the state decided, similarly to that coastal master planning, that it needed a comprehensive approach to think about watershed planning. Flooding like this does not follow political boundaries, parish, state, etc. These watersheds, as you can see here, cross all sorts of lines. And when you're investing in flood risk reduction, you know, actions in one part of the area can really affect the entire system. Next slide.

What Louisiana thought is, okay, here we have an opportunity. There were recovery funds flowing in from those 2016 floods. This is an opportunity to fundamentally change our approach to flood risk management and look at it proactively and think about it for the first time from the watershed perspective. So not just localities, not just individual projects, but looking at it watershed by watershed across the entire state. And once again, thinking about those recovery funds, the goal here was to come up with a structure and an approach to direct those federal recovery funds, as well as mitigation funds, towards really reducing this risk in the future in a systematic way. Next slide.

That brings us to the present day. So, Louisiana has developed what's called the Louisiana Watershed Initiative, which is a cross-agency consortium that is working right now. This was supported in part, and some of the initial funding for this came through HUD, through the Community Development Block Grant Mitigation funds that were provided to Louisiana after those 2016 floods. And I wanted to highlight just sort of three pieces of the Louisiana Watershed Initiative. Much like the master plan, this includes a major modeling component. So, the state is going out and mapping—doing high-quality, high-resolution maps for every watershed across the entire state and making those available to regional and local officials to be able to use for planning purposes. And then they also want to use all of this new analysis to look systematically at flood risk reduction projects—so, retention, drainage, protection, as well as thinking about acquisition and hazard mitigation investments. And then finally, because so much of the structure of this is different than the the actual political structures we have, Louisiana is also developing a set of the institutional and governance components to look at regional watershed coordination and help to implement, at the state scale, land use practices and building codes to lessen the long-term impacts of future floods. And all of these are important for Louisiana now, but of course will be even more important moving into the future.

And I'll note quickly before I end, I mentioned Louisiana's a bit of a canary in the coal mine here. But these are efforts that we are seeing happening in other states at risk as well. Texas is certainly taking some major efforts. You see it really across Gulf Coast states, a move towards this more systematic planning, investment, and coordination. So, I'm hoping that the positive example here can serve to support other states, and especially as they interact with respective federal agencies. So I will stop there. Thank you.

Jessie Riposo

Thank you so much, Jordan, and the rest of the RAND team. We have a couple of questions and not a lot of time left. So, I think I would like to begin with asking a question about relocating and migration resulting from climate change. And the question is: How much should we be advocating for relocation away from at-risk areas versus investing resources for people to stay where we know there are great risks to infrastructure? So, over to the team. Jordan, do you want to go first?

Jordan R. Fischbach

Sure. I'll be brief. So, this is obviously something that has been a point of focus for Louisiana for some time. We saw a significant migration away from New Orleans, for example, after Hurricane Katrina and a real change in the demographic makeup of the city. But this is a really challenging question—challenging, of course, because of the impact on communities and, like, from the individual household to the community scale, what that looks like. And actually, me and Abbie are complementary here. Like, some of the, you know, the first few community-scale relocation projects that have been supported with federal funds, there were Alaska—indigenous communities in Alaska—and then Isle de Jean Charles in Louisiana. So these are the two areas where we've started to take steps along those lines.

But one of the challenges is, where are people going to go? And from, you know, Katrina, for example, two of the major sort of sinks where people ended up after Katrina were in Houston and actually in St. Tammany Parish on the north shore of Lake Pontchartrain. Well, if you look back at the slides that I shared, St. Tammany Parish is actually a very high flood risk, and it's also a coastal parish. So you have to ask the question of, if there are voluntary relocations, how do you ensure that where people are relocating is actually, truly, a safer area? And are you just, are we sort of shifting from one place to another while still keeping the same basic problem in place? And one couldn't say after Katrina that folks that either chose to relocate or were forced to relocate, ending up in Houston or ending up in St. Tammany Parish, necessarily are less at risk now than they were in 2005 living in New Orleans.

Jessie Riposo

Thank you. Abbie, do you want to go next?

Abbie Tingstad

I would just add to Jordan's fantastic answer that there is not a single answer for that. And as much as it would be, I think, for policymakers, useful to have a single set of guidelines, as Jordan alluded to, it really is in some ways a very community-based decision. And because there are so many important equity issues to consider, it ends up being something that communities need to discuss and understand the implications for them.

Jessie Riposo

Sue? Thank you.

Susan A. Resetar

Yeah, I think my colleagues covered it well. I don't really have much to add. Just—yeah.

Jessie Riposo

Okay. All right. Well, we only have one minute left, and I don't believe that is enough to answer any additional questions. But I want to thank all of the panelists very much for a very interesting discussion today and all of the attendees for taking time out of their busy schedules to come in and learn from the RAND team. So thank you all. And next month we will have another webinar focused on mega disasters, and I look forward to seeing you then. Thank you so much.

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