The future could be bad, or it could be better. You can help decide.

By Ayurella Horn-Muller (Climate Central) and Kenton Gewecke (KOMU 8)

Asthmatics hit hard as pollen growing seasons get longer.

This story was produced through a partnership between Climate Central and KOMU 8 in Columbia, MO.

COLUMBIA - When Sherry Miller moved to Columbia from New Jersey, the heavy pollen in the air here triggered her asthma and sent her to the emergency room three times in a matter of months. In the 14 years since, she says the allergy issues she battles have gotten worse.

“It's one of those things you just wish you could get rid of,” she said. Her once seasonal allergies are now affecting her year-round, and they’ve been intensifying — she’s always on antihistamines now, and has started having more frequent sinus infections, even during the winter.

Miller says pollen is “everywhere.”

“I find that it has become like a layer, that you can scrub all you want,” Miller said. “And as soon as you're done, it's still there.”

High concentrations of pollen can make life miserable for anyone and they're particularly dangerous for the one in eleven residents here who suffer from asthma. An analysis of temperature data by Climate Central shows central Missouri’s plant growing season has increased by a week since 1970 — meaning an additional week every year that pollen is in the air.

Local allergist Laurie Fowler says over the last decade the amount of pollen coating Columbia’s landscapes has noticeably increased, coupled with a growing intensity of seasonal allergy symptoms experienced by her patients.

“I used to tell patients, ‘Oh my gosh, surely next year won't be as bad as this year,’” Fowler said. “I've got to where now I’m saying, ‘It's gonna be worse.’ Because every year, it seems like it's getting worse.”

RISING POLLEN AND RISING TEMPERATURES

A mix of plants, weather and geography affects an area’s pollen count. This matters in a state like Missouri, where you can find many trees and weeds not found in other parts of the country, coupled with long pollen seasons and increased humidity — which promotes plant growth — from the Missouri and Mississippi rivers.

Land use also plays a big role, according to Jennifer Albertine, an environmental studies lecturer at Mount Holyoke College. Albertine led research that found pollen counts from grasses alone could double in the next couple of decades, unless emissions of greenhouse gas pollution are aggressively cut.

“We tend to see higher ragweed pollen loads near agricultural lands, where it is a noxious weed for farmers,” Albertine said. “Ragweed, which is the number one most allergenic plant in the USA, is a great colonizer of disturbed land.”

In a state where farms cover nearly two-thirds of the land, with one of the largest number of farms in the nation, ragweed pollen can run rampant.

In addition to lengthening pollen seasons by warming temperatures, research suggests carbon dioxide pollution is contributing to what Columbia University plant physiologist Lewis Ziska called an increased “allergenicity” of pollen.

With warming temperatures, “We think that there's a good case to be made that the season will be longer, the amount of pollen that you'll be exposed to will be greater, and the allergenicity of that pollen may also increase,” Ziska said.

Ziska was one of the scientists behind a new study that found rising temperatures from human-induced climate change to be the main contributor to recent changes in the timing and increasing length of the pollen season across North America.

AN UNEQUAL BURDEN

Because asthma is more likely to affect residents belonging to low-income, minority communities, allergies caused by pollen are also unequally distributed. Understanding how environmental factors underlie health disparities like these is what Icahn School of Medicine at Mount Sinai professor Rosalind Wright specializes in.

Wright stresses the dangerous impact of climate change on childhood asthma and respiratory health. “It's a very costly disease,” she said. “It's the most common chronic disease of childhood. So the healthcare expenditures that are going to be associated with that are astronomical.”

According to the American College of Allergy, Asthma, and Immunology, more than $18 billion is spent managing allergies every year in the U.S. alone, while the medical cost of asthma is an estimated $3,200 per person, every year. The high costs of treatment mean many patients take less medicine than is needed to keep them healthy.

“The fact that people have to ration their inhaler use is so ridiculous to me,” said Margee Louisias, an instructor in medicine at Harvard Medical School, and the director of diversity and inclusion in the division of allergy and immunology at Brigham and Women’s Hospital.

She says a longer allergy season and higher pollen concentrations will continue to put heavier burdens on the most vulnerable populations, including lower-income and minority communities.

Louisias compares the national asthma prevalence in adults and children of about 10% with asthma rates from 25% to 30% among Black and Latinx populations. That disparity is linked to higher levels of air pollution in those communities from sources like highways, power plants and other industrial facilities.

“We’re seeing a constant, higher concentration of exposure to pollution,” Louisias said. “We're seeing more concentration of exposure to toxins, particularly in these areas that have higher concentrations of Black and Latinx communities.”

The burden of allergies extends beyond the cost of managing them. Local allergist Laurie Fowler says allergies can disrupt everyday life in expensive ways. “They get an ear infection, or bronchitis or pneumonia, or they're sick, or they're missing work, or they're missing school,” she said.

As someone accustomed to suffering from allergic asthma, Sherry Miller misses what it was like over a decade ago, living in New Jersey, when she didn’t have such intense reactions to the pollen in the air around her. But she’s grateful she has the resources to lessen her symptoms.

“I feel badly for people that don't have any medical care,” she said. “They have to end up using the emergency room for their medical [needs], but they're not there to put you on a long term path to getting better.”

By Jodie Fleischer, Katie Leslie, Teneille Gibson, Steve Jones (NBC Washington) and John Upton, Kelly Van Baalen, Allison Kopicki (Climate Central)

To read the complete report, including flood risk analyses for all identified sites, please click here for a downloadable PDF.

A new study shows many of Maryland’s most significant sites from Harriet Tubman’s life are in jeopardy of chronic flooding as sea level rise threatens the Eastern Shore. The News4 I-Team’s Jodie Fleischer reports on the impact as archaeologists rush to unearth more of Tubman’s story before it’s washed away.

This story was produced through a partnership between Climate Central and NBC4 in Washington DC.

As a tour guide on the Eastern Shore’s Harriet Tubman Byway, Alex Green has an up-close view of historic landmarks associated with the iconic abolitionist.

Such as Long Wharf, now a park on the water’s edge of Cambridge, which once served as a hub for the trans-Atlantic slave trade. Stewart’s Canal, a seven-mile logging waterway dug by enslaved and free Black people. And the Bucktown General Store, where a young Tubman sustained a brutal head injury during her first act of defiance against an enslaver. 

“This is African American heritage and history in this area,” said Green, who calls this part of the world “Tubman Country.” “I’ve done tours where people just cry.”

But Green, who has lived in the region for decades, has noticed something changing on those historic sites as the years have passed. The water, he said, “is coming closer and closer.”

Green is well aware that rising seas are affecting communities like his. The seas are rising faster along the mid-Atlantic than in most parts of the world, with the sinking of land from natural forces conspiring with sea level rise from climate-changing pollution to push coastlines inland. 

That's not just threatening communities, roadways and buildings. In this section of coast, it’s threatening historical Tubman treasures.

The science and news group Climate Central used its coastal database to pinpoint risks from rising seas to some of this area’s most precious Tubman landmarks. The group published its findings on Tuesday, showing many of the most significant sites along Maryland's portion of the Tubman Byway are already experiencing or are in jeopardy of chronic flooding from sea level rise. 

Climate Central analyzed 45 sites along the byway, which stretches from Maryland to Delaware, and found 16 of the sites will experience significant flood risk by 2050; 25 of them face such threats by century's end. The report singles out 10 significant places around Dorchester County as likely to face occasional, frequent or chronic risk of flooding this century.

“It's entirely possible that some of the sites are going to be so badly flooded that they really won't be very accessible to the public anymore,” said Karen Florini, the non-profit's vice president for programs, adding: “The main message is that climate change is real, it is serious, there is scientific consensus and there are things to be done.” 

Though about a quarter of Long Wharf Park is already at chronic risk of flooding, the report projects 80 percent of the area will be at chronic risk by 2050.  

The marshes at Stewart’s Canal are already experiencing chronic flooding, too. But it's going to get worse. Climate Central found much of the land around the canal will fall below the high tide line before 2050 and the road leading to it could be at chronic flood risk by the end of this century. 

The study also warns the historic Malone’s Methodist Episcopal Church — founded by free and enslaved Black people in the 1860s — and its nearby cemetery could see almost monthly flooding by 2050. The I-Team observed standing water underneath the church, even on a sunny day. 

“I'm hoping that when we talk about it and people hear us talk about it, they start to realize this is for real,” said Herschel Johnson, a local Tubman historian, of the risk of rising seas to the byway. 

Johnson said it’s not just a crucial part of American history at stake, but a key part of the local economy. He said Tubman, the most famous conductor on the Underground Railroad, helps fuel Dorchester County tourism as people seek to learn more about her history. 

“When people come here just to visit because of Harriet Tubman, they spend money at the restaurants, at the hotels,” he continued. “She's very important.”

The rising water is already posing challenges for archaeologists searching to uncover more of Tubman’s history. 

A team of archaeologists from the Maryland Department of Transportation have been searching federal wetlands since last fall for evidence of her father’s cabin. They’re also digging on nearby private land for the site they believe could be Tubman’s birthplace.

This area “was never very dry, but it has never been as wet as it has today,” said Julie Schablitsky, the chief archaeologist for MDOT’s State Highway Administration. “Because of that, we're in a bit of a race against time to try and rescue these sites.”

Schablitsky, whose team just finished a two week stint digging in the Blackwater National Wildlife Refuge, showed the I-Team a collection of nails, fasteners and brick indicative of an old home site — clues that the scientists could be getting closer to confirming the location of Ben Ross’s homestead. 

“Out of a thousand holes we've excavated, this location seems to be the most likely place for Ben Ross's cabin” Schablitsky said. 

Her team spent weeks sifting through the brackish muck to locate tiny bits of plates, cups, bowls and other housewares, which the scientists will now analyze in their laboratory. 

But rising water, she said, can complicate pinpointing the age of these items. 

“As we dig deeper, things usually get older,” she said. “So it's important that we don't have water coming up into our site because, once that happens, it literally muddies the picture.”

Schablitzsky said rising seas don’t just make it harder to identify artifacts, but harder to access the sites themselves. The current sites are located off of long dirt and gravel roads in flooded woodlands.

“We are in a bit of a rush against time because, even certain times of the year when I'm out here, I can't always access the site,” Schablitsky said.

The U.S. Fish and Wildlife Service acquired the property last fall — part of an effort to preserve the land as well as its potential Tubman history, said Matt Whitbeck, supervisory wildlife biologist for the Chesapeake Marshlands National Wildlife Refuge Complex.

“We knew that there was a lot of potential for this area to have a high value for the Harriet Tubman story, and that added to the value of this property, in particular,” Whitbeck said. 

But he warned this area will eventually become an island as the seas rise. Data from the longest-operating tide gauge in the area, located on the opposite side of the Chesapeake, shows tides are already pushing roughly a foot higher than they did 80 years ago. 

“Blackwater National Wildlife Refuge is a bit of a poster child for the impacts of sea level rise and climate change,” Whitbeck told the News4 I-Team, adding the area has already seen over 5,000 acres of tidal marsh convert to open water.

As evidence of the change, he said visitors who travel the refuge’s Wildlife Drive can look to the south and see a vast area of open water. 

“It's beautiful. But if you understand that, in the ‘30s, when the refuge was established, that was all tidal marsh habitat that's been lost to sea level rise and subsidence,” he told the I-Team. “It's shocking.”

The encroaching saltwater kills the trees in this area where Tubman led people on their journey to freedom, turning lush landscapes into “ghost forests” of brittle, hollowed out trees.  

Green, the tour guide, said people sometimes notice the skeletal trees dotting much of southern Dorchester County. He said he explains saltwater intrusion to them and how it has worsened over the past few decades. 

The trees help tell a greater story about what is at risk because of climate change, he said — a conversation he hopes will fuel more efforts to slow the damage and save what’s possible. 

“There's so much information that has been left out of history that we should try to preserve what we have here now,” Green said. 

 By Ayurella Horn-Muller (Climate Central) and Christopher Gloninger (NBC Boston) and Ale Zimmermann (NBC Boston) contributed reporting

In East Boston, affordable housing units are at risk of flooding as the sea level rises.

This video and text story was produced through a collaboration with NBC Boston.

Roxanne De Jesus remembers seeing the waves spill out of the harbor in East Boston. A nor'easter — that grew in force so suddenly it was dubbed a “bomb cyclone” — pushed tides as high as Boston has seen in nearly a century.

“For the first time, we saw the water come out of the harbor,” she said. 

It was early in 2018 and the storm drove the highest tide she’s seen in 22 years from her home at East Boston’s Shore Plaza East apartments. The building is one of many affordable housing units at growing risk of coastal flooding. De Jesus lives on the second floor and a lack of information about climate change has left her dreading that it could one day flood. She says she can't afford insurance.

“We would start from zero with nothing,” she said. 

Residents of affordable housing units, like De Jesus, face greater risks from rising seas and worsening coastal hazards. That’s because older residential buildings in lower-income communities that provide affordable housing opportunities are usually not fortified against storms or coastal flooding. 

The threats to these buildings are growing, too, as heat trapped by fossil fuel pollution intensifies storms and raises sea levels. An analysis by Climate Central's scientists found that Massachusetts has the third highest number of affordable housing units under threat of coastal flooding in the nation.

As low pressure systems form off the coast, nor’easters can develop with explosive speed when ocean temperatures are high enough. With the waters of the Atlantic warming because of the effects of greenhouse gas pollution, such bomb cyclones pose growing threats.

Defined by the federal government as costing 30% or less of an average local household's income, affordable housing is an already scarce resource, leading to rising rates of homelessness locally and nationwide. It’s one that’s only projected to get worse, as coastal flooding and intensifying storms continue to threaten coastal homes and neighborhoods.

A little more than 1,500 of the state’s affordable housing units are at risk of flood waters reaching their buildings once a year on average, the analysis showed — a figure projected to triple to a little under 5,000 units within 30 years unless steps are taken to protect them. Boston, Quincy and Cambridge have the highest numbers of affordable housing units at risk within Massachusetts, the analysis shows. In thirty years, Boston alone could have more than 3,000 units at risk. 

It’s not just the number of homes at risk from coastal flooding that matters — it’s how often flooding takes place. During the next thirty years, increasingly frequent flooding is expected in coastal cities, creating public safety and maintenance challenges for those living in affordable units. By 2050, more than a quarter of Massachusetts’ affordable housing stock could experience flood events at least four times each year on average.

While residents of coastal cities from Texas to the Carolinas face the gravest flood risks from  tropical systems,  the most damaging storm systems in New England are nor'easters. Holding true to their name, strong winds during these storms buffet the coastline from the northeast. With open water, the surf builds and surges slam into the coast.

Flood events disproportionately impact people of color. Extremely low-income renters are more likely to be Black, Native American, and Latinx residents. Affordable housing is more vulnerable to flooding, as it’s usually built in lower cost neighborhoods with an abundance of paving but few trees and fewer protections from floods, such as seawalls and restored wetland.

When seeking solutions to worsening climate change impacts facing those most vulnerable to them, Carolyn Kousky — executive director at the Wharton Risk Management and Decision Processes Center — suggests looking to the environmental justice movement. The majority of those living in America’s most polluted environments are people of color. 

“We've seen communities of color and low income communities in the past have been saddled with excess risk from pollution, and things like that, and not gotten the safety measures they need,” she said. “We can't let that happen again with climate impact.”

Kousky says part of the solution lies in passing laws that require greater management of risks and preparations for disasters by business owners, requiring insurers and property owners to improve buildings, create evacuation plans and mandate insurance. “These need to be explicitly designed to help low and middle income families afford the disaster insurance and afford the mitigation measures that need to be taken,” she said.

Without these initiatives in place, the most vulnerable people living in the most vulnerable places end up bearing the heaviest consequences from a slew of flood risks — including storm surge, nuisance flooding during high tides and floods from heavy rain. All as the seas get higher.

Dominick Dusseau, a research assistant at the Woodwell Climate Research Center in Falmouth, says that climate change is playing a critical role in the increasing flood risks.

“The eastern part of the United States is going to face a significant amount of sea level rise,” said Dusseau. “By 2050, you're looking at about a foot of sea level rise. In 2100, you're gonna see about three to four feet of sea level rise.” 

In Boston, research shows these higher sea levels mean some low-lying parts of the city could experience at least 43 flood events within the next decade. These cyclones have pummeled Boston at a higher frequency and intensity in recent years, with three striking New England over the course of 10 days in 2018. 

“The real question here is ‘Has climate change created the conditions for those events to happen with greater likelihood?,’ Dusseau said. “And the answer is yes.'”

The Northeastern region appears to be moving into a stormy period, with a nor'easter building that's likely to affect Boston during the first couple days of February. Atmospheric conditions expected resemble those that have brought major flooding in the past, including in early 2018. 

Magdalena Ayed works in East Boston making sure locals know what they’re up against. Ayed is the founder of the Harborkeepers — an organization committed to creating awareness about the climate issues facing the predominantly Latinx communities living in East Boston. 

With almost 60% of the area's residents being nonnative English speakers, language can be the biggest barrier to city-led efforts to share information about climate change. 

De Jesus and her family moved to Boston from Puerto Rico when she was a child. They are among those in the area who feel under-prepared to deal with the consequences of climate change.

“We don’t know what's being done or what kinda help is gonna be available to the community — we don’t know,” she said. “We have to move…We have to start planning, that’s something that we have to start, but we don’t know.” 

It’s this confusion that Ayed and her team work to fix, as they partner with other local organizations to try and engage the community on climate issues. She's also been documenting high tides for the past few years. 

Ayed says the last few years have seen significant change, and it’s causing concern in the area’s waterfront communities. 

“I’ve been working with a lot of the communities in East Boston and a lot of them are vulnerable,” she said. “You see the water encroaching more and more, intense rains and flooding areas that perhaps weren’t normally flooded, and you know it is creating an infrastructure issue.” 

Early last year, Boston’s mayor committed to investing $30 million annually into the city’s climate resiliency in the face of rising sea levels and the growing threat of coastal flood risk. Across the city, streets are being raised, portable metal barriers have been installed around new high-rises, and berms — raised barriers made up of pebbles or sand meant to prevent high-tide flooding — are being built. 

As for those depending on affordable housing, the city’s inclusionary development policy mandates that 13% to 18% of new units qualify as 'affordable.' But there’s no requirement that existing, older units be fortified against climate risks. The diminishing availability of affordable housing in the area is also a factor — during the pandemic and the recession it has caused, Boston’s affordable housing wait lists have been getting longer. 

Ayed thinks the city is increasingly prioritizing strengthening Boston’s ability to withstand flooding and expand affordable housing stock — but that there’s more to be done. 

“When you think about evacuation and helping people adapt or mitigate the impacts in a storm event, that’s a big worry for the people here,” she said. “I’m not so sure that the city is catching up.” 

First published by The Washington Post/Capital Weather Gang (January 12, 2021)

Speed kills.

That’s why firing bullets from a gun is more dangerous than tossing them by hand. Why skydivers use parachutes. Why roads have speed limits. And why it’s critical to understand how quickly human activity will drive the climate to change, compared to past rates. Will we cause gradual shifts that civilization and life on Earth can adapt to—or are we igniting a wildfire that can’t be outrun?

And so it is that scientists trek to frigid Antarctica, to drill deep into its ice sheets and pull out thousands of feet of snow compressed into ice. They carefully date each layer, extract tiny bubbles of ancient atmosphere, and measure the concentration of carbon dioxide, tuner of the planet’s thermostat.

From this hard work, we’ve learned the sawtooth pattern of carbon levels over the past million years. It has shot swiftly up during climbs to past warm intervals a bit like the climate of today, and ramped slowly down into the long ice ages in between them. We can also see the sharp recent increase in carbon dioxide that humans have caused, mainly by burning fossil fuels for energy. The graph used to show this jump is arguably the most iconic figure in climate science.

 

To me, it’s long been the most powerful illustration of climate change’s danger. At a glance, it shows how huge a departure we’ve made from normal. Yet there’s a built-in optical illusion that greatly understates human influence.

Simply put, there’s a lot of time squished between the left and right ends of the plot—almost a million years. The eye can hardly tell the difference between the tiny widths occupied by one hundred versus one thousand years. While the most recent jump in carbon is clearly the tallest and steepest, it doesn’t look that much steeper than many increases that came before it.

But the recent increase is in fact way steeper than any past jump in this record or yet discovered. Steepness is what shows the speed of carbon increase—and speed foretells danger. The faster the climate changes, the less ability society has, along with the ecosystems we depend on, to adapt to the new abnormal.

You can begin to see the difference by zooming in to look at only a small recent fraction of the figure’s timeline. New data from Antarctica have just given us our highest-resolution look yet of carbon dioxide during the last 67,000 years:

Within that period, you can see the slow decline of carbon until Earth reached the coldest point of the last ice age, about 20,000 years ago. Then, for seven to eight thousand years (the period between the arrows), carbon naturally shot up, warming the planet to near its current climate—hospitable for agriculture and civilization.

The sheer spike at the far right, linked to human activity since the Industrial Revolution, is obviously much steeper. The problem is that we needed to zoom way in to see this contrast—but have to zoom way out, like the first figure, for the broader context.

Fortunately, there is a simple way to show the difference in speed of change together with a very long record. That way is to focus on the change in carbon dioxide per period of time, instead of on the level. The result reveals the jaw-dropping carbon skyscraper at the top of this piece.

To my knowledge, this is the first time that the historic carbon record has been depicted in this way. My hope in developing this visualization is to clearly show just how dramatic the human influence has been—and how grave our situation may be.  

Importantly, there is an optimistic side to this coin as well. The speed and scale of human industry can also be applied toward solutions, and today, we have the potential to move quickly to reduce emissions. Through renewable energy and other clean technologies, and with smart policy and the will to act, the world’s nations can shut the carbon floodgates much more swiftly than we pried them open—in a few decades, not centuries.

Perhaps the skyscraper plot hasn’t been tried before because we don’t have direct carbon dioxide readings for the exact years needed. There are gaps in the record: for the whole period shown, scientists have direct measurements once per 400 years or so on average—and about once per 800 years in the older parts of the timeline. Some gaps exceed 2,000 years. The reason the traditional graph looks complete is that a line is drawn between observations, essentially connecting the dots. But from a scientific perspective, that’s not the best way to fill in the gaps.

To improve on that approach, my colleague Scott Kulp used neural networks, a form of artificial intelligence, to construct a continuous curve from the patchy data, shown just below, and allow estimates for any year. The carbon skyscraper is constructed by taking readings from the curve every 1,000 years going back from the present.

The reconstructed curve has a good fit to the data. But the 1,000-year skyscraper still understates our predicament.

Why? Time chunks 1,000 years long can’t capture the speed of the modern carbon jump, almost all of which has taken place in the last century. If we could make a 100-year skyscraper plot, its appearance would be even more stark. It would look a lot like the 1,000-year skyscraper, but with the average change per period—except the last spike—divided by ten, creating an even bigger contrast. Unfortunately, data gaps across most of the record are still too long to put confidence in a reconstruction with a 100-year resolution. Or maybe that is fortunate: the 1,000-year version looks daunting enough. 

One thing is clear at any resolution: humankind is on a crash course with rapid, destabilizing climate changes, unless we can dramatically slow down and stop our pollution of the atmosphere. After that, maybe we can even find a way to put it in reverse.

Detailed method for estimating CO2 levels in past years without data 
Developed and implemented by Scott Kulp, Ph.D., Senior Computational Scientist, Climate Central

For raw data on past CO2 concentrations, we used the Antarctic Ice Cores Revised 800KYr CO2 Data (Bereiter et al. 2015) from the World Data Center for Paleoclimatology, Boulder and the NOAA Paleoclimatology Program, accessed in May 2020. For the period from 8,877 - 67,257 years before present (2020), we swapped in more recent data from the WAIS Divide Ice Core Marine Isotope Stage 3 CO2 record (Brook 2020) at the US Antarctic Program Data Center. 

To predict CO2 concentration based on year, in order to fill in years missing from the direct record, we built a multilayer perceptron artificial neural network, trained on observations based on Antarctic ice sheet core samples from present-day to 800,000 years BP.  There are 1952 such observations, though they are not evenly distributed, with more than half representing points before 100,000 BP.

Neural networks are commonly used for highly nonlinear regression analyses, such as this one. Our neural network contains 4 layers: a 1-node input layer (taking the year as a single input), two hidden layers with 100 and 10 nodes, respectively, and a 1-node output layer (the predicted CO2 concentration).  The model was trained using Matlab's Deep Learning Toolbox, employing the Levenberg-Marquardt backpropagation function. 1854 of the samples were randomly chosen to be used as the training set, 49 were used for the validation set, and the remaining 49 were used as the testing set. The training ran until predictions made with the validation set worsened over 6 consecutive epochs, with the final bias at 0.0025 and root mean square error at 4.0 parts per million (ppm) for the training set, and 0.46/4.19 ppm for the independent testing set. These strong and similar performances between the training and testing sets indicate that the model did not strongly overfit.

We then queried the model to get CO2 level estimates at 1,000 through 800,000 years before present (taken as 2019) at 1,000-year intervals, and used 409 ppm as the present level. The global average was 411 ppm in 2019, but CO2 levels over Antarctica run roughly 2 ppm lower than the global average, so we made an adjustment to account for the fact that the ice core CO2 levels come from Antarctica. Finally, we took differences to compute the change in CO2 for each 1,000 years.

WLRN 91.3 FM | By Ayurella Horn-Muller and Jenny Staletovich

The Villa Maria affordable housing building in Miami Beach | Jenny Staleovich / WLRN News

This story and the accompanying audio segments were produced through a collaboration involving journalists from Southerly, Climate Central and WLRN.

A little over four feet of elevation is all that’s standing between some waterfront neighborhoods winding through Miami Beach and the unrelenting force of the Atlantic Ocean. At Eighth and Washington, where Gregario Lopez, 81, lives in a Section 8 apartment, it’s even less. Lopez has been without regular income since 2010, when a bad fall left him injured and unable to work.

“I can’t afford big rent because my check is not so much,” Lopez said. He’s lived in the same apartment for a decade and has no plans to move. “I cannot pay $600 or $500 or $400, because $400 is almost half what I get.”

Parts 1 & 2 of radio story

A shortage of affordable housing across the U.S. is a growing problem. In South Florida, it's a crisis. The government defines affordable as costing 30% or less of a household's income. In Miami-Dade County, about 60% of renters pay more, and 35% of homeowners spend over 30% of their income on housing. Coastal flooding and strengthening storms are threatening the few pockets of affordable housing.

The 15-floor building where Lopez lives is two blocks from the beach, vulnerable to storm surges and, according to sea level rise projections, built on land that could be underwater by 2090. Lopez likes living near the beach.

“I feel comfortable here,” he said. “It's a close neighborhood and very, very nice people around me.”

But he has seen flooding get worse — and that’s expected to continue making housing like his more expensive to maintain and less viable to inhabit.

Miami Beach has more affordable housing units threatened by rising sea levels during the next 30 years than any other city in Florida, according to a new analysis by scientists at Climate Central.

 

Already, 27 of 317 affordable housing units are exposed to the risk of once-a-year flooding, and by 2050 that's projected to increase tenfold. More than half will face flooding at least four times per year, making it harder for residents to access their homes, ushering corrosive bouts of seawater to the bases of the buildings, and pushing storm surges higher up their walls. Miami Beach ranks 11th in the nation for projected coastal flood risks facing affordable housing units in 2050, while Florida’s affordable housing stock ranks fifth among the states.

As the city continues to expand, economic risks that put those housing units at jeopardy are growing with it. It’s a threat policymakers, activists, and residents say they are taking seriously. Nonprofits and city planners are working to create more affordable housing, but they’re up against legislation that rewards rampant development.

“I personally believe that housing is a human right and that people should have access to affordable housing,” said Zelalem Adefris, the vice president of policy and advocacy at Catalyst Miami, an organization that serves low-wealth communities in Miami-Dade County.

The COVID-19 pandemic, which caused an unemployment crisis across the state that left 2.7 million Floridians jobless, has increased the demand for the nonprofit's services.

“Any time there's an economic crisis, I think rent is probably the biggest single cost,” said Adefris. “We've definitely seen a lot of people on the beach and elsewhere looking for housing, worried they are going to get evicted.”

Residents have been vocal about flood risks they face and changes needed to keep them safe.

“Residents want the updates, they want the building to be safe,” said Ranata Reeder, executive director of the nonprofit South Florida Community Development Corporation. “They want their property to be safe. If they're living there, it's their home.”

Affordable housing spans a wide array of housing options targeted to low income households. This includes everything from privately owned subsidized housing, which is managed by the federal Department of Housing and Urban Development, or HUD, to Section 8 housing choice vouchers and public housing, or units available for rent below market rates. Federal and state governments, as well as some municipalities, subsidize rents in many buildings to provide units of affordable housing, often through these vouchers. But the number of families who are eligible usually far exceeds the number of vouchers and units available.

Affordable housing eligibility is determined by the median income of an area and is adjusted for the size of the household. In Miami-Dade County, where 48% of households are renters, the median income is $17,730. The demand for housing that costs a household less than 30% of income persists throughout the county, which has the highest number of low-income households in the state.

According to data from the Miami Affordability Project, a tool developed by the University of Miami, that tracks the entire inventory of affordable housing in South Florida, Miami Beach administers just over 3,000 subsidized units. Only 200 of these are public housing.

Much of that housing stock is older and not well suited to a region that floods more than it used to. More than half of the city’s units were built in the 1950s or earlier; most are low-rise, garden-style and much more vulnerable to flooding than high-rise buildings. Miami Beach has 21 affordable housing properties that receive federal funding; 3,310 residents reportedly use vouchers from the housing authority that cover a portion of rent costs. But there’s little money for upgrades or updates. Five of the 21 will lose their federal funding between 2022 and 2024 when subsidies expire.

Elderly residents make up most of the tenants in affordable housing units, according to the Miami Affordability Project. About 70% report having a disability. According to the city, about 91% of all voucher households are headed by people of color.

“Low-income families unfortunately find themselves in situations where they have to prioritize food or health care or transportation over floodplain location,” said Michelle Meyer, Director of the Hazard Reduction and Recovery Center and assistant professor at Texas A&M University. “Right now we are working from a framework where we do not have enough affordable housing pre-disaster.”

That means when there is a hurricane or significant flooding, low-income households are often the last to recover. Affordable housing often isn't rebuilt. In the wake of a storm, affordable rental units can also become scarce, as workers arrive to help rebuild and displaced families who've lost homes temporarily move in, driving up rental rates.

Meyer says strong incentives for developers from federally-funded programs to focus on low-to-moderate income people don’t seem to make much of a difference.

“If we don't start addressing our extreme inequities and unaffordability or affordability of housing in our communities, then we're on our way to a trainwreck,” Meyer said.

Longtime shortages — especially in the South

Across the U.S., the number of people who live in affordable housing is growing smaller every year. In 2019, more than 18 million households — 1 in 6 — spent more than half of their family income on housing.

Harvard’s Joint Center for Housing Studies published a 2019 report concluding that 31.5% of all U.S. households were paying more than 30% of their incomes on housing. In Miami, those numbers are even higher: 57% percent of Miami’s 94,638 households spend more than 30% of their income on housing, while more than 33% of 39,112 renter households pay more than half their income on rent.

The pandemic has made this harder on urban and rural areas, and it’s also hit city budgets hard. Experts predict there will be long-lasting effects on funding for improving the supplies of affordable housing, exacerbating problems caused by a history of racist policies. These include certain tax programs and redlining policies, which have contributed to economic inequality, particularly for Black and Latinx families.

A University of Minnesota study on economic segregation and gentrification found a pattern of growing poverty in the suburbs, especially in Southern states. And a National Low Income Housing Coalition study on racial disparities among renters found that 20% of Black households make 30% of their area’s median income or less. People of color are also more likely to rent, according to a 2017 Harvard paper.

With the exception of Virginia, every state government in the South prevents local governments from implementing rent control laws, according to the organization Local Solutions Support Center. Florida, Tennessee, and Texas have preemption housing laws that prohibit a requirement for new developments to include a percentage of units that are affordably priced.

Miami-Dade County has long struggled with an affordable housing shortage — made all the worse by the economic crisis of 2008, when many lost their homes or significant amounts of equity in their properties. When the market bounced back, wages failed to keep pace.

“You have a combination of the biggest population, the most renter households, expensive real estate and a lot of relatively low-wage jobs,” said Anne Ray, manager of the Florida Housing Data Clearinghouse at the University of Florida's Shimberg Center for Housing Studies. Founded in 1988 by the state legislature, the program provides county-by-county data on housing cost burdens.

The center’s data shows that Florida currently has a stock of 300,000 affordable rental housing units, 30,000 of which are for assisted living. The vast majority of Florida’s affordable housing stock are vouchers, according to Ray. She said Florida, and South Florida in particular, is failing to meet affordable housing needs.

A sign outside the Villa Maria building in Miami Beach | Jenny Staletovich

This has been a problem for decades, and over the past six months, county officials have spearheaded one of the largest renovations of a public housing development in the county’s history. This project follows Miami’s Affordable Housing Master Plan that proposes launching a bank to fund affordable housing builds and incentivizing the development of thousands of new properties annually for a decade. Success will depend on city commissioners’ buy-in, which has stalled for almost a year.

Ahmed Martin, executive director of the Miami Beach Community Redevelopment Corporation, a housing nonprofit, said they have 323 affordable housing units in the area, with only 16 vacancies. Their waiting list currently sits at 500 people. Thousands applied for public housing, low-income housing, and Section 8 housing choice vouchers during the city’s last application opening —almost a year and a half ago.

Advocates say COVID-19 makes the situation even more urgent.

“After this last year, the need is going to be greater,” said Adefris, of Catalyst Miami.

Gearing up for the flooding to come

Though Miami Beach saw no major damage from hurricanes this season, high tide and storm surge flooding is already a major problem. In November, Hurricane Eta submerged streets, keeping some residents confined to their homes for several days.

The Intergovernmental Panel on Climate Change last year warned that Miami, Key West and other places in Florida could see what previously were considered 100-year flood events occurring yearly within three decades.

Coastal flooding — which includes compound flooding, high-tide flooding and increasingly destructive storm surges — is also on track to intensify, according to Dr. Thomas Wahl, civil engineering and sea level rise scientist and professor at the University of Central Florida.

“If you think about a kid in the bathtub, it plays around, and if there’s only a little bit of water in the bathtub, we won't see much inundation in our bathroom,” Wahl said. “But what sea level rise is doing is it just fills up the bathtub. And even if the kid doesn’t play around more or is more active, you will now see a lot more water on the floor.”

Florida has a history entrenched with battling the effects of climate change, as hurricane seasons have brought increasingly frequent and intense storms. Renters, who tend to have lower incomes than homeowners, are disproportionately impacted by disasters like hurricanes and floods, said Dr. Christopher Emrich, a hazard vulnerability researcher at the University of Central Florida.

Hurricane Irma destroyed nearly a quarter of the housing in the Florida Keys, including most of the area’s 7,500 mobile homes. A year later, thousands of people left Bay County after Hurricane Michael damaged three quarters of the area’s households. Rents rose in an area where 40% of the population were renters; 22,000 residents were left homeless in the weeks following the storm.

“One of the biggest things that the low-income housing community faces is that they are often not in control before, during or after a disaster,” Emrich said. “After disasters, they often have to start over, they often don't have adequate insurance coverage. So they're really susceptible to environmental hazards, including sea level rise.”

Earlier this year, a plan to add 1,300 affordable housing units to the Keys inched forward, but still faces state approval. In Bay County, on the Panhandle, construction has not yet begun on hundreds of subsidized, low-income housing complexes.

For Miami Beach to avoid a similar fate, existing and new affordable housing units need to be fortified against extreme weather and rising water levels — both fueled by climate-warming pollution.

Hurdles to adaptation and renovation

Miami Beach also shares a problem with the Keys: it's a barrier island that needs to evacuate quickly, so there are limits on density.

“You just simply cannot have highly dense areas within areas that are coastal high hazard areas,” said Miami Beach planning director Tom Mooney.

Finding the space to build affordably is also a challenge, he said. Some of the city’s affordable housing buildings are in historic districts, which have strict building codes, and replacing vulnerable two-story buildings with higher, more resilient structures can drive up costs and rents.

According to Mooney, that means developers need to adapt, and not replace, the buildings. His team has linked up with architects and preservationists to help property owners keep older affordable housing buildings, while making them more sustainable and climate resilient. The project is still in early planning stages.

Progress is gradually moving forward. The city is drafting new codes informed by climate science that will regulate where developers can build. However, Florida lawmakers — many of whom are Republican, and some who have denied climate science — are making this process more difficult. Last year, state legislators banned local governments from requiring developers to include workforce housing in projects or keep rents on some units lower, even as rents keep rising in Miami Beach and other areas around the state.

It’s even worse for those living in what developers may deem premium elevation areas — where rising rents mean low-income residents are being priced out of neighborhoods they’ve long called home, a trend often called “climate gentrification.”

Little Haiti and Liberty City — working-class, mostly Black and immigrant neighborhoods — are experiencing an unprecedented building boom. For instance, a billion-dollar project called the Magic City Innovation District is bringing luxury high rises, co-working sites and hotels to Little Haiti. The predominantly Black, low-income residents are being priced out: Since 2016, home values have increased by about 19%.

Former Miami Beach mayor Matti Herrera Bower said this is a widespread problem.

“Wealthy people can afford to live there while it’s good and move on once it gets bad. Whereas people with lower income, that’s the problem. They get shifted from place to place to place, and they get uprooted and don’t have a safety net,” Bower said. “It may be that Miami Beach becomes more affordable again as flooding gets worse.”

Bower, who sits on the board of the Miami Beach Housing Authority, has been a longtime advocate for affordable housing. She led the city from 2007 through 2013, and worked to preserve the Art Deco District and the Miami Beach Community Redevelopment Corporation.

Villa Matti, an affordable housing development constructed during Bower’s time in office, was named after her. It houses one of the units facing future coastal flooding identified in Climate Central research.

The Villa Matti affordable housing building in Miami Beach. | Jenny Staletovich

“To say that the rising sea level is the one that is killing affordable housing, I think is incorrect,” Bower said. “What happens is they're using that to say ‘we need to tear down to build new,’ and then they get condominiums and get more and more higher rent or a higher price for the condominium. And that is what is happening now.”

While federal tax credits and state subsidies help persuade developers and private property owners to build affordable housing, the actual cost isn't always so affordable. Projects can require upfront capital. And developers depend on loans or other sources of money to pay for construction that often require revenues to match costs for approval. Ensuring buildings are flood proof can be event more expensive: Elevating a single-family home can cost $100,000 or more.

Several local officials and advocates said regulation on development in South Florida is key to preventing this from happening in other areas.

“I don't know if we'll ever be able to get ahead of it [affordable housing demand],” said Miami Beach resilience chief Amy Knowles. “[But] I think that as we make improvements to our regulations into our buildings to address vulnerability from climate change, we can do the same thing for workforce and affordable housing.”

'We just need to increase the supply'

Sara Haas is trying to take a grassroots, practical approach. Haas manages Enterprise Community Partners’ Keep Safe Miami program, an initiative in partnership with the South Florida Community Development Coalition and the Florida Housing Coalition. She and her team are preparing to audit properties for climate change risks.

“If they come to the table beforehand, and think about disaster recovery holistically with affordable housing at the forefront, or with the thought that there are vulnerable populations that need to be probably given better protections? That would really make a change,” Haas said.

The pilot launches next year. They're hoping to get 75 property owners to sign up and, if it works, they aim to expand. It’s a step in the right direction for South Florida, but on its own, it’s not enough.

Anne Ray, the Florida Housing Coalition board member and University of Florida housing researcher, says the responsibility to create more resilient affordable housing falls to local and state legislators.

“We know how to create affordable housing. We do it all the time,” Ray said. “You don't need to develop a new vaccine or put a man on the moon. We just need to increase the supply of affordable housing.”
 

Ayurella Horn-Muller is a freelance reporter and regular Climate Central correspondent, based in Florida.
Jenny Staletovich is WLRN's environment reporter.

Recursos Relacionados Resumen de este informe Artículo científico detrás de este informe La herramienta impresa Hojas de datos estatales

RESUMEN EJECUTIVO

• Un nuevo análisis realizado por científicos de Climate Central y publicado en Environmental Research Letters destaca las implicaciones sobre la equidad del aumento del nivel del mar en la primera evaluación nacional de riesgo a la oferta de viviendas asequibles del país.
• Se espera que el número de unidades de vivienda asequible en riesgo de inundaciones costeras y el aumento del nivel del mar se triplique en las próximas tres décadas.
• Para 2050 se espera que prácticamente todos los estados costeros tengan al menos algunas viviendas asequibles expuestas a más de un “evento de riesgo de inundación costera” por año, en promedio, partiendo desde aproximadamente la mitad de los estados costeros en el año 2000. (Un evento de riesgo de inundación ocurre cuando los niveles de agua costera local alcanzan más alto que la elevación del suelo de un edificio, y cualquier barrera conocida no brinda protección completa).
• Nueva Jersey, Nueva York y Massachusetts tienen la mayor proporción de viviendas asequibles y número de unidades en riesgo; las proyecciones para la ciudad de Nueva York, Atlantic City y Boston muestran que cada ciudad podría tener miles de unidades expuestas a inundaciones costeras crónicas para el año 2050.
• Climate Central ha introducido una nueva herramienta de mapeo interactivo en línea que muestra la vulnerabilidad de las viviendas asequibles al riesgo de inundaciones costeras ahora y en el futuro.

U  na vivienda asequible sirve como un salvavidas para millones de personas y familias en los Estados Unidos. Se sabe que las viviendas estables y seguras respaldan un mejor estado de salud, movilidad económica y empleabilidad. Pero hay una grave escasez de viviendas asequibles o disponibles para inquilinos de bajos ingresos. Los científicos de Climate Central analizaron el riesgo que las inundaciones costeras representan para las viviendas asequibles, tanto subvencionadas como no subvencionadas, a medida que aumenta el nivel del mar. Descubrieron que más de 7.600 apartamentos, casas adosadas y viviendas unifamiliares en todo el país están actualmente expuestos a al menos un “evento de riesgo de inundación costera” en un año típico, y más de 24.500 unidades pueden estar amenazadas para el 2050.

La combinación de la vulnerabilidad física de una vivienda asequible, la vulnerabilidad socioeconómica y las inundaciones más frecuentes debido al aumento del nivel del mar presenta una triple amenaza en los próximos 30 años para los residentes y propietarios de las ya escasas viviendas asequibles del país.

Estimación de unidades de vivienda asequibles en el área de Boston en riesgo en 2050 si la contaminación climática global anual continúa al ritmo actual (RCP 8.5) por el Distrito Legislativo de la Cámara de Representantes. Ver https://coastal.climatecentral.org​​​​​

El cambio climático aflige cada vez más a las comunidades más vulnerables

La frecuencia de las inundaciones costeras ha aumentado considerablemente en las últimas décadas debido al calentamiento del planeta. El aumento del nivel del mar seguirá agravando en los próximos años tanto las inundaciones causadas por las mareas (también llamadas inundaciones crónicas) como las inundaciones causadas por fenómenos meteorológicos extremos. Para el 2050, con emisiones de carbono no controladas, el nivel de inundación de 100 años (o el nivel de inundación con una probabilidad anual del 1% de que ocurra, lo cual define la llanura aluvial), podría ocurrir al menos 40 veces más a menudo en la mitad de las ubicaciones de EE. UU. estudiadas. Las inundaciones por marea que ahora ocurren una vez al año pueden ocurrir semanalmente en algunas comunidades costeras.

De particular preocupación es la exposición de viviendas que se consideran asequibles para familias de bajos ingresos: viviendas que están subvencionadas por el gobierno federal o que son “naturales”, lo que significa que no están subvencionadas pero se alquilan por debajo de las tasas del mercado local o por menos del 30% de los ingresos familiares medios locales. Esta vivienda es un recurso extremadamente escaso en todo el país. A nivel nacional, se estima que hay solo 35 unidades de alquiler asequibles disponibles por cada 100 inquilinos de ingresos extremadamente bajos, un déficit nacional de más de 7 millones de unidades. Estos immuebles también son particularmente vulnerables a las inundaciones, ya que las viviendas asequibles tienden a ser más antiguas y rara vez están equipadas con características que mejoren la resiliencia (como a prueba de inundaciones, energía fuera de la red o válvulas de remanso), debido al costo de tales medidas. Además, los residentes de viviendas asequibles a menudo carecen de los recursos financieros para reparar, reconstruir o retirarse de su vivienda después de que haya sido dañada por las inundaciones. 

Las viviendas asequibles dañadas por inundaciones pueden tener consecuencias a largo plazo para los residentes, propietarios y comunidades, incluido el aumento de la falta de vivienda, la pérdida de ingresos por alquiler que pueden dificultar que los propietarios de viviendas proporcionen viviendas asequibles y recesiones económicas a nivel de vecindario. 

Nuevas formas de medir el riesgo para las viviendas asequibles

Los científicos de Climate Central tenían como objetivo cuantificar el riesgo actual y futuro de inundaciones costeras al inventario de viviendas asequibles de la nación para que los interesados locales, estatales y federales pudieran comprender la exposición general de este recurso ya escaso. Al centrarse en el año 2050, el análisis revela las amenazas que podrían afectar a los residentes y brinda a las partes interesadas la oportunidad de planificar mayor resiliencia.

Este estudio en varias maneras representa un avance sobre los métodos anteriores para caracterizar los impactos de las inundaciones costeras y el aumento del nivel del mar. Utilizando datos de alta resolución, utiliza huellas de edificios individuales y evalúa las amenazas que se integran a través de una amplia gama de posibles cantidades de aumento del nivel del mar y la gravedad de las inundaciones encima de ellas, en lugar de elegir una pequeña cantidad de escenarios (más detalles disponibles en el estudio original).

La información se recopiló de la Base de Datos Nacional para la Preservación de la Vivienda de los edificios de viviendas asequibles subsidiados por el gobierno federal. Los datos sobre viviendas asequibles de origen natural o no subvencionadas se recopilaron a través del Sistema de Clasificación de Edificios CoStar (consulte Terminología).

Estimación de unidades de vivienda asequibles en Nueva Jersey en riesgo para 2050, si la contaminación climática global anual continúa al ritmo actual (RCP 8.5) por condado. Ver https://coastal.climatecentral.org​​​​​

Hallazgos: Miles de unidades están en riesgo ahora, y ese número se multiplicará durante las próximas tres décadas.​​​​​​

Utilizando el año 2000 como base para la comparación con los riesgos futuros, el análisis muestra que 7.668 unidades de vivienda asequible fueron expuestas recientemente al riesgo de inundación al menos anualmente en los Estados Unidos. Nueva Jersey tiene el mayor número de unidades y porcentaje de su abastecimiento de viviendas asequibles expuesto, seguido de Nueva York y Massachusetts. Muchas menos unidades están en riesgo en California, pero estas unidades enfrentan un alto riesgo de repetidas inundaciones, similar a las viviendas asequibles en Maine, Maryland, Alabama y Texas.

Para el 2050, bajo un escenario continuo de altas emisiones de carbono, el riesgo aumenta significativamente, con el número total de unidades de vivienda asequible expuestas anualmente más que triplicando a 24.519 unidades. Nueva Jersey podría ver casi 7.000 unidades expuestas, un aumento de cuatro veces; y Nueva York y Massachusetts seguirían figurando entre los tres estados principales en cuanto al número absoluto y relativo de unidades expuestas. Pensilvania (792%), Florida (774%) y Carolina del Sur (669%) enfrentan el mayor aumento porcentual sobre la línea de base de 2000 en unidades expuestas.

Los investigadores también clasificaron las 20 ciudades principales en términos de número anual de unidades expuestas para 2050. Estas 20 ciudades representan tres cuartas partes de todas las unidades de vivienda asequibles en riesgo de inundaciones costeras en los Estados Unidos, lo que demuestra que el riesgo de inundaciones costeras está altamente concentrado. Las ciudades del noreste y California son las más vulnerables, y la ciudad de Nueva York sigue siendo la más expuesta, con más de 4.000 unidades en riesgo por año para 2050. Cinco ciudades de Nueva Jersey se ubicaron entre las 20 principales, cuatro de las cuales (Atlantic City, Camden, Penns Grove y Salem) se encuentran entre las áreas urbanas más pobres del país, con un ingreso familiar promedio de sólo $28.618 (en dólares de 2018). En varias ciudades, más de la mitad del inventario de viviendas asequibles está en riesgo para 2050, incluidas Foster City, California (100%), Crisfield, Md. (92%), Hoquiam, Washington (72%) y Atlantic City (52%).

TABLA 1 - Unidades de vivienda asequibles en riesgo ahora y en 2050, en un escenario de altas emisiones de carbono (RCP 8,5)

Estado	Número anticipado de unidades expuestas por año, referencia a una base del año 2000	Número anticipado de unidades expuestas por año en 2050
Alabama	59	64
California	526	738
Connecticut	156	695
Delaware	60	78
Washington D.C.	69	90
Florida	110	963
Georgia	149	151
Hawaii	0	2
Louisiana	214	685
Maine	126	150
Massachusetts	1,530	4,817
Mississippi	32	56
New Hampshire	29	215
Nueva Jersey	1,640	6,825
Nueva York	1,574	5,293
Carolina del Norte	185	435
Oregon	20	52
Pennsylvania	20	175
Rhode Island	2	4
Carolina del Sur	62	474
Texas	200	332
Virginia	395	1,473
Washington	258	385
EE.UU.	7,669	24,518

Consulte la herramienta impresa y en línea para obtener un análisis más detallado de la exposición futura a múltiples eventos de riesgo de inundaciones por año.

TABLA 2 - Amenaza futura de inundaciones costeras para las 20 principales ciudades expuestas (en términos absolutos) para 2050, en un escenario de altas emisiones de carbono (RCP 8,5)

Ciudad	Número anticipado de unidades expuestas por año en 2050	Porcentaje de viviendas asequibles en la ciudad
New York, NY	4,774	1.3%
Portsmouth, VA	220	3.6%
Boston, MA	3,042	4.0%
Charleston, SC	349	5.5%
Stamford, CT	337	6.2%
Camden, NJ	632	6.7%
Norfolk, VA	710	6.7%
Cambridge, MA	510	7.7%
Quincy, MA	668	11.7%
Miami Beach, FL	317	22.8%
Revere, MA	266	23.5%
Salem, NJ	208	30.3%
Penns Grove, NJ	222	32.5%
Hoboken, NJ	1,118	38.6%
Stamford, CT	217	42.2%
Freeport, NY	275	43.9%
Atlantic City, NJ	3,167	52.1%
Hoquiam, WA	220	71.7%
Crisfield, MD	283	91.8%
Foster City, CA*	279	100%

*La exposición puede ser exagerada en Foster City, CA, donde es posible que no se hayan incluido nuevos diques en un inventario nacional de diques utilizado en el análisis. Consulte el documento para obtener más detalles.

Conclusión

“Una marea que sube eleva a todos los barcos” es una frase que se usa para articular la idea de que una economía próspera beneficiará a todos sus participantes. Pero las mareas crecientes impulsadas por el calentamiento global están aumentando las amenazas de inundaciones para miles de residentes en comunidades y vecindarios de bajos ingresos. Las inundaciones pueden causar estragos en las edificaciones y los residentes que viven en ellas, amenazando la salud pública y causando graves trastornos a las familias que luchan por llegar a fin de mes. Las inundaciones crónicas también pueden dañar automóviles e impedir que los residentes vayan a trabajar, a la escuela, o buscar atención médica.

Entender bien la exposición actual y futura de las viviendas asequibles a eventos de riesgo de inundaciones, incluyendo la cantidad de unidades que podrían verse afectadas y con qué frecuencia, puede respaldar la planificación estratégica de la resiliencia. En las ciudades y estados con las mayores amenazas, las medidas de reducción de la amenaza de inundaciones, como la remodelación de edificios o la protección contra inundaciones, y las políticas reguladoras del uso de terrenos son herramientas para que las partes interesadas protejan el inventario de viviendas asequibles y las vidas y los medios de subsistencia de quienes ahí viven.

Mejora de la resiliencia en viviendas asequibles​​​​​​​ A través de nuestra asociación con National Housing Trust, Climate Central entrevistó a coaliciones y organizaciones sin fines de lucro enfocadas en viviendas asequibles sobre los pasos que están tomando para hacer que las viviendas asequibles sean más resistentes a las inundaciones costeras. A continuación, se muestran algunos ejemplos de algunas de las soluciones de adaptación climática que están implementando las organizaciones de vivienda en los estados costeros. Coalición de Vivienda de Florida. El cuarenta por ciento de todos los huracanes de EE. UU. han tocado tierra en Florida. Desde 1851, más de 120 huracanes han azotado ahí, más que en cualquier otro estado. Frente a esta realidad, la Coalición de Vivienda de Florida, una organización de membresía en todo el estado para los interesados en viviendas asequibles, tiene un empleado que se enfoca exclusivamente en la resiliencia y la recuperación. Organizan un seminario web semanal de una hora para sus miembros sobre huracanes y han desarrollado conjuntos de herramientas para la gestión de desastres y las estrategias de recuperación de desastres de viviendas locales. Socios de la comunidad empresarial. Enterprise Community Partners, una organización nacional sin fines de lucro enfocada en aumentar la oferta de viviendas asequibles ha creado una herramienta en línea que permite a los propietarios, operadores y desarrolladores de viviendas asequibles identificar propiedades en riesgo de desastres climáticos como inundaciones e incendios forestales. Enterprise también colaboró con una serie de socios para producir una guía que ayude a dar forma a la construcción y modernización de viviendas en Puerto Rico, las Islas Vírgenes de los Estados Unidos y los Cayos de Florida. Su guía Keep Safe ofrece formas de hacer que las casas que se reconstruyen después de grandes tormentas sean más resistentes a huracanes, terremotos e inundaciones. New Ecology. New Ecology es una organización sin fines de lucro que promueve la construcción sostenible y las prácticas de modernización, incluida la eficiencia energética, la energía renovable y la resiliencia, con un enfoque en las poblaciones desatendidas. Han desarrollado un sistema de auditoría para la evaluación de resiliencia diseñado para desarrolladores y propietarios de viviendas multifamiliares o de bajos ingresos. New Ecology evaluó Villages of East River, un complejo de viviendas asequibles de 202 unidades en Anacostia, Washington DC para una variedad de peligros climáticos, incluidos huracanes, inundaciones, hielo, nieve y eventos extremos de calor y frío, así como el potencial para la eficiencia energética y del agua. Las recomendaciones de la auditoría incluyeron elevar el equipo de calefacción y enfriamiento HVAC, planificar la gestión de aguas pluviales y mejoras de eficiencia energética. Energy Efficiency for All. Energy Efficiency for All (EEFA) es una organización sin fines de lucro que conecta el clima, la salud y la equidad, y trabaja para llevar la eficiencia energética a viviendas multifamiliares y asequibles a través de coaliciones en 12 estados.

Terminología

Un evento de riesgo de inundación costera en un edificio se define como un día en el que los niveles de agua costera local se elevan por encima del punto más bajo de la elevación del suelo del edificio. Diferentes combinaciones de mareas, marejadas ciclónicas y aumento del nivel del mar impulsan estos niveles de agua. Un evento se cuenta sólo cuando un edificio está hidrológicamente conectado a la costa al nivel del agua alcanzado; en otras palabras, se sabe que las barreras como las crestas o diques no protegerán la edificación a ese nivel.

El hecho de que ocurra realmente una inundación también depende de otros factores, como cuánto sube el agua, cuánto tiempo permanece alta, qué tan cerca está el edificio de la costa, qué tan difícil es el terreno y detalles meteorológicos como la fuerza del viento y dirección y cantidad de lluvia, si la hay, y qué tan lejos llegan las inundaciones tierra adentro durante una marea alta o tormenta en particular.

La exposición anual estimada denota el número promedio de unidades de vivienda asequibles en un área determinada expuestas a inundaciones costeras en un año típico. Esto proporciona recuentos de la cantidad de unidades que podrían potencialmente inundarse en función de las elevaciones del agua y el suelo, no predicciones de cuántas unidades se inundarán realmente, lo que también depende de los mismos factores que distinguen las inundaciones reales de los eventos de riesgo de inundación.

Los datos de existencias de viviendas asequibles subvencionadas que se utilizan en este análisis provienen de un conjunto de datos completo de edificios de viviendas asequibles subvencionados por el gobierno federal a noviembre de 2018. Esos datos se recopilaron a través de la Base de datos nacional para la preservación de la vivienda, administrada por la Corporación de Investigación de Vivienda Pública y Asequible y la Coalición Nacional de Vivienda para Personas con Bajos Ingresos, y analizado por el Fideicomiso Nacional de Vivienda (NHT, por sus siglas en inglés). Para los propósitos de este análisis, cualquier vivienda respaldada por cualquier programa federal se considera subvencionada; También se incluyen las viviendas subvencionadas por subvenciones conocidas financiadas por el estado (estas viviendas constituyen el 2% de la Base de Datos Nacional para la Conservación de Viviendas).

La vivienda asequible de origen natural o normales incluye apartamentos o casas que se alquilan a niveles inferiores a las tarifas de alquiler del mercado medio local sin subsidios, y se identificaron a través del Sistema Nacional de Calificación de Edificios CoStar, que califica las propiedades inmobiliarias comerciales.

Methodología

Se evaluó la huella de cada edificio de viviendas asequibles para determinar la probabilidad anual de experimentar al menos un evento de riesgo de inundación costera en un año determinado. Las proyecciones de aumento del nivel del mar se basaron en Kopp et al. 2014, y las estadísticas de riesgo de inundaciones costeras se basaron en Tebaldi et al. 2012. Estas probabilidades a nivel de edificio se integraron para estimar la exposición anual total anticipada a nivel de código postal, ciudad, condado y estado. Para obtener más detalles, consulte el documento en línea. Para explorar la vulnerabilidad de la vivienda asequible dada una variedad de proyecciones de aumento del nivel del mar y eventos de marejada ciclónica, consulte la herramienta en línea.

 

Climate Central es una organización independiente de científicos y periodistas líderes que investigan y reportan los hechos sobre nuestro clima cambiante y su impacto en el público. El programa de Climate Central sobre el aumento del nivel del mar proporciona información precisa, clara y granular sobre el aumento del nivel del mar y los peligros de inundaciones costeras tanto a nivel local como mundial, hoy y mañana. Ofrecemos mapas y herramientas fáciles de usar, conjuntos de datos y presentaciones visuales de alta calidad.

By Ayurella Horn-Muller (Climate Central), Avalon Zoppo (NJ Advance Media for NJ.com) and Michael Sol Warren (NJ Advance Media for NJ.com)

Residents of affordable housing in New Jersey, like the Walter J. Buzby Homes in Atlantic City, face mounting risk of flood damage due to climate change and decades of policies placing low-income homes in harm's way. Joe Warner | For NJ Advance Media

This story was produced through a collaboration between Climate Central and NJ Advance Media, which publishes NJ.com and a number of newspapers across New Jersey including the Newark Star-Ledger and the Times of Trenton.

When Hurricane Sandy hit Atlantic City in 2012, floodwaters swept up to the second step of the buildings at Julissa Carmona’s apartment complex, wrecking the Honda she had parked on the street.

Carmona had to dig deep for $2,800 to buy a Jeep, a vehicle better suited for rising tides. It was a financial hit for the 49-year-old casino worker, whose affordable housing complex sits beside an expansive, swampy-smelling marsh on the island’s bayside.

“Sometimes I wish I could move to another state where there’s no water around,” she said.

The water is a constant, creeping threat in Atlantic City, where the sea level rise has caused an increase in sunny day flooding. These days, it only takes a particularly high tide, which reaches more than a foot higher than it did a century ago, for water to spill onto the city’s streets.

As many as 1,640 affordable housing units in New Jersey are vulnerable to coastal flooding at least once per year, according to an analysis led by scientists at Climate Central, a Princeton-based non-advocacy research and news group.

That number, which is about 1% of the state’s affordable housing stock, is the highest of any state in the nation.

It’s also expected to get worse.

Sea levels are rising as Earth’s climate changes, a phenomenon driven by the heat-trapping effects of fossil fuel pollution. New Jersey has experienced sea level rise at about twice the global average, because much of the state’s land is sinking at the same time. Beyond sea level rise, climate change is expected to bring more intense storms to the state, increasing the threat of inland flooding.

“Affordable housing” is generally defined as a house or apartment that a family can obtain for 30 percent or less of its income. That includes government-run housing complexes and private developments that receive tax credits for offering some of its stock to low-income renters.

Nearly one in 10 New Jersey residents live below the poverty line, making such subsidized housing crucial to their survival.

By 2050, as many as 24,500 affordable housing units in the United States are projected to be exposed to regular coastal flooding.

For New Jersey, that means 6,825 units could be damaged by flood, potentially displacing an estimated 15,000 people.

NJ Advance Media partnered with Climate Central to examine how affordable housing around the Garden State is already threatened by regular flooding, and how climate change is turning a coastal planning problem into an existential threat to many shore communities.

THE PLACES AT RISK

Five Garden State cities and towns — Atlantic City, Hoboken, Camden, Penns Grove and Salem — rank among the top 20 cities nationwide with affordable housing facing the gravest risk.

Next to New Jersey, New York and Massachusetts have the most affordable housing residents at risk, but nearly every coastal state in the country will be affected, the study found.

It’s not just the number of homes threatened by coastal flooding that matters — it’s how often flooding happens.

Over the next thirty years, the average frequency of flooding affecting affordable housing units is expected to almost quadruple, the analysis showed. By 2050, nearly half of New Jersey’s at-risk affordable housing stock could flood at least four times per year.

And the residents of affordable housing — who are disproportionately Black, Hispanic or Native American — will bear the brunt of it, experts say.

Those residents “live in neighborhoods that are higher risk of multiple adverse environmental conditions” including flooding, said University of California researcher Lara Cushing, the study’s co-author, owing the disparity to redlining and other forms of housing discrimination.

In South Jersey, the affordable housing near the Delaware River and its tributaries in Camden, Penns Grove and Salem are projected to flood regularly in coming decades.

Affordable housing, such as the Terrell Homes in Newark, is threatened by sea level rise. John Jones | For NJ Advance Media

In Newark, New Jersey’s largest city, hundreds of affordable housing units will likely be threatened by flooding by the end of the century. The famed Ironbound neighborhood, which lies at some of the lowest elevations in Newark and is home to the Terrell Homes and Pennington Court public housing developments, are among the most at-risk parts of the city.

New Jersey has rules in place requiring municipalities to construct certain amounts of affordable housing units. But the history of affordable housing in New Jersey is often a story of provincial politics, corrupt construction and environmental racism.

When cities and towns are compelled to build such developments, affordable housing often ends up in undesirable lots — bisected by highways, atop polluted lands or next to smoke-spewing factories and landfills.

And, of course, in floodplains.

“When we’re making decisions about climate change, and what happens where, it’s really important to recognize that communities of color, lower income communities, usually aren’t at the table when it comes to that decision making,” said Peter Kasabach, the executive director of New Jersey Future.

“And (they) are usually at the wrong end of the stick when it comes to how investments get made, and how decisions about who’s safe and who’s not get made.”

In low-lying coastal areas like the Jersey Shore, sea level rise presents an existential threat, raising difficult questions about what to rebuild, what to reenforce — and what to abandon.

“We’re going to be facing daily flooding in places and that starts to break apart the ability of the community to function,” said Rob Freudenberg, vice president of the Regional Plan Association.

“It’s not a storm that comes once, it goes away, and then you rebuild.”

Freudenberg, whose group advocates legislatures in the tri-state area addressing climate change, head on, said policy makers need to have difficult conversations over “managed retreat,” a term for a deliberate push to stop developing on the coasts.

In a statement, the New Jersey Department of Environmental Protection said the findings “underscore the urgency of sea-level rise and flooding in New Jersey” and “highlight the need for resilience planning and investment to ensure that all New Jerseyans, especially those in affordable housing, can be protected from the current impacts of sea-level rise and climate change.”

“We’re going to be facing daily flooding in places and that starts to break apart the ability of the community to function.” — Rob Freudenberg, Regional Plan Association

THE BOTTOM OF THE BOWL

Hoboken is a square mile of a city built mostly on filled-in wetlands. The land beneath the city is shaped like a bowl, rimmed by higher ground close to the Hudson River on the east and the lower reaches of the Palisades on the west.

Today, about 75% of Hoboken lies at the bottom of that bowl.

“Most of our affordable housing units are in the floodplain, because the majority of the city of Hoboken is in the floodplain,” said Caleb Stratton, Hoboken’s Chief Resilience Officer.

A man uses a boat to evacuate his belongings from his flooded Hoboken home after Superstorm Sandy in 2012. Star-Ledger file photo

La-Trenda Ross knows Hoboken’s flood problems well. Though she recently moved to Jersey City, Ross spent more than two decades living in Hoboken Housing Authority dwellings.

“Since starting to live there, I’ve seen nothing but flooding every time it rains,” Ross said. “And it could be just, you know, a typical rainy day.”

Hoboken’s worst-case scenario was realized during Superstorm Sandy, which sent a 14-foot storm surge into the city, dumping rain atop it, stranding more than 20,000 residents.

Ross said her building was without power or heat for days. Flood waters reached the stairwells of her building and knocked elevators out of service.

“It was pitch black dark,” she recalled.

The harrowing ordeal of Sandy and the increase in daily flooding drove city officials to take the dramatic step of suing major oil companies in September, becoming the first New Jersey city to do so.

The lawsuit accuses oil companies of prioritizing profits while ignoring and denying climate science and seeks payment for the havoc climate change has wrought on the city’s infrastructure.

Getting property owners to invest in fortifying affordable housing units against flood risk remains a challenge, given how expensive infrastructure adaptation and resilience can be. It can cost more than $100,000 to elevate a single-family home — money many property owners don’t have.

The burden then falls on low-income families living within floodplains.

Pilar Hogan Closkey, executive director of the Camden nonprofit Saint Joseph’s Carpenter Society, said families in affordable housing may be living on a budget and unable to afford flood insurance to protect their belongings.

The nonprofit rehabilitates abandoned homes in the city and guides low-income families through the process of becoming homeowners, Closkey said. They help residents outline a personal budget, and bring up the option of buying insurance given the proximity of homes to the Cooper River.

“If you have the extra money, you buy the insurance. If you don’t have it, you’re just going to take a chance,” she said.

SOLVING THE PROBLEM

Some officials are thinking of ways to better fortify new affordable housing against storms and nuisance flooding.

Atlantic City Housing Authority Executive Director Tom Hannon said two future projects, including a planned rehabilitation of the Walter Buzby Village, will include flood mitigation in design plans. The renovation plan calls for flood vents and water resistant flooring materials on the ground level of the units, which were originally built in 1951.

Half the units at Walter Buzby Village at the site are already elevated one foot above the Base Flood Elevation (BFE) of nine feet, which is the height FEMA expects water to rise or exceed from a 1% annual chance of flooding in that section of Atlantic City.

The other half are raised two feet above the BFE, as per the municipal building code, Hannon said.

But further north on the island, Stanley S. Holmes Village falls short, Hannon said. A co-developer has been selected to tear down and rebuild the site at an elevated level around next year, he said.

A resident of Walter J. Buzby Homes shares an iPhone photo of flooding on Raleigh Ave. in Atlantic City, Thursday, Dec. 3, 2020. Joe Warner | For NJ Advance Media

In Hoboken, Stratton, the resilience officer, said officials created a city-wide flood mitigation strategy rather than dealing with the issue on a site-by-site basis. The city estimates it is about four to five years away from completing all the planned flood improvements.

“For our affordable housing community, I’m confident that the strategies that we’ve developed both include them and protect them,” Stratton said.

The heart of that work is the $230 million Rebuild by Design program, Stratton said. That effort is in partnership with DEP, and uses federal funding. Adjacent areas of Jersey City and Weehawken are included in the program.

Ross, the former public housing resident, had a front row seat to Hoboken’s resilience efforts as a member of the Rebuild by Design program’s citizen advisory group. Today, Ross said she believes the city has a good plan to deal with future flooding.

But she warns that no plan will completely protect Hoboken from the next Sandy, and whenever the next major storm does hit Hoboken, Ross said public housing residents will dig in again.

“It’s like, oh. Here we go again, it’s another storm. We just gonna ride through it and, you know, do what we got to do,” Ross said.

Building resilient affordable housing isn’t just a job for city or county leaders. It falls to state legislators, who determine what affordable housing policies are pushed through.

One policy change that nonprofit New Jersey Future is pushing for is an update to the state’s municipal planning laws, to require cities and towns to account for future climate change risks when making development decisions. Such an amendment has been proposed by state Sen. Bob Smith, D-Middlesex, in the bill S2607.

Kasabach hopes lawmakers will push legislation to maintain municipal affordable housing requirements while restricting floodplain development. Such a combination, he said, would effectively force cities and towns to redevelop more densely in already disturbed land rather than breaking into New Jersey’s limited open space.

“Redevelopment is the future of New Jersey,” Kasabach said. “We have to get smarter at how we do that. And understanding where you shouldn’t develop is as important as understanding where you should and can develop.”

Whatever happens in the Statehouse, the DEP said affordable housing “will be an ongoing consideration in how we strengthen New Jersey against the current threats of climate change, including New Jersey’s climate resilience strategy, regulatory reform, proposed changes to Flood Hazard Area rules and environmental justice guidance.”

Rouzbeh Nazari, co-director of the Sustainable Smart Cities Research Center, believes New Jersey should first prioritize improving affordable housing rules and alleviate flood insurance costs for those living in government housing.

“If you’re going to build in these flood zones, especially in low-income housing, they should be built to a higher standard,” Nazari said.

The researcher says the responsibility falls to local, state and federal governments.

“We cannot blame governments for major events,” Nazari said.

“But we can hold them accountable for the things they could have done ahead of time.”

Related Resources Summary of this report Scientific paper behind this report Interactive threat maps Spanish version of report State Factsheets Webinar

EXECUTIVE SUMMARY

• A new analysis conducted by scientists at Climate Central and published in Environmental Research Letters highlights the equity implications of sea level rise in the first nationwide assessment of risk to the country’s affordable housing supply.
• The number of affordable housing units at risk from coastal flooding and sea level rise is expected to more than triple over the next three decades.
• By 2050, virtually every coastal state is expected to have at least some affordable housing exposed to more than one “coastal flood risk event” per year, on average—up from about half of coastal states in the year 2000.  (A flood risk event occurs when local coastal water levels reach higher than a building’s ground elevation, and any known barriers do not provide full protection.)  
• New Jersey, New York, and Massachusetts have the largest share of affordable housing stock and number of units at risk; projections for New York City, Atlantic City, and Boston show that each city could have thousands of units exposed to chronic coastal flooding by 2050.
• Climate Central has introduced a new interactive online mapping tool showing the vulnerability of affordable housing to coastal flood risk now and in the future.

A  ffordable housing serves as a lifeline for millions of individuals and families in the United States. Stable, secure housing is known to support better health outcomes, economic mobility, and employability. But there is a severe shortage of homes that are affordable or available to low-income renters. Scientists at Climate Central analyzed the risk coastal flooding poses to affordable housing—both subsidized and naturally occurring—as sea levels rise. They found that more than 7,600 apartments, townhomes, and houses nationwide are currently exposed to at least one “coastal flood risk event” in a typical year, and more than 24,500 units may be so threatened by 2050.  

The combination of physical vulnerability of affordable housing, socioeconomic vulnerability, and more frequent flooding due to sea level rise presents a triple threat within the next 30 years to residents and owners of the country’s already scarce affordable housing.

Estimate of affordable housing units in the Boston area at risk in 2050 if annual global climate pollution continues at current rate (RCP 8.5) by State House Legislative District. See https://coastal.climatecentral.org

Climate change is increasingly afflicting the most vulnerable communities 

The frequency of coastal floods has risen sharply in recent decades due to a warming planet. Rising seas will continue to aggravate both tidal flooding (also called nuisance or chronic flooding) and flooding from extreme weather events in the years ahead. By 2050, with unchecked carbon emissions, the 100-year flood level (or the flood level with a 1% annual  chance of occuring, defining the floodplain), could occur about at least 40 times more often at half of U.S. locations studied. Tidal flooding that now occurs once a year may occur on a weekly basis in some coastal communities.

Of particular concern is the exposure of housing that is considered affordable to low-income households: housing that is federally subsidized or “naturally occurring,” meaning it is unsubsidized but rents below local market rates or for less than 30% of local median household incomes. This housing is an exceedingly scarce resource across the country. Nationwide, there are only an estimated 35 affordable rental units available for every 100 extremely low-income renters—a national shortfall of over 7 million units. These homes are also particularly vulnerable to flooding, as affordable housing tends to be older and is rarely equipped with resilience-enhancing features (such as flood proofing, off-grid energy, or backwater valves), due to the cost of such measures. Additionally, residents of affordable housing often lack the financial resources to repair, rebuild, or retreat from their housing after it is damaged by flood waters. 

Flood-damaged affordable housing can have long-term consequences for residents, owners, and communities, including increased homelessness, loss of rental income that can make it difficult for housing owners to provide affordable housing, and neighborhood-level economic downturns. 

New ways of measuring risk to affordable housing

Scientists at Climate Central aimed to quantify the current and future coastal flood risk to the nation’s affordable housing inventory so that local, state, and federal stakeholders could understand the overall exposure of this already scarce resource. By focusing on the year 2050, the analysis reveals the threats that could affect residents and allows stakeholders an opportunity to plan for resiliency.

This study advances upon prior methods for characterizing the impacts of coastal flooding and sea level rise in a number of ways. Using high-resolution data, it uses individual building footprints and assesses threats that integrate across a wide range of potential sea level rise amounts and flood severities on top of them, instead of choosing a small number of scenarios (more detail available in original study). 

Data was collected from the National Housing Preservation Database’s dataset of federally subsidized affordable housing buildings. Data on naturally occurring affordable housing was collected through the CoStar Building Rating System (see Terminology).

Estimate of affordable housing units in New Jersey at risk by 2050,if annual global climate pollution continues at current rate (RCP 8.5) by county. See https://coastal.climatecentral.org

Findings: Thousands of units are at risk now, and that number will multiply over the next three decades

Using the year 2000 as a baseline for comparison with future risks, the analysis shows that 7,668 affordable housing units were recently exposed to at least annual flood risk in the United States. New Jersey has the highest number of units and percentage of its affordable housing stock exposed, followed by New York and Massachusetts. Many fewer units are at risk in California, but these units face a high risk of repetitive flooding, similar to affordable housing in Maine, Maryland, Alabama, and Texas. 

By 2050, under a continued high-carbon emissions scenario, the risk increases significantly, with the aggregate number of affordable housing units exposed annually more than tripling to 24,519 units. New Jersey could see nearly 7,000 units exposed, a four-fold increase; and New York and Massachusetts would continue to rank among the top three states for absolute and relative number of units exposed. Pennsylvania (792%), Florida (774%), and South Carolina (669%) face the largest percentage increase over the 2000 baseline in units exposed.

The researchers also ranked the top 20 cities in terms of annual numbers of units exposed by 2050. These 20 cities account for three-quarters of all the affordable housing units at risk of coastal flooding across the United States, showing that coastal flood risk is highly concentrated. Cities in the Northeast and California are the most vulnerable, with New York City remaining the most exposed, with over 4,000 units at risk per year by 2050. Five cities in New Jersey ranked in the top 20, four of which (Atlantic City, Camden, Penns Grove, and Salem) are among the poorest urban areas in the country, with an average median household income of just $28,618 (in 2018 dollars). In a number of cities, more than half of the affordable housing stock is at risk in 2050, including Foster City, Calif. (100%), Crisfield, Md. (92%), Hoquiam, Wash. (72%), and Atlantic City (52%).

TABLE 1 - Affordable housing units at risk now and in 2050, under high carbon emissions scenario (RCP 8.5)

State	Expected number of units exposed per year, 2000 baseline	Expected number of units exposed per year in 2050
Alabama	59	64
California	526	738
Connecticut	156	695
Delaware	60	78
Washington D.C.	69	90
Florida	110	963
Georgia	149	151
Hawaii	0	2
Louisiana	214	685
Maine	126	150
Massachusetts	1,530	4,817
Mississippi	32	56
New Hampshire	29	215
New Jersey	1,640	6,825
New York	1,574	5,293
North Carolina	185	435
Oregon	20	52
Pennsylvania	20	175
Rhode Island	2	4
South Carolina	62	474
Texas	200	332
Virginia	395	1,473
Washington	258	385
U.S.	7,669	24,518

See paper and online tool for more detailed analysis of future exposure to multiple flood-risk events per year.

TABLE 2 - Future threat of coastal flooding to the top 20 cities exposed (in absolute terms) for 2050, under high carbon emissions scenario (RCP 8.5)

City	Expected number of units exposed per year, 2050	Percentage of affordable housing in city
New York, NY	4,774	1.3%
Portsmouth, VA	220	3.6%
Boston, MA	3,042	4.0%
Charleston, SC	349	5.5%
Stamford, CT	337	6.2%
Camden, NJ	632	6.7%
Norfolk, VA	710	6.7%
Cambridge, MA	510	7.7%
Quincy, MA	668	11.7%
Miami Beach, FL	317	22.8%
Revere, MA	266	23.5%
Salem, NJ	208	30.3%
Penns Grove, NJ	222	32.5%
Hoboken, NJ	1,118	38.6%
Stamford, CT	217	42.2%
Freeport, NY	275	43.9%
Atlantic City, NJ	3,167	52.1%
Hoquiam, WA	220	71.7%
Crisfield, MD	283	91.8%
Foster City, CA*	279	100%

*Exposure may be overstated in Foster City, CA where new levees may not have been included in a national levee inventory used in the analysis. See paper for details.

Conclusion

“A rising tide lifts all boats” is a phrase often used to articulate the idea that a prosperous economy will benefit all its participants. But the rising tides driven by global warming are increasing flood threats for thousands of residents in low-income communities and neighborhoods. Flooding can wreak havoc on buildings and the residents who live in them, threatening public health and causing profound disruption to families struggling to make ends meet. Chronic or “nuisance” flooding can also damage cars and keep residents from getting to work, school, or medical care. 

Understanding current and future exposure of affordable housing to flood-risk events, including the number of units that could be affected and how often, can support strategic resilience planning. In the cities and states with the greatest threats, flood-threat reduction measures, such as building retrofits or flood-proofing, and land-use regulatory policies are tools for stakeholders to protect affordable housing stock, and the lives and livelihoods of those who live there.

Enhancing Resilience in Affordable Housing Through our partnership with the National Housing Trust, Climate Central interviewed coalitions and nonprofits focused on affordable housing about steps they are taking to make affordable housing more resilient to coastal floods. Below are a few examples of some of the climate adaptation solutions being implemented by housing organizations in coastal states. Florida Housing Coalition. Forty percent of all U.S. hurricanes have hit Florida. Since 1851, more than 120 hurricanes have made landfall there, more than in any other state. Facing this reality, the Florida Housing Coalition, a statewide membership organization for affordable housing stakeholders, has a dedicated staff member focused on resilience and recovery. They host a weekly one-hour webinar for their members on hurricanes and have developed toolkits for disaster management and local housing disaster recovery strategies.  Enterprise Community Partners. Enterprise Community Partners, a national nonprofit focused on growing the supply of affordable housing, has created an online tool that allows owners, operators, and developers of affordable housing to identify properties at risk from climate disasters such as flooding and wildfire. Enterprise also collaborated with a number of partners to produce guidance to help shape housing construction and retrofitting in Puerto Rico, the U.S. Virgin Islands, and the Florida Keys. Their Keep Safe guide offers ways to make homes being rebuilt after major storms more resilient to hurricanes, earthquakes, and flooding. New Ecology. New Ecology is a nonprofit that advances sustainable building and retrofitting practices, including energy efficiency, renewable energy, and resiliency, with a focus on underserved populations. They have developed a resiliency assessment audit package for developers and owners of low-income or multi-family housing. New Ecology assessed the Villages of East River, a 202-unit affordable housing complex in Anacostia, Washington, D.C. for a range of climate hazards, including hurricanes, flooding, ice, snow, and extreme heat and cold events, as well as the potential for energy and water efficiencies. Recommendations from the audit included elevating HVAC equipment, planning for stormwater management, and energy efficiency upgrades. Energy Efficiency for All. Energy Efficiency for All (EEFA) is a nonprofit that connects climate, health, and equity and works to bring energy efficiency to multifamily and affordable housing through coalitions in 12 states.

Terminology

A coastal flood-risk event at a building is defined as a day when local coastal water levels rise higher than the lowest point of the building’s ground elevation. Different combinations of tides, storm surges, and sea level rise drive these water levels. An event is counted only when a building is hydrologically connected to the coast at the water level achieved; in other words, barriers such as ridges or levees are not known to protect the building at that level . 

Whether a flood actually occurs also depends on other factors as well, including how much higher the water gets, how long it stays high, how close the building is to the coast, how rough the terrain is, and meteorological details such as wind strength and direction and amount of rainfall, if any, and how far inland floodwaters reach during a particular high tide or storm.

Estimated Annual Exposure denotes the average number of affordable housing units in a given area exposed to coastal flooding in a typical year. This provides counts of the number of units that could potentially flood based on water and land elevations, not predictions of how many units will actually flood, which also depends on the same factors that distinguish actual floods from flood-risk events.

Subsidized affordable housing stock data used in this analysis comes from a comprehensive dataset of federally subsidized affordable housing buildings as of November 2018. Those data were collected through the National Housing Preservation Database, managed by the Public and Affordable Housing Research Corporation and the National Low Income Housing Coalition, and analyzed by the National Housing Trust (NHT). For purposes of this analysis, any housing supported by any federal program is considered subsidized; housing subsidized by known state-funded subsidies is also included (such housing makes up 2% of the National Housing Preservation Database).

Naturally occurring affordable housing includes apartments or houses that rent at levels below the local median market rent rates without subsidies, and was identified through the national CoStar Building Rating System, which rates commercial real estate properties.

Methodology

Each affordable housing building’s footprint was assessed for the annual probability of experiencing at least one coastal flood risk event in a given year. Sea level rise projections were based on Kopp et al. 2014, and coastal flood risk statistics were based on Tebaldi et al. 2012 . These building-level probabilities were integrated to estimate the total expected annual exposure at zip code, city, county, and state levels. For more detail, see the paper online. To explore affordable housing vulnerability given a range of sea level rise projections and storm surge events, see the online tool.

 

Climate Central is an independent organization of leading scientists and journalists researching and reporting the facts about our changing climate and its impact on the public. Climate Central’s Program on Sea Level Rise provides accurate, clear, and granular information about sea level rise and coastal flood hazards both locally and globally, today and tomorrow. We offer user-friendly maps and tools, datasets, and high-quality visual presentations.