Hurricane Harvey, which hit Texas and Louisiana last August, causing $125 billion in damage, dumped more water out of the sky than any storm in U.S. history. By one calculation, roughly a million gallons fell for every person in Texas. The water rained down on a flat former bayou that had become a concrete and asphalt empire of more than 2.3 million people. Highways turned into rivers and shopping malls into lakes. As the water rose, people scrambled for safe refuge – into attics, onto rooftops and overpasses. A Texas game warden captured a nine-foot-long alligator in the dining room of a home near Lake Houston. Snakes swam into kitchens. A hawk flew into a taxicab and wouldn’t leave.
As the deluge continued, tens of thousands of people fled – some in fishing boats down suburban streets, some in canoes, some on Jet Skis. Others risked a harrowing drive through water, fallen trees and swimming dogs. More than 30,000 people ended up in shelters. Thousands more headed up Interstate 45, toward Dallas, where parking lots at IHOPs and McDonalds were full of desperate people wondering how their suburban neighborhoods had turned into Waterworld. Many of them lived in their cars until the floods receded, and eventually returned to devastated homes.
Some people who hit the road during the storm kept going. A few days after the waters drained away, I was driving across central Arizona on old Route 66, which novelist John Steinbeck called “the Mother Road” – it was the route that hundreds of thousands of people took to escape America’s first man-made environmental catastrophe. Today, the ghosts of the Dust Bowl, the 1930s drought that caused a region roughly the size of Pennsylvania to dry up and blow away, haunt every gas station and roadside ice cream shop.
Near Flagstaff, I pulled into a service station and parked next to a Subaru with the words “We Survived Hurricane Harvey, Orange, Texas” scrawled on the back window in bright-pink letters. The mud-splattered car was loaded with luggage, boxes and a guitar case. A middle-aged woman and a scruffy man with wild brown hair pulled themselves out, looking road-weary and haggard. The man popped open the hood and fiddled with some wiring.
I nodded to the words on their back window. “How bad was Harvey?”
“Bad,” the woman said. She introduced herself as Melanie Elliott. “We had to get out of there.”
“It was a fucking disaster,” the man said, bent under the hood. His name was Andrew McGowan. “We got swamped.”
Orange, I later learned, is an old industrial seaport near the Louisiana border, population 18,643. The town has been hit repeatedly by recent hurricanes: In 2005, Rita savaged the city; three years later, Ike breached the city’s levee and flooded the streets with as much as 15 feet of water. Three people died. “We were just dealing with water all the time, constant flooding,” McGowan continued. “The whole place is going under.”
“Harvey was it for us,” Elliott added. “Too much water, we can’t deal with this anymore. We are going to San Diego.”
“What are you going to do there?” I asked.
“We don’t know,” McGowan said. “I’m gonna play some guitar and see what comes along.”
As they piled back into their Subaru and headed toward the highway, I thought of the old Woody Guthrie song about the farmers fleeing the Dust Bowl: “We loaded our jalopies and piled our families in/We rattled down that highway to never come back again.”
In 2017, a string of climate disasters – six big hurricanes in the Atlantic, wildfires in the West, horrific mudslides, high-temperature records breaking all over the country – caused $306 billion in damage, killing more than 300 people. After Hurricane Maria, 300,000 Puerto Ricans fled to Florida, and disaster experts estimate that climate and weather events displaced more than 1 million Americans from their homes last year. These statistics don’t begin to capture the emotional and financial toll on survivors who have to dig through ashes and flooded debris to rebuild their lives. Mental-health workers often see spikes in depression, PTSD and suicides in the months that follow a natural disaster. After Harvey, one study found that 30 percent of residents in flooded areas had fallen behind on their rent or mortgage. One in four respondents said they were having problems paying for food.
Politicians inevitably vow to rebuild, to make their city stronger than before. But in the coming years, as the climate gets hotter, the seas keep rising and storms grow more intense, those vows will become less and less credible. Climate change is going to remap our world, changing not just how we live but where we live. As scientist Peter Gleick, co-founder of the Pacific Institute, puts it, “There is a shocking, unreported, fundamental change coming to the habitability of many parts of the planet, including the U.S.A.”
In the not-so-distant future, places like Phoenix and Tucson will become so hot that just walking across the street will be a life-threatening event. Parts of the upper Middle West will become a permanent dust bowl. South Florida and low-lying sections of the Gulf Coast will be underwater. Some people may try to stick around and fight it out with Mother Nature, but most will not. “People will do what they have done for thousands of years,” says Vivek Shandas, a professor of urban studies and planning at Portland State University. “They will migrate to better climates.”
One recent study in the journal Nature Climate Change predicts that by 2050, as much as 30 percent of the world’s land surface could face desertlike conditions, including large swaths of Asia, Europe, Africa and southern Australia. More than 1.5 billion people currently live in these regions. In the U.S., a recent study by Mathew Hauer, a demographer at the University of Georgia, estimates that 13 million people will be displaced by sea-level rise alone by the year 2100 (about the number of African-Americans who moved out of the South during the Great Migration of the 20th century). In Hauer’s study, about 2.5 million will flee the region that includes Miami, Fort Lauderdale and West Palm Beach. Greater New Orleans loses up to 500,000 people; the New York City area loses 50,000. The biggest winners are nearby cities on high ground with mild climates, good infrastructure and strong economies: Atlanta; Austin; Madison, Wisconsin; and Memphis.
“Most people don’t realize how much climate affects everything, from their property values to how hard people work,” says Solomon Hsiang, a professor of public policy at the University of California, Berkeley, who led a recent study that predicts, as the climate warms, there will be “a large transfer of value northward and westward.” And the wealthy, who can afford to adapt, will benefit, while the poor, who will likely be left behind, will suffer. “If we continue on the current path,” Hsiang says, “our analysis suggests that climate change may result in the largest transfer of wealth from the poor to the rich in the country’s history.”
The Southeast will be the biggest loser due to damage from increased flooding, higher heat mortality and lower agricultural yield – in some of the poorest counties in the region, the study predicts, income will fall by up to one-third. In contrast, the Northwest will see increased agricultural yields, lower energy costs (due to milder winters) and higher worker productivity. “The lesson of this study is, the future looks good for the Pacific Northwest, especially cities west of the Cascades, like Seattle and Portland,” says Hsiang’s co-author Amir Jina, an economist at the University of Chicago. “For the Southeast, it’s not a very pretty picture.”
There are plenty of unknowns in how this will play out, including unforeseen climate tipping points, technological innovations that help us adapt, and outbreaks of war and disease. But without a doubt, climate change is not only altering the physical boundaries of our world, it is challenging the very 20th-century idea that we can engineer our way out of -whatever chaos comes our way; the big lesson of this century may be that we cannot. As the seas rise and the temperatures soar, we will have to give up ground. We will learn that “retreat” is not a dirty word. And we will become, more and more, a nation of refugees.
At about 5 p.m. on August 29th, 2005, Hurricane Katrina broke through the levee protecting New Orleans’ Lower Ninth Ward. Ten feet of raging seawater tore into this working-class black neighborhood, trapping people in their homes without warning. About 80 people were killed by the storm in the Lower Ninth, the highest flood fatality rate in the city. Virtually every structure in the 25-square-block neighborhood was destroyed.
The Lower Ninth was ground zero, but Katrina devastated a wide area in and around New Orleans. About 1,800 people died; another 400,000 were displaced. This wave of displaced people became known as the “Katrina diaspora,” and researchers are still trying to come to grips with exactly what impact it had on the demographics of the city. By most measures, New Orleans is thriving again, but it is a richer, whiter city than it had been before the storm. It is also smaller: The population of New Orleans today is about 390,000, roughly 100,000 fewer people than before Katrina hit.
In the Lower Ninth, rebuilding has been difficult. Despite hundreds of millions of dollars in aid, large parts of the neighborhood are still abandoned: empty lots, sidewalks that lead nowhere, trash blowing in the streets. New Orleans’ official statistics estimate that the population of the Lower Ninth is 37 percent of what it was before Katrina, but Laura Paul, founder of -Lowernine.org, a nonprofit devoted to rebuilding the neighborhood, contends the reality is much closer to 25 percent. The federally funded storm-recovery program made it almost impossible for homeowners there to get enough money to rebuild, she says; instead, many people took their measly settlements and started over elsewhere. “Every impediment to recovery that could have been thrown up in the path of low-wealth black families was thrown up,” Paul says. “It was basically a form of institutionalized racism.”
Still, there are hopeful signs: more than 100 pastel-colored solar-powered homes built by Brad Pitt’s Make It Right foundation; 85 or so more traditional houses rebuilt with the sweat of volunteers from organizations like Lowernine.org. “We are absolutely committed to the long-term future of this neighborhood for as many pre-Katrina residents as wish to return,” says Paul. But given the risks that New Orleans faces from rising seas and increasingly intense storms, that long-term future is in question. When I bring this up with Paul, she balks: “Worrying about the future is a luxury for privileged people. My friends here are worried about putting dinner on the table tonight, not what is going to happen in the city 20 or 30 years from now.”
The likelihood of another catastrophic levee collapse has been greatly reduced, thanks to $14.5 billion spent in the aftermath of Katrina on bigger, stronger barriers against the sea. But the city has other problems. For one thing, the protective coastline around it is vanishing. Louisiana is losing a football field of land to the sea every hour, due to a combination of subsidence, sea-level rise and reduced sediment flow from the Mississippi River. For -another, large parts of New Orleans, which was originally built on a swamp, have been sinking for 100 years – some parts of the city have subsided as much as 15 feet. As a result, even ordinary rainstorms are becoming existential threats. Last August, nine inches of rain fell on the city in three hours, and it looked like Katrina all over again. “The city is like a big bathtub,” says Ed Link, a professor of civil engineering at the University of Maryland who led the effort to rebuild after Katrina. “You can build barriers to protect it from storm surges, but when it rains, you still have big problems.”
Back in the 1910s and ’20s, a system of pumps powered by steam turbines was installed around the city to help with drainage. Most of those pumps and turbines, poorly maintained and poorly designed for 21st-century mega-rainfall events, are still in operation today. At the time of the flooding last August, only two of the five turbines that power the pumps were working; a week later, a fourth failed.
It will cost billions of dollars to upgrade the system. But city officials can’t even find the money to keep the storm drains and canals free of debris and functioning correctly. At a council meeting after the floods, public-works officials admitted the city could afford to clear only 68 of the 1,300 miles of canals in 2017. And as the climate heats up, rainfall is likely to become increasingly intense. “If you are asking me to drain nine inches of rain, I need six times the pumping capacity, six times the drainage pumps and six times the canals,” Joseph Becker, the former superintendent of the New Orleans Sewerage & Water Board, told the city council shortly after the August floods. “I don’t need three or four more pumps, I need 400 or 500 more.”
At a certain point you have to ask: How long can New Orleans, a city already below sea level, keep pumping? Lisanne Brown, director of evaluation and research at the Louisiana Public Health Institute, thinks about that a lot. She moved to New Orleans with her husband 30 years ago and raised two kids there. They bought a historic house in Bywater, a neighborhood by the river that is on slightly higher ground than most of the city, and so less susceptible to flooding. Nevertheless, Katrina had a big impact on how they think about life in New Orleans. “My husband and I talk about leaving more often now,” Brown tells me. “We have really come to realize how vulnerable we are. We have more anxiety about rising seas and bigger storms. Hurricane season is six months long now – that’s a lot of time to feel stress.”
For Brown and her family, the big concern is the value of their home. “It’s our one asset,” she admits. “We are wondering if we should unload it and move away while it’s still worth something.” In part because she lives in a gentrifying neighborhood, the value of her home has doubled since Katrina. It’s worth $500,000 to $600,000 now. “But my worry is, for how long?”
The decision to move to safer climates is obviously deeply personal, influenced by a person’s connection with the community they live in, their financial situation and their tolerance for risk. But for city officials in at-risk cities, homeowners like Brown are terrifying. “Once people start thinking about the long-term value of their homes and how they will be impacted by climate change, that changes the game completely,” a county attorney in Florida says. What happens to the value of a house in, for instance, Fort Lauderdale, when the cost of flood insurance triples? “When I think about the future of South Florida, it’s flood insurance that scares me the most,” Wayne Pathman, a prominent Miami lawyer and board member of Miami Beach’s chamber of commerce, tells me. Many officials fear a climate-driven exodus that pushes down property values, which in turn reduces property-tax revenues, which are central to funding city services like police and teachers, not to mention road repair and infrastructure maintenance, at precisely the moment when the city needs to spend more to adapt to climate change.
It’s a downward spiral for real estate that’s very hard to reverse. “It’s just like the dynamic in the stock market,” says U.C. Berkeley’s Hsiang. “The longer you hold on, the more you have to lose.” And, in many cases, the regions of the country where climate-change denial is strongest, such as the Southeast, are exactly the regions where residents have the most to lose. “In many places, climate denial is going to turn out to have big economic consequences,” Hsiang says.
Some cities and counties already feel the financial noose tightening. In Monroe County, Florida, which includes the entire Florida Keys, a recent study estimated 150 miles of roads need to be raised in the coming years to prevent flooding. Road-raising costs in Monroe County run as much as $7 million a mile, potentially putting the overall price tag up to $1 billion. In 2018, the budget for all road work and repair in the county was only $25 million. At the same time, the longer places like Monroe County wait to adapt to rising seas, the more it will cost. Moody’s Investor’s Service, the influential credit-rating agency, recently announced that it will weigh climate risks when analyzing ratings for states and cities, thus making borrowing money more expensive for places that ignore climate risks.
To shore up confidence in the future, at-risk cities like Miami and Phoenix tout everything from LED streetlights to carbon–offset programs. But for some climate-savvy residents of these cities, what’s coming is all too clear. “I’ve loved living in Miami Beach,” the poet Chase Twichell wrote recently. “We had a beautiful apartment overlooking the bay, with endless crazy human activity to watch, and astonishing sunsets. But the ecology of the area is so damaged that I can no longer see the beauty. I see impending chaos and suffering. Time to go.”
There were boxes all over Robert Stevens’ apartment in north Phoenix. Some were sealed tight with packing tape, marked “kitchen” or “bedroom,” others open, spilling out shirts, or piled high with heavy programming textbooks. Stevens, 29, a slightly manic software programmer, was wearing jeans, a T-shirt and flip-flops as he carried his possessions out to a dusty RAV4. “I never realized how much shit I own,” he muttered to himself. The next morning, he would be driving to Minneapolis to move in with his sister and do some freelance coding. “I must admit,” Stevens said, motioning to the jagged desert mountains, “it’s kinda beautiful here.”
He had grown up in Buffalo and followed his girlfriend to Phoenix four years ago. He loved the sunrises, and often got up early to hike in the Phoenix Mountain Preserve. In fact, it was while hiking that his romance with Arizona ended. “I was out on a trail last summer, and it was ridiculously hot, and I had gone too far, and, I don’t know, I just collapsed,” he said. “I totally fainted. Banged my head on a rock. Scared the hell out of my girlfriend. She gave me water, and I was OK, but it made me think – what am I doing living here? Maybe it’s a genetic thing or whatever, but I can’t take it. This heat is dangerous.”
Obviously, lots of people feel differently. Maricopa County, where Phoenix is located, had the highest population growth in the country in 2016. People come for the jobs, the relatively inexpensive housing, and some, yes, for the weather. In the winter, it’s lovely. But in the summer, it’s brutal. Last year was the hottest on record in Phoenix. The city’s hot season – when temperatures can exceed 100 degrees – starts an average of almost three weeks earlier than it did 100 years ago and lasts two to three weeks longer in the fall. The heat sucks the moisture out of the soil and turns forests into stacks of kindling wood. Great dust storms, known as haboobs, billow in from the desert. The air gets so hot, planes at Phoenix International Airport can’t get enough lift under their wings to take off. Forests burst into flames, creating some of the worst wildfires in the nation. In the coming years, researchers expect Phoenix’s temperatures to soar. Summer days above 122 degrees, the record high for the area, will become the norm, with the hottest days spiking above 134 degrees, the highest temperature ever recorded on Earth (Death Valley, California, in 1913).
In 2016, there were 150 deaths in Phoenix from excessive heat, hitting people of all ages: Rita Ortiz, 62, died of acute heat stress after the air conditioner in her apartment broke on a day when the temperature reached 108; Katilynn Taylor-Marie Daniel, a 14-year-old visiting Arizona from Washington state, went for a hike with her grandmother on a hot July day and died of heat exposure. “If there were an extended power outage during a hot summer spell, there could be dozens, even hundreds of fatalities,” says Gregg Garfin, a climatologist at the University of Arizona. In the urban areas of the city, temperatures are amplified by a phenomenon called the “urban-heat-island effect.” Concrete and asphalt absorb and radiate heat, turning the city into a kiln. Depending on the season, urban nighttime temperatures can be as much as 22 degrees hotter than the surrounding rural areas. City officials have launched a tree-planting campaign to increase shade, and designated air-conditioned spaces like community centers and firehouses as cooling refuges. These refuges work fine as emergency shelters during heat waves for people who can get to them, but many of the most vulnerable cannot.
Lack of water is another issue. Right now, Arizona gets 40 percent of its water from the Colorado River, 40 percent from groundwater, and the rest from smaller rivers and water recycling. Arizona’s access to the Colorado River is particularly vulnerable, both from declining snowpack that feeds the river and for complex political and historical reasons – California has first dibs on water from the river, leaving Arizona subject to the ever-increasing demands of its western neighbor.
In Phoenix, city officials are not oblivious to what lies ahead. Water planners have made a big push for water efficiency – a typical household uses one-third less water than it did in 1990. They have negotiated complex agreements to “bank” water in underground aquifers, and point out, accurately, that the city may end up recycling water – i.e., treating wastewater from toilets and other sources. They have also unveiled a campaign to “green” the city: The Phoenix City Council approved an ambitious new goal to reduce carbon pollution by 30 percent below 2012 levels by 2025, and a larger goal to achieve an 80 percent greenhouse-gas reduction by 2050, which allows Phoenix to exceed the requirements of the Paris Climate Accord. They passed an initiative to divert 40 percent of waste away from the landfill by 2020 and reach zero waste by 2050. The city is in the midst of replacing nearly 100,000 streetlights with energy-efficient LED lights.
Implicit in all of this is the notion that, however bad things get, Phoenix and the surrounding area will find ways to adapt. But in many cases, this is just another form of denial. One big factor is agriculture, which consumes about 70 percent of the water in Arizona. Especially problematic are water-intensive crops like alfalfa, which require up to 10 feet of water on the fields every year. At the same time, smaller Arizona cities like Flagstaff and Prescott, which do not have access to the Colorado River, depend on fragile groundwater supplies; if they get pumped dry, those cities will have to import millions of gallons of water a day, or become ghost towns. “People have a lot of faith in adaptation,” says Hsiang. “But when you go out and look at it in the real world, it’s much less convincing. And it costs a lot, too.” As Hsiang points out, if people walked around in air-conditioned spacesuits when the temperature soared to 130 degrees or higher in Arizona, they would have no trouble. “But who wants to live that way? And who can afford it?”
In Miami and other cities vulnerable to sea-level rise, there is much talk among architects and urban planners about sea walls and coastal barriers and floating houses. But in practice, it’s much more complex. Dan Gelber, the recently elected mayor of Miami Beach, has already slowed down a $500 million project initiated by his predecessor to raise city streets and install pumping stations, in part because the project is so expensive, but also because residents are sick of living with ripped-up streets and traffic congestion. Longtime Miami Beach resident and political activist Dan Kipnis calls it “a populist rebellion” against the endless construction projects. Kipnis, who has been trying to sell his home in Miami Beach for more than a year, is sick of it too. “Somebody please get me out of here!” he e-mailed me recently.
Rather than struggle to adapt, it’s often easier just to leave. Richard Hornbeck, a professor of economics at the University of Chicago who has studied the Dust Bowl extensively, argues that farmers in the 1930s could have adapted to changing conditions by planting different crops or shifting their fields to pastures for cattle or sheep. But they didn’t. “There was inertia in staying with how things had always been done, and too much investment in certain kinds of farm machinery, for people to make the changes needed,” says Hornbeck. Instead of adapting, many just headed to California.
Of course, some people are more mobile than others. As our world heats up, the line between those who can move to milder climates and those who are left behind will become increasingly stark. Not everyone has the cash to start over, or the fortitude to begin life again in a better place. Shortly after I helped Stevens pack up for Minneapolis, I met a homeless man who looked to be in his sixties outside the Arizona Center mall. He wore shorts and an old gray T-shirt. Sweat beaded on his forehead. “How are you doing in this heat?” I asked.
“I’m all right,” he said. “If I get hot, I go sit in the mall until they throw me out.”
He showed me a thermometer he has on his keychain. “I go in when it gets to 115.”
“Pretty close to that now,” I said.
He nodded. “Heat used to not bother me much. But it does now. I’m thinking of moving somewhere cooler. Ever been to Seattle?”
I told him I had.
“I hear it’s nice, all green, lots of water,” he said, looking out over hundreds of cars in the parking lot, sunlight glinting off their windshields. “Maybe someday I’ll make it up there.”
Jeff Kaplan was six years old, living in Kendall, Florida, just south of Miami, when Hurricane Andrew hit. “My dad and another guy held a mattress up against the door to keep it closed,” he tells me. “Every time a window would blow out in the house, my mother would say, ‘Oh, shit.’ ” But growing up in Florida, Kaplan thought hurricanes were just something you had to live with.
After graduating from the University of Florida, he found a job at a software-development firm and married his college sweetheart. They moved to St. Petersburg, where they rented a condo. “We intended to put down roots there,” Kaplan says. They considered buying a house in Coffee Pot Bayou, a historic neighborhood near Tampa Bay, but it flooded so often that finding affordable insurance would have been nearly impossible. “We looked around St. Pete and saw the troubles they are already having with flooding,” Kaplan explains, “and we realized that with rising seas, it’s not going to be here in 50 years. How do you put down roots in a place that won’t exist?”
They started thinking about other places to live, and settled on Asheville, North Carolina. Set at the edge of the Blue Ridge Mountains, Asheville (population 89,000) is an old railroad town known for good hiking, craft beer, a lively music scene and a mild climate. “When we were looking for a place to move, the choice was obvious,” Kaplan says. Lots of other people apparently feel that way too. Buncombe County, where Asheville is located, is one of the fastest-growing counties in the East – between 2010 and 2016, the population grew about 7.4 percent, compared with 1 percent nationwide. “Construction is going crazy,” says Tom Barr, an Asheville businessman who helps rebuild urban infrastructure around the country. “Realtors complain that they have no houses to sell.”
Asheville also seemed like a good place to ride out climate change: lots of trees, water, a cool mountain climate (average summer temperature is about 82 degrees) and plenty of distance from rising seas. They know it’s not immune to climate impacts: In 2004, back-to-back storms sent several feet of the Swannanoa River into a low-lying area of town; in 2016, after a drought, 60,000 acres burned in North Carolina, a good portion of these fires outside of Asheville. “No place is without risk,” Kaplan says. “But in Asheville, the risks seem -manageable.”
Last year, the Kaplans bought a house in West Asheville, a hip, up-and-coming area. It’s modest, close to the French Broad River, but up on a hill. Before they signed the papers, Jeff checked the elevation with Snapchat: The house was at 2,020 feet. “That ought to do us for a few centuries,” he says.
Asheville is also the home of one of the National Oceanic and Atmospheric Administration’s climate and -weather data centers, which employ hundreds of climate scientists and data experts, as well as a nonprofit incubator of climate-related startups called the Collider. “We like to think of Asheville as the intellectual capital of climate science,” says Josh Dorf-man, a Collider board member. Most important for many new residents, however, is the feeling of protection by the rolling hills that surround the city. “You just feel safe here,” one friend told me. “Of course, when the next big storm hits and everyone flees the Outer Banks and winds up here, it might feel more like a refugee camp.”
Like Asheville, Flagstaff, Arizona, is seen by many as a refuge, a mountain retreat from the heat of Phoenix and Tucson. But it is also not immune to climate risks: It’s surrounded by ponderosa forests that are prone to wildfires, and the city is dependent on a diminishing aquifer for drinking-water supplies. Nevertheless, Flagstaff has seen a boom in people from California and southern parts of the state. When I visited last fall, the mayor, Coral Evans, who grew up in a working-class neighborhood in Flagstaff, was worried about the influx. “In the coming years, we’re likely going to have wealthier people, especially people who are living on the beach now in California and Florida, looking for new places to live when they get flooded out of where they live,” Evans told me. “When they go higher up and inland, are they going to displace the people who are there? I’m concerned about that. I’m concerned about the people who are going to get pushed out. Climate change is going to mean gentrification. And it’s going to mean inequity.”
In Miami, climate gentrification is already underway. Although most of Miami-Dade County is flat, there is some slightly higher ground downtown, as well as in historically African-American neighborhoods like Overtown. Jesse Keenan, a researcher on urban development and climate adaptation at Harvard’s Graduate School of Design, tracked the price-appreciation rate for 250,000 Miami-Dade properties over the past four decades. Keenan found that properties at high elevations have long appreciated faster, mostly due to nonclimate factors. However, since 2000, the correlation between elevation and price appreciation has grown more robust, which Keenan suggests is “early signaling” of preference for properties that may fare better during rising tides and climate change. Albert Slap, president and co-founder of Coastal Risk Consulting, a Fort Lauderdale-based firm that advises property owners on flood risks, has found a similar trend. “Property buyers are getting smarter,” Slap says. “They are moving to higher elevations, one foot at a time.”
While I was in Arizona, I stopped at Canyon de Chelly National Monument, a sandstone canyon on the Navajo reservation near the New Mexico border. This region of the Southwest, where humans have lived for more than 10,000 years, is one of the oldest continually inhabited places in the continental U.S. The Anasazi, an ancient Pueblo people, lived in the area for nearly 1,000 years. Then, in the 13th century, they vanished.
I toured the canyon with TJ Hunter, a Navajo guide who grew up nearby. There are no roads to speak of, just Jeep tracks on the banks of the river that runs through the bottom of the canyon. As we plowed along, Hunter pointed out the ruins of Anasazi dwellings high in the sandstone cliffs and spooky petroglyphs that are still visible on the canyon walls. Most anthropologists think drought, and perhaps the ancient equivalent of water wars with neighboring tribes, ended the Anasazi civilization. “The Navajo believe their spirits still live in the canyon,” Hunter says.
It seems absurd to compare the Anasazi ruins with a modern city like Phoenix. After all, we have iPhones, we have solar panels, we have all this great technology. But that may be a profound miscalculation, especially after you look at the damage Hurricane Harvey did to Houston, or the way that the California wildfires burned through areas no one thought were even at risk, or you wade through the streets of Miami Beach during high tide and try to imagine what the city will look like with six or seven feet of sea-level rise.
U.C. Berkeley’s Hsiang sometimes compares cities like Miami, Houston and Phoenix with Angkor Wat, the 12th-century city in what is now Cambodia. “At its peak, Angkor Wat was the most technologically advanced city in the world,” he explains. “Their engineering skills were remarkable.” But despite all that prowess, when a mega-drought came, that was the end of their city. “Ten years before the drought hit, the people of Angkor Wat probably thought they were invincible,” Hsiang says. “They probably thought they were the biggest bad-asses on the planet.”
When I got back to Phoenix the next day, I couldn’t
help but notice all the for sale signs in suburban yards. President Trump was
on the radio, talking about immigration reform, stoking fears of refugees and
displaced people. By noon, the temperature had hit 110 degrees, and the sky was
hazy with smoke from wildfires farther west. Hsiang’s work projects a
near-total collapse of agricultural yields in the region, part of a decline
from searing heat and drought that will reduce economic output by 25 percent.
As I drove, I wondered if future humans – or humanlike machines – would
interpret the ruins of these shopping malls and car dealerships as 21st-century
petroglyphs. What stories, if any, would they tell about the people who had
once lived here?