On a Friday night in July, as Ferraris and Mercedes cruise past to the thump of the club music pounding behind their rolled-up windows, I squat on the corner of 10th Street and Alton Road in Miami Beach, watching a storm drain spew out salt water. Sea level has risen about eight inches here since 1915, when the first hotel sprouted from the sand. Today the estimated value of the city’s real estate is $31 billion, which means a cluster of buildings worth more than half the GDP of Bolivia is stuck on a string of islands that rise only five feet above sea level, less than the height of your average 12-year-old girl. And the sea is slowly devouring those islands. At high tide during full and new moons, salt water from Biscayne Bay pushes back through the city’s storm drain system and bubbles onto the street, which is what’s happening tonight on this and numerous other street corners. If you want to know what climate change in America looks like, come to Miami Beach.

“I’m not a scientist, but I just think that we have abused Mother Nature,” says Catalina Bertaut, sipping a cappuccino at a trendy coffee shop. A well-dressed woman in her sixties, Bertaut came to Miami in 1960 with her family to escape the Cuban revolution. She attended elementary school in South Beach, had a career as a Braniff stewardess, and now, like some residents, is starting to draw the connection between the recent street flooding and sea-level rise. I ask her if she’ll stay. “By the time we become like Venice and everything is floating around,” she says, “it will be time for me to leave this earth.”

For those of us who remain, what will this coastal resort city be like? Seas in South Florida could rise another half a foot by 2030, and two more feet by 2060, according to a report from the bipartisan Southeast Florida Regional Climate Change Compact. Translate those numbers onto maps produced by Florida International University, and you see the city start to melt away. With two feet of sea-level rise, saltwater ponds form on the west side of Miami Beach, now lined with fancy hotels and a major shopping district. Make it three feet and Biscayne Bay consumes much of the island chain. At four feet, which NOAA says could happen by the end of this century, that average 12-year-old girl is up to her neck in water and the western two-thirds of Miami Beach is completely submerged.

“Approximately 14 million people live along the coast in Florida, and more will be moving there,” warns a very concerned Leonard Berry, director of the Florida Center for Environmental Studies at Florida Atlantic University. Much of the region’s infrastructure is at risk from storm surges and high-tide flooding, says Berry: “Highways, schools, hospitals, water treatment plants, thousands of acres of farmland, and two nuclear power plants.” This list should not frighten just Floridians; the Environmental Protection Agency points out that 23 of the 25 most densely populated U.S. counties border a coast. A 2012 NOAA report estimated that more than 8 million Americans live in areas threatened by coastal flooding. As Hurricane Sandy painfully taught New Yorkers, if your house is in the flood zone, it will flood. The federal government now has a sea-level-rise mapping tool: Zoom in on a city, and watch the ocean drown coastal homes and businesses. That, absurdly, is the world we live in.

South Florida faces a climate nightmare all its own. It sits atop 20,000 feet of porous limestone, the cemented deposits of corals, clamshells, and trillions of tiny balls of calcium carbonate called ooids. The very ground you walk on here was created underwater, when sea levels were higher. And the porosity of that ground can be up to 60 percent; in some stretches of the state, homes, even cities, are built on land that is more holes than rock. Water moves easily through these Swiss-cheese-like formations, which means the levees and walls that protect low-lying cities such as New Orleans can’t protect Miami Beach. Salt water would still bubble up through the storm drains, through the 400-plus gravity wells that once disposed of storm water, and through the ground itself. And the situation will only get worse as warming oceans continue to expand and glaciers and sea ice continue to melt.

Sea-level rise also threatens the source of Miami Beach’s drinking water—the Everglades, South Florida’s enormous freshwater wetland. The ecosystem, home to more than 360 species of birds, is where John James Audubon once observed wading birds “in such numbers to actually block out the light from the sun.” Beneath the subtropical wilderness, and much of southeast Florida, is the Biscayne Aquifer, from which residents from Boca Raton to Miami draw their drinking water. Over the past several decades, as the wetlands have been drained to make way for farms and towns and as sea levels have begun rising, salt water has crept into the aquifer through the porous limestone.

“Plugging canals and putting freshwater back into the marshes is the best way to slow loss of habitat and limit the advance of the sea into this important ecosystem,” says Eric Draper, executive director of Audubon Florida.

There’s a flipside to maintaining freshwater levels in the Everglades, however, argues University of Miami oceanographer John Van Leer. It can make nearby agricultural fields and homes vulnerable to flooding. “Either let the western suburbs flood and maintain the aquifer,” says Van Leer, “or keep them from flooding by pumping water out into the ocean but lose the aquifer.” Actually, it may be a moot point: Under four feet of sea-level rise, the southern reaches of the low-lying Everglades will be awash in salt water. It’s enough to make Miami Beach residents stick their heads into the soft white sand.

“I don’t think the sea is going to raise itself three feet—it’s too massive,” says Miami Beach developer Russell Galbut. “I see it raising an inch here, an inch there.” We’re gliding through the city in his blue Range Rover, headed toward a site on Alton Road just beside Biscayne Bay, where Galbut plans to build a 10-story luxury condominium. He’d been hoping to construct a 550-foot tower that would sit on a landscaped podium, raising it well above sea level, and boast a 3.2-acre stormwater park that would hold rainwater. But it wasn’t approved, Galbut says, because “the city did not understand it.” He might have lost that particular battle, but he’s convinced that more growth is the way forward. “I think rising sea levels offer us opportunity,” he says. “The future of Miami is taller.”

In Miami Beach’s fashionable Sunset Harbour neighborhood, I stroll the waterfront with Elizabeth Wheaton, the city’s assistant building director focusing on the environment and sustainability. “This isn’t the Pacific Northwest,” says Wheaton, trying to convey the local vibe. “But it doesn’t mean water isn’t appreciated; it’s a part of life, it’s everywhere. We recognize the importance of having natural ecosystems.” Wheaton points out a newly installed pump station, designed to return seawater, like that currently flooding Alton Road, to the bay during high tides. Miami Beach now has 20 or so pump stations and will add 50 more over the next five years, at an estimated cost of $300 million. It will also install more than 100 backflow preventers, to block salt water from streaming in through storm drains. “We’re a new city, we’re still forming our identity,” says Wheaton, as we gaze across Biscayne Bay, where Miami’s luxury high-rises jut into the air like technicolored centipedes—and where a scattering of construction cranes makes it clear that more are coming. “I think that’s really exciting.”

The retrofits are smart, and the city plans to add two Alton Road pumps and at least three others by the October 8 full moon, when high tides will be stronger than the ones I witnessed. But in 20 or 30 years, says Wheaton, when sea-level rise renders these adaptations obsolete, Miami Beach will have to find another solution. For now, though, the fixes will allow this vibrant, multicultural city to continue flourishing. “I think people can live how they have been living,” says Scott Robins, a developer and chair of the Miami Mayor’s Blue Ribbon Panel on Flood Mitigation. “Right now Miami is going through one of the hottest real estate booms ever in its history. People are investing enormous sums of money, and many of them really aren’t worried about sea-level rise.”

Yet some Miamians recognize that change is inevitable. “We may have to give up land for the city, we may have to go to taller buildings, we may be unsuccessful in keeping the sea out of parts of the city,” says Miami Beach’s city engineer, Bruce Mowry. “Considering what Mother Nature is putting on us with sea-level rise, we may have to change our culture in order to survive.”

About 170 miles south, the island of Key West faces similar problems. I’m standing downtown on Wall Street with Alison Higgins, the city’s sustainability coordinator, as seawater bubbles up through the storm drains to form gigantic puddles on the road. Tourists on bicycles trail wakes in the water. As a family in a stretch golf cart passes by, the kids giggle and raise their feet to avoid getting splashed. “They think it’s rainwater,” says Higgins.

Key West is trying to make itself more resilient to coming changes. Like Miami Beach, it’s installing pumps to drive seawater back from storm drains during high tides. In 2009, concerned about freshwater shortages, the Florida Keys Aqueduct Authority built a reverse osmosis plant that turns brackish water to fresh, although running the plant is expensive. New homes must be built 1.5 feet higher than the flood plain, be green-certified, and install 1,000-gallon cisterns for irrigation and swimming pools. Residents are largely footing the bill, though there has been an influx of some outside funds. A $28,250 Audubon Toyota TogetherGreen grant, for example, is funding two climate mitigation projects: installing a 9,000-gallon cistern system at the Key West Wildlife Center to fill bird wading pools, and planting salt-tolerant trees to withstand rising seas and serve as habitat for migratory birds.

It’s a good start, but what the tiny island is facing is daunting. “When I first came here and bought a house, it never even occurred to me to look at what my elevation was,” says Ellen Westbrook, a member of Florida Keys Audubon. “I just thought, it’s an island, everything is wonderful.”

Raised near New York City, Westbrook moved here in 1976 to work as a nurse. During Hurricane Wilma, in 2005, one of the most intense tropical cyclones ever recorded in the Atlantic Ocean, her home was flooded more than three feet deep. “It seemed to come up so quickly,” recalls Westbrook. “I was wading through my house, my waterbed was floating, my sofas were floating, and my cats were clinging to the sofas.”

Westbrook likes the island’s calmness, maintained partly with laws like those that cap structures in some parts of town at 25 feet. But she supports a citywide referendum, up for a vote in October, that would increase the height limit to allow people to raise their homes above the flood line. Even if the referendum passes, only those who can afford the price tag—as much as $100,000—will be able to adapt. “It’s not feasible for me to raise my house,” says Westbrook. “I’d have to rebuild.” I ask her if she’ll leave. She draws a breath and smiles. Like Bertaut, the retired stewardess back in Miami Beach, she has a fatalistic attitude. “I live here now,” says Westbrook. “But more near the end of my life I’ll have to leave here, because there won’t be any more ‘here.’ ”

On a shoreline speckled with mangroves, under a sky scrubbed clean by afternoon thunderstorms, Celeste De Palma and Laura Reynolds, of Miami’s Tropical Audubon Society, consider the city’s future. We’re at Deering Estate, a 1900s hotel turned into a Miami-Dade County park. The duo, sponsored in part with an Audubon Toyota TogetherGreen fellowship, recently helped resuscitate the Hold the Line Coalition, launched back in 2004 to prevent urban sprawl into the Everglades. “It’s insane,” says Reynolds. “There is a huge building boom going on right now in Miami Beach.”

At a design charrette hosted recently by Tropical Audubon in Wynwood, Miami’s arts district, more than 200 people joined local leaders and designers to discuss rising seas, diminishing resources, and population growth. The organizers divided attendees into groups based on where they lived and encouraged them to approach their representatives and demand action. Climate change can seem cripplingly impossible to tackle, says Reynolds. “What Celeste and I try to do is boil it down to your neighborhood, your house.”

Image showing the "existing" conditions on the coastline of beaches in Miami, Florida. Image Credit: ©2007 Google, Inc.

As glassy waves roll over manatee-mowed seagrass beds, Reynolds and De Palma run through sundry actions people can take: encourage leaders to fix infrastructure; push for public transportation and use it; demand more street trees, bike lanes, and mixed-use neighborhoods to reduce car use; seal homes to prevent energy loss; eat locally grown food and cut back on meat; create a bird-friendly yard with native plants; use less water and energy. The list goes on.

Image depicting inundation scenario for the Miami, Florida coastline in 2030 where sea level has risen one meter. Image Credit: ©2007 2030, Inc / Architecture 2030 and ©2007 Google, Inc.

Before going to Florida I knew climate change was here, but I didn’t know what it meant. South Florida is disappearing before our very eyes. Even by conservative estimates, the Sunshine State’s easily identifiable peninsula will have become a fizzled shard by the end of the century—unless the inhabitants of this vibrant region are able to engineer their way out of the situation. From the new pump stations to Miami Beach’s recently passed resolution requiring all new development to consider rising seas, they’ve started to adapt. But will they move quickly enough? “As we go forward in time, this is not going to be slow,” says Reynolds. “Once the ice sheets melt, this is going to go fast, and it’s going to be scary.”

Oh, I forgot to mention one thing: hurricanes. At Deering Estate, where De Palma, Reynolds, and I spoke, Hurricane Andrew roared ashore in 1992 with 175- mile-per-hour winds and a 17-foot storm surge. The storm inundated the park and transformed the local ecology.

“I’m afraid the real wake-up call will be a Hurricane Sandy-type event,” says Leonard Berry, of Florida Atlantic University. “And that, unfortunately, is fairly common—that we wait for some major emergency to spring a whole new set of perspectives into action. But let’s hope that I’m wrong.”

Freelance journalist Justin Nobel lives in New Orleans and is currently working on a book of tales about the weather.