|Lost in a Rising Sea|
|Written by Erik Bojnansky - BT Senior Writer, Photo illustrations by Marcy Mock|
Reality check: One day in the foreseeable future, most homes and businesses along the Biscayne Corridor will be under water
The world will be a very different place 50 years from now.
Thanks in large part to centuries of spewing greenhouse gases into the atmosphere, we can expect higher temperatures, unstable weather patterns, and rising seas.
For all who live or work in the Biscayne Corridor, those rising seas will pose unprecedented challenges, many of which we’ll be forced to confront soon, in our lifetimes. But imagine for a moment the scene in the year 2062.
Broad expanses of land -- Aventura, Eastern Shores, Biscayne Landing, Arch Creek East, Keystone Point, Sans Souci Estates -- will flood frequently and severely.
Farther south, eastern Miami Shores will be inundated, as will most of Shorecrest, Belle Meade, Bayside, Morningside, and Edgewater.
The Miami River, the Little River, and the Oleta River will overflow their banks and flood surrounding neighborhoods. Much of Brickell will look like a new bay. Downtown landmarks such as the Freedom Tower, the American Airlines Arena, Museum Park, and the Adrienne Arsht Center will be islands in a vastly expanded Biscayne Bay.
Communities like North Bay Village, Bay Harbor Islands, the Venetian Islands, Star, Palm, and Hibiscus islands, as well as South Beach, will be substantially under water.
This is the conceivable future of the Biscayne Corridor should we experience a two-foot rise in sea level, a scenario local climatologists say is distinctly possible. “Most projections say this is going to happen,” asserts Leonard Berry, director of the Center for Environmental Studies at Florida Atlantic University. “The difference [in scientific opinion] is the timing and how rapidly.”
More detailed information is expected next year, when the United Nations’ Intergovernmental Panel on Climate Change releases a new report on global warming. Until then, the best estimates are that by 2030, Biscayne Bay and the near-shore ocean (they’ll rise simultaneously) will be between three and seven inches higher than they are today. By 2060 sea level is projected to rise between nine inches and two feet.
The bay and ocean won’t stop rising at nine inches or two feet, either. “By the end of the century, a little under 100 years from now, there could be four to six feet or more of sea level rise above the present sea level,” says Harold Wanless, chairman of the University of Miami’s geological sciences department.
With a four-foot rise in sea level, Brickell will be a bathtub, and most neighborhoods east of Biscayne Boulevard will be either submerged or resemble islands. A narrow strip of land will be all that remains of the beaches from South Pointe to Golden Beach. The Keys will, for the most part, disappear. Fort Lauderdale will look like Venice, Italy.
With a six-foot rise in sea level, only 44 percent of Miami-Dade County will remain dry at high tide. By this time, says Wanless, sea-level rise will accelerate from the current rate of slightly less than a foot per century to a foot per decade.
Wanless fears that the world’s seas could rise more than 20 feet if massive amounts of ice from Greenland and Antarctica slip into the ocean. “Ten or twelve years ago, I wouldn’t have thought this would happen so fast,” Wanless acknowledges. “That was before I was able to see what was happening in Greenland and Antarctica. The rates of [melt acceleration] are phenomenal and may be a critical problem for mankind.”
Florida is particularly vulnerable to sea-level rise. According to the Center for Environmental Studies, of the 4.2 million people in the U.S. who live at an elevation of four feet or less, 2.4 million are in Florida. An added threat: Scientists expect the mighty Gulfstream to weaken, which could result in sea levels from Florida to the Carolinas rising ten percent faster than the rest of the world, according to David Enfield, a retired NOAA oceanographer now working for UM as a research scientist.
Even though South Florida’s future appears bleak, Elizabeth Plater-Zyberk, dean of University of Miami’s School of Architecture, insists that the Biscayne Corridor can adapt to sea-level rise with proper planning. “Something is happening,” she says. “Whether it is exactly the way scientists are predicting is less the point than understanding that there is a change and we need to accommodate it.”
Toward that end, Monroe, Miami-Dade, Broward, and Palm Beach counties formed the Southeast Florida Regional Climate Change Compact in 2009 to develop plans for dealing with the threat of sea-level rise and other adverse effects of global warming. Serving on the compact’s committees have been scientists such as Wanless, Berry, and Enfield, as well as city planners and architects (including Plater-Zyberk), county administrators, state officials, environmentalists, and business leaders.
Other strategic efforts are under way. This past June, for example, FAU’s Center for Environmental Studies hosted a climate summit in Boca Raton to examine how rising sea levels might affect South Florida and what can be done about it. The summit included a digital video created by FAU associate professor Francis X. McAfee and students John Michael Wilyat and Jammy Chong. The video uses topographical data and state-of-the-art digital imaging to depict what will happen to downtown Miami as sea levels rise. (To view the video, go to www.ces.fau.edu/SLR2012/media/animation.)
Despite near unanimity among climate scientists that sea levels will rise at an increasingly rapid rate, and that extreme weather will become commonplace, UM’s Wanless complains that many people, including politicians, are either skeptical of global warming or ignoring it altogether. “We are living in a very tenuous time right now,” he warns. “It is mind-boggling to scientists that people are sticking their heads in the sand.”
Frank Nero, president and CEO of the Beacon Council, which seeks to increase economic development in Miami-Dade County, admits he doesn’t hear much talk about sea-level rise during discussions with executives and developers. “I don’t think that is on the top of anyone’s list, quite frankly,” Nero says. “There are other concerns the business community has [about Miami-Dade’s future], but I don’t think the rise of the oceans is one of them.”
However, Nero adds, entrepreneurs and corporations in Miami are becoming more environmentally friendly. “The business community is looking at sustainability and green issues,” he says. Those sustainability issues include more LEED-certified buildings that reduce energy consumption and leave a smaller carbon footprint.
Reducing emissions from fossil fuels could slow the rate of sea-level rise, but it won’t prevent it or turn it back. “We have already kicked the bucket,” says Wanless. To actually reverse the warming trend, he explains, “We have to get below CO2 atmospheric levels back when I was born , and that is unbelievably difficult to do.”
David Enfield says there’s now more carbon dioxide (which retains heat in the atmosphere and oceans) in the atmosphere than there has been in the last million years. The United States may have reduced its CO2 emissions to the lowest point in 20 years, but the burning of fossil fuels elsewhere on the planet, particularly from India and China, has increased.
Adds Wanless: “The bottom line is there are too many people on Earth trying to live a comfortable life.”
Harlem believes sea-level rise will be more obvious 20 or so years from now, when the ocean is about a half-foot higher. In South Dade, areas around Black Point Marina, Turkey Point, and the county’s sewage treatment plant will be inundated at high tide. During high tides, Biscayne Bay and the Oleta River will also begin to spill over into low areas in northeast Miami-Dade.
And that’s without rain. With rain, flooding events will be more extreme as storm drains and other flood-control methods begin to fail. In fact, less than a foot of sea-level rise could mean 50 to 80 percent of the flood-control structures located in Miami-Dade and Broward canals will “have to be looked at,” cautions Jayantha Obeysekera, chief engineer for the South Florida Water Management District.
That’s because the 50-year-old equipment, designed to discharge canal water into the bay following heavy rains, relies on gravity, and there is less than a six-inch difference between the upstream canals and downstream Biscayne Bay. Three flood-control structures serving northeast Miami-Dade are being inspected. “For now we’ve not had any flooding issues,” Obeysekera says, “but we’re concerned for the future.” Modifications won’t be easy. “There are many options and all of them are expensive,” he adds.
Ironically, climate models predict that South Florida and the Caribbean will be hotter and drier in the future, says oceanographer Enfield. But there will be monsoons. “By the end of this century, South Florida is probably going to have less rain, but when it does come, it will come in buckets,” Enfield explains. “That raises the prospect of street flooding.”
In some parts of South Florida, that flooding will be long term, notes Harlem: “When they stop draining because there’s nowhere for the rainwater to go, they become small freshwater lakes.”
Fewer tropical storms and hurricanes are expected, but they will be much more powerful. “Instead of seeing two Category 5 hurricanes in a century, like we did in the 20th Century, we’ll have maybe three,” Enfield says. “Instead of three Category 4s in a century, we may have four or five.” Aside from the powerful storms, the region will be more vulnerable than ever to storm surge as the rising sea level erodes beaches and coastline sediments at a faster rate.
Meanwhile, underground seawater infiltration will speed up, gradually replacing freshwater, shorting out buried power lines, and corroding concrete and steel rebar in buildings. “Saltwater is more likely to damage nonmarine concrete,” says Harlem, “so the building foundations, which are in the ground, will encounter the problem [of corrosion] before the ocean is high enough to flood streets.”
Miami-Dade’s crumbling water and sewer system will have to be completely overhauled and redesigned -- or else. Estimated cost: a billion dollars. “The present system will no longer work and we’ll have increased contamination of surface and ground waters,” UM’s Wanless affirms.
Aside from the prospect of raw sewage escaping the system, rising seas will also erode former landfills such as Biscayne Landing in North Miami, where developer Michael Swerdlow plans to build apartments, retail outlets, and hotels. The low-lying, bayfront land was once a notoriously toxic Superfund clean-up site. Harlem is skeptical that county-funded remediation efforts at the 190-acre property will prevent the six million tons of garbage still there from being exposed by a one-foot rise in sea level.
“Landfills and surface burial sites will not survive very long once the waves can attack them every day,” Harlem explains. “Fact of life about the ocean: It is very, very powerful. The remediation sounds like a temporary fix to appease the development plans, but it’s not good for the coastal waters of the future.”
Enfield is concerned about another potential environmental disaster: nuclear meltdown. At two feet of sea-level rise, Turkey Point will be an island cut off from the mainland. If the nuclear power plant takes a serious hit from a strong hurricane, it could be swamped by a tidal surge of 20 feet or more. Under such a scenario, Enfield worries that pumps used to cool the reactors at the current facility, or at a future reactor Florida Power & Light wants to build at the site, might be rendered inoperable, just like Fukushima. “That’s my concern as a citizen,” he says. “It’s not clear to me that FPL is planning for that sort of event.”
Richard Gibbs, a spokesman for FPL, assures that the current and future nuclear plants will be safe in higher seas, and points out that Turkey Point suffered only minimal damage from the 17-foot-plus storm surge generated by Hurricane Andrew. “The existing nuclear units are 20 feet above sea level, designed to withstand the worst-case tidal surge,” Gibbs says. “And all the critical plant equipment is positioned even higher.” The new power plant, he adds, will be on a foundation 26 feet above sea level, and built according to post-Fukushima flood criteria.
A more certain environmental disaster will be afoot once oceans rise four feet: the end of the Everglades. Seawater at that level will flow into the Shark River Slough, commencing the transformation of the delicate freshwater ecosystem into a saltwater bay, Enfield says. When that happens, groundwater flow to Florida Bay and the Gulf of Mexico simply ends, “causing total collapse of estuaries” and accelerating the salinization of freshwater aquifers.
With developed, inhabited land engulfed by polluted ocean water, drinking water scarce, infrastructure dissolving, and intimidating mitigation costs (assessed in the form of higher taxes), Wanless predicts that South Florida gradually will be abandoned. “It’s just not going to be a desirable place to live,” he says.
The county’s Water and Sewer Department will also take rising seas into account while upgrading its sprawling system. The county even has developed a pilot program to replenish the underground Biscayne Aquifer using sterilized wastewater, although that project is now on hold.
UM’s Elizabeth Plater-Zyberk, who, with her husband, founded the acclaimed urban planning firm Duany Plater-Zyberk, says Miami can adapt to environmental issues. “There are going to be a lot of people living here for decades to come,” she says. “If we plan and act accordingly, Miami can be a profitable and pleasant place to live.”
Peter Zalewski, founder of CondoVultures.com, doubts the real estate market will react to scientific prophecies. Instead, he believes, investors will continue to finance new projects and buy property in low-lying areas. “They are living for the trade,” Zalewski says. “The trade is about today. Whatever is tomorrow is beyond their concern. You eat what you kill.”
Plater-Zyberk agrees that the private sector can’t be expected to make long-term plans on its own. “That’s why government is going to have to take the lead,” she says.
But Antonio Nanni, a professor of civil engineering at UM, says such urban planning will be a daunting task. “We did not build our communities thinking that all of a sudden we’d be underwater,” Nanni observes. “Everything will have to be readdressed.”
That could mean deciding which areas should remain dry and which should be allowed to drown. “If we don’t do it, the insurance companies will do it for us,” predicts Plater-Zyberk. Locales with office buildings, government agencies, and residential high-rises, “you might want to think about protecting more” than places with just retail strip malls, she says.
Within the Biscayne Corridor, Plater-Zyberk names Brickell and downtown’s urban core as communities that likely will be considered worth saving. She doesn’t cite any expendable Biscayne Corridor neighborhoods, but does say that “in West Dade or South Dade, where there is low density and low investment, we probably are not going to do anything.”
How do you defend areas deemed worthy if they are, like much of Brickell, sitting at very low elevation? Pumps will only work temporarily, and seawalls and dikes are going to be useless. Seawater will find its way beneath seawalls, through the porous limestone that is ubiquitous in this region. Says Wanless: “You can build all the walls you want, but it won’t keep the water out.”
While experts ponder that dilemma, others argue for immediate changes to safeguard new development projects. If Nanni had his way, for instance, he’d ban the use of concrete reinforced with steel rebar and require builders to use fiber composite materials that enable a structure to “last forever” in a saltwater environment. He’d also require new construction to be built on at least six feet of fill, which he says would protect it from sea-level rise for at least 20 years.
To help communities last longer, Plater-Zyberk would raise the streets -- literally. That’s what Chicago did in the 19th Century to deal with flooding from Lake Michigan. “It’s not cheap, and one size does not fit all,” she says. Homes and buildings unable to be lifted will either be demolished or become the foundations of new structures.
Raising the ground in existing neighborhoods, Nanni advises, will be at least as difficult as building islands in the middle of the Persian Gulf. “Where are you going to get the material to do such things?” he asks. One option would be to sacrifice up to 15 percent of the county’s land mass by digging a series of canals and using the fill to raise specified low-elevation urban areas, he says. But ultimately, if sea levels keep rising, low-lying land will probably be doomed to saturation. “From a structural construction standpoint,” Nanni says, “there is very little we can do.”
That won’t keep people from trying. When sea-level rise first becomes apparent, property owners will be more concerned with defending their holdings than simply abandoning them, real estate analyst Zalewski expects. This will create a vibrant market for innovative, or smooth-talking, engineers. “There’s always some sort of solution for the right price,” he says.
Harlem agrees that the engineering sector will become lucrative in the future. “Engineers are starting to grasp that this is an issue that they can make some money on,” says Harlem. “I have a hunch that we’re going to see some interesting and spectacular what-ifs from these kinds of folks.”
If the region remains popular, and Zalewski thinks it will, builders might dredge up new communities to replace already-submerged waterfront areas. Or they might just build things directly on the ocean.
Harlem says an architecture firm from the United Arab Emirates has designed a saucer-shaped hotel that can be planted into the sea. Such resorts might be developed where Miami Beach used to be, or in the new Brickell Bay. During one climate conference, Harlem recalls, someone suggested floating cities as an alternative: “A naval architect said, ‘We can do that. We call them cruise ships.’”
Future builders are likely to retreat to higher ground, wherever they can find it in South Florida. But such elevated points will be scarce after five feet of sea-level rise, and over time they would become isolated island communities.
In the end, there will be but one solution, Harlem believes. Simple and straightforward. He puts it this way: “I think it would be smarter to move to plus-170 feet elevation and get it over with, which is north of Tallahassee. Just one move and you’re done.”
Volume 14, Issue 11, January 2017
Many South Florida plants arrived with the slave trade
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