Sea levels are going nowhere but up, and fast: By the middle part of the century, we could see two to four feet of sea level rise in Florida, according to coastal scientist Harold Wanless of the University of Miami. And within 50 years, it could rise by three to six feet, or maybe more.
As rising seas encroach on Miami from the east, they’re also causing grief from below. The city is built on highly porous rock, limestone that’s almost like Swiss cheese. As the sea level rises, it pushes inland under the ground, raising the water table closer to the surface. When a heavy rain comes, the ground is already waterlogged. So instead of trickling down into that Swiss cheese, the water has nowhere to go. It accumulates on the surface, leading to flooding.
Standing water also becomes a breeding ground for disease-carrying pests like mosquitos. “With the water comes more vector-borne diseases,” says Cheryl Holder, also of Florida International University, and co-chair of the Florida Clinicians for Climate Action. “So we already had dengue and Zika, and we expect more of this happening if we continue with stagnant water, sea level rise, and more extreme weather.” Dengue can in severe cases lead to internal bleeding and death, while Zika can lead to severe birth defects. The Super Bowl happens to coincide with a kind of Goldilocks season for Miami, where there’s low risk of extreme weather, and it’s still too cold for mosquito populations to explode. But Floridians have no such guarantees the rest of the year.
And there’s another problem, one that brews underground. As the water table rises, it infiltrates sewage systems. “Septic wastes may be discharging around the surface and people are trudging through them. And maybe some of it’s even getting into their homes under really more dramatic flooding conditions,” says Michael Sukop, a hydrogeologist at Florida International University. “That definitely could be an issue from a public health perspective.”
Meanwhile, as the sea levels rise, salt water taints fresh water aquifers. “Probably with the next two feet of rise we’ll have to be desalinating all our water,” says Wanless, of the University of Miami. “Even with the big Everglades next to us, it’ll probably be significantly compromised.”
So don’t cancel your trip to this weekend’s Super Bowl. But the next few years will be a critical period for Miami to adapt to a host of threats—rising tides, fiercer storms, and an elderly canal system. Engineers have been retrofitting those canals with pumps to get water out of them even during high tides. The city has 20 in operation, with dozens more planned—though these are expensive to build and run.
Sea walls can be useful, but it’s not like engineers can barricade the city and it will never flood again. “You actually have to go below the floor of the ocean to stop the sea level rise, because it’s coming under the land,” says Kirtman. “Sea walls work to some degree in some places, but if you’re looking for a Dutch solution to our problem, it’s not going to happen.” (For centuries, the low-lying Netherlands has held back the sea with dikes.)
Massive undertakings like sea walls raise the specter of inequality. Climate change will in many ways disproportionately imperil the most vulnerable among us, particularly those who can’t afford to insulate themselves against it. Miami Beach is loaded with money that could be used to hold back the tide. But Miami Gardens, where Hard Rock Stadium sits, is a working-class neighborhood with a median household income of $42,000. “Miami Gardens, thank God, they’re about 7 to 10 feet above sea level, so there may be less flooding,” says Holder. “But with salt water incursion into your sewers, you’re going to have other issues.” And extreme weather, like supercharged hurricanes, cares not for sea walls. Insurance premiums in high-risk zones are climbing, premiums that, increasingly, only the rich can afford.