In Miami Beach, they call it sunny-day flooding. Youll be hanging out downtown under clear blue skiesonly to see, whoa, the streets slowly filling with water.
Miami Beach, Florida, is a coastal city built on porous limestone, so as climate change melts polar ice into the oceans, water is literally pushed up out of the ground. Its an eerie, scary, unnerving feeling, like something out of a sci-fi movie, says Philip Levine, mayor of the city of 90,000. On days when Miami Beach actually gets a coastal storm, it can see a 2-foot flood.
So the city decided enough is enough. Levine has begun a $400 million resilience plan that calls for installing high tech drainage systems and painstakingly raising the roads several feet. Its not fun to go and raise peoples fees, Levine says. But what choice do they have?
Global-warming denialists, including, at times, the new US president, claim that climate change isnt happening. This is abject nonsenseask anyone who lives near an ocean. Theyre all dealing with the unsparing laws of physics, and the 2.6 inches the sea rose between 1993 and 2014. Flooded basements dont care whether you believe burning carbon-based fuel is raising Earths temperature or not.
Thats why coastal cities worldwide are pumping more than $280 billion a year into an Adaptation Economy, which puts a price tag on preparing for the future. That amount is increasing by more than 4 percent a year in well-off, developed cities.
The money is propelling some ingenious engineering. The Dutch are great at thisRotterdam already has sophisticated dikes, and the city is building newfangled water plazas, buildings with reservoirs that sequester rainfall, letting it seep out into the ground or into wading pools for kids instead of adding to floods. Other innovations even have aesthetic value: In China, Dutch engineers are building a sponge city that uses a network of grass gardens and ponds to absorb runoff, an approach they call living with water.
Dutch firms, long specialists in the arts of living below sea level, are suddenly in high demand. Climate change, sea level rise, and the risk of flooding is a great business opportunity for us, says a somewhat rueful Piet Dircke, head of water management for Amsterdam-based adaptation firm Arcadis, which is working on the sponge city.
This isnt only about atoms; the Adaptation Economy has to move bits too. If you want to understand how and where water will inundate the coasts, you have to model it. Cloud supercomputing and lidarthe tech that helps self-driving cars seehave already produced better estimates of storm surges. Even greater puzzles remain, such as how intertidal marshland is affected by encroaching salt water. That stuff is really difficult to model, says Scott Hagen, director of the Center for Coastal Resiliency.
Consider this a cursed area of innovationit shouldnt be necessary. But it is, and we need far more of it. Thatll require political action: States and the federal government need to give cities more dough, and Congress should reform flood insurance so that people have greater incentives to protect their homes, with, say, tide-proof ground floors, or to avoid building in endangered coastal areas. Meanwhile, impoverished coastal cities worldwide are in urgent need of foreign aidbefore rising seas create humanitarian and refugee crises.
I recently visited an experimental sponge park created by architect Susannah Drake on the edge of an old toxic canal in Brooklyn. Drake filled recessed concrete boxes with soil and plants specially designed to absorb and dissipate flood runoff. It was postapocalyptically peaceful and strange. This is the one silver lining of our predicament: If we get adaptation right, well not only preserve our citieswell upgrade them.
This article appears in the April issue. Subscribe now.