A recent article in The New Yorker, Elizabeth Kolbert's "The Siege of Miami," details disturbing consequences of sea level rise in Florida. The future will bring higher seas, but we normally think of climate change consequences happening nearer to the year 2100, an arbitrary target used by many climate models. Such projections are not what Kolbert's article investigates. Her article details climate effects we can see right now.
The Miami region of southern Florida averages just six feet above sea level, meaning that many parts of the region are vulnerable to the combination of modest sea level rise and periodic high tides. Here's how this aspect of climate change will manifest: high tides spilling into streets, parking lots with ducks floating by, ephemeral ponds on freeways causing hydroplaning cars, saltwater incursions poisoning landscaping.
This is already happening. The Florida of today, Kolbert reports, has water "bubbling out of the turf" and neighborhoods of multi-million-dollar homes with water "creeping under the security gates and up the driveways."
Not everyone living in Florida recognizes these inconvenient tidal floods for what they are. Kolbert reports that "one of the residents of the street had mistaken the high-tide for a water-main break." As she conducted her reporting, residents repeatedly asked her if she was from the city--as if city workers could hold back the ocean.
Even as residents slosh ankle-deep in the new sea level, they don't seem to get it. Kolbert notes that few living in Florida understand that "much of the region may have less than half a century to go" before it becomes uninhabitable. So it goes.
Many blithely assume that "they" will build levees to keep back the rising oceans. After all, it works in the Netherlands, doesn't it? But there are two big problems with such a plan. The Netherlands indeed has an extensive system of dikes and levees, protecting areas sitting below sea level; however, this kind of armored coastline won't work in Florida, because the underlying rocks are so porous that rising water will simply seep underneath dikes and levees. The second problem can be understood by the crumbling infrastructure throughout the country--collapsing bridges, pothole-filled roads, cities with lead-contaminated drinking water, deferred maintenance at every level. Not only is America no longer choosing to build major new public works, but we are not even maintaining the infrastructure we have. So the idea of America paying for vast coastal levees rising in time to meet the surging oceans is a fantasy. Indeed, the fact that climate change will inevitably require public investment for mitigation and adaptation is a major reason so many "small government" conservatives refuse to accept that it is happening.
Insurance companies may hold the key to the future of coastal cities. As Kolbert writes, "insurers will stop selling policies on the luxury condos that line Biscayne Bay. Banks will stop writing mortgages." At some point in our warmer future, insurance companies will refuse to do business in areas so likely to generate claims; homeowners relying on insurance as part of their mortgage may find their insurance canceled, without any other company willing to pick up the policy. Or they may find their rates increasing dramatically, according to the Lloyd's of London dictum that there is no such thing as a bad risk--only a bad rate.
Imagine the situation for Florida homeowners. To reach Sunday open houses, potential home buyers drive gingerly through shallow lakes flooding unfamiliar streets. "For Sale" signs in front lawns tilt as they stand in saltwater at high tide. Even if buyers could be found for such inundated properties, most of those buyers would need to secure bank loans, and in order for banks to write mortgages, houses would need to be insurable. If insurance companies flee a flooding region and refuse to do business there, the whole system collapses. Buyers could pay cash, potentially. But more likely what we'd see is homeowners slashing prices in a desperate effort to get out from under their literally sinking homes.
In response to these looming problems, the mayor of Miami Beach declared, "We can't let investor confidence, resident confidence, confidence in our economy start to fall away." Why not? Miami Beach was incorporated slightly more than century ago, and given the rising seas, it's hard to envision it physically existing a century from now.
No city enjoys a guarantee that investor and resident confidence will continue indefinitely, that the local economy will sustain at current levels, or that nature will be kind.
In Death Valley, not too far from where I live, there is a long 4x4 road that leads through Titus Canyon, and along this dirt path one encounters Leadfield, a rusty ghost town described by a weathered National Park Service sign that informs travelers, "...a post office was established in August, 1926. In February 1927, the post office closed and the town died." So it goes.
Perhaps someday there will be bronze plaques, visited only by snorkelers and fish, commemorating where great American coastal cities once stood.