By Orrin H. Pilkey and J. Andrew G. Cooper
Floridians are becoming more attuned to sea level rise and more familiar with nuisance flooding related to the rising sea. However, we believe there is less recognition that by century's end it is likely that most of Florida's major beaches will be permanently gone.
Florida has some of the most famous and glamorous beaches in the world that rank right along with the likes of Rio de Janeiro, the Gold Coast of Australia and Waikiki. All these famous beaches around the world have much in common as they are prime spots for national and international vacationers. Unfortunately, another common denominator is that these beaches are lined with high-rise buildings.
A local example of an endangered beach is Sand Key in Pinellas County, which has an eroding shoreline where multiple beach nourishments have been carried out. Sand Key's numerous large beachfront buildings mean it's likely to be a beachless community before the end of the century.
The global problem with high-rises on beaches is their total inflexibility. When the expected 3- to 6-feet (or more) sea level rise occurs by the end of this century, it will be far too costly to move hundreds of very large buildings to higher ground. And in Florida there often is no nearby higher ground.
The universal assumption is that beach nourishment will protect the buildings while maintaining an attractive beach. But as the seas rise, these beaches will be unstable because they are "out of place." In other words, as sea level rise proceeds, the location where the natural beach (assuming no development) would like to be gets farther and farther landward from where the beach is being held in place in front of the buildings.
By the end of the century, a natural Florida shoreline would, in response to sea level rise, be thousands of feet (even miles) back from today's shoreline and 3 to 6 feet higher than the "out of place" nourished beach. When this happens, nourished beaches will no longer be in equilibrium with wave conditions and the level of the sea.
As a consequence, successive nourishments will disappear faster and faster, they will have to be replaced more and more often, and the cost will be higher and higher. The buildings would eventually have to be protected by large seawalls which would in themselves increase the rate of nourished beach disappearance.
Because the recreational beach is the raison d'etre for the existence of most high-rise beach communities, having no beach will be a calamity. Much of the tourist industry must then move elsewhere. We discuss this coming crisis in our book, The Last Beach.
Cape May, N.J., is an example of what can happen with a lost beach. The beach there disappeared in the early 20th century as a result of the emplacement of a large seawall before beach nourishment became a common approach to dealing with erosion. For most of the 20th century, Cape May was without a beach and promenading on top of the wall was the major seaside activity.
Recife, Brazil, has basically given up on the ocean beach and replaced it with a band of sand behind a large seawall. Here, vacationers can feel the sand on their bare feet, can play volleyball, and sunbathe, but these strips of sand are a poor substitute for a wave-washed natural beach. They need to be continually maintained as they attract trash and act as giant cat litter boxes. A number of other high-rise beach communities have likewise abandoned their beaches, choosing to protect private property at the high cost of beach loss.
It is likely that as soon as 50 years from now, some of Florida's tourist communities will suffer the permanent loss of beaches. The state must make every effort to halt the spread of high-rises to the remaining beaches that presently have none. Such beaches are the future of Florida's beach tourism.
Orrin H. Pilkey Jr. is professor emeritus in the Nicholas School of the Environment at Duke University. J. Andrew G. Cooper is a professor in the School of Environmental Sciences at the University of Ulster in Coleraine, Northern Ireland. Co-authors of "The Last Beach," they wrote this column exclusively for the Tampa Bay Times.