Rising Sea LevelRising sea levels have been disturbing geographers and geologists forsome time now. Scientists are constantly trying to prevent the effectsrising waters are causing, which mainly includes beach and island erosion. So far, their attempts with man-made development on beaches along the easterncoast of America have only made things worse. “Up and down the U.
S. coast, public money is subsidizing private propertyon islands made of sand, the stuff on which, as the Bible says, only foolsbuild” (Ackerman 7). In recent years there has been a trend towards livingon the barrier islands of America’s Atlantic Coast. High rise condominiums,numerous shops, and several businesses have been built to sustain largepopulations on these islands and continue to be built. As a result, thisvital chain of islands that lies between the ocean and the mainland areat risk. While interfering with the natural configuration of these islands, humanconstruction has advanced the rate of beach erosion, thus leaving the mainlandwith no barriers during times of high surf.
This effect has also led tocostly, unnatural ways to preserve the barrier islands. Saving these islandsin their natural state by curbing human encroachment will both protectmainland populations from high surf and save a considerable amount of federalmoney. The barrier islands are a chain of islands, stretching from NewYork to southern Texas, that have served as a critical barrier from theAtlantic Ocean for well over the past 4,500 years (Ackerman 23). These islands however are not as stable as those who live on them wouldlike it to be. Beaches, and in fact whole islands, are constantly erodedas they are subjected to varying winds, currents and changing sea levels. Along Florida’s East Coast, roughly 368 miles, the average shoreline changeis retreating 22cm per year.
Under natural conditions, native vegetationand shifting sands constantly replace or withhold sand on the islands (16). Unfortunately for the inhabitants of the barrier islands, this is a geologicalbehavior which can only continue if the islands remain in a natural state. In recent years humans on these shorelines and islands have been respondingto the naturally changing conditions, through the use of man made structuressuch as seawalls, groins, and sand replenishment, in an effort to savebeachfront property from erosion. Obstructing the natural shifts of the islands, says Orrin Pilkey ofDuke University who has studied these islands for thirty years, will causethem to, “be lost forever” (16-17). Attempting to hold beaches in placewith the use of seawalls, groins, and sand replenishment may seem likea good solution in theory, but in practice they probe ineffective.
Oneof the most common methods of attempting to hold barrier island beachesin place is through the use of sea walls, which are costly and ineffective. Seawalls are typically cement walls constructed parallel to the seashorein an effort to block waves from coming over the beach and into property. However, seawalls tend to withhold sand behind the wall during times ofhigh surf and the natural tendency of the beach to respond to waves isdisturbed (Kaufman 207). The structures commonly fail from undermining or erosion by waves breakingover their tops. Under normal conditions sand would be spread out by outgoingcurrents, which in turn would lower the slope of the beach and cause thewaves to break gradually. With seawalls in place, sand remains stationarywhile waves erode the beach as wave energy is deflected against sand notprotected by the seawall (208).
In addition to advancing the erosion rateof the sand and inhibiting the beaches’ natural tendencies, seawalls havebecome quite costly to maintain. For example, in New York $120 millionwas paid by the federal government to sustain and replenish seawall installationsas of 1996, and repairs continue to be made (Dixon 231). Clearly, thismethod is both costly and ineffective. Another commonly used method ofstopping erosion is the placement of groins, which are also ineffective. Groins are pilings of rocks that extend into the ocean and perpendicularto the shore.
Like seawalls, the primary purpose of a groin is to trapsand, but in longshore currents rather than sand deposits already on thebeach. Contrary to their intended purpose, these structures trap sand on theside facing a longshore current and leave the opposite side without sand(Kaufman 207). Over time, the side not facing longshore currents erodesand the initial problem reoccurs. Once again, after the unsuccessful useof groins, money and resources must be spent to restore the beach.
A recentmethod of stopping erosion, and perhaps the most expensive, is that ofsand replenishment. Sand replenishment uses dredging techniques to pipesand from offshore deposits to the beach in an attempt to replace sand. This operation is also costly and the sand is usually lost in a major storm. Renourished beaches have a shorter life due to compaction and sea bottomimbalance differences.
One example of its cost is that of Sea Bright beachwhere, at one million dollars a square mile; their beach was replenished(Ackerman 29). The total cost of this operation, which lasted between 1994 and 1996,was $36 million (29). These are just a few of the myriad of inadequateattempts to stop seashore erosion. Not only do these human obstructionsto the natural course of nature cause an accelerated erosion, millionsof government dollars are being lost in the process of attempting to savebeach front property from natural erosion. There are over 90 Federal navigationprojects and 21 Federal shore protection projects in Florida alone. Theseprojects have an annual maintenance cost of $32 million.
Stephen Leatherman,head of the Coastal Research laboratory at the University of Maryland,suggests that, “In [coastal] nourishment projects locals pitch in about5 percent, state and county tax payers pay about 30 percent, and the federalgovernment pays the rest” (Ackerman 30). Apparently, at the cost of theAmerican government, large sums of money are being spent on these futileefforts to stop natural occurrences. Recently in the past few years, anew attribute has been looked at. A bulge formed by Ice Age glaciers isslowly settling, while the mid-Atlantic coast is falling.
In many places,the sea is taking back the land at the rate of about an inch every 25 years. Originally, scientists pondered why the sea level was rising fasterbetween Florida and New York than farther north. They hypothesized thatit must have been a shift in the Gulf Stream, but this new research showingthe fall of the land proved them wrong. Regardless, sea levels continueto rise and scientists are running out of ideas to prevent this from happening. Global sea level has risen 4 to 10 inches during the past 100 years becauseof global warming. By year 2050, a 16-inch sea-level rise is projected.
Consequences of a higher sea-level to our coastal areas have not only includederosion, but some believe other effects it will have will include: tourism,the availability of drinking water, and damage from storms. The only effectivesolution that seems practical at the moment, without risking such largesums of money, is that human occupations of these islands become restricted. In most cases, people probably come to the seashore for recreation andrarely for necessity. Why not just live minutes away on the mainland andavoid having millions of dollars being spent on keeping beachfront propertyfrom washing away? This way federal money currently being spent on coastalprojects, such as seawalls, groins and sand replenishment, can be allocatedto more pressing problems of our nation. Until another economical solution,which does not contribute to the problem of erosion, is possible peopleshould minimize residential development on the barrier islands before boththe beaches and money wash away.
Bibliography Ackerman, Jennifer. “Islands at the Edge. ” National Geographic. August, 1997:2-31. Dean, G.
Robert M. D. “Review of Long-Term ShorelineChanges in Florida” Online. AOL.
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C: Island Press, 1996. Head, M. Clarence and Marcus, B. Robert. The Faceof Florida.
Kendall/Hunt Publishing Company 1998:144-147 Kaufman, Wallace,and Orrin H. Pilkey. The beaches are moving: the drowning of America’sshoreline. New York: Anchor Press, 1979.