Climate Change - Coastal Zones

Coastal zones are extremely susceptible to a climate change. Particular concerns include a rise in sea level, land loss, changes in storm patterns, and their implications for water resources.

Sea Level Rise
Sea levels along the coastline of the United States are rising along with those of the rest of the world. Data from the past century alone has shown that sea levels around the United States have risen 5 to 6 inches more than the global average. The Environmental Protection Agency (EPA) is heading the development of a federally mandated study titled “Coastal Elevations and Sensitivity to Sea Level Rise.” This study will include information that will assist in the planning of community and environmental strategies. A public review of this report will be made available on the U.S. Climate Change Science Program (CCSP) website this year.

Many studies have been released to support the EPA report. Higher temperatures across the world have contributed to the sea level rise by melting glaciers and snowcaps and expanding sea water. Some estimates show a rise of 2 feet in this century alone.

The massive increase in sea levels raises uncertainty about temperature projections and how fast ice sheets can melt or slide into the ocean in a response to warmer temperatures. Data provided by satellite and hydrographic observations show that sea levels are not rising uniformly across the world. In some geographical areas, sea levels have risen several times the global average. While recent model projections have predicted various results in future sea level rises both at local and regional scales, the Intergovernmental Panel on Climate Change (IPCC) is confident that the impacts are “virtually certain to be overwhelmingly negative”.

Increased sea levels inundate wetlands, reduce beaches, increase flooding, and intensify the salinity of rivers and groundwater tables. These effects can be complicated by the uncertainties of a changing climate. Furthermore, the steps that individuals take to secure private property against rising sea levels can have adverse effects on the environment. Local and regional governments have already begun taking steps to minimize the environmental and economic impact of this potentially disastrous problem.

Land Loss
Wetland ecosystems in coastal areas, including salt marshes, have shown to be extremely vulnerable to rising sea levels because of their proximity to coastal seawaters. Wetlands offer shelter for many species of flora and fauna, play vital roles nutrient uptake, and serve as a basis for the livelihoods of individuals and communities. Some of the most economically vulnerable areas to this phenomenon include recreational resorts and barriers along the Atlantic and Gulf Coasts.

As sea levels rise, the boundaries of wetlands will bring to erode. New wetlands will form inland as a result of flooding. Scientists agree it is very unlikely that newly formed wetlands will be able to replace the amount of lost area.

Many local governments are already working closely with the Army Corps of Engineers to take steps in minimizing the potential impact of rising sea levels. Coastal cities are adding sand to their beaches to prevent erosion and property owners are raising existing structures. The aggregate effect of these measures will hopefully prevent any drastic impact of sea level rises, but only time will tell.