Sea Level Change Statistics

• Sea levels have risen an average of 5 to 6 feet along the Atlantic and Gulf coasts in the past 100 years. Higher-then-average global temperatures have caused the melting of ice caps and glaciers, adding to the sea level rise. Higher atmospheric temperatures increases storm activity as warmer air leads to more evaporation and more cloud development. Sea level change over the past 100 years has had significant impact on coastal erosion.
  
  

Coastal Erosion and Wave Action

• Sea level rise increases coastal erosion in several ways. First, as the sea level rises, wave action moves higher onto the beach. The surf washes sand and dunes out to sea or makes the sand migrate parallel to the shoreline. The loss of the beach equals a loss in a buffer zone between the land and the sea, and this can lead to erosion of inland areas.
  
  

Coastal Erosion and Wetlands

• The loss of coastal wetlands also contributes to coastal erosion. Some IPCC models suggest that 33 percent of the global coastal wetlands will be under water by the year 2080. Areas with small tide ranges, such as sandy beaches, will see the greatest effect. Coastal wetlands will begin to migrate inward, destroying other habitats and inundating homes. In steep terrains, the loss of coastal wetlands means the water does not have a chance to slow down before entering the ocean. More sediment is washed out to sea, rather than settling on the shore.
  
  

Coastal Erosion and Storms

• Storms are the biggest factor in coastal erosion. The intensity, number and duration of the storms effects how much of the shore is eroded. The increase in the intensity and number of storms in the past few decades has eroded a number of coastlines. Storm surge and wave height increases devastate beaches. The higher the sea level, the further the storm surge moves onto the beach. Humans contribute to the increase in coastal erosion through engineering techniques used to save homes. Many times, humans move sand dunes in an attempt to protect a specific structure, only to have the dune wash away. Sea walls can protect structures but often lead to complete loss of beaches along the bays. Some states have enacted laws allowing sand dunes and wetlands to migrate naturally, without human interference. The theory is by allowing nature to take its course, less coastal loss will occur over time.