Sea-level Rise and Coastal Inundation

Global sea levels are rising due to melting continental ice sheets, melting glaciers, and warming-induced expansion of the oceans. In some parts of the South such as the Louisiana Gulf Coast, sea level rise is compounded by subsidence, the gradual “sinking” of land surface to geological processes, removal of oil, gas, groundwater or other pressurizing substances from the ground, and the lack of offsetting sediment deposition. As sea levels rise, saltwater intrudes and increases the salinity of estuaries, coastal wetlands, and tidal rivers. As a result, salt-sensitive plants and trees die and related ecosystems are forced to migrate further inland to survive, unless prevented by barriers such as roads, farms, and towns. In addition, at certain elevations, saltwater can intrude into freshwater aquifers.

By disrupting coastal forest ecosystems such as cypress swamps, sea-level rise and coastal inundation can have adverse effects on forest-related ecosystem services. For example, coastal forests and wetlands act as natural barriers to storm surges. Thus, the loss of these ecosystems increases the vulnerability of inland communities to flooding caused by tropical storms and hurricanes. Likewise, the loss of coastal forests can increase the loss of sediment to the sea. In addition, it can decrease the recreational and hunting benefits people derive from these ecosystems.

Sources: 

Hoyle, Zoe (2008). That Carbon Dance: Compass 10. Online at http://www.srs.fs.usda.gov/compass/issue10/issue10.pdf

Karl, Tom; Melillo, Jerry; Peterson, Thomas; Hassol, Susan Joy. (Ed). Global Climate Change Impacts in the United States. United States Global Change Research Program. Cambridge University Press: 2009.

Images: 

Dead Cypress Saltwater Intrusion

Category: 
Forest Cover Gain/Loss
Climate