Under the conditions of global warming sea levels globally are expected to rise considerably this century. The sea levels will rise largely due to expanding water due to elevated ocean temperatures and from melting ice, especially ice sheets. Many studies have been done on the conditions but the west coast of the United States recently evaluated potential rises in order to plan accordingly.
The states of Washington, Oregon and California collaborated to commission the sea rise report recently released. Performed by the National Research Council, the report detailed previous studies, including the Intergovernmental Panel on Climate Change’s 2007 report. The researchers also included satellite data of the coastal region, tidal readings and further climate models.
The report indicated that a large portion of the coast is expected to see rising seas of six inches by 2030. North of the San Andreas Fault, Northern California, Oregon and Washington will see a rise of four inches. The difference is attributed to the rising land due to seismic activity in this region counteracting the rise.
By the year 2100, sea levels are expected to rise by three feet south of the San Andreas Fault. North of the fault the region will likely see a rise of two feet. However, the report indicated that if a major seismic event occurs off the coast of Oregon it could drastically alter events in the region. If an earthquake similar to one 300 years ago were to occur the region would see a land elevation decrease which would essentially cause a three foot additional rise in sea level in the region.
Agencies along the west coast will use the information to plan for erosion, structure loss and to be prepared for heavy storm damage and potential flooding. The planners also have to contend with the fact that El Nino effects could add an additional foot of sea level during El Nino events. Globally sea levels will rise similarly as to the U.S. west coast, however, there is variability depending upon the locations such as seismic activity reducing the impacts in the Northwest.