Regional Sea Levels and Future Scenarios

New analysis for Coastal Communities: Using the Past to Help Plan for Future Sea Level Rise In Your Region

Information from satellite altimeters show that global sea level has been rising at about 3 mm/year over the last several decades. But that is not necessarily what is happening in every region. Local sea level trends from NOAA tide gauges with a minimum of 30 years of data provide the clearest picture of the historical rise or fall of sea level relative to the land. Now NOAA has taken local sets of sea level data and calculated a composite "index" to compare to satellite altimeter observations within a region. Trends computed on the tide gauge or altimeter regional "indices" can be compared to the global rates.

The NOAA regional indices provide communities a baseline to better understand how the height of the ocean has varied within a region. Regional tide gauge indices, which have vertical land motion effects removed, are shown with satellite altimetry indices from the same region and four future scenarios of global sea level rise. These scenarios are the most recent put forth by the U.S. National Climate Assessment and they show a "possible" range of global average sea level rise by 2100. These graphs can be used to show how your region compares with the global scenarios.