Sea Level Change: Past, Present, and Future

This presentation provides an overview of the fundamental concepts of global sea level change. Basic definitions are reviewed and illustrated followed by an overview and discussion of the basic causes of global sea level change, including thermal expansion and ice mass loss. After a brief review of historical sea-level change over ice-age time scales, the present rates of sea level change determined from tide gauges and satellite altimeters are presented. Projected rates of sea level rise for the rest of this century from IPCC and the National Climate Assessment at the time of this presentation are given along with a discussion of uncertainty. Regional variations in the rates of sea-level change are illustrated by looking at the results from the measurements systems.

When this presentation was given Stephen Gill was the Senior Scientist for NOAA’s Center for Operational Oceanographic Products and Services (CO-OPS). As Senior Scientist, Mr. Gill was involved in strategic planning, budget initiatives and technical and scientific direction for CO-OPS. He developed science and technology plans for office programs involving tide, currents, sea level measurement, and vertical datums. He prepared reference manuals and specification documents for the measurement and application of tides and water levels and sea level change, and gave training sessions, seminars, and workshops to NOAA, other Federal agencies, and the general public. During his tenure he provided technical direction for CO-OPS activities related to climate, including the application and determination of sea level trends, exceedance probabilities, as well as the frequency and duration of inundation. Stephen served as the NOAA lead author for the US Climate Change Science Program on Coastal Sensitivity to Sea Level Rise in the Mid-Atlantic, and on several climate-related technical peer-review panels, including several government national review panels for IPCC Working Group chapters and panel studies.

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