Rapid sea-level rise

Several global and regional factors contribute to observed sea-level change along any particular coast. Global processes include changes in ocean mass (glacio-eustasy from ice melt), ocean volume (steric effects), viscoelastic land movements (glacioisostatic adjustment GIA), and changes in terrestrial water storage. Regional processes, often connected to steric and glacial changes, include changes in ocean circulation (Meridional Overturning Circulation [MOC]), glacial melting, local GIA, regional subsidence and others. Paleoclimate, instrumental and modeling studies show that combinations of these factors can cause relatively rapid rates of sea-level rise exceeding 3 mm yr−1 over various timescales along particular coasts. This paper discusses patterns and causes of sea-level rise with emphasis on paleoclimatological records. It then addresses the hypothesis of late Holocene (pre-20th century) sea-level stability in light of paleoclimatic evidence, notably from reconstructions of sea-surface temperature and glacial activity, for significant climate and sea-level variability during this time. The practical difficulties of assessing regional sea-level (SL) patterns at submillennial timescales will be discussed using an example from the eastern United States.