Eustatic Rise

Eustatic rise is the change in global-mean ocean volume expressed as a sea-level rise, driven by added water from melting land ice and by thermal expansion of the warming ocean (the steric term). It is the global, geocentric signal, distinct from relative sea level, which adds local vertical land motion such as glacial isostatic adjustment and subsidence. Satellite altimetry since 1993 puts global-mean rise near 3.3 to 3.4 mm per year and accelerating, with the budget closed by adding the steric and ice-mass (GRACE) components. A coast’s actual flood exposure depends on relative, not eustatic, sea level.