1.8 to 3 millimeters a year from 25 years of satellite sea surface laser altimetry. Its not an easily obtained number because you have to account for the &quot;noise&quot; of much larger waves, seafloor topography gravitational distortion, multiple satellite generations, and other phenomena. But its is considered a more accurate number than local tidal gauge measurements, which is subject to local interference causes like subsidence.<p>I do not know if any paper has claimed an observable acceleration or deceleration of this rate yet.