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 "noise

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 "noise" 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. I do not know if any paper has claimed an observable acceleration or deceleration of this rate yet.