Some people were commenting on this post about Boston sea level acceleration. Tamino didn't calculate acceleration, but here's what I get, though without any error bars. (I haven't done this before in Excel, so I don't have a spreadsheet I can just plug data into.) This is the acceleration from any date (x axis) onward to the latest value (here, Dec 2019):
So (cherry picking), since about 1970, the acceleration has been about 0.2 mm/yr2. Also about the same since 1996, though obviously with bigger error bars, whatever they are.