I think this is mostly addressed in the article > Hes saying the sea has risen and the people who say it hasn't are wrong. Quoting from the webpage >> To be

I think this is mostly addressed in the article > Hes saying the sea has risen and the people who say it hasn't are wrong. Quoting from the webpage >> To be fair to those folks, it's true that – as they claim – the water level of various landmarks around the world... has not "visibly" risen since they were erected... The fact... is that the global average sea level has risen by 15-25cm (6-10") since 1900. That is – there has been some sea level rise, but not that much (yet) and therefore people may not have noticed it. Venturing beyond the first paragraph, the main point seems to be this paragraph (emphasis mine) >> *The thing is, sea level rise lags behind global warming by several decades.* So (if you'll excuse my hitting-rather-close-to-home choice of pun), what we've seen so far is just the tip of the iceberg. We've already locked in another 10-25cm (4-10") of sea level rise between now and 2050. And we're currently looking at a minimum 28-61cm (11-24") of sea level rise between now and 2100, and a minimum 40-95cm (16-38") of sea level rise between now and 2200.