Although it's probably true that my attitude here isn't the most constructive, it's also true that for some people (I'll yet withhold final judgement regarding OP), any attempt to educate or have dialog falls on deaf ears.
This gets really tiring when online forums are replete with people willing to espouse opinions based on incomplete or distorted understanding with little more than an offhand remark. So if I come across as frustrated, well, maybe you can try to forgive that. It's harder for me to forgive pseudoscientific evangelism.
The sea level has been rising for over 20,000 years. Just to give you perspective on the changes since the Halocene era began, here's more documented evidence for you to snark about: https://en.m.wikipedia.org/wiki/Early_Holocene_sea_level_ris...
This shows 20K years of sea level rise since the end of the last glacial period. Numerous centuries in that time contain more rapid sea level rise than present. So, all of that hundreds of feet of rise for the past 20 millenia were natural...except for the past few dozen centimeters of rise? That's all man-made? Give me a break.
It's really frustrating when history deniers like you try to act like you're more educated than the people you're debating when you have a huge gap in your knowledge.