Water levels have been rising since the last glacial period started ending, about 20,000 years ago. We've been cycling in and out of ice ages for the last few million years.
Oops, water levels have been rising for at least 2,500 years.
I had heard 13,000, but I was wrong. It was more like 16,000
https://en.wikipedia.org/wiki/Past_sea_level#/media/File:Post-Glacial_Sea_Level.png
Water levels have been rising since the last glacial period started ending, about 20,000 years ago. We've been cycling in and out of ice ages for the last few million years.