They’re not talking about sea level rise in this case, but sinking land. Most beaches are the same as they’ve been the last 1,000 years.
IIRC, a lot of this dream-data comes from haphazard measurements of low lying land in some Florida coastal city where MAN-involved large scale terrain change was a significant factor. They must have gotten some UF or other Florida doctoral student to fabricate some ‘hockey stick’ curves from that data.
“They’re not talking about sea level rise in this case, but sinking land.”
Global warming freaks appear to be unable to tell the difference.