This assumes the demand for property stays the same. Is it likely, once it becomes obvious there's a chance your property will be destroyed by rising sea levels?
I used to think that obviously coastal real estate would plummet in value after a few high profile losses. After this pandemic I no longer think it will happen except very, very slowly. But the beaches will be gone for perhaps centuries, the sand will wash away / get covered in water. Sand does not form in a day. I have seen this in areas of Greece where there were earthquakes decades ago. Not even a hint of a beach remains.