The book discusses sea level rise spread over several centuries at slow rates but there is clear evidence presented in this book of a couple of periods of rapid sea level rise. (realclimate.org)
It was identified then and remains today the single largest threat of rapid sea level rise. (nasa.gov)
This was a period of very rapid sea level rise that lasted some 400 - 500 years when global temperatures were rising very quickly. (sciencedaily.com)