A significant concern the author is not considering is soil salinity. Most of the coastal land is not easily defendable cities, but productive agricultural land

A significant concern the author is not considering is soil salinity. Most of the coastal land is not easily defendable cities, but productive agricultural land. When sea level rise then the salty water infiltrates into the ground water and makes vast amounts of soil infertile, from what I understand a much larger area than the zone lost directly to flooding. This will destroy massive wealth and push rural farmers inland, in conflict with each other or the wild areas.