The Daily Mail has a fascinating story about submerged settlements between the British Isles and what is now mainland Europe. Of course, anyone who has been folowing things knows that there were various landbridges over which people and animalsl travelled since we began roaming around.
Catastrophic events occurred in the past too. Besides the volcanic eruptions that wiped ou Pompei and other cities, it's quite probable that the flooding from the Mediterranean basin into the Black Sea happened when people were around. Hence the cluster of stories and myths about a colossal flood in many cultures from Noah to Gilgamesh.
Word to the wish: might be good to take a lesson from the past and plan for big changes, now that the sea level is rising.