New York City and the Shifting Coastline

I think this means he was really off on the date, or I was stupid enough to buy a house underwater. (It's a dump, but it's not underwater.)

"New York will not exist as we know it today after January 21, 1980. Shifting ocean currents and earth tremors will begin to remake the eastern coast of the United States beginning in 1971. At first changes will be small, but within three years our geologists will know what is happening. As the coastline shifts, the land will sink and the ocean will pour inland. Before 1978, Long Island will be mostly underwater. Only the areas that can be protected by hastily erected dikes will escape--and they, not for long. Manhattan will become a city of canals, like Venice. Billions of dollars will be spent to save New York, but by 1980, all efforts will have failed and a new New York will rise, further inland, at great expense."