What Will Happen After the Flood

"As the oceans heat up, they expand—up to eight inches in height already—and melting glaciers in Greenland and Antarctica continue to pump up the volume. The flow of ice into the sea has doubled over the past decade and over the next century could cause a 20-foot rise, making densely populated regions like the Nile Delta uninhabitable. In the U.S., even three more feet would flood every city on the Eastern seaboard. If you remember the aerials in An Inconvenient Truth, you know how this might look: Whole coastlines shrink as water spills inland and redraws the map of the world."

"The ascent is likely to happen gradually, so there is time to plan. Mass migration is inevitable, but abandoning every affected area isn't practical. Monumental seawalls will spring up, but New Orleans' levees are a tragic demonstration that this strategy isn't fail-safe."

"The real test will come with larger metropolitan areas. A report released in December by the Organisation for Economic Co-operation and Development (OECD), an international governmental organization based in Paris, lists New York among the 10 places most threatened by future flooding. For a wealthy city, its protection is minimal, so the images of a deluged Manhattan in the 2004 film The Day After Tomorrow may not be a Hollywood fantasy."