By John Ostapkovitch

PHILADELPHIA (CBS) – It’s the end of the world as we know it, says an oceanographer, not quite “Waterworld” but closer to it.

“How long can you tread water?”

The question from Bill Cosby’s Noah routines may be applicable in the wetter world oceanographer John Englander sees coming.

The worst case is sea level 212 feet higher. He says it has changed before, but not so people noticed.

“The last 6,000 years, which tends to be our recorded human history, is an anomaly because sea level hasn’t moved much whereas seas level moves up and down hundreds of feet, moving the shoreline in and out miles.”

In ‘High Tide on Main Street’, Englander presents ways to deal with the coming change. He says he foresees a thousand years of higher sea, what he considers the most profound aspect of man-made global warming.