>>>NEW YORK - The continued warming of the earth's climate is melting mountain glaciers and polar ice sheets and that's causing the world's oceans to rise - slowly, but surely.  Most scientists agree that sea levels could rise by more than one meter by the end of this century, and that could spell trouble for low-lying island nations and coastal cities around the world - such as New York.  America's most populous city is studying ways to keep those rising waters at bay.

When Hurricane Sandy struck last October, New York got a taste of what its future could be.

One Brooklyn youngster, Jerry Gonzalez, was in the midst of it.
   
“The water was up to half of the door, and then we had to get buckets and try to take out all the water," he said. "Until we opened the door, and we saw the refrigerator floating on the water."

In New York City, the waters surged more than four meters above the average high tide mark.

Klaus Jacob is a research scientist at the Lamont-Doherty Observatory at Columbia University.  He describes what New York would look like if sea levels around the island city rise by 70 centimeters, as some studies predict they will by the year 2100.

“It would look like Wall Street doesn’t have yellow taxis. But it might have yellow taxi boats," said Jacob.

Jacob says below-grade basements would have to be sealed, and heating, cooling and electrical equipment would move to higher floors.  Subways entrances and air grates would have to be redesigned.

The federal government's Emergency Management Agency, FEMA,  has released new flood zone maps for New York to review.  New York City Mayor Michael Bloomberg calls the maps a blueprint for the future.

“Those maps will guide us in setting new construction requirements to ensure that buildings can withstand intense winds and waves that we expect down the road," he said. "The fact of the matter is we live next to the ocean, and ocean comes with risks . If , as many scientists project, sea levels continue rising, however, there may be some coastline projections we can build that will mitigate the impact of a storm surge-from berms and dunes, to jetties and levees."

Columbia University's Klaus Jacob believes elevation is key. Like the Highline, an abandoned railroad track turned into a fashionable promenade, life above sea level could become routine.
 
"And we may want to have many more Highlines connecting skyscrapers," he said. "Some of them even may have transportation systems above ground instead of just subways."  

Michael Byrne is FEMA's coordinator in New York. He says decisions about building and rebuilding after Hurricane Sandy must be planned intelligently.

“Elevation is only one of the methods to protect," said Byrne. "We can build sea walls, we can build levees, we can choose not to rebuild at a place.  We can do buyouts so that people can move on with their lives in a safer place.”

Scientists say the seas have risen 20 to 30 centimeters over the past 100 years and some experts believe they could rise another 1.5 meters by the end of this century. Coastal cities and island nations are at greatest risk.

But whether the sea rises by five centimeters or 70 - the prediction for New York - residents of this city know they will either have to keep the ocean out or retreat to higher ground.

Camera, editing: Daniela Schrier.