According to a new research carried out by researchers at Pennsylvania State University, melting of ice caps triggered by climate change is not just the only thing that could put New York City underwater. The new study showed that the city could face a repeat of hurricane Sandy flooding.

Researchers said a storm surge like the one similar to that of 2012 that made its way through the barricades, swamping roadways and flooding subway tunnels, could happen again.

Andra Reed, study author and graduate student in meteorology at Penn State in a university release said that in the pre-anthropogenic era, the return period for a storm producing a surge of 2.81 meters or higher like sandy at the Battery would have been about 3,000 years.

But they have found that in the anthropogenic era, the return period for this same storm surge height has been reduced to about 130 years.

They said storm surge occur when winds and atmospheric pressure from a large storm stir up seas higher than normal resulting in inland flooding. But the storm's power isn't the most influential factor in storm surges.

Michael Mann, meteorologist at Penn State, said, “Sea level is rising because of climate change. But climate change also appears to be leading to larger and more intense tropical storms”.

The Federal Emergency Management Agency (FEMA) also issued a revised floodplain map following the 2012 storm. The new map provides a fresh look, as the last one was made in 1983 by the agency.

Historic records of flooding in New York only date back to the mid-19th century, but by examining the distribution of microfossils called foraminifera in nearby salt marshes, researchers were able to reconstruct the history of tropical cyclones and flood events all the way back to 850 AD.

“It was necessary for the city to do it, to try to keep that affordability for homeowners,” Donovan Richards, a City Council member who represents parts of Queens, told the Journal. “But we also have to be cautious, and not shrink the map to the extent that if another storm comes, these homeowners would not have been in the flood zone.”