Using modeling programs developed by the University of North Carolina, the scientists simulated the observed flooding of Sandy as it hit New York City and also what would have occurred in the absence of the 20-centimeter sea level rise. They applied wind and atmospheric pressure data from Sandy and elevation maps of the city, along with information from the city’s Office of Emergency Management, which identified 33 different types of buildings in flooded areas and their locations within each census block.
Flooding from Sandy actually affected 579,529 people in 250,569 housing units, totaling $11.9 billion in damage, according to the simulation. In the absence of 20th century sea level rise, those figures would have been 520,115 people, 224,540 housing units, and $9.6 billion in damage, said [Scott] Kulp.
In other words, he said, “The last 7% of the storm surge affected 11.4% more people and 11.6% more housing units than it would have without sea level rise, as well as 24% of the total New York City property damage due to Hurricane Sandy.”