A new study has warned that New York might face extreme floods of the same magnitude as 2012's hurricane Sandy or may even be higher, at least three times more frequently in the coming decades than today, all because of climate change and rising sea levels.
According to the study conducted by a team of researchers from the University of Princeton, University of Rutgers and the Woods Hole Oceanographic Institution, surge floods are estimated to occur 17 times more likely between the years 2000 and 2100 in the worst case scenario. Notably, hurricane Sandy, which struck coastal areas of New York and New Jersey back in 2012, left more than 157 people dead. The devastating 9-foot-high floods caused around $71 billion in damages. Hurricane Katrina of 2005 was even more destructive.
For the purpose of the study, the researchers collected historical data such as tidal-gauge records and geological records from New York City since 1856. They used the data to develop computer model projections to ascertain how frequent floods will be in the area in the years to come. The projections included models of storm intensity, storm surges and sea levels.
The researchers found that the frequency of a Sandy-like flood increased around threefold between 1800 and 2000. The likelihood of New York encountering severe floods has increased to once every 400 years in 2000 compared to once every 1,200 years in 1800. In fact, by 2100, the floods are expected to occur once every 90 years. The rise in sea level mostly resulted from natural effects, such as the gradual sinking of the mid-Atlantic region at the end of the last ice age. However, during the late 20th century, human-caused climate change largely increased the sea level.
Lead author of the study, Ning Lin, who is an Assistant Professor of Civil and Environmental Engineering at Princeton University, said the frequency of extreme floods like hurricane Sandy has grown significantly over the last two decades. Lin added that because of rising sea levels and changes in storm climatology, the frequency is likely to rise more sharply over the 21st century.
"The grand answer is that things are going to get worse by 2100. If nothing changes with hurricanes, sea-level rise alone will increase the frequency of Sandy-like events by 2100," said Researcher Benjamin Horton, from Rutgers University.
Lin expects that with more refined hurricane dynamic and climate models, they would be able to make more accurate predictions that will help planners better design flood mitigation strategies.
The study is published in the journal Proceedings of the National Academy of Science.