The flooding, damage and misery from weather systems as powerful as superstorm Sandy — now estimated to take place every 400 years — could occur as often as every two decades by the end of this century, according to new research.
“Because sea level is rising and climate change may affect hurricanes, it’s going to happen maybe every 20 years,” said Benjamin Horton, a researcher at Rutgers University who co-wrote a study that projects 9-foot floods bursting onto the shores of New York City between three and 17 times more frequently than they do now, if current conditions continue.
The researchers focused on New York City after Sandy devastated the region, causing billions of dollars in damage, but Horton said the findings also apply to Long Island and New Jersey.
The study’s central thesis is that while no one can say which day such powerful storms and their attendant flooding and disasters will come, the calamities will be coming more often unless greenhouse gas production is curbed, Horton said.
Horton published the study, “Hurricane Sandy’s Flood Frequency Increasing From Year 1800 to 2100,” in the Proceedings of the National Academy of Sciences. The lead author was Ning Lin of Princeton University and the other two researchers were Robert Kopp of Rutgers and Jeff Donnelly of the Woods Hole Oceanographic Institution.
The study, which comes shortly before the fourth anniversary of Sandy, was commissioned by the federal government in 2011 to study the whole Atlantic coast, Horton said. Then superstorm Sandy happened on Oct. 29, 2012, an event whose magnitude was forecast by scientists based on the strength of previous maelstroms, but whose timing, they argue, was impossible to predict.
It found that, due to climate change, the planet on average has been recorded as getting warmer, and subsequent sea level rise has increased the impact of more storms occurring between the years 1800 and 2000. This finding led the researchers to estimate that future storms will create flooding and damage of similar impact even more frequently between 2000 and 2100.
“Because of the accelerating rise in [relative sea level], NYC’s flood hazard will increase more significantly over the 21st century than over the past two centuries,” the study said. “This effect of RSL rise may, again, be further intensified by the change of surge climatology.”
Horton said the effects are even apparent in the nation’s most recent storm, Hurricane Matthew, which was a weaker hurricane, registering at Category 3 when it hit the U.S. mainland, yet still caused massive flooding — evidence to Horton of the fact that sea levels were already higher to begin with.
Horton said the trend toward greater flooding due to storms can be lessened only through worldwide reduction in carbon dioxide emissions. And he said he was heartened by the Paris Climate Change Agreement, a landmark UN-generated pact that was signed by nearly 200 countries last year and is set to take effect next month.
“There is no place where the flooding is going to decrease,” Horton said. “The Paris Climate Change Agreement is a step forward. . . . I have hope because the young, bright minds of the United States and elsewhere will develop the technology to reduce our carbon dioxide emissions.”