Study finds N.Y. vulnerable to storms

“The increase will be for two reasons,” Michael Oppenheimer, professor of geosciences and international affairs, explained. “One, as temperatures get warmer, there will be more intense hurricanes, and two, higher sea levels means bigger storm surges, more intense floods.” Oppenheimer is one of the co-authors of the study.

The researchers performed simulation studies using New York City as a test case to predict the nature of the storms that may hit such areas. They coupled a hurricane model with hydrodynamic models to simulate large numbers of synthetic storms under different climate conditions. They then applied statistical analysis to the simulated dataset to estimate the probabilities of the surges.

“We developed a physically based methodology that can be used to estimate surge risk in any coastal area,” Ning Lin, the leading author of the report and a post-doctoral fellow at MIT, said in an email. “This method is based on the current hurricane science and surge modeling techniques.”

Civil and environmental engineering professor Erik Vanmarcke, another co-author of the study, said that he was surprised by the results.

“It was most surprising to me that the simulation study found such a significant increase in the chance of extreme storm surges — by factors of three to five — under future-climate scenarios,” he said in an email.

The results of the simulations have significant implications for how current cities should prepare for storm-related disasters in the future, including changes in infrastructure for flood-protection in coastal cities.

“The effects of climate change really do need to be considered in risk-based design of civil infrastructure systems in coastal cities throughout the world,” Vanmarcke said.

Oppenheimer added that it is important for cities such as New York City to realize that the risk of an unprecedented storm will increase over time because, in the event of such a storm, an evacuation on a much larger scale would have to be carried out than, for example, the one executed during Hurricane Irene this past summer. He explained that there will need to be more effective evacuation plans and warning systems and that it will also be important to renew and strengthen existing infrastructures.

Looking to the future, Oppenheimer said that the reduction of greenhouse gas emissions is crucial.

“We will need to reduce greenhouse gas emissions and be prepared for an increase in risk of intense storms as time goes,” he said.

Moving forward, Lin said, the research team plans to apply the methods developed in the study to other coastal areas in the country and worldwide to identify areas particularly prone to such disasters and to develop strategies for mitigating risk.