New York City will be increasingly susceptible to hurricane-triggered blackouts in coming decades, despite the mitigation efforts put into action since Superstorm Sandy slammed into the East Coast two years ago, a new study has found.

While the direct impacts of hurricanes, such as loss of life, flooding, slowed or lost wages and infrastructure damage, are punishing to cities recovering from a storm, electrical blackouts represent a grave concern, as well.

An examination of how potential changes in hurricane intensity and activity could influence blackouts in 27 American cities, including New York City, the report from Johns Hopkins University used a computer simulation to predict the growing vulnerability of electrical grids in major urban areas up and down the Atlantic and Gulf coasts.

"If hurricanes become stronger, a lot of the country will see a lot more outages," said Seth Guikema, a geography and environmental engineering professor at Johns Hopkins and one of the report's authors.

The study, Guikema said, was crafted to address a specific question: How would power outage risk at the city level change if hurricane patterns and trends shift? The findings, he noted, could provide insight into how climate change will affect power systems along the Gulf and Atlantic coasts.

Whether the report forecast a significant increase in blackout risk or just a negligible jump hinged largely on a city's distance from the coastline. Also, some cities that experience hurricanes frequently, like Miami, may be better prepared for future storms, while other cities farther inland, such as Hartford, Conn., and Jacksonville, Fla., will see large jumps in their power outage risks.

"If I'm the mayor of Miami, we know about hurricanes, we know about outages and our system has been adapted for it," Guikema said. "But if I'm the mayor of Philadelphia, I might say, 'Whoa, we need to be doing more about this.'"

Uncertainty 'isn't a good excuse' for inaction
The 10 cities most likely to see the significant increases in their power outage risk, the authors project, are New York City; Philadelphia; Jacksonville, Fla.; Virginia Beach, Va.; Hartford, Conn.; Orlando, Fla.; Tampa Bay, Fla.; Providence, R.I.; Miami; and New Orleans.

"The top five are somewhat surprising," said Guikema of the cities the report found to be at the greatest risk for electric blackouts.

While climate scientists and researchers are loath to connect specific hurricanes, as well as other extreme weather events, with global climate change, there is widespread scientific consensus that national and local governments worldwide should expect to experience more extreme storms with greater frequency as long as carbon emissions continue to climb unabated.

Balancing historical weather and storm data against various climate models—a spectrum of simulations that predicted future storms of varying intensities—the study found Houston, New Orleans and Miami would be "heavily impacted even for scenarios of lower intensity storms."

In September 1900, a hurricane ripped through Galveston, Texas, killing between 6,000 and 8,000 people. Today, Houston, a brief drive inland from Galveston City, is the fourth-largest U.S. urban center, home to more than 2 million people in the city itself. The 1900 storm, which lacks a name because it predated the practice of naming hurricanes and tropical storms, registered as a Category 4 event and, Guikema said, would have been far more damaging under present conditions.

"That area wasn't nearly as highly populated," said Guikema, when asked about how U.S. cities should prepare for future storms. "Uncertainty isn't a good excuse for no action in the future."

A report compiled by the Organisation for Economic Co-operation and Development found that because of climate change—coupled with a rapidly rising global population and swelling emerging economies—current economic trends could lead to a ninefold increase in flood risk among the world's major port cities by 2050.

That report placed Miami, New York City, New Orleans, Tampa Bay and Boston among the 10 cities worldwide at the highest risk due to severe flooding. Miami and New York City were the second- and third-most at-risk cities, respectively; Guangzhou, China, was the major port city at the greatest risk.

All climate change is local
Andrea Staid, a doctoral student at Johns Hopkins and the study's lead author, said the results were very "location-specific."

"Planning for future climate change is a difficult task due to the high degree of uncertainty about potential changes in tropical cyclone frequency, intensity and track," the report reads.

"Coastal areas are particularly sensitive to increases in storm intensity. 100-year wind speeds are projected to increase by more than 50 percent in some areas with a 20 percent increase in storm intensity. The probability of customer power outages in a given area increases slightly, but the actual number of customers losing power would change more drastically as a result of stronger, and often larger storms."

Guikema and Staid said cities and utilities nationwide prioritize auditing, improving and overhauling their policies, plans and infrastructure, such as emergency preparedness and planning, backup water systems and sanitation networks, differently, but the team's research could serve as a guide.

"The average American can evaluate the risks at the local level," Staid said. "[This report] brings it down to a much more local level."

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC., 202-628-6500