When Hurricane Sandy blew in with a vengeance, Rae Zimmerman was distressed but not particularly surprised. As a professor of planning and public administration at the Robert F. Wagner Graduate School of Public Service, she had long investigated and flagged risks to the city’s shoreline communities from rising sea levels and other consequences of world-wide climate change.
The founder and director of the Institute for Civil Infrastructure Systems (ICIS) at the school, Zimmerman published this year a new book called Transport, the Environment, and Security (Edward Elgar Publishing), which makes a case for thinking in new ways about transportation planning and policy.
You served on the NYC Panel on Climate Change, whose final report warned in 2009 of risks from warming temperatures and rising seas. What were the key findings?
The panel was set up by Mayor Michael Bloomberg with funding from the Rockefeller Foundation through Columbia and CUNY. I served with more than a dozen experts in various aspects of climate change. The panel provided a framework for carbon emission reduction initiatives and adaptations to our changing climate. It did so through a planning process, including climate estimates tailored to New York City, and identified risks, adaptation measures, and benchmarks. Its key findings were its estimates of increasing temperature, precipitation, and sea level rise over time.
What kind of response did the report meet with?
The planning process created the impetus and context for numerous studies by the city—annual emission inventories, waterfront planning, the incorporation of climate change into the environmental impact assessment process, and adaptation strategies. The report contributed to awareness of climate change and its inevitability. It pointed the way to an emphasis on adaptation while still controlling emissions.
So what kind of protections can we realistically expect?
The tragedies from severe storms underscore the need for a portfolio of strategies customized for individual areas and needs—a multi-pronged approach with many players and at many scales. The world has dabbled in very useful safeguards. Expanding the mileage we have gained with green infrastructure and renewable energy can reduce infrastructure outages. The rapid increase in green technologies and the public buy-in for them are hopeful signs. However, assembling resources and building institutional capacity are required to fulfill these needs.
For example, fuel-charging stations, essential to support alternative fuel vehicles, need more road access. According to my analysis of U.S. Department of Energy data, although 60 percent of the stations are within five miles of an interstate highway, more than 20 percent are greater than 10 miles away.
What about waterside locations?
The more extensive shoreline barrier technologies that exist will have to be evaluated thoroughly. Coastal populations and population density have increased in spite of existing safeguards. We can reduce population exposure by offering to relocate individual homeowners and communities that have experienced substantial destruction, fortifying those that are already built up and show signs of being able to resist inundation, and restricting development in more flood-prone areas. Another problem is that poorer populations may have less access to transit in order to escape from the consequences of extreme weather events before or after they happen. When I connected data on rail transit usage to Brookings Institution data on areas with increasing low-income suburban populations, I showed that many of these areas are not connected, or have little access, to transit.
A key strategy is promoting flexible infrastructure. The NYC subway system’s recovery after Sandy built upon its flexibility, and that should be institutionalized. Using a network approach, I showed that much transportation infrastructure is highly concentrated geographically in the U.S. in terms of roadway intersections and rail interconnection points. For heavy rail with the highest ridership, about a third of NYC’s intersections are within Manhattan, a third of Chicago’s are within its downtown Loop area, and a third of Washington, D.C.’s are downtown, near federal government buildings. This kind of concentration provides alternative routes supporting a dense traveling population before and after an emergency. That is, flexibility.