Climate scientist Cynthia Rosenzweig has been studying the impacts of global warming on New York City since the 1990s, and was part of a group that analyzed the unique risks faced by the Big Apple way back in 2001. The group's report predicted what a once-a-century superstorm like Hurricane Sandy proved: the Brooklyn Battery Tunnel between major boroughs flooded, La Guardia Airport runways were underwater, and so on.
More recently Rosenzweig helped chair the New York City Panel on Climate Change, brought together to update the city on the latest climate science and to help city agencies prepare to adapt. The Mayor's Office calls such preparation "climate resilience"—and it got a trial during and after Hurricane Sandy as well as Hurricane Irene in 2011.
Scientific American spoke with Rosenzweig, head of the climate impacts group at the NASA Goddard Institute for Space Studies, while she prepared her Tarrytown home—threatened by trees listing in the wake of Sandy—for yet another northeaster storm.
[An edited transcript of the interview follows.]
Did you predict Superstorm Sandy's impacts, in some sense?
Sea-level rise and climate change were already on the radar screen in the New York metropolitan region way back in our  report. In that report we have the critical elevations, the one-in-500-year projections for the [flooding] impact on the Brooklyn Battery Tunnel and all the La Guardia [airport] runways.
What could or should have been done differently to better prepare the metropolitan region for such a huge storm?
Virtually everything that happened [after Sandy] had been highlighted in our reports. What we're doing now is going over the science of Hurricane Sandy and identifying the scientific work that needs to be done. One [task] is this key issue of redefining the one-in-100-year storm. Everyone is saying: "What's up with this one-in-100-year storm happening every year?" But scientifically we still need to look at the data and address if there should be a change. Our reports have noted that the one-in-100-year storm is now one in 15 to 35 years, on the conservative end [not assuming rapid meltdown of glacial ice in Greenland and Antarctica].
Mayor Bloomberg had initiated a climate change adaptation task force with 40 agencies. New York City is one of the leaders in this country and even the world in setting up adaptation and assessing how climate risks are increasing. All of this had begun, but to have an event of this very large effect and impact—a one-in-a-multi-century storm—would be challenging for any city in its path. It's just that this was such a whammy. That's the nature of risk.
The [Metropolitan Transit Authority] had clearly learned how to shut down the subways [after Hurricane Irene in 2011]. It's not a complete surprise. It's almost a: "Yes, we've been learning about this, understanding that the risks are increasing and, in fact, now for sure they are."
Any loss of life is unacceptable [but] the loss of life and the damage would have been so much greater, think of it, if we hadn't had the evacuation plan in place and also closed the subways and the tunnels. It could have been far more devastating.