She leads scientists advising New York on climate change. Did the city listen?
Hurricane Sandy hit New York City in October 2012, killing more than 40 people and causing $19 billion in damage. Researchers at Columbia University played a key scientific and policy role in the city’s preparedness for and response to the storm. In this Q&A series a decade later, we ask several people in important public roles to look back and look ahead.
Cynthia Rosenzweig is a senior research scientist at the Columbia Climate Institute and leads the Climate Impacts Group at the affiliated NASA Goddard Institute for Space Studies. Since the 1990s, she has organized and led several large-scale local, national and international studies on climate change impacts and adaptation in rural and urban environments.she co-chairs New York City Panel on Climate Change, a group of experts convened by Mayor Michael Bloomberg to advise New York City from its inception in 2008 through 2019. When Sandy struck, the panel had already gathered a wealth of information about the climate-related threats New York City faced, and what the metropolis should do.
When did scientists and others start thinking seriously about how extreme weather and sea level rise could affect New York, and how did you get involved?
My first involvement was when I co-led Metro East Coast Assessment, published by the Columbia Earth Institute in 2002. Not only is it the first major study of the effects of climate change in New York City; it is also one of the first studies of how climate change will affect the entire urban area. Representatives from FEMA, EPA, the Army Corps of Engineers, the Port Authority, and others were actively involved, with many stakeholders involved from the beginning. By the Sandy era, disaster preparedness, evacuation plans and policies were in place, but they were limited. Sandy was a key turning point, as it prompted the city to incorporate sea-level projections into its rebuilding policy. More broadly, it has sparked awareness of the importance of providing local climate risk information.
In 2008, you were named co-chair of the newly formed New York City Panel on Climate Change. How effective is this group in bringing climate issues to city officials?
Our first report, published in 2010, undoubtedly succeeded in bringing the issue of climate change to city officials. This was thanks in large part to the leadership of then-Mayor Michael Bloomberg, who recognized that sustainability could not be addressed without considering the growing risks of climate change. The report focuses on short- and long-term adaptation measures by developing the concept of flexible adaptation pathways. In this approach, strategies evolve with ongoing risk assessments and extreme events. Just a few weeks before Sandy 2012, local method 42 Our group is empowered to update climate change projections at least every three years, and within one year of new projections issued by the Intergovernmental Panel on Climate Change.
Has the storm changed your or anyone else’s view of the expected outcome?
Large hurricanes have long been part of the New York area. The 1821 hurricane caused high water levels to reach 13 feet in an hour, and in 1893 another hurricane flooded southern Brooklyn and Queens. Hurricanes Donna and Gloria in 1960 and 1985 caused extensive damage on Long Island and New Jersey, respectively. So we know that New York should have a Sandy-level event with a storm surge of about 14 feet. In 2011, we published our forecast for century-old storms due to sea level rise. We found that with a 2-foot rise, the centennial storm would significantly increase flood risk, especially on the Brooklyn and Queens coastlines, around Jamaica Bay, and on the Rockaway Peninsula. It is calculated that the subway tunnel will fill up in less than an hour. Sandy proved to be in line with our predictions, but the actual experience was a huge wake-up call. New York City has 520 miles of coastline. Projects need to be carried out consecutively in all five boroughs. A continuous climate change indicator and monitoring system can better inform decision-making. Effective disaster communication and public risk perception are also central to emergency response.
How well is the city preparing for another Sandy-like event and climate change in general?
New York has Successfully embedded in climate change predictions Rebuild work and policy. The Department of Environmental Protection is developing a city-wide model to better estimate runoff for various climate scenarios. All construction projects in areas expected to be at risk of flooding must submit a Resilience Design Checklist to the city. Engineering projects, including subway gates and storm barriers, are one of three major components of urban transformation. Other components are nature-based solutions, as well as policies such as community planning, zoning and insurance. An example of a nature-based project is the Living Breakwater, which enhances the resilience of the South Shore of Staten Island with underwater concrete units that will dampen wave forces, reduce erosion, and provide habitat for oysters and other marine life. The city has arguably made the most progress in strengthening coastal protection. The Big U is a 10-mile continuous flood barrier that will wrap around Manhattan’s southern tip by 2026. On Coney Island, construction of tidal barriers, a water recirculation system, and a natural stormwater treatment system is currently underway. Much of this is infrastructure-oriented, but this has been complemented by nature-based solutions such as dune protection and bioswamps. While many of Sandy’s post-Sandy efforts have focused on preparing for long-term risks, sea level rise has increased “sunny day” flooding in low-lying areas. The 2022 hurricane season is not over. Even as we prepare for long-term adaptation, we must be prepared for both minor and major near-term impacts.
Do we have to consider further measures?
Equity needs to be at the forefront and centre of all adaptation measures. Low-income communities are most vulnerable to climate change, and communities need to be actively involved in decision-making. This is the main focus of the current consideration of the New York group. Compounding and cascading risks of extreme events must also be considered. For example, heavy precipitation and flooding can quickly lead to power outages, water pollution, and the spread of water-borne pathogens. The fields of psychology, trauma-informed care, and public health should be more integrated into emergency management and preparedness. Finally, Hurricane Sandy and this year’s Hurricane Ian in Florida have shown that we must have a serious debate about coastal development and the potential to strategically move people and infrastructure off the coast.
Are you or someone close to you affected by the storm?
I live in Tarrytown, New York, about 40 minutes north of Manhattan. I weathered this storm with my 97-year-old mother. It made me realize how vulnerable older people are. With our power, phone and internet lines out, we had to leave the house and couldn’t return for weeks. Many of our neighbors have experienced devastation from basement floods and fallen trees, as well as the same long-term power outages we experienced.
How do you see the future of New York?
New York is and will always be a great city in the world. It is one of the leaders in tackling climate change and reducing greenhouse gas emissions. That’s the definition of resilience: the ability to bounce back after adversity, to prepare for, cope with, and recover from difficult conditions—and be very resilient.
