Resilience in Flood-Prone Lower Manhattan

New York was hit by an enormous flood in 2021 that damaged its infrastructure and caused it to declare its first flash flood emergency. Much of this damage was concentrated in Lower Manhattan, a uniquely vulnerable area that is spending more and more money recovering from such disasters. If this trend continues and we are unable to adapt Lower Manhattan to climate change, it will flood almost daily by the year 2080.

In the long term, these intensifying floods will render the vast majority of Lower Manhattan uninhabitable. This is mostly due to climate change, which has made hurricanes and other large storms significantly more common. Storms lead to storm surges, which increase flooding and stress our anti-flood infrastructure. Warmer temperatures have also thermally expanded the water, raising the height of the tides and making flooding a more common occurrence. Lower Manhattan is uniquely vulnerable to spikes in flooding due to its low-lying shoreline and urban environment.

Hurricane Sandy in 2012 knocked out power in Lower Manhattan, necessitating mass evacuations from downtown. In Lower Manhattan alone, this amounted to $19 billion in property damage, but it is only the beginning of the devastation we will suffer if we continue down our current trajectory. Within the next 40 years, Hurricane Sandy-level storms may flood over 25 percent of New York City.

If Lower Manhattan becomes even remotely close to uninhabitable in the coming century, the impacts on wider New York would be catastrophic. To start, it would displace 382,654 people and effectively eliminate the entirety of the United States’ fourth-largest financial district, destroying New York’s economy. Hundreds of thousands of jobs would be lost almost immediately as workplaces would simply vanish and people would sink into poverty, their livelihoods completely destroyed.

Luckily, Sandy served as a wake-up call for the New York government to improve flood defenses. These efforts are all centralized under one plan called The Financial District and Seaport Climate Resilience Master Plan. The program includes miles-long floodgates that close when hurricanes draw near, significantly reducing flooding. However, these gates—like most structures built underwater—make it very difficult for fish populations to migrate and remain healthy. They are also incredibly expensive to maintain and only serve as a temporary solution to this ever-growing problem. We can build as much anti-flood infrastructure as we want, but so long as we continue to pump more carbon dioxide into the atmosphere, floods will continue to jeopardize our city. The only way to permanently solve this problem is to halt the increases in temperatures caused by global warming.

The city has taken significant steps in reducing its own carbon pollution. It’s recently passed a climate package that regulates the carbon emissions of existing large buildings, phases out fossil fuel plants, covers the roofs of buildings with plants to cool the areas surrounding them, slightly offsets carbon dioxide emissions, and eases the construction of wind turbines. These are all great steps that will no doubt help reduce New York’s carbon emissions in the future.

However, climate change is a global issue, and the actions of a single city—even one as big as New York—won’t significantly change Lower Manhattan’s flooding trajectory. Global warming was never an issue solvable by any single government, whether it be at a city, state, or national level.

This doesn’t undermine our efforts, though. After all, if every city in the world chose to do nothing about climate change because their individual actions would have little impact, no action would ever be taken. New York is an economically and politically influential city; we can serve as a model by improving New York’s sustainability and slashing our carbon emissions until we achieve net zero.

Flooding in Lower Manhattan is a critical issue—one that threatens millions of lives, creates billions of dollars in property damage, and causes irreversible harm at a national level. It’s a problem New York can delay and mitigate, but not solve on its own. However, there is hope: New York has begun constructing flood defenses that will significantly improve the city’s resilience to climate change. The only thing we can do as a community is hold our governments to their anti-climate change promises and push them to make more radical climate reforms. Otherwise, there will be far more places just as threatened as Lower Manhattan.