Hazard Profiles

The 2024 Hazard Mitigation Plan has identified a spectrum of 10 natural hazards, each posing distinct challenges to New York City. Coastal erosion is reshaping the city’s boundaries, amplifying vulnerabilities to storms and economic impacts. Coastal storms, intensified by climate change, threaten New York City’s densely populated coastline, echoing concerns of rising sea levels and increased storm frequencies. The city’s remarkable water system remains susceptible to droughts. Even without a major fault system, earthquakes pose risks due to New York City’s infrastructure age and dense urban setting. The city’s urban heat island effect heightens risks from extreme heat, further aggravated by climate change projections of increased temperatures and prolonged heat waves. High winds, a common phenomenon, impact the city’s dense high-rise structures and open construction sites. Flooding impacts not only New York City’s low-lying coastal areas, but its interior floodplains as well, impacting residents, businesses, infrastructure, and the natural environment. Winter weather brings cold temperatures, snow, and ice, though climate change may alter these patterns. Poor air quality, although improved, still presents health risks, with climate change demanding continuous monitoring. Beyond natural hazards, the plan also addresses non-natural hazards, including cyberattacks and chemical, biological, nuclear, and radiological releases, emphasizing their importance even as the primary focus remains on natural hazards.

Coastal erosion plays a significant role in the retreat of New York City’s coastlines. It also amplifies the city’s vulnerability to coastal storms, leaving the city more at risk for natural resource depletion, infrastructure damage, physical harm, and economic hardship. Unfortunately, future coastal erosion rates are difficult to predict, underscoring the need to collect more robust baseline data from monitoring stations along the coast to determine annual shoreline changes.

Coastal storms are a reality for New York City. Among cities in the United States, New York City’s extensive, densely populated, highly developed coastline makes it one of the most vulnerable to damage from coastal storms.

Any type of coastal storm — tropical cyclone or nor’easter — can have a major impact upon millions of people in the greater region around New York City and potentially create a ripple effect throughout the country.

In the future, climate change and rising sea levels are likely to increase the frequency, severity, and impact of coastal storms in New York City.

Drought is a natural phenomenon characterized by an extended period of deficient rainfall relative to the statistical multiyear average for a region. The complexities of droughts are evident in the five types classified by the National Weather Service: meteorological (related to weather patterns and prolonged absence of precipitation), agricultural (associated with water shortages impacting farming, although less relevant to New York City due to minimal agricultural activity), hydrological (related to surface and subsurface water supply deficits, influenced by factors like land use and dam construction), socioeconomic (where water scarcity affects the supply and demand of goods and services), and ecological (where ecosystems are pushed beyond their vulnerability thresholds due to inadequate water).

New York City’s expansive water supply system, a testament to engineering, extends over 125 miles, sourcing high-quality water from upstate reservoirs. This system, though impressive, is susceptible to droughts and potential infrastructure failures, with prospects intensified by climate change.

Although New York City does not sit on a major fault system, like the San Andreas Fault in California, earthquakes are possible here.

The likelihood that a strong earthquake will occur is moderate, but the risk is heightened by New York City’s population density, the scale of its built environment, the interdependencies of its critical infrastructure systems, the age of its infrastructure, and the high proportion of buildings that were built before seismic design provisions were adopted in city building codes in 1995.

In the future, the impact of any earthquake affecting New York City should be diminished due to improved building construction codes and infrastructure replacement initiatives.

More deaths occur related to heat in New York City and the United States annually than as the result of all other extreme weather events combined. New York City is particularly susceptible to this hazard due to its dense urban environment, which absorbs and traps heat. Prolonged periods of increased temperatures and humidity create a dangerous situation for individuals at greater risk for heat-related illness and strain the city’s utilities and infrastructure. Climate scientists project that average temperatures will increase, and heat waves will become more frequent, more intense, and last longer in duration due to climate change.

High-wind events are a common occurrence in New York City. A variety of windstorm types can occur with little warning — damaging property and infrastructure, disrupting transportation, downing trees and power lines, and causing serious personal injuries.

New York City’s dense, high-rise environment, high number of older buildings, and many open construction sites heighten its vulnerability to dangerous winds.

New York City has 520 miles of shoreline, with its large natural harbor, rivers, ocean, inlets, canals, and bays, which support its economic, social, and environmental context. Today, many New Yorkers and businesses inhabit low-lying coastal areas, former wetlands and watercourses, and interior floodplains. The natural landscape in the city has been historically transformed in such a way that impedes natural floodplain functions, causing vulnerability to a variety of types of flooding ranging from severe flash flooding to urban and nuisance flooding. Climate change has and will continue to exacerbate flooding conditions in New York City.

Air quality has improved significantly since the passage of the Clean Air Act in 1970; however, there are still many areas of the country where the public is exposed to unhealthy levels of air pollutants and sensitive ecosystems are damaged by air pollution. Poor air quality is responsible for an estimated more than 100,000 premature deaths in the United States each year. Costs from air pollution-related illnesses are estimated at $150 billion per year. As our climate and environment change, it is imperative to consider the effects of our ozone and how poor air could impact our city.

The winter months in New York City subject residents to prolonged periods of extremely cold temperatures and various storms that sometimes deliver large amounts of snow, ice, sleet, freezing rain, and strong winds.

The number or absence of storms per season, the amount of snow from each storm, and prolonged periods of extreme cold can affect people, buildings, infrastructure, and the economy. Hazardous wintry conditions also induce dangers like traffic accidents, power outages, hypothermia, and frostbite.

In the future, climate change could cause winter weather to be warmer, the length of New York City’s snow season to decrease, and snowfalls to become less frequent, leading to “snowless” winters. However, despite these overall climate trends, individual winter weather events in New York City will still have the potential in the future to deliver as much snow and snow cover as they do today.

While the primary focus of the Hazard Mitigation Plan (HMP) revolves around the identification of natural hazards, it is important to acknowledge non-natural hazards as well.

Non-natural hazards stem from deliberate and purposeful human actions. These encompass immediate incidents like shootings, bombings, cyberattacks, and hazardous material releases, as well as gradual occurrences like mass migrations, deteriorating infrastructure, and homelessness.

This non-natural hazard profile will offer brief and condensed insights drawn from previous plans, accompanied by links to comprehensive reports and resources for further exploration. It is important to note that the depth of detail provided for non-natural hazards will differ from that of natural hazards due to the distinct scope and character of the HMP.