New York City’s future environment will be affected by climate change, population growth, and land use development trends.
Climate change poses several significant risks to New York City by changing the pattern and frequency of hazardous weather events, such as heat waves, torrential downpours, high winds, and more frequent and more severe snow storms and coastal storm surges.
The New York City Panel on Climate Change (NPCC), a body of leading climate and social scientists and risk management experts, convened in 2008 to produce climate projections for New York City that would inform the City’s decision-making as well as the public. NPCC used data associated with large-scale climate-change patterns and downscaled them to find out how New York City’s local vicinity could be affected.
The NPCC has begun to research potential changes in climate in the New York metropolitan region beyond 2100, especially regarding sea level rise. The panel has identified various climate extremes such as extreme heat and humidity, heavy downpours, droughts, sea level rise and coastal flooding, extreme winds, and cold snaps.lii
Average temperature increase
According to the 2019 report by the New York City Panel on Climate Change (NPCC3), the 2015 projections for the city’s climate remain valid and are confirmed for use in resiliency planning. The NPCC 2015 report had projected that New York City’s mean annual temperatures are expected to increase by 3 to 7.1°F by the 2050s and by 4.8 to 11.6°F by the 2080s. These projections, based on climate analyses, regional and global trends, and a comprehensive review of scientific literature, are essential for guiding the city’s strategies in addressing and adapting to the challenges posed by climate change.
Extreme Heat and Humidity
The NPCC3 report built upon the NPCC2 projections for temperature extremes by expanding the number of reference weather stations and confirming the NPCC2 projections as those of record for the New York City. The NPCC2 report had identified a baseline of two heat waves per year on average (covering the period 1970-2000), projecting that the number of heat waves could increase to seven per year by 2050. Additionally, the NPCC2’s report stated the average annual number of days over 90°F could more than triple from 18 to 57 by 2050.
According to the NPCC2 report, annual precipitation (flash flood events due to heavy rainfall) in New York City is projected to increase between 4 and 11 percent by the 2050s, and between 5 and 13 percent by the 2080s. NPCC3 does not introduce new projections for heavy rainfall but reaffirms the projections made in NPCC2 as the standard for the city’s planning and adaptation efforts. The report does, however, offer new insights into the patterns of heavy rainfall events within the New York metropolitan area. These analyses are suggested as a foundation for developing updated projections to be potentially included in the future NPCC4 report.liii
Annual precipitation (flash flood events due to heavy rainfall) in New York City is projected to increase between 4 and 11 percent by the 2050s, and between 5 and 13 percent by the 2080s as per NPCC2. The NPCC3 report indicates that the New York metropolitan region hasn’t experienced a significant drought since the 1960s, however, tree-ring analyses spanning approximately the last 250 years indicate the occurrence of droughts lasting 10 years or more. Therefore, the potential for future droughts should be taken into account in planning activities.
Sea Level Rise
The NPCC2 report projected a mid-range (25th–75th percentile) sea level rise of 11–21 inches at The Battery by the 2050s and 18–39 inches by the 2080s. The worst-case scenario projected up to six feet of sea level rise by 2100. The NPCC3 report introduced a new upper-end, low-probability scenario. This scenario projects 6.75 feet of sea level rise in the 2080s and 9.5 feet of sea level rise by 2100. This projection takes into account the potential for rapid ice melt in Greenland and Antarctica.
In the future, sea height during New York City’s coastal storms could potentially be above the normal levels expected at that time and place based on the tides alone.
As per the NPCC2 report, New York City is projected to experience increases in both the frequency of the 1 percent annual chance floods and in the height of these floods. NPCC3 analyzes sea level rise effects on monthly tidal flooding, uses of a broadened set of sea level rise scenarios including the Antarctic Rapid Ice Melt (ARIM) scenario, and examines the latest science on extreme winds. In addition, NPCC3 report continued the work of NPCC2 by providing new citywide maps of mean sea level rise, monthly tidal flooding, and 100-year return period flooding under a high-end scenario of sea level rise.
The likelihood of extreme hurricane winds is expected to increase in the North Atlantic Basin. The NPCC3 report indicates that the main meteorological phenomena impacting New York City are cyclones, which are areas of low pressure leading to air convergence and uplift. These cyclones encompass extratropical cyclones, formed by mid-latitude weather fronts like Nor’Easters, and tropical cyclones that develop over tropical oceans, such as hurricanes. The paths of both these cyclone types are instrumental in linking extreme precipitation events to specific storms.
According to the NPCC2, the frequency of extreme cold events, defined as the number of days per year with minimum temperatures at or below 32 ̊F, is projected to decrease by the 2020s by approximately 25 percent, by the 2050s by over 33 percent, and by the 2080s by approximately 50 percent.
Projections are uncertain about whether there will be changes in the degree or frequency of extreme ice storms in the future. NPCC3 confirms the analysis of NPCC2 days with minimum temperatures below 32 °F as the projections of record for New York City planning. NPCC3 further examines historical extreme cold events, using two measures of extreme cold:
- A day below freezing occurs whenever minimum temperature is equal to or less than 32 °F
- A cold day occurs whenever its minimum temperature is equal to or less than the 10th percentile of daily minimum temperature of a given year.
New York City’s population is dynamic, with several hundred thousand people moving in and out each year. Since 1990, New York City’s population has shown a net increase in every ten-year census.
Based on the latest projections released by New York City Department of City Planning (DCP), this growth pattern is anticipated to continue. By 2040, New York City’s population is projected to increase by almost 10 percent, surpassing 9 million residents for the first time in history.
The Over-65 Population Trends
By 2040, the age composition of New York City residents will be different than it is today. New York City has a large baby-boomer cohort that will be at least 75 years old by 2040. The most dramatic change between today and 2040 will be an increase of approximately 41 percent in the number of New York residents over 65, a change that reflects expected lower fertility rates and continued improvements in life expectancy.
As a share of New York City’s total population, the over-65 age group today is about 12 percent. By 2040, this share is expected to grow to more than 15 percent.
This growth might not be spread evenly across the boroughs, though. Between 2010 and 2040, the number of Staten Island residents in the over-65 age group is predicted to increase by 65 percent — the largest increase among the five boroughs. As a share of Staten Island’s total population, the over-65 age group today is slightly less than 13 percent. By 2040, this share is expected to grow to nearly 20 percent.
School-age Population Trends
Between today and 2040, the number of New York City’s school-age population (ages 5-17) is projected to grow approximately seven percent. However, as a percentage of total New York City residents, the share represented by these school-age children will decrease by 2040.
When these projections are broken out by borough, the share of school-age children as a percentage of total borough population is expected to decline in the Bronx, Brooklyn, and Staten Island by 2040. As shown in the table, school-age children as a percentage of Queens and Manhattan populations will remain largely unchanged between today and 2040.
New York City’s land use and development are influenced by economic and population changes, and are guided by long-term strategic planning initiatives. In 2023, the City released PlaNYC: Getting Sustainability Done, New York City’s long-term strategic climate plan. The plan aims to protect New Yorkers from climate threats, improve quality of life, and build the green economy. It is the fifth in a series of climate plans released every four years by the city, as required by local law, and was developed with input from the New York City Climate Cabinet, the Sustainability Advisory Board, and stakeholders.
The main goals of PlaNYC: Getting Sustainability Done are:
- Act with urgency and focus on implementation: The plan emphasizes the need for immediate action to address climate change and its impacts on New York City. It aims to implement strategies that have been developed over the past 16 years.
- Achieve near-term benefits for New Yorkers while implementing long-term goals: The plan seeks to provide immediate improvements to the quality of life for New Yorkers, such as cleaner air and better mobility, while also working towards long-term sustainability goals.
- Center environmental justice: The plan aims to ensure that the benefits of climate action are felt equitably across the city, particularly in vulnerable communities that are disproportionately affected by climate change.
- Create a circular economy starting with organics and asphalt: The plan includes initiatives to expand the production and use of recycled asphalt, collect organic materials and turn them into energy and reusable assets, and develop new markets for recycling and reuse.
- Protect New Yorkers from climate threats: The plan includes measures to protect residents from the impacts of climate change, such as extreme heat and flooding.
- Improve quality of life: The plan aims to make the city a cleaner and healthier place to live, for example by reducing air pollution and improving mobility.
- Build the green economy: The plan seeks to create jobs and stimulate economic growth through initiatives that promote sustainability, such as expanding the green economy and fostering innovation.
- Align with state climate law: The plan aims to run the city on electricity from non-emitting sources like solar, wind, and hydropower by 2040, and to slash emissions from transportation, buildings, and waste a decade after that.liv
Changes to Housing
The 2021 New York City Housing and Vacancy Survey (NYCHVS) revealed several changes in the city’s housing landscape compared to the 2017 survey. Between 2017 and 2021, the total number of housing units in New York City increased by 175,000 units. The distribution of this growth across boroughs was as follows:
- Brooklyn led with a net increase of 56,000 units.
- Queens followed with an addition of 49,000 units.
- Manhattan added 40,300 units.
- The Bronx contributed 24,300 units.
- Staten Island saw an increase of 5,000 units.
However, the city experienced a net loss of about 96,000 units with rents less than $1,500, while there was a net increase of 107,000 units with rents of $2,300 or more. This shift in the housing market has led to a decrease in affordable housing options for low- and middle-income residents.
In terms of vacancy rates, the 2021 survey showed a citywide rate of 4.54%, up from 3.63% in 2017. The borough with the highest vacancy rate was Manhattan, with more than 10% of apartments vacant. In contrast, the Bronx had a vacancy rate of less than 1%, while Brooklyn had a rate of 2.73%, and Queens and Staten Island had a rate of 4.15%.
The survey also revealed that asking rents increased by 34% above inflation between 2017 and 2021, making it more challenging for many residents to afford housing in the city.
Mayor Eric Adams has launched a significant effort to address New York City’s housing crisis, which is characterized by a severe shortage of homes and high rents. His plan, known as the “City of Yes for Housing Opportunity,” aims to create an additional 100,000 homes for over 250,000 New Yorkers. This initiative is part of Adams’ broader goal of delivering 500,000 new homes to New Yorkers over the next decade.
The plan includes several key measures:
- Eliminating mandates that require parking spaces to be constructed with new homes, which has previously made some housing construction impossible for developers.
- Creating additional affordable and supportive homes.
- Enabling the conversion of empty offices into homes, a move bolstered by the emptying of Manhattan offices during the pandemic.
- Allowing the construction of two- to four-stories of apartments above laundromats, shops, and other businesses along certain commercial strips.
- Making it easier for owners of one- and two-family homes to turn basements, attics, or backyard garages into apartments.
- Making it easier for institutions with large, underused lots, such as churches and schools, to build housing.
Since 2014, there has been an effort to rebuild and elevate homes damaged by Hurricane Sandy in the city’s hardest-hit coastal areas, such as the Rockaways, Howard Beach, Canarsie, and Midland Beach. As a result of such efforts, there has been a significant change to New York City’s housing stock.
The New York City Mayor’s Office of Housing Recovery (HRO) created the Build It Back program to help New York City residents repair, rebuild, and elevate the homes of residents impacted by Hurricane Sandy. The United States Department of Housing and Urban Development (HUD) Community Development Block Grant disaster recovery funds (CDBG-DR) are used for this program.
Currently, the Build It Back program helped 8,319 homeowners and landlords of one-to-four-unit homes, which house over 12,700 families. The recovery effort included repairing and elevating 838 homes above base flood elevation, rebuilding over 492 homes , including 103 modular homes and repaired 3,914 moderately damaged homes in New York City’s hardest-hit coastal areas.
Through Build It Back, 6,138 homeowners have received reimbursement checks for homeowner completed repairs totaling over $135 million. In addition, 247 New York City homeowners with storm-damaged properties were acquired through acquisition and buyouts either for resilient housing or open space for drainage by the City and New York State.
The Build It Back Multi-Family Program, managed by the New York City Department of Housing Preservation and Development (HPD), assisted an additional 19,600 households in 143 developments with repairs, resiliency upgrades, and reimbursement services.lv
Mayor Eric Adams has proposed significant zoning changes in New York City under his “City of Yes for Housing Opportunity” initiative. This plan aims to address the city’s severe housing shortage and affordability crisis by enabling the creation of more housing in every neighborhood. The initiative is part of a series of citywide zoning changes that will be presented to all five borough presidents, all 59 community boards, and the New York City Council.
The proposed changes include allowing the creation of homes instead of parking spots, creating additional affordable and supportive homes, eliminating exclusionary zoning, and enabling the conversion of empty offices into homes. The plan also allows for up to four stories of new units to be built above existing single-story buildings like laundromats and delis, and for new units to be built in basements and attics. It also incentivizes building owners to convert office spaces into residential dwellings and repeals mandates that require new residential buildings to have parking spaces.
Accessory dwelling units (ADUs) are a significant part of the plan. Mayor Adams aims to build 100,000 new homes for 250,000 New Yorkers, with a “moonshot” goal of delivering 500,000 new homes over the next decade. The plan also includes the idea of building smaller dwelling units than are currently legal to pack in as many rentals in new buildings as possible.
Figure 1: ADUs also make it easier for younger generations or caregivers to live nearby. And they can deliver big benefits while fitting in with existing buildings. (City of Yes for Housing Opportunity, 2023)
The “City of Yes” proposal is a strategy for building thousands of new homes through a series of reforms and incentives, using the language of the “Yes in My Backyard” (YIMBY) movement. If the plan passes environmental review and wins all the necessary city approvals, it would give affordable housing developers a leg up by allowing apartment buildings to grow by 20% when the extra units created are affordable.
In 2021, New York City approved significant rezoning plans for the SoHo/NoHo and Gowanus neighborhoods under the administration of Mayor Bill de Blasio:
- The SoHo/NoHo Neighborhood Plan sought to expand housing opportunities for New Yorkers and promote equity, support continued cultural and economic success in a holistic way and reduce regulatory burdens for the people who live and work there. Critically, the plan sought to create housing and especially affordable housing in these high-opportunity, transit-rich neighborhoods. The land use actions of the Plan were adopted in 2021.
- The Gowanus rezoning plan was approved by the New York City Council and was considered the biggest rezoning this administration had done over eight years. The plan aimed to upzone an 82-block swath of the Gowanus neighborhood to add an estimated 8,500 new apartments by 2035. About 3,000 of these units would be considered affordable, or reserved for people making a percentage of area median income under the city’s Mandatory Inclusionary Housing (MIH) program.
Further details about capital and programmatic commitments associated with neighborhood-scale rezonings are available in the NYC Rezoning Commitments Tracker interactive map.
As of the writing of this report, Mayor Adams lunched community-led neighborhood planning processes for the Bronx Metro North Station Area, Atlantic Avenue in Brooklyn, and Long Island City in Queens.
Other Resiliency Initiatives
Since the 2019 Hazard Mitigation Plan, New York City’s land use and development trends have been shaped by resiliency initiatives designed to ensure where and how building happens in New York City is guided by the best available climate science.
The 2023 PlaNYC document outlines several resiliency initiatives aimed at addressing climate change and its impacts on New York City. Some of these initiatives include:
- Creation of a new Bureau of Coastal Resiliency at DEP: The city plans to establish a new leadership structure for coastal flood resilience in 2023, headed by the New York City Department of Environmental Protection (DEP). This bureau will focus on implementing a multilayered strategy for flood resilience and coordinating efforts across various city agencies.
- Blue Sky Housing Mobility: As part of the city’s efforts to prepare and protect New Yorkers from the risks of current and future flooding, the city will launch a voluntary housing mobility and land acquisition program. This program aims to provide housing counseling and facilitate future land acquisition with federal and state funds.
- Climate Strong Communities: The Climate Strong Communities initiative is a part of the city’s broader AdaptNYC program, which identifies climate change hazards, populations and neighborhoods at risk, and the resiliency and adaptation measures the city is taking to protect residents, property, and infrastructure. Some of the programs under this initiative include Cool Neighborhoods NYC, Rainfall Ready NYC, and the Wastewater Resiliency Plan.
- Cool Neighborhoods NYC: A $100 million program designed to combat extreme heat by expanding the city’s tree canopy and investing in social resiliency programs.
- Rainfall Ready NYC: Offers short-term, actionable steps for New Yorkers and city government to prepare for extreme rain together.
- Wastewater Resiliency Plan: identifies and prioritizes infrastructure that is most at risk of flood damage for resiliency upgrades.
Following Hurricane Sandy in 2012, New York City adopted the Flood Resilience Zoning Text Amendment on a temporary, emergency basis to increase the city’s resilience to climate-related events, including coastal flooding and storm surge. This zoning text amendment encourages flood-resilient building construction throughout designated flood zones by enabling new and existing buildings to comply with new, higher flood elevations issued by FEMA, as well as new requirements in the New York City Construction Code. Buildings that conform to these new standards will reduce vulnerability to future floods and will help owners avoid higher flood insurance premiums.
DCP advanced a permanent version of these rules, called Zoning for Coastal Flood Resiliency, which was adopted in 2021. This text amendment enables new and existing buildings to comply with requirements in Appendix G of the NYC’s Building Code as well as exceed them in order to be better prepared to withstand future storms. Additionally, DCP expanded the applicability of zoning rules to include areas that will be subject to high-risk of flooding in the future. Doing so allows buildings that are not currently required to meet Appendix G to also make resiliency improvements in advance of being mapped within the 1% annual chance floodplain. This not only improves the ability of the city’s many coastal neighborhoods to withstand and recover quickly from future storms, but also allows building owners to potentially save on flood insurance costs.
In addition to the citywide Zoning for Coastal Flood Resiliency text amendment, DCP also created a zoning designation known as a Special Coastal Risk District (SCRD) to use in areas where the magnitude and frequency of flood risks are exceptional. SCRDs restrict growth in the most high-risk coastal neighborhoods and in sensitive natural areas by limiting future residential development, while also allowing continued investment in existing buildings. Residents in southern Brooklyn, the East Shore of Staten Island, and southern Queens worked with the DCP to tailor SCRDs to the unique conditions in their neighborhoods.
DCP released the City’s third and latest Comprehensive Waterfront Plan in 2021 which promotes climate resilient and adaptation, waterfront public access, economic opportunity, water quality and natural resources, ferries, and governance. The Plan establishes New York City’s policies for waterfront planning, preservation, and development projects to ensure consistency over the long term. The plan’s goals for climate resiliency and adaptation focus on expanding climate risk awareness and action, using climate risk information in public policies and investments, supporting the housing needs of waterfront residents, managing flood risk in NYC’s coastal communities, and promoting climate-resilient design of buildings and infrastructure systems. Through these goals and strategies, the City will continue to proactively and permanently weave urban coastal adaptation into processes for long-term planning and everyday decision-making.
In addition to these resiliency-focused initiatives, DCP is continuing to modernize and update New York City’s zoning regulations to support small businesses, create affordable housing, and promote sustainability – part of Mayor Eric Adams’ vision for a more inclusive, equitable “City of Yes.” City of Carbon Neutrality would modernize zoning regulations and clear the way for much-needed green investments in NYC buildings. City of Economic Opportunity would remove outdated limitations on businesses, and support thriving commercial centers and retail streets to better serve NYC communities. City of Housing Opportunity is part of an inclusive, citywide approach to expanding and diversifying our housing supply.
Other resiliency initiatives that will shape the future development of New York City’s built environment include the Climate Resiliency Design Guidelines. The design guidelines, updated to version 4.1 in May 2022, provide technical guidance for engineers, architects, and planners to design infrastructure and public facilities that can withstand the worsening impacts of climate change, including intense rainfall, coastal storm surge, chronic high tide flooding, and extreme heat. City agencies build upon this foundation by developing their own, more specific guidelines that fit the design criteria suited to their specific assets.
In 2021, Mayor de Blasio announced a five-year pilot program that mandates the use of these guidelines in the design and construction of new city infrastructure and public facilities. Under this program, 23 city capital agencies began designing and constructing dozens of new projects using the standards in the NYC Climate Resiliency Design Guidelines. The pilot program is also the first step in implementing Local Law 41, which requires the creation of climate resilience guidelines for capital projects and a resilience scoring system. By 2026, all capital projects must meet a stringent set of climate resilience guidelines. The projects included in the pilot program are connected to 23 city agencies and range in budget between $3 million and $1 billion. The selection process for these projects included considerations of climate exposure, project scope, and equity.
To incorporate climate-change considerations in the future design of parks and open space, the New York City Department of Parks and Recreation has created Design and Planning for Flood Resiliency: Guidelines for NYC Parks. These guidelines help planners, designers, engineers, and consultants develop and renovate resilient waterfront parks.