Case study: Air pollution in New York City

By Matt Burdett, 2 January 2020

On this page, we look at New York City as a case study of air pollution in one city and its varying impact on people.

Introduction to air pollution in New York City

New York City has long had a problem with air pollution. In 1953, 1963 and 1966, high pressure reduced winds which normally moved polluted air from the city, resulting in widespread health issues and even some deaths. In the twenty first century, air pollution continues to cause health issues across the city, as shown on the maps below.

  • Health problems from air pollution in New York City. Source: (One NYC, 2018, p190).

However, on a global scale New York City’s air pollution is currently quite low. This page will look at the factors that have led to this low level of air pollution and the impacts of these strategies.

  • Brooklyn’s pollution is a problem, but is very mild compared to some other cities such as New Delhi in India. Source: Popovich et al., 2019. Data reflects regional estimates by Berkeley Earth based on observations at ground-level monitoring stations.

Causes of pollution in New York City

New York City’s Environmental Protection agency identifies several different types of air pollution. While some types, such as sulfur dioxide, may be relatively low, others such as ozone can be high. Being aware of the different pollutants is also important because they are caused by different emitters. Knowing this can help to tackle the problem.

The types of air pollutant and their main sources are (NYC Environmental Protection, 2019):

  • Fine Particulate Matter (PM2.5) – all types of combustion sources
  • Nitrogen Oxides (NOx) – emission from vehicles
  • Elemental Carbon (EC) – fossil fuel combustion, including diesel exhaust
  • Sulfur Dioxide (SO2) – fossil fuel combustion at power plants and other industrial facilities
  • Ozone (O3) – motor vehicle exhaust, industrial emissions, and natural sources

New York’s response to air pollution

New York City has introduced several steps such as congestion charging (from 2020 onwards), switching taxis to cleaner fuels, and changing the oils used in heating. These are part of a wider sustainability plan.

Sustainability planning frameworks

In 2007, New York City began its first sustainability plan, known as PlaNYC. To achieve clean air, it set out fourteen initiatives that would reduce PM2.5 emissions by 40%. These were in five broad areas (Charles-Guzman, 2012):

  • Reduce vehicle emissions from roads
  • Reduce general transport emissions (including ferries, trains and so on)
  • Reduce emissions from buildings
  • Develop natural solutions, such as planting trees
  • Engage in research to develop further understanding of air pollution in New York

In 2015, PlaNYC was taken over by One NYC. One NYC is a comprehensive planning document that looks at all aspects of New York City’s future, including the issue of air pollution. It includes the stated goal “New York City will have the best air quality among all large U.S. cities by 2030” (One NYC, 2018, p188).

Specific strategies

The strategies mentioned below are not necessarily mentioned in the One NYC plan for air pollution reduction, but are all strategies that are being used that will reduce the problem of air pollution.

Congestion charging

A congestion charge is a payment made by drivers who want to enter the city centre. Similar schemes have been very successful in other cities such as London where, since 2003, drivers have avoided paying the charge by not entering (and therefore not polluting) the city centre, or switching to cycling. The result in London is a drop of about 30% of vehicles in the city centre (Edmond, 2014).

New York City’s congestion charge began on 1 January 2019 for some commercial vehicles (NYC Taxi and Limousine Commission, 2019) and covered all of southern Manhattan. It is being extended in 2020/2021 to cover all vehicles and will be the first such scheme in the United States (Durkin and Aratani, 2019).

Clean air taxi fuels

Vehicles are subject to national standards decided by the US Environmental Protection Agency, so New York City cannot impose its own emissions standards on private vehicles, However, the PlaNYC and One NYC plans both included plans to convert the city-owned or controlled vehicles (such as dustcarts, cleaning vehicles and emergency vehicles) to more fuel efficient sources which pollute less. By 2012, over 30% of the city’s taxis had been converted (Charles-Guzman, 2012) and by 2017 there were over 200 electric vehicle charging stations in the city.

The result was that between 2007 and 2015 the “overall fuel efficiency of the medallion taxi fleet climbed from 15.7 to 33.1 MPG [miles per gallon], and corresponding estimates of nitrous oxide and particulate exhaust emissions declined by 82 percent and 49 percent, respectively” (Columbia University’s Mailman School of Public Health, 2019).

Switch to more efficient heating oils in buildings

New York City gets cold in winter, and most buildings are independently heated using oil burning systems. In 2010, the City legislated to reduce the sulfur content of some of the types of fuel used, and in 2012 the City launched its ‘Clean Heat’ programme which offered advice and financial and technical assistance to help owners change their buildings to better sources of fuel. Between 2012 and 2015, over 6000 buildings were converted most buildings to more efficient sources of fuel. This is projected to reduce related hospital visits by 700 per year and avoid 300 premature births due to the associated air pollution. (New York City Department of Health and Mental Hygiene, 2016).

Planting trees

New York City’s ‘Million Trees Initiative’ aimed to plan trees in among the existing city infrastructure including in parks, as part of new developments, and on streets. The initiative has multiple aims including flood water management, but the top reason for planting is to reduce atmospheric pollution (NYC Parks, n.d.).

According to the Million Trees Initiative, “one tree can remove 26 pounds of carbon dioxide from the atmosphere annually, the equivalent of 11,000 miles of car emissions. Our trees remove about 2,200 tons of air pollution per year, valued at $10 million annually” (Million Trees NYC, 2015). The aim to plant one million trees by 2017 was exceeded and they were planted by 2015 (Dumplemann, 2019).


These initiatives appear to have worked. As the map below shows, in all but a few central areas (some of which are where congestion charging will be introduced in the 2020s) air pollution has decreased.

  • Citywide improvements in air quality between 2009 and 2017. Source: NYC Health, 2019a.

It is not only PM2.5 particles that have reduced. All of the main pollutants have decreased between 2009 and 2017 (NYC Health, 2019b):

  • Fine particles (PM2.5) -30%
  • Nitrogen Dioxide (NO2) -26%
  • Nitric Oxide (NO) -44%
  • Black Carbon (BC) -30%

Perhaps most successfully, the amount of sulfur dioxide has declined by 96%, mainly as a result of the new regulations on heating oils used in buildings.


Charles-Guzman, 2012. Air Pollution Control Strategies In New York City:mA Case Study Of The Role Of Environmental Monitoring, Data Analysis, And Stakeholder Networks In Comprehensive Government Policy Development.

Columbia University’s Mailman School of Public Health, 2019. Clean air taxis cut pollution in New York City. In ScienceDaily. Accessed 3 January 2020.

Dumpelmann, 2019. How a Massive Tree-Planting Campaign Eased Stifling Summer Heat in New York City. Accessed 2 January 2020.

Durkin and Aratani, 2019. New York becomes first city in US to approve congestion pricing. Accessed 3 January 2020.

Edmond, 2014. 4 bold new ways New York is going clean and green. Accessed 3 January 2020.

Million Trees NYC, 2015. NYC’s Urban Forest. Accessed 3 January 2020.

New York City Department of Health and Mental Hygiene, 2016. New York City Air Quality Programs Reduce Harmful Air Pollutants. Accessed 3 January 2020.

NYC Environmental Protection, 2019. Air Pollution & Regulations. Accessed 7 November 2019.

NYC Health, 2019a. Health Department Releases Report on Improvements in Citywide Air Quality. Accessed 2 January 2020.

NYC Health, 2019b. The New York City Community Air Survey: Neighborhood Air Quality 2008-2017. Accessed 3 January 2020.

NYC Parks, n.d. Street Tree Planting. Accessed 3 January 2020.

NYC Taxi and Limousine Commission, 2019. New York State’s Congestion Surcharge. Accessed 3 January 2020.

One NYC, 2018. One New York: The Plan for a Strong and Just City. Accessed 2 January 2020.

Popovich et al., 2019. See How the World’s Most Polluted Air Compares With Your City’s. Accessed 2 January 2020.

Case study: Air pollution in New York City: Learning activities


  1. Briefly outline the history and causes of air pollution in New York City. [3]
  2. Briefly summarise the differences between the PlaNYC and One NYC frameworks for sustainability. [2]
  3. Describe and explain the initiatives used in New York City to reduce air pollution [4+4]:
    1. Congestion charging
    2. Clean air fuels
    3. Efficient heating oils
    4. Planting trees
  4. Evaluate the success of these strategies. [6]

Other tasks

Does your nearest city have an air pollution problem? Does it have an air pollution strategy? Write to a local government representative suggesting what they could do regarding air pollution and why. You may like to check the current levels of air pollution in your nearest city using

© Matthew Burdett, 2020. All rights reserved.

All secondary material on this site is clearly referenced and may be subject to copyright restrictions by the original authors. All original material on this page is subject to copyright.