Proposal

Farhan Khan, Jayden Garcia, and Brendan Johnson

Grove School of Engineering, City College of New York

ENGL 21007: Writing For Engineering

Professor Julia Brown

May 6, 2025

Summary

The most prominent source of greenhouse gases in New York City is its buildings. These greenhouse gases cloud our Ozone layer and perpetuate global warming. The program we propose to mitigate this is to add an easy-to-install, self-maintaining rooftop garden onto the majority of the buildings in New York. We would use easy-to-manufacture mechanical systems that automate the process and require little interference. The budget would range from about 50-100 million dollars. The team comprises one of New York City’s financial advisors, Jayden Garcia, former NASA engineer Farhan Khan, and well-known environmental scientist and activist Brendan Johnson.

Intro

This proposal focuses on the implementation of rooftop green spaces/gardens across residential, commercial, and municipal buildings across New York City, aiming to reduce air pollution, specifically carbon emissions. The scope of this project includes buildings across all five boroughs with flat, open rooftops that meet structural load requirements, access standards, and zoning regulations. The initial implementation would prioritize neighborhoods with high levels of air pollution, such as East Williamsburg and Brooklyn Heights, low green space per capita, and buildings compatible with rooftop adjustments.

New York City faces some of the highest air pollution levels in the country, primarily driven by emissions from buildings, automobiles, and industrial sources. When ranked on which state emits the most CO₂, New York places 8th among the 50 states. (Choose Energy.) According to the NYC Climate Dashboard, building energy use, such as heating, cooling, and electricity, contributes to nearly 70% of the city’s greenhouse gas emissions. (New York City Comptroller). The emissions from New York City alone account for 20% of the CO₂ emissions in the entire state. These emissions result in climate change as well as serious public health issues, including increased rates of asthma, heart disease, and other respiratory conditions.

    Rooftop gardens, also known as green roofs, present a practical, sustainable solution to this problem. These systems typically include layers such as a waterproof membrane, a root barrier, a drainage layer, soil, and vegetation. While they may seem simple in concept, their impact is significant and multifaceted. One of the main objectives of rooftop gardens is to absorb carbon dioxide from the atmosphere. Through photosynthesis, plants pull CO₂ out of the air and store it in their biomass and the surrounding soil. For example, a single mature tree can absorb about 48 pounds of CO₂ annually.

They also help cool the surrounding environment through a process called evapotranspiration, a process where plants release water vapor into the air, lowering the overall temperature. This helps fight the urban heat island effect, which worsens air pollution by increasing ozone formation (Brooklyn Grange). 

Green infrastructure, particularly rooftop gardens, has gained increasing popularity for its environmental and economic benefits. In major urban centers such as Lower Manhattan, rooftop gardens have been implemented to reduce stormwater runoff, combat high-pollution urban zones, and improve air quality.

According to Brooklyn Grange, New York City already hosts several functional green roofs, including farms that grow produce and reduce building energy use through insulation (Brooklyn Grange). Additionally, The Nature Conservancy reports that green roofs in NYC reduce CO₂ emissions and combat the heat island effect by lowering surrounding temperatures by several degrees (The Nature Conservancy). Current market analyses suggest that the return on investment (ROI) for green roofs is competitive, especially in cities where heat, stormwater, and emissions pose costly infrastructure burdens (BIMsmith). The ROI of these green roofs could come from many sources. The property value of the buildings could increase as green roofs gain popularity. The installation of these green roofs requires workers, which means jobs are created and the money is funneled back into the economy. The reduction of emissions could lead to a cooler New York, which in turn decreases the electrical costs that go into cooling systems such as air conditioners and fans. Green roofs are said to have an estimated ROI of 224% (GSA).

    Perhaps most importantly, rooftop gardens play a key role in the broader ecosystem of urban vegetation. A 2023 study by Columbia University’s Climate School found that the combined greenery of New York City, including trees, parks, and rooftop plants, absorbs a surprising amount of the city’s CO₂ emissions, especially during the peak growing season (Schlossberg). This reinforces the idea that rooftop gardens have a significant impact on the city’s green infrastructure rather than just contributing cosmetically or aesthetically.

The scale of implementation remains modest relative to NYC’s potential. The opportunity exists to position NYC as a national leader in green infrastructure by expanding rooftop garden adoption. Other states could take influence and develop their own similar programs after seeing one work successfully in practice. The benefits of this proposal could spread worldwide if done correctly.

There are about 730 Rooftop gardens in New York, or “green roofs”(The Nature Conservancy). If we could expand this to have even the smallest rooftop garden on each of the 1 million buildings (NYC Mayor’s Office) in NYC, we could easily offset the carbon emissions in the city.

Project Description

The way we will use our budget is by manufacturing rooftop garden units. These garden units are intended to maximize the effect of the little space they occupy. Our units will include plants that can manage to survive in close proximity, in order to increase the concentration of plant life on the roofs. It will also be easy to install and maintain. Ideal plants for these rooftop gardens should be durable, low-maintenance, and pollution-absorbing. One plant species that would be effective in our solution is the serviceberry plant, which is a small shrub that is effective at sequestering CO₂ and filtering pollutants like fine dust out of the air. Another good choice of plant would be the sedum plant, which is a durable flowering plant. It is able to withstand drought-like climates and is also effective for filtering particulate matter from the air and absorbing CO₂. Additionally, its size and minimal root structure make it suited for shallow soil rooftops. The installation of one of these units shouldn’t take more than a few days. The maintenance will include cheap mechanical automatic systems, such as automatic sprinklers and fertilizers. The units are designed in a modular way. This means that they break down into separate parts that can be installed onto any flat surface on the roof. This allows for a non-invasive and passive approach to having a rooftop garden. The residents of the building will be able to easily co-exist with and maintain their gardens. The city would fund and provide these gardens to the major buildings in New York, with typically higher scores on the CO₂ and energy efficiency chart.

    However, there are several limitations to our approach. Firstly, structural feasibility is a concern given the weight of the gardens. Not all rooftops can support the added weight of a garden without significant reinforcement, which may increase costs (BIMsmith). Next, although the units are automatic, rooftop gardens still require regular upkeep, irrigation systems, and seasonal care, which can be financially challenging to sustain on a city-wide scale (Ecosustainable House). One way to introduce a degree of automation into our system is to use smart irrigation systems that rely on rainwater to drip water onto the gardens. These systems can be powered by solar panels and monitored remotely to ensure efficient water use, reducing both labor and utility costs over time. While automatic maintenance is ideal, realistically, there has to be some human intervention. The baseline we propose would be watering once a month, if the smart irrigation systems fail. Alternatively, the residents could hire specialists to fix these issues. This process could take indefinite amounts of time and cost unpredictable amounts of money. On a small scale, the cost is reasonable, but the scope raises this cost. The high initial cost creates barriers for widespread adoption. Although long-term benefits are notable, the upfront installation costs can deter adoption, especially in low-income communities (BIMsmith). However, using low-maintenance and durable plants like sedum and serviceberry can minimize these costs.

There are a few limitations associated with this proposal. Due to climate limitations, seasonal changes in NYC may restrict year-round plant growth and CO₂ absorption efficiency (Ecosustainable House). Additionally, gaining permissions from building owners and navigating property laws presents logistical challenges. There would have to be laws put in place and voted on that allow the city to intervene in the building owner’s property. However, there are ways to counteract these limitations. To avoid the expensive process of litigation, we can use incentives and assistance to motivate and educate the public to adopt green roofs. For example, programs such as New York City’s Green Roof Tax Abatement currently offer up to $15 per square foot of green roof. We can incentivize building owners to adopt green roofs by strengthening these kinds of programs and making them easier to access and more economically feasible for them. In residential or multipurpose buildings, we can employ tenants and local neighborhood organizations in co-managing these rooftop gardens to increase community involvement and reduce the workload on the property owner. Finally, we can offer pre-built green roof templates or installation kits to reduce the knowledge barrier to adoption and simplify the process for potential green roof adopters. 

Budget 

To begin with the process of the idea, an estimated budget and how many buildings are in New York must be considered. According to NYC.gov, New York has an approximate amount of 1 million structures/buildings of every type and combination (NYC Mayor’s Office). With this amount of buildings, the estimated cost of each rooftop garden will vary depending on how much space the roof has. However, for most rooftops, the average price to install a rooftop garden will be at most $100 more or less. To do this for almost half of the buildings in NYC, it would take about 50-100 million dollars to ensure this can be done successfully and without future issues. Additionally, making sure that the building is suitable enough to hold the garden, the materials, design, and labor also increases the cost. These can impact the cost, all depending on where the area is, how the resources around them are, and if creating more space is needed for the garden to survive. 

Budget Breakdown
Items:	Prices/Total cost:
Waterproof membrane	$5,000-$15,000
Draining system	$22 per square foot
Lightweight containers	$12-$50
Lightweight soil	$60-$85 per cubic yard
Trellises (Windbreak)	$60
Water Source	Varies between method
Water Storage	Varies between method
Plants	Varies between plant
	Total: $5,154+

Conclusion 

The purpose of this proposal was to find a solution to reduce carbon emissions in the five boroughs of New York using rooftop gardens. From what was researched and calculated to the positives, negatives, and budget for this, it should be possible for this to work correctly as long as everything is done correctly. Having this project go through can greatly improve the air quality in all five boroughs and the surrounding environment, overall making the lives of people here better. New York ranks 8 out of 50 for the states that emit the most carbon gas. This means that New York is one of the top ten states in America that contributes to climate change negatively. New York’s pollution level is already bad, and if this continues, the air we breathe every day will become toxic to the point of no return.  If New York City managed to balance out the carbon emissions it created by using our proposal, then the whole state of New York would rank at 11. (US Energy Administration) With your help, we can make everyone’s lives here better. So please, help us give the citizens of this State in all five boroughs a healthier experience to live. 

Works Cited

“Buildings.” NYC Mayor’s Office of Climate and Justice, https://climate.cityofnewyork.us/subtopics/buildings/#:~:text=With%20over%201%20Million%20buildings,and%20resiliency%20in%20this%20sector

“Carbon Dioxide Emissions by State.” Choose energy, https://www.chooseenergy.com/data-center/carbon-dioxide-by-state/

“Emissions.” Office of the New York City Comptroller, https://comptroller.nyc.gov/services/for-the-public/nyc-climate-dashboard/emissions.

“Energy-Related CO2 Emission Data Tables.” US Energy Administration, https://www.eia.gov/environment/emissions/state/

“Green Roofs.” U.S. General Services Administration, https://www.gsa.gov/governmentwide-initiatives/federal-highperformance-buildings/resource-library/integrative-strategies/green-roofs

“Green Roofs in New York City.” The Nature Conservancy, https://www.nature.org/en-us/about-us/where-we-work/united-states/new-york/stories-in-new-york/green-roofs-new-york-city.

“How Much CO2 Does One Tree Absorb?” One Tree Planted, https://onetreeplanted.org/blogs/stories/how-much-co2-does-tree-absorb.

“How Much Impact Do Green Roofs Actually Have?” BIMsmith, https://blog.bimsmith.com/Rooftop-Gardens-How-Much-Impact-do-Green-Roofs-Actually-Have

“NYC Green Roof Advocacy.” Brooklyn Grange, https://www.brooklyngrangefarm.com/blog/nyc-green-roof-advocacy.

“New York City’s Greenery Absorbs a Surprising Amount of Its Carbon Emissions.” State of the Planet, Columbia Climate School, 5 Jan. 2023, https://news.climate.columbia.edu/2023/01/05/new-york-citys-greenery-absorbs-a-surprising-amount-of-its-carbon-emissions.