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Pitch

Establishing green roofs around areas can provide environmental, public-health related, and economic benefits.


Description

Summary

Green roofs are extensions to the conventional building roofs through additional layers of filtering system and vegetation. These innovative roofs will be an effective solution to the urban heat island effect, an accumulation of heat from urban building materials such as concrete and asphalt. Green roofs can reduce a building’s energy output by reducing the need for temperature regulation in that building, while reflecting and cooling down the hot surfaces in the urban environment. In the summer, they can cool the air around buildings by the process of plants wicking water into the atmosphere through the stomata of leaves. In the winter, green roofs keep heat inside the buildings, reducing the need for internal heating. All of these benefits can add up to provide significant energy savings by residents living in green-roofed buildings as opposed to those living in traditional-roofed buildings.

Green Roofs are also financially beneficial. By their benefits to the public health, green roofs will benefit between “$29.2 and $111 million" from cleaner air if 10 percent of Chicago roofs are covered with green roofs. In Detroit, the same percentage of green roofs would benefit between “$24.2 and $91.9 million”(University of Michigan). Green roofs could also “reduce a building’s air conditioning bill by about 21 percent” compared to a traditional black roof (University of Texas).

The green roofs’ ability to protect the roof membranes can significantly extend the life of the roof by “two or three times beyond its typical lifespan” (Hanway, Gardenista). The cost benefits in the long-term of green roofs are greater than normal asphalt roofs.

Green roofs offer more “green jobs” and marketing opportunities of the buildings. Moreover, low income families, who may not typically have access to fresh produce due to distance or income, can access produce grown on these roofs that can feasibly be fresh vegetables at a reduced cost as transportation is not required.


Category of the action

Geoengineering


What actions do you propose?

We propose a widespread implementation and installation of green roofs into an urban setting, such as Boston or Chicago. Ideally, this pilot project, Green Roofs Environmental Activists Team (GREAT), would take place in an urban area with limited resources, few historical buildings, and low income rates. This would minimize the risk of placing a green roof on a cherished or architecturally unsound historical building. Produce grown on these roofs could also feasibly provide fresh vegetables to these urban areas, which may not typically have access to fresh produce due to distance or income, at a reduced cost as transportation is not required. The project will also spread awareness of climate change outside of the academic circles.


Who will take these actions?

We will take these actions by utilizing education and the job market. The major universities, such as in those in Boston, can establish a coalition, which hires interns from public high schools. This coalition can begin a pilot project which will focus on bringing green roofs and all of their benefits to areas of the city which are in need of resources.  In doing so, you would provide educational opportunities for the youth while raising awareness among the youth and the public about the risks and possible solutions for climate change and actively decreasing the effect our city has on energy use and CO2 emissions. Alternatively, the local or city government could provide funding for green roofs. This initial cost would lead to long term benefits, as the installation and upkeep of green roofs would create job opportunities within the community.


Where will these actions be taken?

This pilot project would ideally take place in an urban area with limited resources, few historical buildings, and low income rates. Currently, cities such as Basel, Linz, Toronto, Portland, and Chicago have green roofs on their buildings and are benefiting greatly both financially and environmentally.  GREAT hopes to further these accomplishments to other cities, such as Boston, Seoul, and more.


What are other key benefits?

Cooler buildings diminish the risk of heatstroke and dehydration among their inhabitants. Decreased pollution will also alleviate respiratory problems.

Green roofs will provide cleaner water in addition to cleaner air. Excess precipitation can stress urban sewage systems; however, this water could be efficiently used by green roofs. Water collected by green roofs will support plant life, while any excess can be used to drink, as plants and soil act as a natural filter.

Green spaces also improve the mental health of inhabitants. Studies have shown that hospital patients with access to nature have an 8.5% improvement in recovery time. Patients who are provided visual access to greenery are demonstrated to have lower blood pressure, use less pain medications and have fewer postop complications. Green roofs can reduce indoor sound by as much as 40 decibels, serving as a noise barrier to city traffic, which can result in improved sleeping and concentration among inhabitants.


What are the proposal’s costs?

Green roofs are more expensive than a traditional asphalt roof, ranging between $10 to $20 per square foot, while an asphalt roof has an average of $1.20 a square foot; however, the green roofs’ ability to protect the roof membranes can significantly extend the life of the roof by “two or three times beyond its typical lifespan.” For example, currently in Europe there are buildings with green roofs since the 1960s and “have been known to last for from 30 to 50 years.” According to a study done by researchers at the University of Michigan, by its benefits to the public health, green roofs will benefit between “$29.2 and $111 million, due to cleaner air” if 10 percent of Chicago roofs are covered with green roofs, which would cost approximately 2 million dollars. Initially, the cost may seem overwhelming, yet the cost benefits in the long-term of green roofs are far greater than normal asphalt roofs.


Time line

Short term: The first step will be installation. Each roof takes about a week to install. A reasonable goal would be to cover about 123,552 square feet in green roofs (this is a little over 10 percent of Chicago’s roofs for comparison) in five years.

 

Medium term: The next many years will only require the maintenance of the roofs, and installation of green roofs across greater areas when possible. This will bring the benefits of green roofs to to lower income families and raise more awareness about the benefits of green roofs and dangers of climate change.

 

Long term: In the long term, green roofs will provide a significant change to the public health and the image of a city as a cleaner and safer area. More people, especially the younger generation, will be taking action in the establishment of green roofs and preventing further climate change, while the job market will side toward more environmental-friendly and green jobs. The urban heat island effect would have significantly decreased along with a cleaner source of air and water.


Related proposals

https://www.climatecolab.org/contests/2015/geoengineering-workspace/c/proposal/1326815

 

This proposal is similar in concept in reducing greenhouse gas levels through green areas; however, green roofs are different from rooftop gardens as mentioned in the related proposal, for green roofs provide exponentially more benefits both to the environment and the public. They cover the entire and provide more green surface area, they have a soil base, and are integrated into the building itself, providing temperature and sound regulation.


References

http://www.greenroofs.org/index.php/about/greenroofbenefits

https://www.gsa.gov/portal/mediaId/158783/fileName/The_Benefits_and_Challenges_of_Green_Roofs_on_Public_and_Commercial_Buildings.action

www.aue.bs.ch/aa-flachdach

Brenneisen, S. ‘Green Roofs and Biodiversity – International Context.’

www.toronto.ca/greenroofs/

Report on the Environmental Benefits and Costs of Green Roof Technology for the City of Toronto, Dept. of Architectural Science, Ryerson University

http://www.greenroofs.com/projects/

http://www.facilitiesnet.com/roofing/article/Financial-Benefits-Of-Green-Roofs--10073?source=next