Manhattan’s density, supported by its mass transit infrastructure, is the principle reason the average New Yorker has a smaller carbon footprint than her counterpart in another large US city. At the urban scale, this density is, of course, enabled by a singular combination of geographic, economic, social and political factors. But at the scale of the city’s individual buildings, high-rise living and working are made possible by technological factors. And some of the technologies developed for lifting people, water, hot and cool air to great heights currently work in much the same way as they did when initially introduced. How often do we stop to consider the systems required to make a building function?

This question bears more urgency than casual wonder. 39% of CO2 emissions derive from building operations, including plumbing, electricity, heating, ventilation and air conditioning (or HVAC) and, in the case of high-rise buildings, the elevator system. To be sure, innovative work in architecture and engineering is improving the performance and efficiency of building operations, yet many people are unaware of the scope of energy intensive activities required for a building to function. So, with this in mind, we spent a day with Jim Ferrari, the chief mechanic of 515 Madison Avenue, a midtown Manhattan office building designed by J.E.R. Carpenter and completed in 1931, to find out more about what exactly goes on behind doors that typically only maintenance workers pass through. What Ferrari revealed was a series of day-to-day systems that many of us — those concerned with the environmental sustainability of our building stock — talk about improving without necessarily being able to visualize.

-C.S.

This Urban Omnibus video is the third in a series called City of Systems, a suite of short videos intended to offer a poetic peek behind the scenes of some of the complex systems that enable New York City to function. This video series is made possible by IBM as part of its commitment to use technology and information to help build more sustainable and intelligent cities.

515 Madison Avenue | Photo courtesy of Newmark Knight Frank

The music in the video, “Mistral” by Loscil, appears courtesy of kranky.

Last fall, we recapped a landmark symposium that the Citizen’s Housing and Planning Council convened to challenge housing officials, designers and developers to reform housing and zoning codes based on analysis of how people are actually living. Fewer and fewer people can afford to live within the existing legal housing standard, so more and more live outside of it. In addition to increased vulnerability to fire and safety hazards, tenants in illegal units have few enforceable rights. And the recent immigrants who comprise a large percentage of tenants in illegal units are often unwilling to seek official help. Some of them end up seeking help from community-based organizations like Chhaya, a community development corporation in Jackson Heights that works to address the unique housing needs of New York’s South Asian community – immigrants from India, Bangladesh, Pakistan, Nepal and Caribbean nations such as Guyana and Trinidad. Seema Agnani, Chhaya’s executive director, has seen firsthand the challenges that illegal dwelling units – particularly basement apartments – pose to immigrant tenants. And she’s also seen the opportunity that legalizing some of these units presents.

For these immigrants and other low-income New Yorkers priced out of the legal housing market, illegal subdivisions provide an undeniable source of affordable housing in New York City. Many of these units are unfit for habitation or otherwise unsafe. But not all of them. In some cases, legalizing a unit would simply require the filing of architectural plans with the Department of Buildings. In others, the impediment to legalization is not the Building Code but the zoning map – the unit might meet legal requirements for safe habitation but the property cannot legally accommodate multiple families. Still others are very close to meeting legal requirements but fall short in a minor way. Architects and planners need to get involved to help community advocates realize this potential for creating affordable housing out of our existing building stock.

Bringing illegal units into the scope of regulation could have a number of positive impacts: tenants’ living conditions would improve; forced displacement would decrease; rental income might lessen the burden on overleveraged homeowners at risk of mortgage default; landlords would begin to report rental income, increasing City revenues and potentially lessening the burden on social services in neighborhoods with large populations of undocumented residents. But how do you do that? Step 1: create an Accessory Dwelling Unit (ADU) code and bring those basements that can be made into safely habitable apartments up to the standards of that code.

What follows is Seema Agnani, executive director of Chhaya, explaining the context and need for an ADU code in her own words. -C.S.

"Do you know your rights as a tenant?" Flyer detail. Chhaya offers services in Bangla/Bengali, English, Hindi, and Urdu

In 2000, as we were in the process of establishing Chhaya, we completed a needs assessment survey of the South Asian immigrant community around the city and found that 50% of people we talked to didn’t have a lease. Over the years, both owners and tenants have sought us out with concerns: tenants who were living in illegal units and owners who were frustrated because tenants were not paying rent. So education, advocacy and organizing around the issues of illegal dwelling units have become a priority area for our organization.

Basement apartments are a legitimate source of affordable housing; the issue is that they need to be brought up to code. If they were, unsafe conditions would be improved, tenants could be guaranteed their rights, and owners could regularize their ability to collect rent and insure the protection of their property. But we’ve found that many elected officials are afraid to touch this issue; they see it as an issue of neighborhood preservation, with a lot of the more established residents feeling that new immigrants are coming in and ruining their communities. But the City is draining all sorts of resources. Judges in the court system are frustrated with the number of complaints, but there is nothing they can do to tackle the issue. The Department of Buildings is tired of having to issue these fines, despite the revenue. It’s also a huge drain on public resources, resulting in overcrowded schools and overstretched social service provision. But if these units and the population that resides in them could be planned for, it could really be a resource for the city. So last year we went about the process of documenting how many of these units actually exist.

Jackson Heights zoning map. Jackson Heights was one of the first of New York's neighborhoods designed with the car in mind, which required creating lots with larger areas at the back for garages. This characteristic allows for the existence of separate rear entrances to additional basement units.

The Housing and Secondary Unit Survey – which was designed in partnership with the Citizen’s Housing and Planning Council – was intended to document that these units exist and to assess the feasibility of legalizing them, looking at means of egress, the size of the windows, etc. We looked at two census tracts, one in Jackson Heights and one in Briarwood, Jamaica. Our goal was to look at what the actual data was versus what was on record. We surveyed 446 homes, all registered as single-family, and found that 80% had signs of basement use, and we estimate that 35% of these basement units could potentially be legalized.

These are decisions that should be based on health and safety not necessarily on inches.After analyzing the data, we put forward a series of recommendations that would remove some of the impediments to bringing illegal basement apartments to code. It basically comes down to implementing an Accessory Dwelling Unit (ADU) code. The concept is that the zoning doesn’t necessarily have to change. Many of the neighborhoods in question are zoned for single-family homes, which makes converting a property into a two-family home much more complicated. An ADU code is a way of getting around all of that – it remains a single-family home with an accessory unit.

Many places have already implemented ADU codes: Washington State, Santa Cruz, Yonkers and other parts of Westchester County, for example. But in New York City, the current building code is so strict that it makes legalization very difficult. For example, there is a legal difference between a cellar and a basement. A cellar is more the 50% below ground, a basement is more than 50% above. We’ve seen apartments that are more that 50% above ground at the front of the unit and less in the back. Our argument is that these are decisions that should be based on health and safety not necessarily on inches. If there is enough air and light and if it is safe, then the codes should be more flexible.

144th Street in Briarwood / Jamaica. Briarwood is a mostly residential, multi-ethnic community of one and two-family homes, many of which have basements, backyards and garages. Out of 305 homes surveyed in this area, 52 properties had received some form of complaint related to an illegal conversion.

Photo: Flickr user Peter Manzari

Our proposal is to create an ADU code, starting with a pilot project in a specific area, and then move on to the creation of financial incentives and the establishment of loan programs and grant programs. The ideal scenario would be to pass something at both the state and city level, but because of this issue’s political sensitivity, we are proposing that the City start with a pilot project. We would set a goal of helping maybe one hundred owners go through the process of legalizing a basement unit. That way, the City could learn from this process and also expedite it. One of the challenges is that these apartments already exist, so how do you insure that they have been converted properly in terms of the built-in wiring, piping, etc. A lot of architects are afraid to sign off on these apartments because they can’t do a proper inspection.

We need more architects involved in this work. There’s a real need for spatial, design and construction expertise, as well as help getting into the specifics of building codes. I think that is the actual missing piece for us right now.  We have advocates, we have legal experts but we don’t have enough of the design community involved in the process. And if we can get a pilot program going, then we’re going to need architects to help us  help individual homeowners through the process of legalization.

Detail of Building Code, Chapter 5: General Building Heights and Areas, Section BC-501

The design community could help us think through energy conservation approaches and ways to improve energy efficiency as well. There are a lot of resources available now – through weatherization programs and other stimulus money – that could be used to help with this process. And I think that we could think of an ADU plan as an opportunity to green these neighborhoods.

The majority of these units exist in the outer boroughs, they exist in immigrant communities that have established hubs. Their temples are here; their mosques are here; their community is here. People are willing to live in overcrowded conditions in order to be in these communities. Particularly in Queens, there really has been very little investment in affordable housing developments. If you look at where all of the development has occurred by the non-profit or for-profit sector, it’s pretty shocking when you see how little has been done in this borough. Of course there are political reasons for that, but I also think there’s a perception that everyone in Queens lives in historic single-family homes or nice condos and co-ops. There’s really a need to educate the broader public about the borough itself and what’s going on here. This is where the majority of new immigrants have settled in New York City.

With such a dynamic population, we need to build a base of tenants and owners who want to push for this. So there is a big community organizing component in addition to the policy advocacy work. The forums we convene can get pretty heated. Owners are stressed out about fines they’ve received, tenants are upset because they’re being evicted – we heard cases where families had been living in a neighborhood for over ten years, with kids in local schools, and then a forced eviction pushes them out, often into another illegal basement apartment, given the lack of legal affordable housing – and both groups are angry at their elected officials for not helping them. It’s not an easy issue to organize around. So we’re taking it to the streets. And we’ll see how it goes.

The staff of Chhaya Community Development Corporation

Seema Agnani is Executive Director of Chhaya CDC and was one of its initial founders. Before returning to Chhaya as Executive Director in 2007, she was the Coordinating Consultant to the Fund for New Citizens at The New York Community Trust, a donor collaborative supporting immigrant rights work. She was also the Director of Training and Technical Assistance at Citizens for NYC.  In addition, she worked with Asian Americans for Equality for several years as a housing development associate while also focusing on fundraising and development; and later served as a coordinator of the Lower Manhattan Health Care Coalition. She currently serves on the Board of Directors of the National Coalition for Asian Pacific American Community Development. She is a former recipient of The Charles H. Revson Fellowship at Columbia University, earned her Bachelors at the University of Wisconsin at Madison and a Masters of Urban Planning and Public Administration at the University of Illinois in Chicago.

The views expressed here are those of the author only and do not reflect the position of Urban Omnibus editorial staff or the Architectural League of New York.

Starting from scratch is not the only way. Given the urgency of the massive changes to our way of life that must take place over the next seven to ten years, I believe that strategies which involve a retrofit or a clip-on to our existing structures and infrastructures deserve a serious look.

Retrofitting our urban building stock to address climate change need not be limited exclusively to increasing their energy efficiency. If “one of the primary causes of global environmental change is tropical deforestation” (Geist & Lambin, 143), then we should approach the adaptation of our buildings as an exercise in reforestation. Deforestation is too often divorced from urban discourse around climate change. In an attempt to redress that, my investigation into sustainable retrofits has included research into some causes of and solutions to deforestation, including a list of interventions already being implemented in the developing world (click here to read more). We must learn from both the causes of climate change and attempts to combat it as we attempt to reforest the city.

It is estimated that the Amazon rainforest absorbs approximately 28% (7.34 billion metric tons) of carbon emissions from the burning of fossil fuels every year. Tropical rainforests are the planet's defense against global warming. Deforestation is one of the greatest sources of carbon dioxide which is the principal cause of global warming. "If converted to cattle operations, rainforest land yields about $60 per acre. If timber is harvested, the land is worth around $400 per acre. But if its renewable and sustainable resources are harvested, the land could yield an average of $2,400 per acre. "Each acre of rainforest prevents 75,000 to 100,000 pounds of carbon dioxide from being released." (Source: http://www.ecoclicknetwork.com/devEvo/MoreEcoFacts.cfm)

The City as Usable Surface Area
A densely populated city replicates its ground surface area many times over in the surfaces of the buildings that populate it. New York City, for example, covers some 309 square miles (801 sq km) of land area, much of which is built up. As of the 2000 census, there were 7,679,307 housing units in the five boroughs. A recent New York Times article quantifies the amount of available roofspace in the city alone as 944 million square feet, 11.5% of the total building area the city holds. Given that the population on the planet is rapidly increasing and due to double over the next 100 years, we may soon need all the available arable land for growing crops, with marginal lands where food crops provide inadequate yields relegated to biofuel crops (Killeen, 39). As the available space for the necessary green technologies is limited, it makes sense, therefore, to consider the city as the surface for our intervention.

A hypothetical six story apartment building has a footprint of approximately 2,100 square feet. The vertical surface area available on the facade for the deployment of green technologies using wind and solar power, or green screens for vertical gardening, or water walls for cooling, is approximately 12,000 sf if the building is freestanding, and around 3,600 sf if it is in an infill condition. Add on the roof area, much of which remains unused, and you get 14,100 sf for the freestanding and 5,700 sf for the infill building. Multiply that by the sheer number of buildings occupying any densely populated urban condition and the number becomes more significant still. (Buildings are only one field of action among many: New York State also has 113,000 miles of highway, another overlooked infrastructure to which clip-ons may be added.)

Sustainable Solutions
Even something as simple as painting roofs white, instead of black, has been shown to provide a significant savings in terms of the amount of energy expended to cool buildings, as well as reflecting heat away from the city rather than absorbing it. Read more about other sustainable solutions currently being implemented in the developing world here.

Greening our cities: Exterior Applications

	WHITE ROOF: “Hashem Akbari, a physicist at the Lawrence Berkeley lab, just released a study showing that the average American 1,000-square-foot white roof could offset 10 metric tons of carbon dioxide. According to his data, roofs constitute 20 to 25 percent of urban surfaces, while pavement is about 40 percent. Therefore, if all of those surfaces were switched to a reflective material (or color) in the 100 largest urban areas in America, his calculations show, this would offset 44 metric gigatons of carbon dioxide. That’s more than all countries emit in a single year. Further, that’s worth about $1.1 trillion at current carbon trading rates.” – from “Paint your roof white, save the planet”
	GREENSCREEN: By integrating more trees and photosynthesizing plants within the fabric of our existing cities, we harness the power of plants to absorb carbon from the atmosphere. The surface area of buildings multiplies the ground footprint of the city many times over, making vertical gardening and the integration of growing walls into our buildings an interesting practical solution. The roofscape of most cities is an area that is often forgotten but that could easily be used for the application of green technologies beneficial to all. Greenscreen is a type of metal structure that can be attached to existing walls or used to create freestanding growing walls.
	.
	WINDBELTS AND GREEN ROOF: Wind belts are a recent technology which harness the power of the wind to generate electricity. They are relatively inexpensive and suitable for both developed and developing countries and are the first wind technology not to employ turbines: according to Matt Vella, “About the size of a cell phone, the final Windbelt prototype employs a taut membrane that, when air passes over it, vibrates between metal coils to generate electricity.”  Windbelts could be used on the facades and roofs of existing buildings as a sculptural element, taking advantage of the building envelope as an available surface upon which to attach. Trees may be planted on the roof by using either planters or by using a new Japanese soil substitute, Pafcal, which is much lighter than earth.
	.
	WINDBELTS AND GREEN ROOF: Windbelts can also be attached to functional structures such as canopies which are normally used to protect the building entry from rain.

	ROOF POND:Roof ponds can be used for cooling in areas that are warm and not very humid. This technology has a lot of potential, but has been underused to date because of a fear of leakage on the part of architects and clients, however, if properly detailed it is a promising strategy and can help to reduce the heat island effect in cities. Water is placed between two layers of insulating material. The area covered with water should be 85% to 100% of floor area in places with winter temperatures between 25 and 35 degrees Fahrenheit (-4 to +2 Celsius) and 60% to 90% of floor area in places with winter temperatures between 35 and 45 degrees Fahrenheit ( +2 to +7 degrees Celsius). Average pond depth is between 3 and 6 inches (Stein & Reynolds, 2004.Insulating panels cover the roof and are opened during the day in the winter to absorb the heat of the sun, and at night, the panels are closed, allowing heat to radiate to the building’s interior. In the summer, the process is reversed.
	.
	ROOF SPRAY: This is another method for cooling which could be employed in a retrofit of existing buildings. It can be used in combination with the roof pond, or independently with the water being stored in a tank. Here water is cooled by spray at night, via evaporation and night sky radiation, and then stored for use during the day in the building’s cooling system (Stein & Reynolds, 379-80).
	.
	WATER WALL, WATER COLLECTION AND SOLAR PIPE: It is well known that electricity can be generated from fast moving water. Here, we propose that a water wall be added to a blank facade on an existing building as a means of generating electricity. Water can be collected via a system of gutters on the building, and then can be piped and recycled to generate the necessary flow. This water can also be used to flush toilets and for other non-potable applications. In addition, the water provides cooling to the building’s inhabitants.The roof in this scheme is envisioned as a space in which the entire surface area is covered by solar coils. This is a recent development: “Solyndra’s panels employ cylindrical modules which capture sunlight across a 360-degree photovoltaic surface capable of converting direct, diffuse and reflected sunlight into electricity. This self-tracking design allows Solyndra’s PV systems to capture significantly more sunlight than traditional flat-surfaced solar panels…”

Implementation Strategies
How might all this begin to be implemented? Below you see a piece of New York City to which we have applied some of the technologies discussed above. Large scale urban farming which takes place indoors and on large expanses of roof, greenscreens to let plants to climb the vertical surfaces of the city, trees which are now able to grow on the city roofscape. Roof ponds and artificial waterfalls for cooling and electrical generation. Solar and wind devices which form sculptural elements in the city, performing a function as well as having an aesthetic. Ports for plug-in electric vehicles which gather energy from photovoltaics. Solar panels incorporated into street poles, and vertical wind turbines which form a rhythm in the streetscape. Bicycle lanes, room for walking and the incorporation of still more trees.

click on image to enlarge

The government of New York City might choose to provide tax breaks that would give economic incentives to building owners who implement the strategies we have illustrated. A demonstration project of a square city block could be facilitated in this way, perhaps involving the participation of large scale property owners or local community groups such as PACC, 5th Ave Committee, and HCCI, which are already spearheading initiatives aimed at reducing the city’s carbon footprint. Justin Garrett Moore, an Urban Designer at the Department of City Planning suggests targeting groups with large property holdings, such as the New York City Housing Authority or the Abyssinian Development Corporation.

A demonstration project may also fall under the aegis of HUD’s Choice Neighborhoods Initiative, which has as one of its goals the transformation and energy efficiency upgrade of housing in economically distressed communities. In addition to the tax break provided by the city, property owners involved in the demonstration project would see a significant reduction in their utility bills, and could potentially sell the energy they produce as excess capacity back to Con Edison. In the distant future, energy production may become a much more localized phenomenon, with the old, formerly centralized public utilities being rebranded into producers of alternative energy. Perhaps the current dilemma, rather than being seen as a death sentence or a depressing indictment of wasteful society, can provide an opportunity to rethink and retool our existing way of life. Our chance is now.

Research Team:  Fay Alkhalifa, Marcus Brooks, Graziela Gimenes, Akiko Hagiwara, Anna Obratzsova, Gabriela Rodriguez, Allison Schwartz.

This article is adapted from “Clip-on Architecture: Reforesting Cities and Potential Solutions to the Climate Crisis” by Vanessa Keith, a PDF of which can be downloaded here. Right-click here to download the bibliography (PDF).

All images courtesy of Vanessa Keith.

Vanessa Keith, AIA is a principal at StudioTEKA. She is a registered architect who received her Master of Architecture degree from the University of Pennsylvania and her Master of International Affairs from the School of International and Public Affairs at Columbia University, graduating with a concentration in Economic and Political Development and a focus area in urban planning.

The views expressed here are those of the author only and do not reflect the position of Urban Omnibus editorial staff or the Architectural League of New York.

Deforestation “is not a recent phenomenon; it is as old as the human occupation of the earth, and one of the key processes in the history of our transformation of its surface.” (Williams, xxi) The desire to expand ever outward, the thirst for the frontier, the unconquered lands, the uncharted waters, thus seems to be a fundamental part of being human. What follows summarizes research into tropical deforestation and some sustainable solutions being applied in the developing world. But first, read about some ways we can combat the effects of tropical deforestation in New York here.

Altering the Landscape
“Every newly planted tree seedling in the tropics removes an average of 50 kilograms of CO2 from the atmosphere each year during its growth period of 20-50 years, compared with 13 kilograms of CO2 per year for a tree in the temperate regions” (Brown, 167).

“Market regulations take many forms, but the most effective are those based on financial incentives that motivate individuals to choose voluntarily what is in their short-term economic interest” (Killeen, 74).

Even in its earliest days, it appears that human alteration of the landscape was a bottom-up event, rather than something centralized and disseminated from the top down. Is there some fundamental pattern at work, somehow hardwired into our systems as human beings that makes us repeat the same tragic steps over and over?

Whatever the local cause, it appears that many of the cause of climate change – such as deforestation – finds its larger origins in the tragedy of the commons (Diamond, 428). Underlying the tragedy of the commons is the premise that individuals benefit in the short term from the overharvesting of commonly harvested resources, but suffer collectively in the long term when they are depleted (Diamond, 428). As deforestation and environmental degradation are strongly linked to patterns of individual short term self interest, the question becomes how we can work with rather than against these interests in order to promote a different outcome?

Wouldn’t it be great if we could just turn on a carbon vacuum cleaner and clean up the whole mess?One solution is for those who share the resource to recognize their common interests and collectively agree to police themselves. This tends to work best in smaller and more isolated homogeneous communities where there is some stake in a common future and the boundaries of the resource and those who exploit it are well known (Diamond, 429). The government can also enforce quotas, though this may be impractical as the cost of policing the resource may be high. A third solution is to privatize resources, making individuals custodians of them; this practice can be something that emerges from the top down as a governmental initiative. It can also be bottom up as in the case of farmers in Niger who, in the 1980s, noticed that the soil was more fertile and there was reduced erosion when they planted acacia trees in their fields. This practice spread and now there are around 120 million trees on Nigerian agricultural land: “The key to this success story was the shift in tree ownership from the state to individual farmers, giving them the responsibility for protecting the trees” (Brown, 158).

The solution, then, would appear to have something to do with examining the factors at play which encourage environmentally destructive behaviors, and setting out to change them. While it is obvious that some top down decision making is involved in creating the conditions which have fostered the dire circumstances in which we now find ourselves, much of what happens afterwards would often appear to be the workings of many individual decision makers. Current economic models sadly do not take into account the services provided by forests. As in the case of the destructive flooding of the Yangtze River in 1998, which caused an astonishing $30 billion dollars worth of damage due to landslides, these services may be worth far more money than the lumber in the trees. After the destruction, the Chinese government paid loggers to replant the trees, noting that the flood control service of trees was worth three times the value of cut timber (Brown, 86, 166).

How Tropical Deforestation Affects the Rest of the World

	HADLEY CIRCULATION: The long-distance effects “of Amazonian deforestation are modulated by a phenomenon known as the Hadley circulation in which warm air rises at the equator, moves toward the poles, descends at higher latitudes, and returns toward the equator along the surface of the earth…” According to climatologists, as deforestation increases, precipitation will be reduced and temperatures will rise in the Amazon. As a result, these impacts will cause climate change in other parts of the world and global warming will continue at a faster rate (Killeen, 60).
	.
	IMPACT ZONE OF THE AMAZON RAINFOREST: Deforestation in the Amazon severely reduces rainfall from Mexico to Texas and into the Gulf of Mexico most notably in the spring and summer growing seasons when rainfall is essential for agriculture. Similarly, the deforestation of lands in Central Africa affects precipitation in the upper and lower U.S Midwest, while deforestation in Southeast Asia was found to alter rainfall in China and the Balkan Peninsula most strongly. It is important to note that such changes primarily occur in certain seasons and that the combination of deforestation in these areas often increases rain in one region while reducing it in another (NASA).
	.

An Urgent Deadline
“…we do have a short time left to cut back emissions in order to avoid a ‘dangerous’ level of warming and can still aim for a ‘safe landing’ within the one to two degree corridor. This window of opportunity is very nearly closed, however. … we have less than a decade remaining to peak and begin cutting global emissions. This is an urgent timetable, but not an impossible one” (Lynas, 270).

Though a few degrees Celsius of warming may not seem all that severe, here are some chilling examples as food for thought. The last Ice Age, which occurred some eighteen thousand years ago, saw average world temperatures about six degrees colder than those of today (Lynas, 17). A world six degrees warmer would be something akin to Dante’s Sixth Circle of Hell, a world subject to powerful storms far beyond what we are currently able to imagine, including hurricanes able to circumnavigate the globe, and methane explosions which “would dwarf even the most severe modern battlefield weapons” (Lynas, 257). How can we become more efficient and, moreover, how can all that excess carbon be absorbed? Wouldn’t it be great if we could just turn on a carbon vacuum cleaner and clean up the whole mess?

Tree as Carbon Vacuum Cleaner
Well, we already have carbon vacuum cleaners, of a sort. They’re called plants and trees, and they do the opposite of what we do when we breathe in oxygen and breathe out CO2, or when we take a trip by car to the supermarket. They also have the potential to absorb much of the CO2 we emit year after year, when combined with other sustainable strategies. Not every tree absorbs the same amount of carbon, and trees in the tropics absorb more CO2 than temperate trees. However, on average, a tree absorbs approximately 3 kilograms of carbon dioxide from the air per year. Scientists have pointed to the importance of forests in carbon capture:

“…a heavily forested region in northern Michigan could store more than 350,000 tons of carbon per year. With the area population emitting about 573,000 tons of carbon annually, the forests would sequester approximately 62 percent of the region’s human-caused carbon emissions – the equivalent of yearly emissions from about 225,000 cars” (Science Daily).

Many cities around the world are adopting environmental initiatives independently of their national governments and are participating in the Cities for Climate Protection campaign (Dow & Downing, 78). Certainly the idea of reforesting for the purpose of carbon sequestration is a worthy one. However, another untapped resource for the application of strategies of efficiency and carbon capture remains the structure and fabric of the city itself. Like the urban clip-ons described in the accompanying post, the schemes below envision retrofitting an existing infrastructure (in this case, highways through the tropical rainforest) to lessen the damage our built environment causes our climate.

	AMAZON BARRIER ROAD WITH CLIP-ON SOLAR PANELS: While it would be better not to construct roads through the rainforest at all, IIRSA is forging ahead. Here we envision a potential compromise solution to the roads proposed by the IIRSA project. If the problem is that roads increase access, it may be worthwhile considering the development of road systems which limit access or have access at specific entry points which are controlled. A barrier of the type shown here still provides a view of the surroundings, and also provides an infrastructure upon which can be mounted solar panels, wind belts, and other sustainable energy generating devices.
	.
	AMAZON ELEVATED ROAD: Elevating roads makes access by human beings to pristine forest areas more difficult, and yet still allows animals to migrate and move freely beneath the road surface. While not ideal from a conservation standpoint where leaving such areas entirely alone is best, this represents a compromise solution, given that road construction projects are already planned for the area. Animal overpasses and underpasses have been used very successfully in Canada: “… Parks Canada has upgraded portions of the highway. This includes dividing and twinning the lanes and installing fencing and wildlife overpasses and underpasses. These crossings allow animals to pass safely over or under the highway. The system has reduced collisions with wildlife by more than 80%. By monitoring the wildlife crossings, Parks Canada has learned that 10 species of large mammals have used them more than 60,000 times since 1996.”
	.
	AMAZON BARRIER ROAD WITH GREEN STRIP: The roads in the Amazon, or any other road for that matter, provide an opportunity for planting, thus giving back a bit of the surface area taken up by the road. Here a simple underground tunnel allows access by wildlife to the two sides of the road. A barrier which discourages human interventions in the forest also prevents animals from being killed on the road. Wind belts and other technologies can be incorporated into roads, which represent a vast amount of surface area which could be used to generate energy sustainably. It is our belief that we should view all surfaces, whether infrastructure or buildings, as potential sites for the deployment of green strategies. Electric cars at their current level of development can be used for day to day travel and commuting, thus reducing a huge source of greenhouse gas emissions.
	.
	ROAD WITH ANIMAL BRIDGE: Similar to the concept of the fish ladder, a device used to aid fish migrations over dams, the animal bridge provides a connective link between the otherwise isolated parts of the ecosystem on either side of the road. This diagram is envisioned as a limited access road with checkpoints, and so has a reduced need for side barriers preventing access to the forest.
	.

Sustainable Solutions
In addition to the ambitious retrofits proposed above, many low-tech options are currently being developed for and by developing countries. Notably, in many cases it takes a relatively small investment to make a huge difference. USAID is working in Kenya to distribute 780,000 solar cookstoves which, as they are more efficient, require less wood, relieving some of the pressure on local forests as a source of cooking fuel (Brown, 154). Non turbine windbelts are being developed for the market by a team from MIT which, in 2004, got the idea as they were working to solve the energy needs of the local Haitian population in Petite Anse. The belts function by converting the vibration caused by the wind passing over them into energy. Other pole-mounted wind turbines have also been developed at a scale that is more readily deployable within the confines of the city, and able to harness wind energy coming from all directions. Rooftop solar water heaters in China have made a big splash and, at $200 each, they are widely being used in villages which do not yet have electricity. There are around 40 million of these heaters being used in China today (Brown, 246).

Special gutters are now available for the collection of rainwater for passive heating and cooling, or for the generation of electricity via waterfalls. There is great interest in the potential of algae, which can be grown almost anywhere, and is faster growing even than bamboo. Certain types of algae may be as effective in capturing CO2 as trees, and algae is currently being used in a pilot project at MIT where it absorbs 40% of the CO2 emissions from a power plant and is then converted into biofuel. In-stream turbines for rivers allow for the generation of electricity without the expense and environmental damage that can be caused by large scale dams. The Spiteri Water Pump in Malta, a machine which generates electricity when immersed in a body of water by harnessing its latent electrostatic energy, does not need any fuel to operate. It has low operating costs and generates energy 24 hours a day. Geothermal energy is another, virtually limitless supply of power from the earth’s core that is presently used to heat over 90% of the houses in Iceland, and constitutes more than one third of the country’s energy usage. About half of the world’s geothermal capacity is concentrated in the United States and the Philippines, with other countries bordering the ring of fire in the Pacific not far behind (Brown, 253-54).

Lightweight soil substitutes such as Pafcal are being developed which will allow for roof planting without the heavy loads associated with soil. Greenscreens have been developed which can allow vertical gardens to grow up the facades of existing buildings. Urban farming, which could take place in buildings within the city limits, thus drastically reducing the travel distance for foodstuffs, is being explored. Indoor farming does not require fossil fuels for plowing fields and driving harvests to market, nor does it require fertilizer or pesticides, and plants can be grown 24 hours a day. Indeed, “a 30 story farm that covered a city block could feed 50,000 people year round” (Fischitti, 74). Solar modules are being designed that can be attached to light fixtures, or which come in rounded tubes and are able to collect more energy from the sun than traditional solar panels, converting direct, diffuse, and reflected sunlight into power. So it would appear that Socolow and Pacala are correct in their assumption that all or most of the technology needed to reduce carbon emissions to stabilized levels already exists. So the challenge is how to implement these strategies. Maybe a good first step is to try to clip-on some of these solutions to a city block in New York. Here’s how.

Research Team:  Fay Alkhalifa, Marcus Brooks, Graziela Gimenes, Akiko Hagiwara, Anna Obratzsova, Gabriela Rodriguez, Allison Schwartz.

This article is adapted from “Clip-on Architecture: Reforesting Cities and Potential Solutions to the Climate Crisis” by Vanessa Keith, a PDF of which can be downloaded here.  Right-click here to download the bibliography (PDF).

All images by Studioteka.

Vanessa Keith, AIA is a principal at Studioteka. She is a registered architect who received her Master of Architecture degree from the University of Pennsylvania and her Master of International Affairs from the School of International and Public Affairs at Columbia University, graduating with a concentration in Economic and Political Development and a focus area in urban planning.

The views expressed here are those of the author only and do not reflect the position of Urban Omnibus editorial staff or the Architectural League of New York.

Like most of my colleagues, I tip my hat to Mayor Bloomberg and the City Council for devising a plan to make landlords retrofit older buildings. And like the cleantech advocates who stood beside me on a Rockefeller Center terrace to hear the mayor outline the plan on Earth Day, I shrugged when I tried to gauge which engineering recipes will help landlords meet the requirements. And now, I’m biting my nails a bit.

Landlords tend to hate mandates, in part because it’s bedeviling to legislate engineering: no two buildings respond optimally to the same efficiency fixes. A building’s optimal tune-up depends on what its tenants do, how frequently they move in and out, where the building faces, and so on. But the Greener, Greater Buildings Plan requires energy audits and upgrades from all  landlords in big buildings, and lighting fixes from all their commercial tenants. Bold and properly so. But maybe we would get greener sooner if the mayor had offered incentives to a subset of landlords whose huge portfolios make investing in efficiency a surer bet than nitpicking over why they shouldn’t have to.

“It speaks volumes to see who isn’t standing with the mayor,” a City Hall staff member confided on Earth Day. The landlords’ lobby has clamored for slow-track changes to their buildings since the mayor’s focus turned green in 2007. I now worry that the mandates in the new plan – five year paybacks, full benchmarking, code compliance after even minor upgrades – will embolden the small landlords to cry “oppression in a Depression!” and swoop us all into a political Punch and Judy show. Hey, it happened with congestion pricing.

So what do urban enthusiasts do about it? Focus. The audacity that brought us Rockefeller Center, Dumbo and the High Line crackles through the mayor’s plan – except that the stakes are much higher. Before the mayor spoke on Earth Day, I turned and paused to geek out at St. Patrick’s Cathedral. The next few years will ask us to choose economic constraints to free us from a flood of climate-related disasters. If we tell our landlords, our pension funds, our architects and our mayors to keep thinking big, we will build something as sublime as Rock Center. If we listen to the silence of landlords who worry about short-term costs, the bright cheer of recent days will fade to a painful echo.

Alec Appelbaum writes about how cities can become greener and fairer for the New York Times, the Architect’s Newspaper and others. He lives on the Lower East Side. Photo: Spencer T. Tucker / City of New York, Office of the Mayor

The views expressed here are those of the author only and do not reflect the position of Urban Omnibus editorial staff or the Architectural League of New York.