The Future of Mobility: Greening the Airport

Flight Patterns, Aaron Koblin. [Image courtesy of Aaron Koblin]

We live in an era of unprecedented speed and mobility. Urban geographer and anthropologist Manuel Castells has famously characterized our time as being shaped by the “space of flows,” in which multiple communication systems enable powerful and often instantaneous connectivity. 1 Nowhere is the space of flows more manifest than in the extensive and overlapping networks of global air transportation. In the past half century, in the United States and around the world, air travel has progressed from an elite prerogative to a popular option. The key historical events of U.S. commercial aviation are well known: the jetliner, introduced in the 1950s, facilitated longer, transcontinental flights, and the Airline Deregulation Act, of 1978, removed restrictions on the number of routes a carrier could operate and the fares it could charge. As a result, from 1975 to 2010, the number of scheduled aircraft departures in the United States more than doubled, from 4.5 million to 9.3 million. 2 Indeed, plane travel is now so firmly established — so widely expected, as a choice for business and leisure — that the U.S. has effectively ceased to invest in other long-distance (and even middling distance) transportation technologies (e.g., high-speed rail); we are a nation on the move, and much of that movement depends upon the ease and accessibility of flight.

To be sure, some current trends are cause for concern. In recent years, rising fuel prices have caused airline companies to decrease the number of flights and even eliminate some routes, and passengers today face fewer choices and higher fares — and of course, cramped and crowded planes; meanwhile, as a result of reduced demand and bankruptcy filings during the great recession, major carriers have been pursing mergers — a process that only intensifies the unvirtuous cycle of service cutbacks and customer dissatisfaction. According to the Federal Aviation Administration, few major U.S. airports — only six out of what are designated as the Core 30 — have experienced any increase in activity since 2005 and most have seen reductions in regional connections. A reporter for The New York Times captured the mounting frustration; in “When Flying 720 Miles Takes 12 Hours,” Jad Mouawad recounts the odyssey of a passenger who needed “three separate planes, two connections and a two-hour drive” to travel from Mobile, AL, to Cincinnati, OH — “about the same [time] it would have taken him to drive.” Yet despite these interlocking pressures, passenger counts are again rising. According to the U.S. Department of Transportation, 55.3 million people traveled on U.S. airlines in January 2013, and increase from 54.4 million in January 2012. And even amid ongoing concern about rising fuel prices, the FAA predicts that domestic air travel will nearly double in the next two decades, reaching 1.2 billion annual passengers by 2032.

But if the continuing viability of air transportation is good news for global business and tourism, it poses serious challenges for the global environment. By now most green-conscious citizens recognize the high carbon footprint of air travel — even if we have yet to translate knowledge into action. In an essay for Yale Environment 360, reporter Elisabeth Rosenthal confesses a common conundrum: “In most departments I have excellent green credibility. … But my good acts of responsible environmental stewardship are undercut by one persistent habit that will be hard to break, if it is possible at all: I am a frequent flyer. … Flying, particularly on long-haul flights, is so highly emitting that it dwarfs everything else on an individual carbon budget.” Rosenthal continues, quoting a researcher in the United Kingdom: “Many climate groups have calculated that in a sustainable world each person would have a carbon allowance of two to four tons of carbon emissions annually. Any single long-haul flight nearly ‘instantly uses that up,’ said Christian Jardine, a senior researcher at the Environmental Change Institute at Oxford University.” Adding to the dilemma of responsible travel is the fact that there are limited opportunities to offset one’s travel footprint, and in any case the ultimate effectiveness of doing so is dubious; as a reporter for Outside put it: “buying offsets doesn’t wipe away your environmental sins. … It simply pays off the guilt. The only true way to reduce your footprint is to live more sustainably, not pay someone to plant a tree.” 3

The environmental agenda is further exacerbated by inconsistent and volatile legislative frameworks. The U.S. Environmental Protection Agency recently rejected demands from environmental groups that it regulate aircraft CO2 emissions; meanwhile late last year the European Union, which had been poised to extend its successful carbon-trading program to the aviation industry, bowed to pressure (in part from the United States) and delayed implementation. Environmental protections laws are further complicated by the difficulty of calculating aircraft CO2 emissions, with industry groups and environmental organizations disagreeing about the choice of a standard metric — as the Airports Council International points out, emissions can be measured in by “cruise fuel burn only, or climb, cruise, and descent.” Only lately have consistent figures begun to emerge; according to a 2012 report from the Center for Biological Diversity: “Aircraft emit 11 percent of carbon dioxide emissions from U.S. transportation sources and 3 percent of the United States’ total greenhouse gas emissions.” In that same report, which details the EPA’s “indefinite delay” in regulating pollution from aircraft, the Center points out that the U.S. “is responsible for nearly half of worldwide CO2 emissions from aircraft,” and notes that these emissions are anticipated to increase substantially due to the doubling of traffic mentioned above.

Top: Logan Airport, Terminal A, HOK Architects. [Image: HOK]. Bottom left: Logan Airport, wind turbines on roof of office building. [Image: AeroVironment ] Bottom right: Logan Airport: Solar “trees” on roof of parking garage. [Image: Massport]

Green Terminals

Clearly the sustainability of air travel will remain a vital issue for decades to come, and to a large extent will depend upon designing more fuel-efficient aircraft and reducing CO2 emissions. But it will depend as well upon the architecture and urban design of airports.

The greening of airport terminals is in fact well underway; in the past decade the design and retrofit of terminals in the U.S. and around the world has benefited from ongoing improvements in green building technologies. To cite some notable American examples that have achieved certification from the U.S. Green Building Council: In August 2006 Logan International in Boston became the first U.S. airport to receive LEED certification after an extensive redesign of Terminal A, by HOK in collaboration with Massport, that included new roofing and paving (to reduce heat island effect and stormwater runoff) and systems for daylighting, water conservation and waste recycling. Logan has since installed 16 “solar trees” on the roof of a parking garage, which are expected to contribute 2.5 percent of the structure’s power needs, and, and 20 one-kilowatt wind turbines on the roof of its main office building. 4

In March 2010, the renovated Terminal 2 at Oakland International Airport became the first passenger terminal to achieve LEED Silver certification; its innovative features include a system of perimeter swales that filters pollutants from runoff before the water is channeled into San Francisco Bay. In June 2010, the new Terminal B at Mineta San Jose International Airport, by Fentress Architects, earned LEED silver for its focus is on water conservation and smart heating, cooling and lighting systems. Terminal 2 at San Francisco International Airport, by Gensler, was certified LEED Gold; its many eco-conscious components include systems for waste recycling and composting, natural lighting and water conservation, air filtration and ventilation, as well as the extensive use of recycled materials. Several months later, in July 2012 the new International Terminal at Hartsfield-Jackson Airport earned LEED Silver for its incorporation of multiple energy-saving systems, including lighting controls and rainwater harvesting.

Top: Mineta San Jose International Airport, Fentress Architects. [Image: Fentress Architects] Middle: Hydration Station, Terminal 2, San Francisco International Airpport, Gensler. [Photograph by Bruce Damonte, Gensler] Bottom: Maynard H. Jackson International Terminal at Hartsfield-Jackson Airport, Atlanta, Gresham, Smith and Partners. [Photo: Gresham, Smith and Partners]

Hartsfield-Jackson is the world’s busiest airport, but the greening trend extends to smaller terminals as well. In 2011 the 1.2-million-square-foot Midfield Terminal at Indianapolis International Airport earned LEED for the entire complex; in early 2012 the new 9,000-square-foot corporate flight center at Chattanooga Airport, in Tennessee, earned the first LEED Platinum for an aviation facility. Later that year Sacramento International Airport earned LEED silver for its new Terminal B; its site development includes 9 acres of groundwater-irrigated natural habitat, reclaimed from parking lots.

Field Systems

Greening the terminal building is just one component of the larger project of making airports sustainable. Steven Howards, founder and executive director of the Clean Airport Partnership, a not-for-profit U.S. corporation focused on the environmental sustainability of airports, highlights strategies that augment the eco-design of buildings. These include replacing older ground-transport vehicles with hybrid and electric fleets and offering priority access to more fuel-efficient taxis and rental cars. He cites Seattle-Tacoma International Airport for its new consolidated rental car facility which received LEED silver for measures that include so-called “salmon safe” construction processes that mitigated the project’s impact on aquatic systems, and also for its recycling program, which includes the cooking oil used in terminal concessions. 5 In a similar effort, in early 2012 the Charlotte-Douglas International Airport, in North Carolina, installed a $1.1-million recycling center that includes a vermicomposting system, in which a couple million worms compost the food scraps and organic waste from the airport’s restaurants.

These strategies underscore that airport sustainability planning encompasses more than USGBC certification — that it will ultimately need to encompass the larger environs of the entire airfield complex and its connections to the metropolitan region. Although there is little sustained research to date on their eco-footprint, airports are unquestionably the source of significant local pollution. The extensive hardscapes — runways and taxiways, acres of surface parking, related facilities like car-rental agencies and freight distribution outlets — cause air temperatures to rise and produce heat island effects; de-icing chemicals like propylene and ethylene glycol contaminate groundwater; the continual roar of jet engines has been shown to damage the health of nearby residents, with consequences ranging from hearing loss to heart disease, and air pollution too is a significant health concern. 6

Top: Constructed wetlands, Buffalo Niagara International Airport. [Image: NaturallyWallace]  Middle: Solar farm, Denver International Airport. [Image: Urban Land Conservancy] Bottom: Aeroponic garden O’Hare International Airport. [Photo: Children & Nature Network]

Airports have begun to address these challenges. Some of the solutions involve material technologies; in 2009 Logan became the first U.S. airport to repave one of its runways with warm-mix asphalt, which has been used for years in Europe and which, according to Engineering News-Record, “produces nearly 4,000 fewer tons of carbon-dioxide emissions than traditional asphalt, about 400,000 fewer gallons of diesel fuel and an energy savings of about 53 billion BTUs.” To mitigate the toxicity of glycol-laced stormwater runoff, several north-latitude airports, including Buffalo Niagara International, have installed engineered wetlands — subsurface, aerated and earth-bermed gravel beds that filter pollutants on site. 7

Other sustainability initiatives call for reprogramming airport landscapes for uses ranging from solar farms to bio-fuel cropping. Many transport authorities and carriers already support off-site bio-fuel production; a pilot project undertaken by the Wayne County Airport Authority (which operates Detroit Metropolitan and the smaller Willow Run Airport), in collaboration with Michigan State University, is taking this further. The AgriEnergy Technology Demonstration Project, which is funded by a state grant and is the first such endeavor in the Midwest, is now testing the feasibility of growing, harvesting and processing bio-fuel crops, including canola and mustard seed, on three acres of airport property. 8 In 2011, in my home city of Chicago, O’Hare International installed an aeroponic garden in Terminal 3; created in partnership with the food-service corporation HMS Host, the garden produces herbs and greens for airport restaurants. That same year the airport also installed an apiary in a vacant lot on the northeastern edge of the complex. According to the Chicago Department of Aviation, the 28 hives, which are staffed by a job-training center that employs ex-convicts, now comprise the world’s largest on-site aviation apiary; the CDA notes that airport apiaries were pioneered in the late 1990s in Germany, where the sensitive insects function as “bio-monitors” of airborne toxins. And just this year O’Hare has begun another low-tech eco-project; ever since May a herd of goats has been grazing the grass. San Francisco International has also used goats to manage its landscape, and Hartsfield-Jackson has brought in sheep.

Some airports have dedicated acreage to solar farms. The leading user of solar power among U.S. airports is Denver International, which since 2008 has constructed three large photovoltaic arrays; the 45-acre installation now produces about six percent of the power for the country’s fifth busiest airport. Fresno Yosemite Airport, in eastern California, draws approximately 40 percent of its power from a 9.5-acre 2.4-megawatt solar farm comprising 11,700 panels. Late last year Chattanooga received a federal grant to double the size of its solar installation to 8,000 panels; Indianapolis International has announced plans to install a 75-acre, 12-megawatt farm, which would make it the largest at any U.S. airport; and O’Hare is in the early stages of planning a 52-acre farm to be distributed in various lots around the airfield. 9

Robert Smithson, “Wandering Earth Mounds and Gravel Paths,” Dallas – Fort Worth Regional Airport Layout Plan, 1966–67. 

Provocative Precedents

As we consider the future of the airport, it’s useful to recall older projects that recognized the larger potential of the airfield environs. One of the most compelling is the proposal by Robert Smithson for the “Dallas – Fort Worth Regional Airport Layout Plan,” created in 1966–67 when the artist was retained as a consultant by the New York-based architecture firm TAMS, which was competing to design the terminals for the then-new airport. Smithson was interested not only in the large scale of the airport landscape — 30 square miles of prairie between Dallas and Fort Worth — but also in the airfield as edge between the measured and controlled spaces of the terminal and the wilder expanse of north Texas beyond. Smithson’s first proposal was to foreground the airfield-as-edge, especially the borderlands adjacent to the runways, with four land-art projects: a series of concrete triangles that would join together to form a spiral, by Smithson himself; a 1,000-foot-long earth mound, by Robert Morris; a crater supposedly created by the dropping of a bomb, by Carl Andre; and a cube, filled with unspecified contents, to be buried in an unspecified location at the airport, by Sol Lewitt. Smithson continued his Dallas-Forth Worth airport project with a plan for Wandering Earth Mounds and Gravel Paths: here the geometry of eponymous mounds and paths contrasts with that of the rectilinear taxiways and runways. For Smithson, who was just then turning his attention to land art — Spiral Jetty would follow three years later — part of the fascination with the airport project was to create works visible from the air, works that would acknowledge the new scale of land-art. But in the end TAMS lost the contract and Smithson’s project was never built.

Top and bottom: Schiphol International Airport, landscape master-planning, West 8. [Images: West 8]

More recently, starting in 1992, the Dutch landscape firm WEST 8 developed and implemented a landscape master plan for Schiphol Airport, in Amsterdam, with a strategy both strong and simple: rather than create a conventional park, the firm proposed that the airport plant groves of birch trees — 25,000 every season for eight years — between buildings and throughout the open spaces of the complex. As West 8 principal Adriaan Geuze has explained the concept: “the birch plantation will grow into an unpretentious green counterpart of the buildings, billboards and infrastructure.” To my knowledge there are no rigorous analyses of the atmospheric benefits of the Schiphol birch groves; but in a recent conversation Maarten Buijs, a project manager in the firm’s Rotterdam office, did confirm that almost 200,000 trees were planted. He also noted that there are fewer trees today due to maintenance and pruning, and that birch trees were chosen partly for their ornamental quality, partly because their fibrous roots do not interfere with subterranean infrastructure, and also because birds don’t tend to perch on the soft thin branches (like many airfields, Schiphol struggles to manage bird strikes). As part of a 2008 update to the airport master plan, Buijs described new measures that include planting wildflowers in areas that would previously have been mowed. 9

The landscape of Schiphol — the “green counterpart” to the buildings and infrastructure — underscores the value of providing a strong spatial identity to the airport, of enhancing rather than degrading the macro-environment, and of creating productive and multidimensional complexes that move beyond the utilitarian programs of the conventional airport. Ultimately airport and airfield sustainability will depend upon deploying this holistic approach as much as upon selecting from a repertoire of green technologies. 11

O’Hare Super Strip, speculative project by CLUAA. [Image courtesy of CLUAA]

O’Hare Super Strip

It is within this larger conceptual context that my own firm, CLUAA, has created a speculative planning proposal: O’Hare Super Strip, which was originally produced for a 2009 exhibition at the Chicago History Museum, Burnham: A Patchwork Plan for Chicago, and has since undergone several iterations. I’ve already described some of the eco-conscious initiatives at O’Hare, including the apiary and the aeroponic garden; and indeed sustainability has a long history at the airport, dating back to 1982, when the Chicago Department of Aviation began funding the acoustic insulation of nearby schools to reduce classroom decibel levels. Today a wide-ranging program — ranging from regional wetlands restoration to green roofs to a low-emissions vehicle fleet to the annual Airports Going Green conference — is administered under guidelines outlined in the 2009 Sustainable Airport Manual. O’Hare Super Strip aims to leverage and extend these initiatives with the goal of recasting the airport as a sustainable and civic amenity at the local, regional and even global scales. Its chief strategies include the following.

A temporal ecosystem: These days every major airport has got to negotiate the volatility of the airline industry. Cautionary tales abound: Pittsburgh International Airport has suffered a steady decline in traffic since 2004, when US Airways downsized and closed its local hub; Lambert-St. Louis, once the national hub for TWA, has lost almost half its traffic since the airline was bought by American more than a decade ago. Beyond the economic repercussions, shrinking route maps result in vast areas of under-used space; the midfield terminal at Pittsburgh, built for $1 billion to accommodate 40 million passengers, last year served an estimated 8.3 million; as a reporter for the Pittsburgh Post-Gazette put it, the half-empty terminal feels “like a Ferrari on blocks.” But even a bustling hub like O’Hare — second busiest in the country, fifth in the world — experiences substantial swings in use. With hundreds of flights arriving and departing from midday to early evening, the airport concourses and lounges are incredibly energetic for short periods — especially late afternoon, as countless passengers with connecting tickets discover daily — and almost empty at other times. Yet the entire complex remains in operation no matter these variations.

O’Hare Super Strip, speculative project by CLUAA. [Images courtesy of CLUAA]

Sustainable airport planning can help manage the effects of both industry instability and daily fluctuations in terminal use. Thus Super Strip conceives O’Hare as a multi-programmed urban zone serving the quarter million citizens who live within five miles of the airfield in northwest Chicago. In addition to the myriad retail and entertainment options that cater to travelers with a couple of hours to fill between flights — options that range from restaurants and cafes to shops and art exhibits to yoga rooms and live stages — the project proposes that the airport integrate community and institutional entities as well. A program cluster at the west edge of the Strip is zoned for diverse uses, including schools, offices, groceries, daycare centers and religious spaces; the cluster is linked to parking and Chicago public transit. Altogether it aims to function as a genuine urban center that blurs the bounds between O’Hare and the neighboring communities, and encourages the kind of urban intensification that can organize (if not replace) the unsustainable horizontal urbanism that now surrounds the airport.

An integrated and multimodal network: More than one-third of the flights that depart O’Hare every day are hour-and-a-half flights to nearby cities. There are approximately 35 daily flights just to Minneapolis, and despite reductions in routes, regional airlines account for more than 50 percent of commercial U.S. flights. The obvious environmental solution is high-speed rail; a fast and efficient rail system would reduce emissions (trains have a lower carbon footprint than planes) and provide the kind of modal redundancy that makes for a resilient transportation system. Imagine arriving at O’Hare and — rather than weathering the all too typical delays and cancelations — transferring directly to a high-speed train for a two-hour trip to the Twin Cities. While air-to-rail linkages are increasingly common in Europe (and encouraged as policy by the European Union), they are uncommon on the American continent and in the U.S. a hard political sell. The proposed high-speed rail map published by the Obama administration in 2009 includes the Midwest Corridor; with stations at three of the region’s busiest airports: O’Hare, Detroit International and Mitchell International in Milwaukee. In response, Super Strip provides for an HSR interchange that also links to Chicago metropolitan transit.

A new formal model: Super Strip comprises a narrow sub-surface strip that stretches across the three-and-a-half-mile width of O’Hare and connects the existing terminals on the east side of the airfield with the proposed Terminal 7 on the west. “Sub-surface” is the crucial move here: the proposal positions various amenities and some airfield operations underground, which acknowledges not only the safety concerns of air traffic control but also provides the acoustic isolation that public programs require. To bring in daylight and fresh air, we have carved large voids into the subterranean strip; in various “safe zones,” new programs emerge out of the Strip. One of the voids, for instance, is a public park: a 45-acre open space that functions partly as a gateway from the parking layer to the terminals but also as a local destination for neighbors, a playground for students at the new schools at the airport, a quiet spot for delayed passengers and airport employees (O’Hare employs 45,000 people). The park does ecological duty too: it features a subsurface wetland (similar to the one described above, at Buffalo), and the extensive plantings mitigate the heat island effect of the airport. Most of all, these constructed landscapes, with their civic and environmental agendas, is intended to counter the unplanned and often unattractive edges that typify so many airports.

O’Hare Super Strip, speculative project by CLUAA. [Images courtesy of CLUAA]

Next Generation

For several years now the Federal Aviation Authority has been sponsoring a design competition for university students focusing on “issues relating to aircraft technology and airports” and, more specifically, on “environmental issues and constraints and ways to improve the management, safety, capacity and efficiency of the nation’s airports.”

The competition is open to students from any field and interdisciplinary entries are encouraged. Yet nowhere do the competition guidelines engage the broad topic of the “future of airports” from the perspective of the design of buildings, landscapes and regions. The “technical design challenges” specify airport management, operation and maintenance, runway safety, environmental interactions (like fuel spills), electric/hybrid aircraft technology, and the application of FAA data; the submission requirements include an executive summary, literature review and safety risk assessment. Not surprisingly, most of this year’s winners come from the fields of civil engineering, computer science, applied aviation, mechanical and systems engineering, and the like.

The challenge for architects and landscape architects is clear: we need to make a stronger case that the future of the airport — the sustainability of air travel — is as much a design opportunity as an engineering or computational one. We need to show that green airport design is not only about LEED-accredited terminals but also about alternative visions for large-scale airport planning — visions that encompass multimodal transit, that transform the left-over peripheries of airfields into new productive and public spaces, that better integrate airport buildings with each other and into their neighborhoods, cities and regions. We need to argue for the broader incorporation of design thinking into infrastructural planning in the United States, in order to resolve the pressing environmental concerns created by our increasing dependence on mobility.

  1. Manuel Castells and Martin Ince, Conversations with Manuel Castells (London: John Wiley & Sons, 2003), 52–56.
  2. See United States Department of Transportation, Bureau of Transportation Statistics: Table 1-37: U.S. Air Carrier Aircraft Departures, Enplaned Revenue Passengers, and Enplaned Revenue. See also “Air Travel Is Projected To Double In 20 Years,” Business Insider, March 9, 2012.
  3. In 2009 San Francisco became the first airport to install kiosks for carbon offsets in the terminal.
  4. The effectiveness of these small wind installations remains the subject of much debate. See for instance, Alex Wilson, “The Folly of Building-Integrated Wind,” Environmental Building News, May 2009.
  5. Conversation with the author, February 7, 2013.
  6. A recent study from the Laboratory for Aviation and the Environment at MIT calculates that “airport-related emissions cause 50 premature deaths throughout the U.K,” and projects that a proposed expansion of Heathrow Airport would cause that figure to increase to “increase to 110 by 2030.”
  7. See James Higgins and Michael Maclean, “The Use of a Very Large Constructed Sub-Surface Flow Wetland to Treat Glycol-Contaminated Stormwater from De-Icing Operations,” Water Quality Research Journal of Canada, Vol. 37, No. 4, 785-792, 2002. Higgins and Maclean conclude that there are a very limited number of feasible, on-site treatment options for glycol-contaminated stormwater runoff at airports and that constructed wetlands are the only practical option.
  8. Dennis Pennington of Michigan State University, manager of the AgriEnergy project, told me he received approval from the Federal Aviation Authority only after U.S. Fish and Wildlife Service provided written confirmation that the bio-fuel crops would not attract flocking birds and thus endanger the aircraft. The FAA imposes a three-kilometer separation limit for certain land uses such as agriculture around airfields.
  9. In most cases, airports lease the land to an independent contractor or consortium, which finances the installation and allows the airport authority to buy back some or all of the energy produced at below-market rates.
  10. Author phone interview with Maarten Buijs, February 12, 2013. Buijs also mentioned that West 8 has been collaborating with theGrounds, an organization set up to focus on sustainability at Schiphol.
  11. One of the most provocative proposals for the “airport of the future” in recent years is described in Aerotropolis: The Way We’ll Live Next, by John D. Kasarda and Greg Lindsay (Farrar, Straus & Giroux, 2011). To some degree this is related to my arguments here, but for the most part Kasarda and Lindsay view cities and air travel — and the aerotropolis — in economic terms, given the airport’s role as a gateway to global production flows and supply chains. Privileging factors like personal mobility and material flows, the authors conceive the aerotropolis as “an urban machine not for living but for competition.” Not surprisingly — and despite the fact that the consolidation of development around airports might densify land use in our post-Fordist landscapes — the idea has been widely contested, with various critics pointing out the hazardous implications of living and working adjacent to a busy airport, and also the authors’ tendency to discount the environmental effects of air travel.
Clare Lyster, “The Future of Mobility: Greening the Airport,” Places Journal, July 2013. Accessed 01 Jun 2023.

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