Airports and environmental sustainability: a comprehensive review

Abstract

Over 2500 airports worldwide provide critical infrastructure that supports 4 billion annual passengers. To meet changes in capacity and post-COVID-19 passenger processing, airport infrastructure such as terminal buildings, airfields, and ground service equipment require substantial upgrades. Aviation accounts for 2.5% of global greenhouse gas (GHG) emissions, but that estimate excludes airport construction and operation. Metrics that assess an airport’s sustainability, in addition to environmental impacts that are sometimes unaccounted for (e.g. water consumption), are necessary for a more complete environmental accounting of the entire aviation sector.
This review synthesizes the current state of environmental sustainability metrics and methods (e.g. life-cycle assessment, Scope GHG emissions) for airports as identified in 108 peer-reviewed journal articles and technical reports. Articles are grouped according to six
categories (Energy and Atmosphere, Comfort and Health, Water and Wastewater, Site and Habitat, Material and Resources, Multidimensional) of an existing airport sustainability assessment framework.
A case study application of the framework is evaluated for its efficacy in yielding performance objectives. Research interest in airport environmental sustainability is steadily increasing, but there is ample need for more systematic assessment that accounts for a variety of emissions and regional variation. Prominent research themes include analyzing the GHG emissions from airfield pavements and energy management strategies for airport buildings. Research on water conservation, climate change resilience, and waste management is more limited, indicating that airport environmental accounting requires more analysis. A disconnect exists between research efforts and practices implemented by airports. Effective practices such as sourcing low-emission electricity and electrifying ground transportation and gate equipment can in the short term aid airports in moving towards sustainability goals. Future research must emphasize stakeholder involvement, life-cycle assessment, linking environmental impacts with operational outcomes, and global challenges (e.g. resilience, climate change adaptation, mitigation of infectious diseases).

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Environ. Res. Lett. 15 (2020) 103007 https://doi.org/10.1088/1748-9326/abb42a
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TOPICAL REVIEW
Airports and environmental sustainability: a comprehensive review
Fiona Greer1,2, Jasenka Rakas1and Arpad Horvath1
1Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720, United States of America
2Author to whom any correspondence should be addressed.
E-mail: fionagreer@berkeley.edu,jrakas@berkeley.edu and horvath@ce.berkeley.edu
Keywords: aviation, greenhouse gases, environmental impact, environmental footprint, infrastructure
Supplementary material for this article is available online
Abstract
Over 2500 airports worldwide provide critical infrastructure that supports 4 billion annual
passengers. To meet changes in capacity and post-COVID-19 passenger processing, airport
infrastructure such as terminal buildings, airfields, and ground service equipment require
substantial upgrades. Aviation accounts for 2.5% of global greenhouse gas (GHG) emissions, but
that estimate excludes airport construction and operation. Metrics that assess an airport’s
sustainability, in addition to environmental impacts that are sometimes unaccounted for (e.g.
water consumption), are necessary for a more complete environmental accounting of the entire
aviation sector. This review synthesizes the current state of environmental sustainability metrics
and methods (e.g. life-cycle assessment, Scope GHG emissions) for airports as identified in 108
peer-reviewed journal articles and technical reports. Articles are grouped according to six
categories (Energy and Atmosphere, Comfort and Health, Water and Wastewater, Site and Habitat,
Material and Resources, Multidimensional) of an existing airport sustainability assessment
framework. A case study application of the framework is evaluated for its efficacy in yielding
performance objectives. Research interest in airport environmental sustainability is steadily
increasing, but there is ample need for more systematic assessment that accounts for a variety of
emissions and regional variation. Prominent research themes include analyzing the GHG emissions
from airfield pavements and energy management strategies for airport buildings. Research on
water conservation, climate change resilience, and waste management is more limited, indicating
that airport environmental accounting requires more analysis. A disconnect exists between research
efforts and practices implemented by airports. Effective practices such as sourcing low-emission
electricity and electrifying ground transportation and gate equipment can in the short term aid
airports in moving towards sustainability goals. Future research must emphasize stakeholder
involvement, life-cycle assessment, linking environmental impacts with operational outcomes, and
global challenges (e.g. resilience, climate change adaptation, mitigation of infectious diseases).
List of acronyms
ACI Airport Council International
ACRP Airport Cooperative Research
Program
APU auxiliary power unit
CO carbon monoxide
CO2carbon dioxide
EUI energy use intensity
GHG greenhouse gas
GPU ground power unit
GSE ground service equipment
HVAC heating, ventilation, air conditioning
IAQ indoor air quality
ISO International Organization for Stand-
ardization
LCA life-cycle assessment
LEED Leadership in Energy and Environ-
mental Design
LTO landing and take-off
NOxnitrogen oxides
PKT passenger kilometer traveled
PM particulate matter
PV photovoltaic
SCM supplementary cementitious materials
SFO San Francisco International Airport
© 2020 The Author(s). Published by IOP Publishing Ltd

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
URTS underground rapid transport system
VOC volatile organic chemical
WLU work load unit
WW wastewater
1. Introduction
Airport infrastructure is a vital component of soci-
ety’s transportation network. There are more than
40 000 airports worldwide (CIA 2016). Around 2500
airports processed over 4 billion passengers in 2018
(IATA 2018). The onset of COVID-19 has drastically
decreased air traffic levels (IATA 2020). It is likely that
air travel will recover over the next couple of years and
continue to rise. In the United States, massive invest-
ment is required (ASCE 2017, ACC 2020) to modern-
ize and retrofit aged, inadequate airport infrastruc-
ture (e.g. terminals, airfields, service equipment).
Similar expansion projects and necessary reconfigur-
ation projects for post COVID-19 processing of pas-
sengers are occurring worldwide. Airports are not
solely transport nodes. The onset of ‘airport cities’
make this critical infrastructure a catalyst for eco-
nomic, logistical, and social development (Appold
and Kasarda 2013).
The environmental impacts attributed to airport
construction and operational activities (e.g. building
operation, ground service equipment (GSE)) are sig-
nificant to consider, especially in light of the fact that
as other transport sectors go ‘green,’ the air trans-
port sector will face more challenges in reducing
their environmental impacts. It is estimated that the
aviation industry accounts for approximately 2.5%
of global greenhouse gas (GHG) emissions in 2018
(IEA 2019), but that estimate excludes the impacts
from airport construction and operation. An ana-
lysis of 2019 data for San Francisco International
Airport (SFO 2018,2020) reveals an approximate
annual breakdown of 85% for aviation GHG emis-
sions and 15% for airport GHG emissions. Although
not accounting for life-cycle impacts and not repres-
entative of every airport, this breakdown offers a sense
of scope of how GHG impacts are divided between
aviation (i.e. flights) and airport activities. The envir-
onmental impact of airport infrastructure/operations
is not just limited to their GHG emissions. Airport
construction and operation also results in emissions
of air pollutants such as carbon monoxide (CO),
nitrogen oxides (NOx), and particulate matter (PM),
displacement of and damage to natural ecosystems,
generation of waste, and consumption of resources
such as water.
In the public policy sphere, airport sustainab-
ility is an emerging area of interest. The aviation
and airport communities recognize the important
role that airport infrastructure plays in promoting
beneficial environmental and human health out-
comes. However, how the public sector addresses air-
port sustainability is fragmented and lacks rigorous
appraisal of suggested best practices. Oftentimes,
airport operators rely on other airports’ existing
sustainability guidelines for selecting ‘green’ prac-
tices that are not explicitly defined and quantified
(Setiawan and Sadewa 2018). This review offers the
public aviation sector, in particular, a much-needed
overview of relevant sustainability indicators and
methods for airport infrastructure and guidance in
pursuing future research and implementation of sus-
tainable practices and projects.
The expected increase in demand for air travel
and the necessary upgrades for airport infrastruc-
ture compound the environmental impacts of airport
construction and operation. In designing and operat-
ing the next generation of airport infrastructure (e.g.
terminal buildings) there must be a systematic way
for evaluating the resulting environmental impacts.
Measures that assess the sustainability of the design,
construction, and operation of airport infrastructure
offer a potential solution for airport operators to
consider.
1.1. History and background
Sustainability, as defined in the United Nations’
Brundtland Report, states that present society must
manage and consume resources so as not to com-
promise future society’s needs (Brundtland et al
1987). While the Brundtland definition acknowledges
human activity’s environmental impact, it does not
offer concrete guidance for achieving sustainability.
A less abstract framework is the ‘triple bottom line’
approach, which aims to identify solutions that bal-
ance environmental, social, and economic interests
(Elkington 1994).
Sustainability indicators, or metrics, can be used
to measure the ‘sustainability performance’ of an air-
port. Metrics are critical because they allow for:
•Comparing the sustainability of one airport (or
one type of airport) against another;
•Identifying the weak points or opportunities for
improvement in airport infrastructure;
•Measuring progress towards meeting targeted
goals.
A standardized, empirical metric is also crucial
for making decisions about sustainable design and
operation of airport infrastructure (Longhurst et al
1996). Stakeholder involvement in developing these
indicators is necessary (Upham and Mills 2005).
Sustainability metrics are a component of a larger-
scale sustainability plan. Ideally, formalized sustain-
ability plans developed by airports should incorpor-
ate metrics for tracking progress towards goals.
Airport sustainability, as defined by the aviation
industry, incorporates the ‘triple bottom line’ concept
with a fourth pillar focused on operational effi-
ciency. Airport Council International (ACI) refers
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Environ. Res. Lett. 15 (2020) 103007 F Greer et al
Table 1. Airport industry concept of sustainability or EONS, as defined by Prather, 2016.
Economic viability Operational efficiency Natural resource conservation Social responsibility
•Economic vitality •Delivering services in a
cost-effective manner
•Accounting for life-cycle
costs
•Air quality enhancement/climate
change
•Energy conservation/renewable
energy
•Noise abatement
•Water quality protection & water
conservation
•Land & natural resources manage-
ment
•Land/property use
•Pavement management
•Materials use & solid waste reduc-
tion/recycling
•Hazardous materials & waste manage-
ment/reduction
•Surface transportation management
•Buildings/facilities
•Socioeconomic
benefits
•Community outreach
& participation
to this approach to sustainability as EONS (Martin-
Nagle and Klauber 2015, Prather 2016). Common
subcategories of EONS are shown in table 1. An
important research dimension of the airport industry
is the U.S. National Academies of Sciences’ Air-
port Cooperative Research Program (ACRP), which
researches and publishes synthesis reports and guid-
ance for current sustainability practices at airports.
ACRP reports are largely compiled through literature
reviews of airports’ published sustainability reports
and through interviews, surveys, and questionnaires
with airport operators. Recent topics of ACRP reports
include:
•overall sustainability (Brown 2012, Delaney and
Thomson 2013, Lurie et al 2014, Prather 2016,
Malik 2017);
•feasibility of on-site energy provision (Lau et al
2010, Barrett et al 2014) and microgrids (Heard
and Mannarino 2018);
•GHG emission reduction strategies (ACRP, FAA,
Camp, Dresser, & McKee et al 2011, Barrett 2019);
•air quality impacts (ACRP, FAA, CDM Federal
Programs Corporation et al 2012a, ACRP 2012b,
Lobo et al 2013, Kim et al 2014,2015)
•water efficiency (Krop et al 2016) and stormwater
management (Jolley et al 2017);
•habitat management (Belant and Ayers 2014);
•sustainable ground transport (Kolpakov et al
2018);
•sustainable construction practices (ACRP, FAA,
Ricondo & Associates et al 2011);
•waste management (Turner 2018);
•climate change adaptation of airports (Marchi
2015).
The definition of environmental airport sus-
tainability in the academic literature varies with
some defining it according to multiple categories of
environmental impacts (Chao et al 2017, Ferrulli
2016, Gomez Comendador et al 2019; Kilkis and
Kilkis 2016) and others limiting that definition to
traditional environmental aviation impacts such as
emissions and noise (Lu et al 2018). Environmental
sustainability is assessed using both quantitative and
qualitative metrics/measures, and using both gener-
alized, average airports (Chester and Horvath 2009)
and data from operating airports (Chao et al 2017;
Kilkis and Kilkis 2016, Li and Loo 2016).
In both industry and academic research, envir-
onmental impacts are often disaggregated according
to the airside and landside components of the air-
port system boundary. Figure 1shows a plan view
schematic of the typical features included in the air-
port system boundary. It should be noted that energy
generation, water/wastewater (WW) treatment, and
waste management infrastructure can be located
within airport-owned property (i.e. decentralized)
or within the surrounding community of the air-
port (i.e. centralized). Table 2identifies the purpose
and primary stakeholders for each airport compon-
ent. Understanding the scope of airport infrastructure
aids in identifying the most relevant environmental
impacts and the stakeholders best equipped to mitig-
ate those impacts.
1.2. Research objectives and goals
While previous studies have examined sustainabil-
ity practices of individual airports (Berry et al 2008,
Prather 2016), this work represents the first compre-
hensive systematic review of academic and industry
literature on airport environmental sustainability.
The five objectives of this research are: (1) synthes-
ize the existing literature on environmental sustain-
ability indicators and metrics for airports; (2) review
the application of sustainability indicators developed
3

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
Figure 1. Plan view of airport system boundary. Key infrastructure features are identified.
Table 2. Purpose and primary stakeholders of key airport infrastructure.
Component Infrastructure Purpose Primary stakeholder
Runway Support aircraft take-off/landing Aviation regulatory agency
Taxiway Move aircraft from gate to runway Aviation regulatory agency
Apron Passenger boarding/aircraft maintenance Airline
Airside
Gate Connect passengers from terminal to aircraft Airline
Terminal Process passengers from landside to airside Airport
Curb Passenger drop-off/pick-up Airport
Access road Transport passengers/employees to/from airport Airport/local community
Energy generation Provide energy for airport operation Airport/local community
Water/WW treatment Provide safe water for airport operation treat effluent Airport/local community
Waste Manage waste from airport operation Airport/local community
Landside
Parking garage Provide space for passenger/employee parking Airport
for the construction of terminals and other airport
facilities at a case study airport (San Francisco Inter-
national Airport also known as SFO); (3) identify
gaps in the literature; (4) recommend what sustain-
ability indicators/metrics should be employed at air-
ports based upon the results of the literature review;
(5) provide recommendations for future directions
of research. Sustainability indicators are grouped
according to the SFO framework: Energy and Atmo-
sphere, Comfort and Health, Water and Wastewa-
ter, Site and Habitat, Materials and Resources. These
five categories provide a framework for stakehold-
ers to begin exploring the scope of relevant envir-
onmental impacts. The breadth of the five categories
also highlights that sustainability encompasses more
than one type of impact (e.g. GHG emissions) and
underscores that airports have multiple priorities in
addressing their environmental impacts. The expec-
ted outcome from this review is the identification
of gaps in the existing literature and practice as it
pertains to evaluating the sustainability of airport
infrastructure. Recommendations for future research
directions will provide those in the academic realm,
as well as in the public aviation sector, a robust assess-
ment of what metrics, practices, and methods should
be applied to achieve optimal performance outcomes.
1.3. Overview of article
Section 2presents the methodology for conduct-
ing the systematic review. Section 3follows with a
characterization, trend analysis, and synthesis of the
reviewed literature, along with a review of the sustain-
ability indicators used at a current SFO infrastructure
project. Section 4discusses the limitations and gaps of
the existing literature, analyzes the efficacy of SFO’s
sustainability assessment framework, and provides
guidance for future research directions. Section 5con-
cludes with a summary of the overall work and a
recommendation for practices that airports should
implement in the short term.
4

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
Table 3. Summary of GHG scope emissions for airports.
Scope 1 Scope 2 Scope 3
Definition GHG emissions come from on-
site sources that airport owns
GHG emissions come from pur-
chase of off-site energy
GHG emissions come from on-
site sources that are controlled
by tenants
Examples •On-site natural gas combined
heat and power plant
•Airport-owned vehicles
•Utility-supplied electricity •GSE owned by airlines
•Concessionaire activities
•Passenger/employee trans-
portation to and from airport
2. Methods
2.1. Systematic literature review
2.1.1. Criteria for selecting research papers
The foremost criterion in selecting peer-reviewed
research articles and technical reports is that they per-
tain to indicators (i.e. metrics or measurements) for
environmental sustainability. Although the concept
of sustainability also includes economic and social
factors, they are outside the scope of this review.
We excluded corporate sustainability reports pub-
lished by individual airports as data from these
reports often appear in non-standard formats. How-
ever, individual airport sustainability practices were
explored as part of the review of academic and ACRP
literature. We iteratively searched for peer-reviewed
research articles and technical reports in Web of Sci-
ence, Google Scholar, and the National Academies
of Science’ ACRP database that were relevant to ‘air-
port sustainability,’ using the key terms of ‘airport’
and variations of ‘sustainability’ including ‘environ-
mental sustainability,’ ‘sustainable development,’ and
‘environmental impact.’
Searches were conducted with key terms related
to the five categories of the SFO framework (i.e.
Energy and Atmosphere, Comfort and Health, Water
and Wastewater, Site and Habitat, Materials and
Resources). Additional searches also included art-
icles that incorporated life-cycle assessment (LCA),
a method for assessing the ‘cradle-to-grave’ envir-
onmental impacts of a product, process, or project.
We elected to also include search terms for Scope 1,
Scope 2, and Scope 3 GHG emissions. Table 3sum-
marizes the definitions and examples of Scope GHG
emissions.
Characterizing GHG emissions according to
the three Scopes aligns with airport industry prac-
tice of allocating responsibility for GHG emis-
sions among airport stakeholders (ACA 2020).
Exact search terms for all criteria are provided
in table A1 in appendix A (available online at
https://stacks.iop.org/ERL/15/103007/mmedia). Art-
icles that were relevant to at least more than one of
the five sustainability categories were considered as
part of a Multidimensional category.
Articles that focused on sustainability indicat-
ors for the construction and operation of physical
airport infrastructure were prioritized. Articles were
excluded if they concentrated on aircraft, aircraft fuel,
or on aircraft operations within the airport boundary
such as taxiing, queuing, and the landing and take-
off (LTO) cycle. The rational for this exclusion is that
aircraft-related sustainability is an already extensively
reviewed subject (Agarwal 2010, Blakey et al 2011,
Sarlioglu and Morris 2015). However, articles per-
taining to aircraft servicing operations at airports (e.g.
ground service equipment or GSE, de-icing) were
included. All screening criteria are listed in table A2 in
appendix A. Note that the time period of 2009 to 2019
is selected to provide a meaningful analysis of the aca-
demic literature, as interest in airport environmental
sustainability as a research field began in earnest at the
end of the 2000s.
The searches yielded a total of 108 articles
grouped according to Energy and Atmosphere
(n=22), Comfort and Health (n=25), Water and
Wastewater (n=14), Site and Habitat (n=16),
Materials and Resources (n=18), Multidimensional
(n=13). Common themes of sustainability indicat-
ors for each category are depicted in figure 2. A bib-
liography for all articles included in this systematic
review is provided in appendix A (table A3). Section
3provides a trend analysis of the articles included in
the systematic review.
3. Results
3.1. Characterization of systematic literature
review
A trend analysis of the reviewed articles indicates that
interest in airport environmental sustainability has
steadily increased over the period of 2009 to 2019
(figure 3). Article counts in each category theme
(figure 4) reveal that research among the various cat-
egories is relatively balanced, with some prominent
exceptions. Article counts for ‘Ambient Air Quality,’
‘Airfield Materials,’ and ‘Multidimensional’ research
themes are the highest. The high article counts for
‘Ambient Air Quality’ and ‘Airfield Materials’ sug-
gests that research in the field of airport environ-
mental sustainability largely focuses on the charac-
teristics of an airport that are most prominent and
apparent (i.e. the runway, taxiway, and apron). The
high article count for the ‘Multidimensional’ category
5

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
Figure 2. Themes for each of the five sustainability categories.
0
2
4
6
8
10
12
14
16
18
20
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
Number of Articles
Year
Article Count by Year
Figure 3. Cumulative articles by year (dotted line =moving average).
0
2
4
6
8
10
12
14
Number of Articles
Article Count by Theme
Figure 4. Cumulative articles by theme.
6

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
indicates that the research community is beginning
to recognize that airport sustainability is comprised
of multiple environmental impacts across multiple
airport functions. In categories such as ‘Waste Man-
agement’ and ‘Building Materials,’ the small article
counts imply that these specific subjects are still emer-
ging as relevant research areas.
3.1.1. Synthesis of research by category
3.1.1.1. Energy and atmosphere
Common themes among the articles featured in
the Energy and Atmosphere category include energy
management of airport infrastructure, use of renew-
able energy on-site, and energy-related air emissions.
3.1.1.1.1. Energy management
Energy management refers to a process by which
airports can characterize and monitor their energy
consumption and enact measures to reduce it. Air-
ports use fossil fuels (natural gas, petroleum) and
electricity to perform various operational require-
ments such as controlling the thermal environment of
buildings, lighting runways and buildings, and fuel-
ing airport ground equipment and vehicles. Using
Seve Ballesteros-Santander Airport in Spain as a case
study, it is estimated that most of the energy con-
sumption at an airport is attributable to the ter-
minal building with heating, ventilation, air condi-
tioning (HVAC) and lighting being the most energy-
intensive practices (Ortega Alba and Manana 2017).
A best practice for energy management is imple-
mentation of an energy monitoring system (Lau et
al 2010). Although not analyzed from an environ-
mental perspective, airports represent an opportun-
ity for exploring the implementation of microgrids,
which allow for on-site energy generation and storage
(Heard and Mannarino 2018).
Some literature indicates that if an airport has
implemented specific energy management practices,
then those practices are a marker of sustainability.
A sample of practices that are considered sustainable
and have been implemented at two case study airports
(Baxter et al 2018a,2018c) is provided in table 4. An
airport that implements a standardized energy man-
agement system is considered to be sustainable (Uysal
and Sogut 2017). Implementation of specific practices
depends upon site characteristics including climate,
occupancy level, and operating hours (Malik 2017).
An analysis of energy related to the lighting of a Turk-
ish airport terminal indicates that indoor lighting is a
critical energy consumer (Kiyak and Bayraktar 2015).
3.1.1.1.2. Renewable energy
Implementation of on-site renewable energy is
another typical indicator of sustainability as dis-
cussed in the literature. There are safety concerns
(e.g. glare, radar interference) with some forms of
renewable energy such as solar and wind (Barrett et al
2014), but airports are ideal candidates for employing
on-site renewables because of their expansive land
areas (Lau et al 2010). Metrics for evaluating the
efficacy of on-site renewable energy such as solar
photovoltaic (PV) systems include percentage of
energy demand met by on-site renewables (Dehkordi
et al 2019) and exergy (Kilkis and Kilkis 2017, Suku-
maran and Sudhakar 2018). Exergy, as it relates to
provision of on-site solar PV, refers to the quality
of the energy delivered; solar power tends to have
high thermal losses unless cooling intervention is
taken. In assessing the emissions impact from dif-
ferent energy sources in a district heating system at
Schiphol Airport in the Netherlands, it is argued that
GHG emissions should be estimated by accounting
for both the first and second laws of thermodynamics
(Kilkis and Kilkis 2017). Accounting for GHG emis-
sions from both the quantity (first law) and quality
(second law) of energy provides a more realistic ana-
lysis of the feasibility for achieving practices that are
considered sustainable (e.g. net zero-carbon airport
terminal buildings). Another metric for assessing
environmental impacts from renewable energy at
airports is absolute reduction of fossil fuel consump-
tion, which is applied to evaluate a solar PV and bat-
tery storage project at Cornwall Airport Newquay in
the United Kingdom (Murrant and Radcliffe 2018).
Modeling of a solar PV farm at a rural U.S. airport
indicates that this form of renewable energy can meet
both the airport’s and local community’s electricity
needs without compromising pilot or airspace safety
(Anurag et al 2017). A groundwater source heat pump
was found to meet indoor thermal requirements in
a more energy-efficient manner (i.e. a higher coeffi-
cient of performance) than conventional heat pumps
for a Tibetan airport (Zhen et al 2017). LCA is used to
inventory the GHG emissions from using a biomass-
fired combined heat and power plant at London
Heathrow Airport to meet terminal building heat-
ing needs (Tagliaferri et al 2018).
3.1.1.1.3. Energy-related emissions
Recommended GHG emission reduction strategies
related to energy use at airports pertain to design-
ing building envelopes to be more energy efficient,
using energy efficient equipment and fuels, relying
on renewable energy, and managing use of refriger-
ants (ACRP, FAA, McKee, Dresser Camp, & Synergy
Consulting Services 2011, Barrett 2019). GHG emis-
sions from annual airport energy consumption are
a typical sustainability evaluation metric (Monsalud
et al 2015, Baxter et al 2018a,2018c). In practice,
GHG emissions are often inventoried according to a
framework developed by ACI, which recognizes that
an airport is under direct control of GHG emissions
from Scope 1 sources (e.g. on-site power generation)
and Scope 2 sources (e.g. purchase from grid electri-
city), and only able to influence Scope 3 sources (e.g.
emissions from an airline’s GSE) (ACRP, FAA, Camp,
Dresser, & McKee et al 2011, Ozdemir and Filibeli
7

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
Table 4. Example energy conservation practices at airports as reported in Baxter et al (2018a,2018c).
Airport Copenhagen (CPH) Kansai (KIX)
Energy conservation prac-
tices at airports
•Reliance on fixed electrical ground
power for parked aircraft
•Optimized energy consumption from
airport’s ventilation systems
•Energy conservation measures related to
tenant and concessionaire activities
•Use of solar PV
•Use of LEDs
•Monitor energy consumption
•Utilize sensor-controlled escalators
•Use of groundwater for heating and
cooling
•Reduce voltage for site’s equipment
•Control air conditioning
•Use of ceiling fans
•Using electricity from renewable sources
(solar PV, wind)
•Installation of LEDs
•Driving low-emission vehicles
•Reliance on fixed electrical ground
power for parked aircraft
•Reducing vehicle idling times
2014). The ACI framework accounts for the annual
amount of electricity and natural gas consumed and
the amount of fuel used to power airport ground
vehicles. A similar method allocates emissions to each
macro unit (e.g. GSE) at an Italian airport (Postorino
and Mantecchini 2014). A more holistic approach for
measuring an airport’s energy consumption accounts
for the loss of a carbon sink from the deforestation of
the site on which Istanbul International Airport was
built (Kılkıs¸ 2014).
3.1.1.2. Comfort and health
The Comfort and Health themes in the literat-
ure include building occupant comfort and health
impacts related to ambient and indoor air quality.
3.1.1.2.1. Building occupant comfort
Passengers and airport/airline employees spend a
considerable amount of time inside airport build-
ings such as terminals, maintenance facilities, and
control towers. Occupant comfort in these buildings
is relevant for environmental sustainability because
aspects of comfort (i.e. thermal, ventilation, light-
ing) are directly related to metrics such as energy
consumption. Research into novel air conditioning
and heating systems in terminals at Chinese airports
indicates that thermal and ventilation comfort can
be satisfied while saving energy (Meng et al 2009,
Zhang et al 2013, Zhao et al 2014; Liu et al 2019).
An investigation of preferences at airports in the U.K.
demonstrates that occupants tolerate higher thermal
levels and prefer natural lighting, which have energy-
saving implications (Kotopouleas and Nikolopoulou
2018). Designing airport buildings to emphasize nat-
ural lighting should incorporate the functional oper-
ational characteristics of air travel (i.e. operational
peaks occur in the early morning and early to late
evening) (Clevenger and Rogers 2017).
3.1.1.2.2. Indoor air quality
Exposure to air pollutants is known to cause negat-
ive human health impacts including increased risk of
respiratory illness, cardiovascular disease, and death
(Apte et al 2012, Kim et al 2015). Indoor air quality
(IAQ) research focuses on the pollutants and factors
(e.g. ventilation systems, building design) that con-
tribute to occupant exposure while inside facilities
such as terminals and control towers. Research on
exposure in indoor settings at airports has been lim-
ited to the concentrations of nitrogen dioxide (NO2)
and volatile organic compounds (VOCs) in a main-
tenance room at a Lebanon airport (Mokalled et al
2019), PM in a terminal building at a Chinese air-
port (Ren et al 2018), VOCs, PM, odorous gases, and
carbon dioxide (CO2) at an Italian airport terminal
(Zanni et al 2018), and CO, VOCs, and PM in a con-
trol tower at a Greek airport (Helmis et al 2009, Tsakas
and Siskos 2011). One study linked IAQ at eight large
Chinese airports with passenger satisfaction, finding
that IAQ satisfaction is correlated with CO2concen-
tration (Wang et al 2015).
3.1.1.2.3. Ambient air quality
Ambient, or outdoor, air quality at airports is a func-
tion of both aircraft and non-aircraft operations.
Sources of non-aircraft emissions include the equip-
ment used to clean, load, or reposition parked air-
craft (i.e. GSE) or used to provide power to parked
aircraft (i.e. ground power units or GPUs). Another
source of emissions from parked aircraft is the auxili-
ary power unit (APU), an external rear engine on the
aircraft which provides electrical power and thermal
conditioning (ACRP , 2012b, Lobo et al 2013). Other
outdoor sources include emissions from construction
(Kim et al 2014) and operation of airport ground
access vehicles (e.g. maintenance trucks, firetrucks).
Much of the exposure to pollutants such as black car-
bon (a component of PM) occurs on the airfield’s
apron where aircraft are often positioned for pas-
senger boarding and luggage loading (Targino et al
2017). Outdoor exposure to VOCs near a U.S. air-
port revealed higher-than-expected concentrations of
toluene (Jung et al 2011). Construction of a terminal
building at a major airport in Spain was a critical
8

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
contributor to ambient levels of PM (Amato et al
2010).
A review of airport contributions to ambient air
pollution suggests that research on emissions related
to GSE, GPU, and APU operations is more limited rel-
ative to research on emissions from aircraft (Masiol
and Harrison 2014). Concentrations of CO2, CO,
PM, hydrocarbons, NOx, sulfur dioxide, sulfate, and
black and organic carbon are estimated for APU and
GSE use at 20 U. K. airports (Yim et al 2013), emis-
sions of CO, hydrocarbons, and NOxfrom APUs
and GSE are calculated for turnaround operations at
major European airports (Padhra 2018), and concen-
trations of NOxand PM for APUs and GSE at Copen-
hagen Airport are calculated (Winther et al 2015).
Provision of fixed electrical power and external air
conditioning units is considered a sustainable solu-
tion for mitigating PM and NOxemissions from APU,
GPU, and GSE operation (ACRP, 2012a, Yim et al
2013, Winther et al 2015, Padhra 2018, Preston et al
2019). Use of alternative fuel (hydrogen) for power-
ing GSE is considered another sustainable measure
to improve ambient air quality on the airport apron
(Testa et al 2014).
3.1.1.3. Water and wastewater
The major themes related to Water and Wastewa-
ter in the reviewed articles include water conserva-
tion strategies at airports and water quality concerns
related to airport activities.
3.1.1.3.1. Water conservation
Airports consume water for indoor operations such
as toilet-flushing, food preparation, and HVAC sys-
tems and for outdoor operations including irrigation
and aircraft/infrastructure washing and maintenance
(Krop et al 2016). The amount of water that major air-
ports consume is not insignificant, and is on par with
consumption patterns of small and medium-sized cit-
ies (de Castro Carvalho et al 2013). A typical met-
ric for assessing airport water consumption is volume
per day (Baxter et al 2019), but this metric fails to
offer a broader picture of what sources of water are
consumed and what management practices yield the
best results (Couto et al 2013). The water conserva-
tion techniques proposed for airports include mon-
itoring of water consumption, use of water efficient
fixtures/fittings, reducing irrigation demand, and use
of alternative water sources (e.g. rainwater, greywater,
recycled wastewater).
An important point in the literature is that much
of airport water consumption is for activities that
do not require potable water. There is an opportun-
ity for airports to rely upon alternative sources of
water which have been studied for: rainwater har-
vesting at an Australian airport (Somerville et al
2015); wastewater reclamation for a Brazilian airport
(Ribeiro et al 2013); greywater usage at a Brazilian
airport (Couto et al 2013,2015); seawater and grey-
water use at an airport in Hong Kong (Leung et al
2012). These studies assess the efficacy of alternative
sources in terms of demand met.
3.1.1.3.2. Water quality
Water quality concerns related to airport activity can
be categorized as persistent, seasonal (e.g. from de-
icing operations), and accidental (e.g. fuel spills)
(Baxter et al 2019). Airports make efforts to pre-
vent hazardous pollutants and fluids from entering
groundwater or surface water bodies. Stormwater
management strategies include use of bioretention
basins, green roofs, harvesting, porous pavement,
sand filters, and wetland treatment systems (Jolley et
al 2017). The academic literature focuses on water
quality issues stemming from de-icing activities, a
necessary operation for aircraft and runways in cold-
weather climates. De-icing fluid runoff can create
negative surface water quality effects that impact
aquatic flora and fauna by causing higher levels of
chemical oxygen demand and lower levels of dissolved
oxygen (Fan et al 2011, Mohiley et al 2015). Potential
mitigation measures for managing aircraft de-icing
include utilization of novel soil filters (Pressl et al
2019) and treatment with constructed wetlands (Hig-
gins et al 2011). Most studies assess the water quality
impact of de-icing fluid, but one article examined the
GHG impact from forgoing collection and treatment
of de-icing fluid at a wastewater treatment plant and
instead using on-site recycling (Johnson 2012).
3.1.1.4. Site and habitat
Major themes of the Site and Habitat category in
the literature refer to the impact airport construc-
tion and operation have on existing natural ecosys-
tems, the effects from on-site and public transporta-
tion options, and the implications of airport resilience
to climate change.
3.1.1.4.1. Site
Airport development and operation requires suitable
land area. In regions where existing land is not suit-
able, land reclamation is used to create a suitable air-
port environment. Research into the effects of land
reclamation on existing ecosystems focus on impacts
to soil, water, air, and animal species (Yan et al 2017;
Zhao et al 2019). Another indicator in the literature
refers to efficiency of airport land utilization, or how
many aircraft operations occur per given unit area
(Janic 2016). Airport operation and its impacts on
wildlife populations is another area of research, with
the goal of finding specific strategies to discourage
and accommodate wildlife populations on airfields,
airport water resources, terminal buildings, and con-
trol towers (Belant and Ayers 2014). Work done in the
academic literature focuses on identifying the factors
that attract avian species to green roofs (Washburn
et al 2016), on the impacts of solar arrays on avian
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Environ. Res. Lett. 15 (2020) 103007 F Greer et al
species (Devault et al 2014), and on the effects of
airport expansion on bat populations (Divoll and
O’Keefe 2018).
3.1.1.4.2. Transportation
Sustainable transportation, as it relates to airports,
refers to the modes of transportation for shuttling
passengers from terminals to parked aircraft and for
bringing passengers to airports. Common sustainab-
ility practices for on-site transportation include: use
of alternative vehicles (e.g. electric vehicles); restric-
tion of vehicle idling; and reducing the number
of empty trips (Kolpakov et al 2018). One study
examined the use of an underground rapid trans-
port system (URTS) for transporting airport passen-
gers the long distances from main terminal build-
ings to satellite and midfield concourse terminals
(Liu and Liao 2018). This study did not include spe-
cific environmental indicators, but noted that use
of URTS is sustainable because it frees up conges-
tion from passenger transport on the airfield con-
course. Sustainable public transport options might
include using automated vehicles (Wang and Zhang
2019), encouraging passengers to use existing pub-
lic transport options by enhancing their capacity,
discouraging private vehicle use, integrating with
other transport hubs (Budd et al 2016), or installing
dedicated electric vehicle charging infrastructure
(Silvester et al 2013).
3.1.1.4.3. Resilience
The resilience of airports to climate change impacts
is a significantly under-researched subject. Relevant
risks that airports in coastal locations will face include
impacts from sea-level rise and increased frequency
of flooding events (Marchi 2015, Burbidge 2016, Poo
et al 2018). Another site implication related to cli-
mate change is that increased mean air temperat-
ures will make it harder for aircraft to generate lift,
thereby necessitating the construction of longer run-
ways (Coffel et al 2017).
3.1.1.5. Materials and resources
Themes from the literature for Materials and
Resources center around selection of materials for
the construction of airfield (e.g. runway, taxiway,
apron) and terminal building infrastructure, as well
as management of waste from airport construction
and operation.
3.1.1.5.1. Airfield materials
Estimation of environmental effects of airfield pave-
ments is a fairly well-researched subject area, relat-
ive to other airport infrastructure. Airfields are either
made from asphalt or concrete, which are known
major sources of GHGs (Horvath 2004, Santero
et al 2011, Miller et al 2016). The sustainability of air-
field pavements is constrained by structural integrity
requirements and safety standards (Pittenger 2011).
Evaluation metrics for sustainable airport pave-
ment can be general, such as implementing sugges-
ted best practices, including: using recycled aggregate
in pavement mixes; using locally sourced construc-
tion materials; reducing idling times of construction
equipment (Hubbard and Hubbard 2019). More spe-
cific critical factors of a sustainable airport pavement
relate to its construction (i.e. the raw materials and
equipment used, transportation, waste management)
and its operation, which is a function of the pave-
ment’s structural characteristics (Babashamsi et al
2016). Table A4 in appendix A highlights the specific
sustainable practices and assessment methods/met-
rics found in the literature as they pertain to differ-
ent parts of the airfield. Example sustainable practices
include use of supplementary cementitious materi-
als (SCM) in concrete runways and use of recycled
aggregates in taxiway and apron construction. LCA is
frequently used in measuring the environmental sus-
tainability of airfield pavements. The scope of most of
the LCAs is limited to impacts from the raw material
and construction phases of the airfield.
3.1.1.5.2. Building materials
Relative to the airfield, environmental impact analysis
of other airport infrastructure (e.g. terminal build-
ings) is much more limited. LCAs have been per-
formed to determine the optimum level of thermal
insulation for terminal buildings at two Turkish air-
ports with a focus on selecting a design that reduces
GHG emissions (Akyuez et al 2017, Kon and Caner
2019). An extensive overview of construction meth-
ods and building materials that are standard practice
(e.g. using locally sourced materials) among the green
building community is applied for airports (ACRP,
FAA, Ricondo & Associates, R. &, Center for Trans-
portation, C. for, & Ardmore Associates 2011). It is
common practice, as mentioned in the ACRP literat-
ure, for airports to aim for green building certification
from groups such as the U.S. Green Building Coun-
cil’s Leadership and Energy in Environmental Design
(LEED) like LEED provides a checklist framework
where building owners (municipalities in the case of
airports) earn points for choosing ‘green’ building
materials and design attributes, among other criteria.
There are over 200 LEED certified airport buildings
worldwide (USGBC 2020), with SFO’s Terminal 2 the
first LEED Gold airport terminal in the U.S. (SFO
2011).
3.1.1.5.3. Waste management
Analysis of waste management at airports is another
emerging research area. Waste sources at air-
ports include food waste from retailers/concession-
aires, construction waste, and aircraft-related waste
(Turner 2018). Metrics applied for analyzing waste
at a major international airport include quantity of
waste, waste source fraction, and waste amount per
operation (Baxter et al 2018b). One article assessed
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Environ. Res. Lett. 15 (2020) 103007 F Greer et al
the life-cycle impact, in terms of air emissions, of six
waste management scenarios at Hong Kong Inter-
national Airport determining that on-site incinera-
tion with heat recovery yielded optimal results (Lam
et al 2018).
3.1.1.6. Multidimensional studies
Sustainability, as expressed in ACRP reports (Brown
2012, Delaney and Thomson 2013, Lurie et al 2014,
Prather 2016, Malik 2017), encompasses many cat-
egories including energy and climate, water, waste,
natural resources, human well-being, transportation,
and building design and materials. Many of the met-
rics that the ACRP literature use to assess the specific
categories of sustainability mirror those described in
the academic literature. A theme among the ACRP
work is the evaluation of sustainability practices from
an economic and practical perspective, recognizing
that implementation can yield economic benefit but
takes concerted, coordinated effort.
Table 5identifies metrics used for quantifying
impacts and strategies used to reduce impacts. These
metrics and strategies are extracted from the mul-
tidimensional journal articles included in the sys-
tematic review. Each metric or strategy is prioritized
to the one of the five categories of interest. While
the focus of this review paper pertains to metric-
s/strategies that evaluate the sustainability of physical
airport infrastructure, and not does focus on environ-
mental impacts related to the aircraft LTO cycle, some
of the multidimensional papers include indicators
for evaluating those specific environmental impacts
(e.g. noise from near-airport aircraft operations). The
indicators in table 5range from explicit, quantifi-
able metrics (e.g. tonnes CO2per passenger) to more
vague best practices (e.g. conserve energy in airport
buildings). The metrics and strategies that are expli-
cit and quantifiable are more informative for enact-
ing policy measures than are vague strategies such as
‘conserve energy’ or ‘reduce emissions.’ It is also more
effective for metrics and strategies that connect envir-
onmental impacts to operational outcomes and level
of service (e.g. number of passenger-miles traveled).
Connecting impacts to level of service allows for air-
ports to track how efficiently they are managing their
impacts as numbers of operations increase.
Indicators from each multidimensional paper do
not always span all five categories of environmental
sustainability, suggesting that consensus building on
the definition of environmental sustainability needs
to occur. The Energy and Atmosphere category dom-
inates with metrics often related to reducing airport
building and airfield energy consumption and air
pollutant emissions. Of the eight journal articles
included in table 5, all include metrics for addressing
noise pollution in the Comfort and Health category,
but none provide explicit metrics for assessing indoor
air quality for airport buildings. The indicators in the
remaining three categories vary in level of specificity.
As an example, in the Materials and Resources cat-
egory, four of the articles suggest airports use ‘green
building materials’ but only one article (Ferrulli 2016)
identifies in some detail what that means.
A theme that emerges from the multidimensional
papers are the different methods utilized in determ-
ining the overall sustainability of an airport. Utility-
based methodologies are utilized in two of the mul-
tidimensional articles (Chao et al 2017, Lu et al
2018) in the ranking of the most critical indicat-
ors by weights applied from expert opinion. Another
method for assessing an airport’s environmental sus-
tainability is the application of a checklist-based point
system where the most sustainable airport imple-
ments the most indicators with the highest level of
points (Gomez Comendador et al 2019). One method
incorporates cost-benefit analysis where each envir-
onmental indicator for an airport development pro-
ject is transformed into a financial amount and the
highest benefit-cost ratio yields the most sustain-
able outcome (Li and Loo 2016). A composite rank-
ing indicator is created by normalizing indicators
across all categories to compare the environmental
sustainability of multiple airports (S. Kilkis and Kilkis
2016). Only one method applies life-cycle assessment
in inventorying the environmental impact from the
LTO cycle, APU and GSE operation, de-icing activ-
ities, lighting, and construction of an airport ter-
minal, airfield, and parking lot (Chester and Horvath
2009).
The multidimensional articles that include case
study airports are listed in table 6, along with each
airport’s location. All of the case study airports are
considered major international hubs, averaging mil-
lions of passengers per year. Their locations span
the primary airport markets including Asia, Europe,
and the United States, but do not reflect the emer-
ging markets of Latin America and Southeast Asia. By
comparing airports of a similar operational capacity,
the multidimensional papers offer some insight into
how varying regions influence environmental impact.
However, more case study airports are necessary to
capture local impacts. Insight is lacking on whether
the sustainability indicators developed in these multi-
dimensional articles result in distinct environmental
outcomes for disparate levels of airport service (e.g.
small, regional airports; medium hub airports). Mod-
eling environmental impacts from an average airport
(Chester and Horvath 2009) allows for generalization
of results, which might yield more far-reaching out-
comes (i.e. sustainability indicators can be applied to
a greater range of airports).
3.1.2. Summary of trends in existing research
Figure 5shows a word cloud diagram of the article
titles included in each of five sustainability categories
and the multidimensional category. Frequently used
11

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
Table 5. Sustainability indicators from multidimensional papers.
Citation Energy and atmosphere Comfort and health Water and wastewater Site and habitat Materials and resources
Gomez
Comendador
et al (2019)
•Control emissions of NOx, Sox, CO, PM,
VOCs, CO2Limit use of APUs & GPUs
•Use ecological cars
•Offer infrastructure to support biofuels
use
•Manage energy consumption
•Use renewable energy
•Control air conditioning equipment for
energy conservation
•Use efficient indoor lighting
•Create noise map &
mitigation plan
•Take steps to isolate
community buildings
from noise pollution
•Acoustic efficiency
(number of people
exposed per annual
number of aircraft
movements)
•Restrict engine testing
during certain time
periods
•Monitor indoor air
quality
•Control water consumption
•Reduce indoor/outdoor water con-
sumption
•Reduce water consumption in
handling
•Manage stormwater runoff
•Treat wastewater
•Integrate with public/private trans-
port
•Select a site that meets aeronautical
safety requirements
•Measure soil quality
•Protect native flora & fauna
•Reduce light pollution
•Reduce heat island effect
•Treat hazardous waste
from maintenance
activities
•Recycle waste
•Implement a construc-
tion/maintenance/
demolition plan for
infrastructure
•Choose green building
materials
Lu et al (2018)•Carbon emission reduction & energy
conservation
•Prevention & monitor-
ing of noise
•Green building practices
Chao et al
(2017)
•Conserve energy in buildings
•Use ground power units over auxiliary
power units
•Use low-emission vehicles
•Use energy-savings control devices
•Use renewable energy
•Monitor air quality
•Shorten runways to reduce queuing time
•Monitor noise •Install water-saving devices
•Use recycled water
•Recycle wastewater
•Practice ecological conservation •Use green building
materials
•Engage in waste reduc-
tion, reuse, & recycling
Ferrulli (2016)•Design airside layout to minimize air-
craft emissions
•Design infrastructure & buildings to
minimize CO2emissions
•Reduce building-level energy consump-
tion
•Reduce outdoor energy consumption
•Use alternative & renewable energy
•Design airside layout to
reduce noise impact
•Provide physical mitig-
ation barriers between
operating areas & sur-
roundings
•Landscape & design to reduce
water use
•Design for water efficient use
•Design to maximize water harvest-
ing, recycling, reuse
•Design to reduce stormwater
quantity
•Design to improve stormwater
quality
•Reduce parking footprint
•Integrate infrastructure for public
transport
•Avoid destruction of sensitive hab-
itats
•Avoid attracting certain species
•Design to reduce heat island effect
•Design to reduce light pollution
•Design for storage &
collection of recyclables
•Design for deconstruc-
tion, reuse & recycling
•Use recycled, bio-based,
& rapidly renewable
materials
•Use materials with a
high design service life
12

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
Table 5. (Continued).
Citation Energy and atmosphere Comfort and health Water and wastewater Site and habitat Materials and resources
Kilkis and Kilkis
(2016)
•Energy Consumption (toe)
•Energy Consumed per Passenger (toe/-
passenger)
•ISO 50 001 Certificationa
•Implementation of energy-saving meas-
ures
•Use of on-site energy
•CO2emissions (tonnes)
•CO2per passenger (tonnes/Passenger)
•CO2emissions per unit energy (tonnes/-
toe)
•Recognition under ACI’s airport carbon
accreditationb
•Aiming for CO2Neutrality
•Concentration of PM10 (µg/m3)
•Use of low-emission ground vehicles
•Noise abatement for
decibels ≤60
•Water withdrawal (m3)
•Percentage of utilized recycled
water
•Amount of conserved area (hec-
tares)
•ISO 14 001
Certificationc
Li and Loo
(2016)
•Mass of CO2, SO2, NOx, PM, VOCs, HC,
NH3per annual operations
•Level of Noise Pollution •Amount of Water Pollution •Amount of Habitat Loss
Janic (2010)•Energy efficiency (energy consumption
per annual WLUd)
•Air pollution efficiency (total air pollu-
tion per annual WLU)
•Noise efficiency (num-
ber of households, pop-
ulation, or area exposed
to specified noise level
per year)
•Land Use efficiency (number of
aircraft operations per unit area
per year)
•Waste efficiency
(amount of waste gener-
ated per annual WLU)
Chester and
Horvath (2009)
•CO2emissions per passenger-kilometer-
traveled (PKT)
•Energy consumption per PKT
•CO, SO2, NOxper PKT
•CO2emissions per
passenger-kilometer-
traveled (PKT)
•Energy consumption
per PKT
•CO, SO2, NOxper PKT
aISO 50 001 Certification =International Standard Organization’s Energy Management System.
bAirport Carbon Accreditation =ACI certification that recognizes an airport’s efforts to manage CO2emissions.
cISO 40 001 Cert ification =International Standard Organization’s Environmental Management System.
dWLU =Work Load Unit, a standardized metric for airport operations in terms of number of passengers processed or mass of freight handled.
13

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
Table 6. Case study airports/locations from multidimensional papers.
Citation Case study airport (code) Location
Chao et al (2017)•Narita (NRT)
•Incheon (ICN)
•Kaohsiung (KHH)
•Istanbul (IST)
•Miami (MIA)
•Japan
•South Korea
•Taiwan
•Turkey
•United States
Kilkis and Kilkis (2016)•Amsterdam (AMS)
•Ataturk (IST)
•Barcelona (BCN)
•Frankfurt (FRA)
•Gatwick (LGW)
•Heathrow (LHR)
•Munich (MUC)
•San Francisco (SFO)
•Seoul (ICN)
•the Netherlands
•Turkey
•Spain
•Germany
•United Kingdom
•United Kingdom
•Germany
•United States
•South Korea
Li and Loo (2016)•Hong Kong (HKG) •Hong Kong
Chester and Horvath
(2009)
•Average airport
modeled after Dulles
International Airport
(IAD)
•United States
words appear larger relative to less frequently used
words. Figure 5provides a visual representation of
the key themes for each category. A summary of key
trends in the five sustainability categories and the
multidimensional category include:
•Energy and atmosphere: Articles focus on invest-
igating the efficacy of on-site renewable energy
at various case study airports. Common sustain-
ability indicators are total energy consumed and
mass of GHG emissions from energy consump-
tion. Best practices are considered as: monitoring
of energy consumption; utilization of energy effi-
cient HVAC equipment and lighting; installation
of on-site renewable energy. There is some effort,
particularly in the ACRP literature, to evaluate best
practices from a practical perspective (e.g. address-
ing the safety implications of PV installations). Use
of LCA in this category is limited.
•Comfort and health: Most of the research is
focused on indoor comfort and health indicators
like preferences for thermal and lighting condi-
tions and concentrations of PM, VOCs, CO, and
CO2. Studies on exposure to ambient air pollut-
ants from non-aircraft sources are limited. Most
of the research on ambient air quality aggregates
emissions from all sources. There is recent effort
to investigate the impact from non-aircraft sources
such as APUs, GSE, and GPUs and to identify
possible solutions for these equipment (e.g. use
of external electrical power and air conditioning
units).
•Water and wastewater: Articles focusing on estim-
ating the potential utilization of alternative water
sources at airports dominate. Water quality
research pertains to impacts from stormwater and
de-icing fluids. A typical article in the Water and
Wastewater category includes annual water con-
sumption per passenger or flight operation. There
is discussion in the literature on whether a disag-
gregated metric (e.g. indoor water consumption
per passenger, outdoor water consumption per
passenger) might be a more effective performance
indicator.
•Site and habitat: This category is the least explored
in the literature. Few articles offer measurable
indicators, with most of the quantifiable metrics
relating to land use efficiency and destruction of
wildlife habitat. There is need for quantifiable
indicators for research in on-site, public/private
transport and for climate change adaptation prac-
tices.
•Materials and resources: Research on the environ-
mental sustainability of airfield pavements domin-
ates this category. LCA is the most frequently used
assessment methodology, with life-cycle GHG
emissions and energy consumption the most com-
mon assessment metrics.
•Multidimensional: Research that investigates air-
port sustainability from a multidimensional per-
spective is grouped according to efforts by ACRP
and by the academic community. ACRP largely
defines environmental sustainability across the five
categories (i.e. energy and atmosphere, comfort
and health, water and wastewater, site and hab-
itat, materials and resources), but often focuses on
economic and practical factors of implementing
sustainability best practices. These best practices
14

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
Figure 5. Word cloud diagram of article titles included in systematic review. Frequently used terms appear larger relative to less
frequently used terms.
are often identified through interviewing and sur-
veying U.S. airports. Sustainability indicators in
the academic literature predominantly focus on
energy consumption and GHG emissions. Sus-
tainability is assessed with a number of meth-
odologies (e.g. utility-based theories, cost-benefit
analysis, LCA), suggesting that within the aca-
demic community there is a lack of consensus on
what attributes and indicators make an airport
sustainable.
3.2. Application of an airport sustainability
assessment
This section reviews the application of the SFO envir-
onmental sustainability framework on an existing
infrastructure project at the airport.
3.2.1. Selection of case study airport
San Francisco International Airport (SFO) is one of
the United States’ large hub airports and it serves
major domestic and international routes. The air-
port ranked seventh among busiest airports in 2018,
with enplanements totaling close to 28 million (FAA
2020b). The airport was an early adopter in imple-
menting sustainability efforts and in developing met-
rics to assess the sustainability of construction and
operation of airport infrastructure projects (SFO
2020, FAA 2020a). A review of the implementation
of SFO’s sustainability framework answers two crit-
ical questions: (1) how sustainability efforts practic-
ally get implemented at airports, and (2) how their
implementation is or is not effective in yielding meas-
urable benefits. Featuring SFO as a case study offers
stakeholders (e.g. regulators, airport operators, the
public) insight into what is considered best practices,
or acceptable methods, for managing environmental
impacts for major international airports. Addition-
ally, it provides some understanding of how sustain-
ability measures at an airport like SFO might not
work as well for other airport types (e.g. small hub,
regional, general aviation, etc.).
3.2.2. Development of sustainability indicators
SFO is redeveloping their Terminal 1 as part of a
capacity-enhancement upgrade for the entire airport;
the upgrade will increase the terminal’s total num-
ber of annual enplanements to 8.8 million. Sustain-
ability indicators were developed in conjunction with
SFO’s planning, design, and construction guidelines
as a measurable index for determining whether the
Terminal 1 project will comply with the airport’s over-
arching environmental goals (e.g. achieving GHG
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Environ. Res. Lett. 15 (2020) 103007 F Greer et al
0
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40
50
60
70
80
SFO Average T1 Expanded Requirements
GHG Intensity (kg CO2/m2/year)
Change in GHG Intensity with Expanded
Requirement Implementation
Figure 6. Reductions in GHG Intensity associated with implementing energy reducing ‘Expanded Requirements’ in Terminal 1
(T1) project relative to the SFO average. Savings are relative to 2018 data.
emission reductions relative to a baseline year).
Each sustainability indicator is grouped according
to relevant themes in the five categories of Energy
and Atmosphere, Comfort and Health, Water and
Wastewater, Site and Habitat, and Materials and
Resources. Indicators are either considered ‘Man-
datory Requirements’ or ‘Expanded Requirements.’
‘Mandatory Requirements’ outline metrics and prac-
tices that must be achieved according to applicable
federal, state, regional building codes and city-wide
mandates (e.g. meeting LEED requirements). ‘Expan-
ded Requirements’ are voluntary metrics and prac-
tices that project participants (i.e. contractors) are
obligated to implement where feasible. For example,
a city-wide ‘Mandatory Requirement’ in the Energy
and Atmosphere category mandates 40% reductions
below 1990 GHG emissions by 2025. An example
‘Expanded Requirement’ calls for reduced GHG
emissions from natural gas consumption by using
automated HVAC systems.
3.2.3. Implementation of indicators
The indicators are intended to be used for the plan-
ning, design, construction, and operation/mainten-
ance phases of airport facilities. An additional level
of evaluation is applied to each ‘Expanded Require-
ment.’ Requirements are rated as ‘Baseline,’ ‘Baseline
Plus,’ or ‘Exceptional Project Outcome.’ Per the pre-
vious ‘Expanded Requirement’ example, ‘Baseline,’
‘Baseline Plus,’ or ‘Exceptional Project Outcome’ rat-
ings would be given to 10%, 20%, and 30% reductions
in GHG emissions, respectively. Such a rating system
allows SFO to discern between project outcomes that
are more ‘sustainable’ than others.
The results of an analysis of the projected reduc-
tion in annual GHG emissions per square meter from
implementing Energy and Atmosphere ‘Expanded
Requirements’ in SFO’s Terminal 1 project are shown
in figure 6. The specific ‘Expanded Requirements’
include practices that rely on reduced natural gas and
electricity consumption in terminal buildings (e.g.
energy-efficient escalators, dynamic glazing, radiant
heating and cooling). It is projected that these ‘Expan-
ded Requirements’ will reduce Terminal 1’s energy
use intensity (EUI). The EUI indicates how much nat-
ural gas and electricity is consumed by buildings. By
converting the EUI to an equivalent amount of GHG
emissions per square meter, it can be shown that the
GHG intensity of the Terminal 1 project will be less
than the average of other SFO buildings. The blue bars
in figure 6show the amount of GHG emissions per
square meter, while the dotted outline indicates the
amount of annual GHG savings per square meter in
the Terminal 1 project. The GHG emissions account
for the upstream processes related to natural gas pro-
vision and electricity generation. See appendix B for
the complete methodology in producing figure 6. The
savings represent an approximate 57% reduction rel-
ative to the average GHG intensity for all SFO airport
building infrastructure.
4. Discussion
4.1. Limitations and gaps of existing research
With few exceptions on airport energy (Kilkis and Kil-
kis 2017, Tagliaferri et al 2018), overall sustainabil-
ity (Chester and Horvath 2009,2012, Taptich et al
2016), and airfield pavements, much of the research
fails to holistically analyze the environmental impacts
through supply chains and regional variations. While
the ACRP literature provides a sample representa-
tion of current best practices at airports, its analysis
is sometimes limited by the responses it receives from
case-study airports. For both the ACRP and academic
literature, analysis of sustainability indicators is often
limited by the scope of a case-study airport, so it is
difficult to link research results with suggested prac-
tice or policy outcomes.
16

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
The literature in the Energy and Atmosphere cat-
egory lacks a broader understanding of how much
energy is used at different airports, what it is used
for, and where it comes from. Current estimates
are limited by the number of existing case-study
airports. With an exception (Ozdemir and Filibeli
2014), the academic literature limits its character-
ization of GHG emissions according to Scope 1,
Scope 2, and Scope 3. This limitation in the lit-
erature indicates that there is a slight disconnect
between the academic research community and the
airport industry and stakeholders as the Scope char-
acterization is how the industry thinks about and
manages GHG emissions. Research that investig-
ates different energy sources (e.g. solar; bioenergy)
and energy provision strategies (e.g. grid versus on-
site storage) is just beginning, and more effort in
this area is needed. Additional gaps in the research
include:
•Environmental impacts of energy consumption in
terms of other pollutants besides GHG emissions;
•Environmental assessment of airports and supply
chains using local and regional models and data
(Cicas et al 2007);
•Characterization and environmental impact
assessment of energy consumption patterns for
specific airport infrastructure and equipment by
region (e.g. U.S. airport terminals are focused on
food consumption; European/Asian airports serve
as retail/recreational centers);
•Energy consumption impacts from construction
of new airport expansion/retrofitting projects.
As with the Energy and Atmosphere category,
research in the Comfort and Health category could be
broadened to include more research and innovative
and exploratory case studies. In light of COVID-19,
more research is urgently needed to investigate how
terminal building design and ventilation equipment
might influence spread of infectious diseases. Ambi-
ent air quality research tends to aggregate sources,
which makes it difficult to determine if mitigation
policies are effective. Additional gaps in the research
include:
•More human health-focused exposure studies
related to operation of non-aircraft equipment,
such as GSE, GPUs, APUs, and ground access
vehicles;
•Investigation of air pollutant concentrations
related to landside operations, such as passenger
pick-up and drop-off;
•Research on human health impacts from airfield
and terminal building maintenance, retrofit, and
construction;
•Air quality impacts related to selection of different
building materials and cleaning/daily maintenance
procedures.
As suggested in the Water and Wastewater liter-
ature, assessing an airport’s water consumption in
terms of volume per day provides minimal insight.
More research should be conducted to provide a thor-
ough overview of disaggregated water consumption
at the airport level so that sustainable practices can
be implemented appropriately. A major gap in the
literature is the complete lack of research into the
linkage between water consumption, water quality,
energy needed to convey, treat and heat water, and the
resulting GHG and other environmental emissions
and impacts. This water-energy nexus is particularly
relevant in examining the environmental sustainab-
ility of using alternative sources of water at airports,
especially with respect to potable versus non-potable
demands and options.
Much of the literature in the Site and Habitat cat-
egory lacks explicit, quantifiable sustainability indic-
ators and there is vast room for investigation into the
following gaps:
•Energy and environmental implications of con-
structing resilience infrastructure, such as sea walls
and stormwater systems;
•Environmental impacts of onsite transportation
systems, such as underground rapid transit sys-
tems;
•Overview of the types of suitable, environmentally
efficient transportation modes within and outside
of the airport boundary, which is dictated by air-
port configuration and location;
•Environmental trade-offs between site selection
and terminal building orientation and layout of
runways.
Research in the Materials and Resources category
is predominantly focused on environmental impacts
of airfield pavement construction and maintenance,
with life-cycle energy consumption and GHG emis-
sions as common metrics. Within the theme of air-
field pavements, more research regarding innovative
designs and maintenance techniques are warranted.
There is a lack of understanding on what sustain-
able pavement practices can be implemented at air-
ports of different operational capacities. Small and
medium-sized airports might be good candidates for
testing out innovative practices because their load or
volume requirements tend to be smaller than those
of larger airports. In terms of sustainable materi-
als and design for airport buildings, research results
are limited. In practice, it is more common for air-
ports to strive for LEED certification of airport build-
ings. LEED, for practical purposes, is a relatively easy
standard to implement, but is not sufficient for meet-
ing quantified performance goals throughout the life
cycle of airports. Additional gaps in the research
include:
17

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
•Environmental impact of conventional and altern-
ative construction materials in terminal building
infrastructure;
•Sustainability impacts of supply chains and
sourcing of airport construction materials;
•Deeper understanding leading to defensible
actions on waste generation and waste manage-
ment techniques at airports, especially in the con-
text of waste-management policies such as ‘zero-
waste’ and bans of single-use plastics.
A review of articles in the Multidimensional cat-
egory indicates that there is no cohesive, agreed-
upon definition of airport environmental sustainab-
ility. Gaps in the research include:
•Determining optimal methods for achieving over-
all environmental sustainability at an airport, also
integrated with achieving specified city, regional-
level, airline, or civil aviation targets;
•Integration of life-cycle, or holistic, thinking
within a specified time horizon into decision
making (e.g. should an airport implement an
electricity-based strategy if the electricity is gener-
ated from fossil fuels?);
•Specifying environmental sustainability indicators
in the context of airport operational safety;
•Investigating the overlap between environmental
sustainability and airport resilience;
•Rigorous analysis of environmental sustainability
and operational parameters;
•Integration of actions in achieving societal sus-
tainable development (economic, environmental,
social) with airport, airline, air traffic control, and
in general, civil aviation goals.
4.2. Efficacy of case study application
A projected 57% reduction in annual GHG emis-
sions per square meter from consuming natural gas
and electricity on-site within the airport terminal
buildings suggests that SFO’s sustainability assess-
ment indicators have the potential to be effective. A
more meaningful expression of results would relate
saved GHG emissions to the airport’s level of service
(e.g. GHG emissions per passenger or per revenue
dollar). There are limitations to stating one airport’s
efforts as ‘best practice.’ It should be emphasized
that applicability from the results of the case study
are dependent upon local factors. For SFO, imple-
menting energy-efficient strategies saves more GHG
emissions because SFO’s electricity is supplied from
hydropower, which is less carbon-intensive relative
to the state average. Utilizing low carbon-intensive
energy is a key sustainability performance indicator.
While post-facto analysis would be able to confirm
actual GHG reductions from implementing ‘Expan-
ded Requirements,’ the project is still ongoing. Some
important observations can still be made regarding
SFO’s sustainability indicators.
In discussions with parties involved with the Ter-
minal 1 reconstruction projects, having sustainability
criteria at the outset of project development is cru-
cial. All involved parties must be aware of their spe-
cific commitments. It is a good practice going forward
for project contracts to incorporate strong sustainab-
ility performance indicators. SFO plans to integrate
language more thoroughly into the Architectural and
Engineering standards and guidelines that specifically
align with two of SFO’s guiding environmental prior-
ities, namely climate change and human and ecolo-
gical health. Regarding the former, the new contract
language will explicitly require that decarbonization
be reflected in project design and procurement. For
example, instead of a voluntary consideration as part
of an ‘Expanded Requirement,’ low-carbon structural
steel would have to be selected as a building material.
The voluntary aspect of the framework (i.e. the
‘Expanded Requirements’) and the evaluation of
‘Expanded Requirements’ as baseline, baseline plus,
and exceptional project outcome are rather subject-
ive. Such subjectivity does not necessarily result in a
completed project with the best environmental per-
formance. Additionally, the SFO framework relies
upon building codes that while they are ‘state of the
art’ compared to building codes outside of Califor-
nia, represent a minimum standard. If interested in
attaining a facility or project that meets a specified,
quantifiable environmental outcome, the subjectivity
of a rating system or checklist is not the most effective
approach.
SFO’s sustainability indicators do not explicitly
consider the tradeoffs that potentially occur with pri-
oritizing one criteria over the other; it is a rather static
framework that could benefit from incorporating
spatial and temporal factors. For example, electing to
use a decentralized recycled water source (which is an
‘Expanded Requirement’ in the Water and Wastewa-
ter category) is sometimes an energy-intensive pro-
cess which can result in increased GHG emissions
while enhancing resilience. In this anecdotal example,
there is a potential tradeoff between achieving water
conservation and reducing GHG emissions. While the
SFO framework might work well for an airport that
explicitly prioritizes overarching goals (e.g. reducing
GHG emissions and climate change impact), it might
need to be reevaluated for airports that must equally
consider sometimes conflicting environmental
priorities.
4.3. Suggestions for direction of future research
The roadmap for future research of airport envir-
onmental sustainability emphasizes increased stake-
holder involvement, more life cycle-based analysis,
linkage of environmental impacts with operational
outcomes, and addressing major challenges such as
adaptation to climate change and mitigation of infec-
tious diseases like COVID-19.
18

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
Figure 7. Suggested best practices for improving airport environmental sustainability.
Airport environmental sustainability is often
addressed at project scale. There is a need for invest-
igating the larger role that airports have in impact-
ing the environment, especially in the context of
achieving city- and regional-level environmental out-
comes that lead most directly to higher environ-
mental quality of people and ecosystems. This ties
in with stakeholder involvement because for sus-
tainability indicators including GHG emissions, an
airport only claims responsibility for Scope 1 and
Scope 2 emissions. Airports often exclude own-
ership of Scope 3 emissions (e.g. emissions from
an airline’s GSE, without which there are no air-
ports). The outcome of an airport excluding own-
ership of Scope 3 emissions is twofold: (1) it is
more difficult to manage Scope 3 emissions, and
(2) it is difficult to understand an airport’s total
GHG impact at the city/regional/state/national level,
which is important for meeting larger-scale climate
performance targets. Therefore, a broader analysis
of how different stakeholders should be included
in addressing environmental sustainability efforts is
necessary.
Society faces important challenges such as adapt-
ing to climate change, mitigating the spread of
pandemic-causing diseases, and enhancing environ-
mental quality of people and ecosystems. An air-
port’s role in addressing these challenges is largely
undefined, but sure to be a significant one. It is imper-
ative that thorough research on an airport’s role in
managing these challenges gets organized.
5. Conclusion
A comprehensive, systematic review of 108 peer-
reviewed articles and technical reports related to
assessing and measuring aspects of airports’ envir-
onmental sustainability has been conducted. Articles
have been characterized according to the following
categories: Energy and Atmosphere, Comfort and
Health, Water and Wastewater, Site and Habitat,
Materials and Resources, Multidimensional. Along
with a systematic review of academic literature, a
review has been undertaken of the application of an
existing airport sustainability assessment framework
for a case study airport, SFO.
19

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
A broad conclusion from the systematic review
is that interest in airport environmental sustainabil-
ity as a research topic is steadily increasing, but that
there is ample need for more investigation. Prominent
research themes within the scope of airport environ-
mental sustainability include analyzing the environ-
mental impacts (namely GHG emissions) from air-
field pavements and energy management strategies
for airport buildings, but not from other compon-
ents of airports and for other environmental emis-
sions and impacts. There is a dearth of research on
the impacts of indoor air quality at airports. In the
research community, there appears to be a lack of
consensus about the scope of environmental impacts
that should be included when evaluating the over-
all sustainability of airports. GHG emissions from
energy consumption are one of the most commonly
used metrics in research focused on overall airport
sustainability.
Methods for evaluating environmental impacts
vary. Systems like the World Resource Institute’s
Scope 1, 2, and 3 designation for GHG emissions and
the LEED system for buildings are well-represented
in airport-industry practice. The Scope designation
primarily divides responsibility for mitigating emis-
sions between airports and airlines, creating a gap
whereby airports cannot directly control all emis-
sion sources. LEED is a minimum standard that is
not sufficient for meeting quantified performance
goals throughout the life cycle and supply chains of
airports.
Moving forward, the increased use of assessment
methodologies such as LCA will be useful in guid-
ing decision-makers and policy outcomes in a more
robust, granular direction. In the academic literat-
ure, LCA is primarily used for evaluating the envir-
onmental impact of airfield pavement construction.
However, LCA can and should be applied to evalu-
ate all components of airport construction and oper-
ational activities and to guide decision-making as
to what practices will yield optimal results. LCA
is the only comprehensive, systematic methodology
(defined in ISO 14040 and 14044) that estimates
the entirety of life-cycle environmental impacts of a
product, process, or service. This method is very use-
ful for accounting for regional differences in impacts,
for comparing among alternative strategies, and for
identifying weak points or activities that result in
the greatest environmental burdens. There are also
economic and social aspects of LCA that are help-
ful for decision-makers. One LCA approach, Eco-
nomic Input-Output LCA, can be used to evaluate the
resources, energy, and emissions resulting from eco-
nomic activity throughout a product’s supply chain
(Hendrickson et al 1998). There are efforts to use a
life-cycle approach to focus on the social aspects of
a product’s impacts (Grubert 2018). While address-
ing the economic and social impacts from airports
is beyond the scope of this review, the economic
and social implications of airports are likewise very
important and demand thorough investigations and
actions.
In conjunction with LCA, future research should
apply analysis that connects environmental impacts
with operational parameters for specific airport occu-
pant groups (e.g. ground handlers), airport infra-
structure (e.g. apron), and airport scale (e.g. small,
medium, large hubs). Accounting for operational
parameters at different scales will provide a bet-
ter understanding of how environmental sustainabil-
ity efforts impact different stakeholders and the air-
port’s primary function (i.e. processing passengers
and cargo).
A key aspect of addressing the environmental sus-
tainability of airports is the involvement of differ-
ent stakeholders. As identified in figure 1, the airport
is comprised of airside and landside components.
Historically, these components have been managed
by distinct stakeholders. Understanding the relation-
ship among the airport components, their respect-
ive environmental impacts, and their ways of man-
aging stakeholder groups is critical because it leads to
identifying who must act to mitigate environmental
impacts. Figure 7depicts an annotated version of the
airport system boundary with suggested best prac-
tices for major airport components. Based on the lit-
erature review and the application of the SFO case
study, effective sustainability practices that airports
can implement in the short term are: (1) supply elec-
tricity from renewable, low-carbon sources whether
on-site or from local utilities; (2) electrify trans-
portation vehicles (e.g. shuttles, maintenance trucks)
within the airport system boundary; (3) electrify all
gate and ground service equipment; (4) implement
water conservation practices like installation of water-
efficient faucets and toilets; (5) install energy-efficient
fixtures like LED lighting in all airport infrastruc-
ture; (6) select durable interior building materials for
improved maintainability and reduced waste produc-
tion.
These six suggested sustainability practices can
result in prompt, substantive environmental benefits
without significant tradeoffs. For example, relying on
low-carbon electricity reduces GHG as well as other
emissions. Electrifying ground service equipment and
other airport vehicles results in reductions of air pol-
lutants (NOx, PM) within the airport vicinity, which
is a human health benefit. These practices are con-
sidered implementable in the ‘short term’ as opposed
to longer-term projects such as changing the mater-
ial composition of the airfield or installing on-site,
decentralized wastewater treatment. These measures
cover activities and operations that essentially occur
at all airports, but to varying degrees of scale (e.g.
all airports consume electricity). In that vein, ease
of strategy implementation depends upon airport
type, the resources (e.g. cost, accessibility, expertise)
available to the airport for successful implementation
20

Environ. Res. Lett. 15 (2020) 103007 F Greer et al
and the controlling stakeholder. Further analysis of
those distinctions is needed in future research.
One common tendency is for airports to adopt a
perceived ‘best practice’ based upon another airport’s
successful implementation. But progress is needed
to ensure that every airport considers all relevant
environmental sustainability indicators systematic-
ally to account for regional and supply-chain effects
rather than simply follow others’ actions. This ties in
with the further need to connect all relevant envir-
onmental impacts with local human health and eco-
system effects as communities living in proximity of
airports bare a greater burden of airport operations.
Future research should concentrate on the devel-
opment of quantifiable indicators or performance
metrics. Research and practice that increase stake-
holder involvement, incorporates life-cycle assess-
ment, and links environmental impacts with opera-
tional outcomes will help airports as well as the avi-
ation industry to address their roles in major global
challenges (e.g. climate change adaptation, mitigation
of infectious diseases).
Acknowledgments
FG and JR acknowledge the financial support of the
Sustainability Office at Groupe ADP.
Data availability statement
All data that support the findings of this study are
included within the article (and any supplementary
information files).
ORCID iDs
Fiona Greer https://orcid.org/0000-0001-9453-
0640
Jasenka Rakas https://orcid.org/0000-0001-9694-
3588
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