Abstract
BACKGROUND:
The recent growth of the aviation industry, which poses significant environmental challenges, has heightened the pressure on the sustainability of airports. Airport sustainability requires a holistic approach that encompasses economic, social, environmental, and operational aspects. In this regard, the United Nations’ 17 Sustainable Development Goals (SDGs) Agenda provides a roadmap for the aviation industry. However, despite recognizing the importance of SDGs, aviation authorities and airports often fail to effectively integrate them into their activities and annual reports.
OBJECTIVE:
This study aims to evaluate the significance of SDGs for airports and select the airport that prioritizes SDGs the most using Multi-Criteria Decision Making (MCDM) methodologies.
METHODS:
This study introduces a novel approach that integrates Step-wise Weight Assessment Ratio Analysis (SWARA) and Weighted Aggregated Sum Product Assessment (WASPAS) methods, which are MCDM techniques, to enhance airport sustainability. The SWARA method is employed to evaluate and assign weights to the SDGs in the context of airports.
RESULTS:
SDG 8 holds the highest level of significance among the goals concerning airports, while SDG 14 falls outside the scope of airport sustainability aspects. Then, five international airports that have been designated as green airports by aviation authorities and assessment organizations are selected, and the optimal alternative is determined using the WASPAS method, considering the weights obtained through SWARA.
CONCLUSION:
Dallas/Fort Worth International Airport is the top choice due to its successful implementations and reports aligning with the SDGs.
Introduction
Aviation is one of the key drivers of economic and social development. Pre-pandemic data from 2019, as reported by the International Civil Aviation Organization (ICAO) in 2020, revealed that approximately 4.5 billion passengers and 61 million tons of cargo were transported by air [1]. However, this growing demand for air transportation brings significant responsibilities for the industry, particularly in terms of environmental sustainability. As the fastest-growing sector of the global economy in recent years, aviation has been associated with various environmental issues, including air pollution, noise pollution, depletion of natural resources, high energy consumption, disruption of local ecosystems, and carbon and greenhouse gas emissions [2–5].
On the other hand, airports are vital components of the aviation industry, providing essential services, facilities, and supporting infrastructures for the smooth and continuous operation of air transport. To achieve sustainability, airports must adopt a holistic approach that encompasses economic sustainability, operational efficiency, conservation of natural resources, and addressing social challenges [6, 7].
Sustainability is established upon a harmonious balance between social engagement, economic progress, and environmental protection. The United States Environmental Protection Agency defines sustainability as the creation of conditions that enable both humans and nature to support present and future generations while maintaining a direct or indirect commitment to the natural environment [8]. The United Nations’ 2030 Agenda outlines a comprehensive plan for attaining these objectives, which encompass eradicating poverty, safeguarding the environment, promoting peace and prosperity for all, and establishing a framework for local and global sustainable development practices [9]. However, as noted by Beguin and Duarte [10], the human labor aspect of sustainable development often receives less attention compared to the environmental and economic dimensions. It can be argued that the work dimension is sometimes overlooked in discussions on sustainable development. The Sustainable Development Goals (SDGs) seek to redirect global development towards a more sustainable trajectory, and this includes enhancing employee awareness of environmental issues and promoting the creation of environmentally-friendly workplaces within specific sectors.
The COVID-19 pandemic in 2020 had severe consequences on human life, the economy, the environment, energy, and transportation. This situation has magnified the significance of the 2030 targets in ensuring the sustainability of all sectors [11–15]. Within this context, the global aviation sector has a role to play in promoting sustainable operations by embracing the SDGs and cultivating a positive corporate image [16]. Aviation authorities acknowledge the importance and benefits of implementing the SDGs, and they actively support their integration within airports [17–19]. While research and discussions have predominantly focused on the environmental impacts of airports, there has been limited exploration of the significance of SDGs in the airport industry airports [20–24]. Table 1 provides a general overview of the studies conducted on the SDGs in the aviation industry and airports.
General review on research related to the United Nations’ Sustainable Development Goals (SDGs)
General review on research related to the United Nations’ Sustainable Development Goals (SDGs)
Most airports have already integrated the SDGs into their annual reports and underscore the importance of these objectives. However, the annual reports of airports tend to concentrate on the SDGs that directly align with their long-term goals, resulting in a limited exploration of all 17 goals presented in Table 1. This lack of comprehensive examination is a common occurrence. Moreover, there has been no systematic weighting of the SDGs carried out by aviation authorities or airports. Consequently, the current findings reveal a significant gap in the existing literature, as there has been no previous study that comprehensively evaluates all 17 SDGs from the perspective of airports. Thus, there is a notable deficiency in the literature in terms of describing the importance of the SDGs specifically with regard to airports.
In this study, the 17 SDGs were weighted using the Step-wise Weight Assessment Ratio Analysis (SWARA) method, which is a Multi-Criteria Decision Making (MCDM) approach. Subsequently, five airports considered sustainable were selected by aviation authorities and these 5 airports were compared using the weights of the SDGs and the WASPAS method. The selection of these airports was based on three criteria: (1) possessing LEED (Leadership in Energy and Environmental Design) certification, an internationally recognized standard for environmentally friendly buildings, (2) being acknowledged as environmentally friendly by Skytrax, an international air transport rating agency, and (3) being labeled as green airports by aviation authorities.
The SWARA method is widely recognized as an effective approach that enables decision-makers (DMs) to prioritize their preferences. Its key feature lies in estimating the importance ratios of criteria during the criteria weighting stage, allowing for the aggregation of expert opinions. The SWARA method has found significance in collecting information from experts and consolidating their insights [41]. It has been successfully applied in various sustainability studies [42–44] and has been utilized in different decision problems within the aviation industry. For instance, it has been employed for assessing airport service quality [45], prioritizing sustainable design requirements [46], and aiding in location selection [47]. Previous research has utilized the SWARA technique for decision-making in aviation involving pilots, aircraft maintenance technicians, air traffic controllers, and others [48–50]. However, there has been a notable absence of research focusing on airports and sustainability using the SWARA technique.
The WASPAS method is known for its superior ranking accuracy compared to other MCDM methods, while also offering simplified mathematical calculations. This approach has been applied in various fields, including construction site selection [51], aircraft type selection [52], assessment of airport ground access modes [53] and evaluation of airlines based on service quality [54]. Furthermore, the SWARA and WASPAS methods have been employed in a range of other studies, such as the assessment of digital health interventions [55], evaluation of sustainable suppliers in manufacturing companies [56].
Based on the literature review conducted, it is evident that the SDGs have not been approached as a MCDM problem specifically in the context of airports. Moreover, neither the SWARA nor the WASPAS methods have been implemented for this purpose. Thus, this study proposes a novel hybrid approach that combines the SWARA and WASPAS methods to evaluate the achievement of Sustainable Development Goals in the airport domain. This approach aims to fill the existing research gap and provide valuable insights into the assessment of SDGs within the airport industry.
The study is structured as follows: Section 2 provides a concise overview of the 17 SDGs and the selection of sustainable airports. Section 3 outlines the research methodology and presents the steps involved in applying the SWARA and WASPAS methods. Section 4 describes the application of these methods in the study. Section 5 presents a comprehensive discussion of the findings and concludes with overall conclusions and recommendations for future research.
In this section, a comprehensive explanation of the calculation steps involved in the SWARA and WASPAS methods is provided.
First of all, DMs are determined as DM k ={ DM1, DM2, … DM l }; (k=1,2, . . . ,l). The criteria are defined as C j ={ C1, C2, … C n }; (j=1,2, . . . ,n) and alternatives as A i ={ A1, A2, … A m }; (i=1,2, . . . ,m).
Where DM k is kth participant, C j is jth criterion and A i is ith altenative.
SWARA method
The SWARA method, developed by Kersuliene et al. [57], is an export-oriented strategy used to evaluate and assign weights to criteria. It enables the numerical estimation of experts’ or interest groups’ opinions and knowledge in various domains such as economics, management, policy, and environmental sustainability. This method allows decision-makers to play a crucial role in assessing the significance of each criterion, taking into account the current environmental and economic conditions [58].
The steps involved in determining weights using the SWARA method, as outlined by Prajapati et al. [59], are as follows:
Each decision-maker ranks the criteria based on their importance (from the most important to the least important) according to their own expertise.
Starting from the second criterion, each decision-maker determines the relative importance of criterion j in relation to the previous criterion (j - 1) for each particular criterion. This ratio is commonly referred to as the average comparative importance value, as described by Keršuliene et al. [57] and Stanujkic et al. [60].
Where
Where
In this step, Equation (2) is applied to determine the recalculated weight of each criterion for every DM as follows:
Where
The relative weight of each criterion is determined using Equation (3).
Where
The WASPAS method was initially developed by Zavadskas et al. [61] by integrating the Multi-Criteria Decision Making (MCDM) methodologies Weighted Sum Model (WSM) and Weighted Product Model (WPM). This method utilizes the performance values and criterion weights of alternatives based on criteria to solve the problem. Moreover, the method can ensure consistency in alternative rankings by conducting sensitivity analysis within its own framework [62].
The steps of the WASPAS method are outlined below [63].
The decision matrix is constructed using the alternatives and criteria defined in Equation (4).
The decision matrix formed in the previous step is normalized using Equations (6) as follows:
The relative significances of the i
th
are evaluated using Equation (7) as follows:
Where Qi is total relative importance of i th alternative for WSM.
w j is obtained SWARA method.
The relative significances of i
th
are evaluated using Equation (8) as follows:
w j is obtained SWARA method.
A joint generalized criterion of weighted aggregation of additive and multiplicative methods is evaluated using Equation (9) as follows:
The WASPAS technique develops a more generalized equation for determining the overall relative significance of the i th alternative in order to improve accuracy and effectiveness of the decision-making process.
In this study, the best alternative among the evaluated airports was selected based on the 17 SDGs published by the UN. The objective is to assess the importance of SDGs in relation to airport sustainability and promote the implementation of sustainability practices and necessary measures in airports.
In the first part of the study involved applying the SWARA method, a weighting technique, to determine the level of importance of the SDGs. In the next section, the WASPAS method, a selection method, was utilized to assess and compare different airports in order to identify the best alternative.
SWARA
First, a panel of DMs was formed, consisting of experts in the field of aviation. The panel included two academics with more than 25 years of experience and consultancy roles, one quality manager from an international airport, and two ground services supervisors (one from Istanbul and the other from Antalya). Each DM was assigned a unique numerical identifier from 1 to 5, as indicated in Table 2. The DMs were then asked to individually rank the 17 SDG criteria based on their perceived importance in relation to airports. The rankings provided by the DMs are presented in Table 2.
Sustainable Development Goals (SDGs) evaluation criteria
Sustainable Development Goals (SDGs) evaluation criteria
The DMs individually evaluated each criterion relative to the previous one and assigned separate scores (
The coefficient (
Relative importance and coefficient of criteria for each decision-maker (DM)
The recalculated weights (
Calculated weights of criteria for each decision-maker (DM)
The final weights of the SDGs are calculated by using Equation (3), as shown in Table 4 for each DM.
Then, final weight w
j
is obtained geometric mean of
Final weights and ranking
According to the obtained criteria weights, the final ranking is as follows:
At this stage, using the weights determined by the SWARA method in the previous step, five airports were compared in terms of their implementation of SDGs, and the best airport alternative was determined.
First, a decision matrix was created for the five selected airports, incorporating the 17 SDG criteria.
Airports develop their sustainability practices based on their geographical regions, national legal regulations, and cultural differences. While the specific practices may vary, the adoption of sustainable development goals is essential to ensure the long-term viability of airports globally. For this study, five airports were selected based on their certification as sustainable airports by international aviation authorities and organizations.
Singapore Changi Airport, established in 1981 and located in Changi, Singapore, is the largest airport in Southeast Asia, serving 382,000 aircraft movements and accommodating 68.3 million passengers annually. The airport has made significant strides in sustainability and has been awarded Level Three of the Airport Carbon Accreditation. This achievement reflects their efforts in carbon footprint mapping, implementing emission reduction plans, and engaging stakeholders to minimize the airport’s carbon emissions. Notably, Singapore Changi Airport has recently announced its plans to introduce a fully electric fleet of baggage handling tractors at Terminal 4, demonstrating their commitment to reducing greenhouse gas emissions [64].
Munich International Airport, established in Munich, Germany in 1992, is a prominent hub in Europe and the second-largest airport in terms of traffic volume. Annually, it serves approximately 48 million passengers and handles 471,000 aircraft movements. The airport is recognized for its advanced renewable energy initiatives, notably its block heat and power facilities that utilize environmentally friendly natural gas to generate more than half of its annual energy requirements. Munich International Airport is also notable as the world’s first major commercial airport to incorporate energy-efficient LED technology throughout its premises. Additionally, the airport actively utilizes renewable energy sources such as biogas, bioethanol, and solar energy within its operations. Furthermore, it employs alternative biofuels and electricity to power airport vehicles and equipment, demonstrating its commitment to sustainable practices [65].
Dallas/Fort Worth International Airport, situated in Texas, United States, commenced operations in 1973 and has since become one of the busiest airports worldwide. Annually, it serves approximately 75 million passengers and handles 720,000 aircraft movements. In 2019, the airport achieved a significant milestone by becoming the first carbon-neutral airport in North America, as certified by the Airports Council International (ACI) for a period of three years. Dallas/Fort Worth International Airport has implemented numerous environmental strategies to reduce its carbon footprint. These include utilizing 100% renewable electricity and adhering to green building standards for all new construction projects. Furthermore, the airport focuses on optimizing the energy efficiency of its existing facilities to minimize its environmental impact [66].
Oslo-Gardermoen Airport, situated in the capital city of Oslo, Norway, was inaugurated in 1998. It ranks as the second busiest airport among Scandinavian countries, serving approximately 28 million passengers and handling 254,000 aircraft movements annually. The airport is operated by Avinor Group. Oslo-Gardermoen Airport has taken significant strides in promoting sustainable aviation practices. Through collaborations with airlines and fuel suppliers such as Neste, SkyNRG, Lufthansa Group, KLM, and SAS, it achieved a remarkable milestone by becoming the world’s first international airport to introduce biofuels into its fuel supply system and make them available to airlines. In 2019, the airport phased out the use of fossil fuels with low priority in its energy supply, replacing them with biofuels. Moreover, Oslo-Gardermoen Airport has transitioned to utilizing the biofuel HVO (Hydrogenized Vegetable Oil) for energy production since 2020, while operating its backup power units solely on fossil diesel [67].
Amsterdam Schiphol Airport, located in the capital city of The Netherlands, Amsterdam, was initially established as a military airport in 1916. Over time, it has transformed into one of the largest airports globally, handling an impressive annual passenger volume of 71.7 million and accommodating 496 thousand aircraft movements. The airport is operated by the Royal Schiphol Group, and it actively supports sustainable aviation initiatives promoted by the European Union (EU). Furthermore, Amsterdam Schiphol Airport collaborates with other airport management entities such as the Single European Sky Project. The airport is also actively involved in sustainable aviation policy and partnerships, including participation in the European CO2 Emissions Trading Scheme (EU ETS) and the Clean Skies for Tomorrow (CST) initiative. The CST initiative aims to foster the alignment of the aviation value chain with sustainable aviation fuels in order to facilitate the transition toward a more sustainable aviation industry [68].
Decision-makers were requested to provide scores for the applications implemented at the airports, and subsequently, an initial decision matrix was formulated based on their collective assessments. Table 6 presents the initial decision matrix, reflecting the evaluations and opinions of the decision-makers.
The initial decision matrix
The initial decision matrix
The initial decision matrix, as presented in Table 6, was subjected to a normalization process to create the normalized decision matrix, as shown in Table 7. The normalization method employed in this study, indicated by Equation (5), was utilized to ensure that all criteria are utility-based and appropriately scaled.
The normalized decision matrix
The weighted sum of the normalized scores of the airports based on the criteria was calculated using the weight values obtained from the SWARA method, as shown in Table 4. The calculations were performed using the weight values w j and Equation (7). The results of these calculations are presented in Table 8.
Relative significance values based on the Weighted Sum Model (WSM)
The weighted product of the normalized scores of the airports based on the criteria, using the weight values obtained from the SWARA method (shown in Table 4) and Equation (8), is calculated. The results of these calculations are presented in Table 9.
Relative significance values based on the Weighted Product Model (WPM)
The values determined by the weighted sum and weighted multiplication methods of each alternative were calculated using Equation (10). The results of the alternatives evaluated using different λ values are shown in Table 10.
Alternatives assessment with different λ values
When examining the WASPAS results based on the SWARA weightings, it was observed that the order of the alternatives did not change for different λs values. According to Table 10, the order of the alternatives is A3> A1 > A4 > A2 > A5. It appears that A3 is the airport that implements the best practices for the 17 SDGs.
According to the results of the SWARA method, it has been determined that SDG8 (
The objective of SDG11 (
According to the methodology employed in the study, SDG14 (
In accordance with the results obtained from the WASPAS method, the airports were ranked as follows: Dallas/Fort Worth International Airport (
Sustainability practices, such as collaborations and initiatives, support almost all SDGs, and their relationships with the implementations are transparently and comprehensively described in their annual reports. Similar to Dallas/Fort Worth International Airport, Singapore Changi Airport, which ranked second according to the method, demonstrates numerous successful sustainability practices. It is noteworthy that Singapore Changi Airport places significant emphasis on the SDGs in its annual reports. The airport acknowledges the crucial role of the SDGs in airport sustainability and effectively integrates them into its reports and operations. On the other hand, Oslo-Gardermoen Airport stands out with its remarkable and successful environmental sustainability initiatives. However, in comparison to the other two airports, Oslo-Gardermoen Airport ranks third as it places the least emphasis on the SDGs in its annual reports. Conversely, Munich International Airport and Amsterdam Schiphol Airport mention the SDGs solely in their corporate goals and priorities within their annual reports. However, when compared to other airports in the study, these airports rank last in terms of their applications, as they do not adequately support all SDGs.
The results of this study have demonstrated that the best airports excel in implementing successful initiatives for specific SDGs, such as SDG6 (
Conclusion
As airports play a vital role as service providers on a global scale, they have a significant impact on economic, social, and environmental aspects of development. It is crucial for decision-makers in the aviation sector to effectively manage resources and develop sustainable and efficient airport management methodologies. The United Nations’ Sustainable Development Goals have a profound influence on various industries, including aviation, and many airports establish their sustainability goals and publish annual sustainability reports aligning with these SDGs. Despite the importance of achieving sustainability in the aviation industry, there is a scarcity of studies specifically focusing on airport sustainability practices related to the UN SDGs. Existing research in the literature mostly adopts qualitative methods to assess environmental criteria of the SDGs through general comparisons and evaluations of operations and organizations. In contrast to previous studies, this research proposes a hybrid approach using multi-criteria decision analysis (MCDA) as a tool to evaluate the SDGs in the context of airports. The SWARA method is initially employed to assign weights to the 17 SDGs based on their relative importance for airports. Subsequently, the WASPAS method is utilized using the calculated weights to determine the best alternative among the airports considered in the study.
This study highlights the importance of airports prioritizing the UN SDGs to enhance their sustainability performance and contribute to the achievement of the 2030 Agenda targets. It emphasizes the need for airports to establish new strategic and tactical targets, as well as performance indicators, to effectively work towards their sustainability goals. The findings of this study can serve as a valuable guide for aviation authorities, airport managers, municipalities, and researchers in the field to align their efforts with the specified sustainability goals and make progress toward a more sustainable future.
The limitation of this study pertains to its exclusive reliance on the analysis of the most recent annual sustainability reports of airports. To enhance the comprehensiveness of future investigations, it is recommended to broaden the scope by incorporating airlines into the evaluation process and employing diverse MCDM methods. Such an expanded approach would enable a more comprehensive assessment of the significance of SDGs for airlines and facilitate the identification of airlines exhibiting exemplary sustainability practices. By considering multiple stakeholders within the aviation industry, these extended studies would provide a more nuanced and holistic understanding of sustainability endeavors in this sector.
Ethical approval
Not applicable.
Informed consent
Not applicable.
Conflict of interest
The authors have no conflict of interest to report.
Footnotes
Acknowledgments
This article is a part of the Master’s thesis by Beste Pelin Çelem, entitled “Evaluation of United Nations 2030 Sustainable Development Goals in Airports using Multi-Criteria Decision Making Methods”.
Funding
None to report.
