Mega Ports’ Mitigation Response and Adaptation to Climate Change

Abstract

Mega ports, defined in this study as those handling over 5 million TEUs annually, are major hubs within the dynamic framework of global trade, influencing both economic and environmental landscapes. This study identifies climate change as the foremost environmental concern for these ports, necessitating urgent and strategic responses. Through comprehensive research, this paper explores the main Climate Change Mitigation (CCM) strategies and evaluates their implementation across mega ports worldwide. Findings indicate widespread adoption of certain strategies, such as setting greenhouse gas (GHG) reduction targets and providing on-shore power supply (OPS), while also identifying challenges, particularly in implementing environmentally differentiated port fees. Additionally, this paper outlines key strategies for climate change adaptation (CCA) in ports. The results of this research offer insights into sustainable practices and collaborative efforts to confront climate change challenges effectively. These findings have the potential to significantly improve maritime policy and ship management strategies.

1. Introduction

Seaports play a pivotal role in the complex global supply chain, acting as vital connections that unite nations, facilitate trade, and drive the international trade engine. Positioned strategically along coastlines, these maritime hubs are essential, serving as smooth pathways that enable the movement of goods and foster economic development [1]. The significance of seaports goes beyond their geographical location. They represent a point where various economic sectors come together [2].

In today’s world, where goods travel long distances to reach consumers across the globe, seaports play a crucial role in the complex system supporting international trade. Their multifaceted roles extend beyond the mere transfer of cargo; seaports function as dynamic hubs fostering connectivity among diverse modes of transportation, including shipping, railways, and road networks. The efficiency and effectiveness of seaports directly influence the velocity of trade, impacting the competitiveness and economic strength of a country [3].

In the context of global challenges, seaports are faced with the need to adapt and innovate. Issues such as climate change, progress in technology, and changes in global politics are reshaping the dynamics of international trade, placing seaports at the forefront of strategic considerations. As the global economy becomes increasingly interconnected, seaports assume a pivotal role not only in driving economic prosperity but also in influencing employment opportunities and community development, strengthening resilience against emerging challenges, ensuring sustainability, and mitigating environmental impacts [4].

In this setting, port activities have diverse effects on the environment, affecting water, soil, sediments, and air. Water pollution is a significant issue as ports discharge effluents into surrounding waters. The consequences include acidification, eutrophication, and ecotoxicological effects, posing threats to aquatic ecosystems [5]. Port activities also impact the soil through contamination from hazardous substances such as oil and chemical spills, leading to soil degradation and loss of soil productivity. Additionally, the dredging of contaminated sediments, acknowledged as an environmental challenge, highlights the complex relationship between maritime commerce and the necessity for ecological preservation [6]. In addition, the contamination of sediments significantly impacts the benthic organisms within the ecosystem, altering their exposure to and accumulation of harmful metals [7]. On the other side, air pollutants like sulfur and nitrogen oxides (SO_x and NO_x), originating mostly from vessels using heavy fuels, may contribute to the formation of acid rain, the formation of ground-level ozone, and air quality degradation. Particulate matter (PM), generated from diesel engines, can have adverse effects on respiratory health and overall air quality [8]. Finally, one of the main concerns is the release of greenhouse gas (GHG) emissions, especially from ships, since between 70% and 100% of port emissions originate from shipping activities [9]. Additionally, the fleets of vehicles and handling equipment within ports, such as diesel-powered trucks, cranes, and other machinery, generate significant amounts of GHG emissions by emitting CO₂ and other pollutants during their operation, contributing to global climate change [4].

These environmental impacts are significantly magnified in the context of mega ports, which are defined as large port facilities with extensive infrastructure and the capacity to handle a high volume of cargo. Mega ports experience a continuous flow of vessels powered by fossil fuels, making them an important contributor to CO₂ emissions and amplifying the overall carbon footprint [10].

To address the global issue of climate change, seaports may employ two primary strategies: Climate Change Mitigation (CCM) and Climate Change Adaptation (CCA) [11,12]. Through CCM, ports aim to reduce their GHG emissions. In contrast, CCA focuses on adapting port infrastructure and operations to withstand the effects of climate change [13].

In recent decades, notable progress has been made in energy efficiency to reduce emissions, enabling vessels to transport the same cargo at the same speed with lower installed power, thereby reducing fuel consumption and CO₂ emissions. Despite a doubling in the volumes of cargo transported by sea, emissions have risen by only 40% [14]. However, considering the overall growth in global transportation, total emissions have continued to rise over the past decade [15].

International organizations have implemented various efforts to combat GHG emissions and promote sustainable practices. The United Nations (UN), through the Paris Agreement adopted in December 2015, set ambitious targets to limit global temperature rise to below 2 °C, striving for 1.5 °C [16]. Subsequent Conferences of Parties (COPs), from COP 25 in Madrid in 2019 to COP 28 in Dubai in 2023, have built upon these goals, promoting accelerated carbon emission reductions.

The International Maritime Organization (IMO) has also been pivotal in reducing maritime GHG emissions. In April 2018, IMO adopted an initial strategy aimed at decreasing emissions from ships, which was followed by a strategic program in October 2018 to ensure compliance with this timeline [17]. By July 2023, the IMO introduced the Strategy on Reduction of GHG Emissions from Ships, aiming for net-zero emissions by around 2050. This strategy includes targets to reduce annual GHG emissions from international shipping by at least 20% (targeting 30%) by 2030 and by at least 70% (targeting 80%) by 2040, relative to 2008 levels [18]. These efforts reflect IMO’s commitment to mitigating the environmental impact of international maritime transport.

The European Union (EU) has articulated its climate ambitions through the European Green Deal, launched in 2019, which aims to make Europe the first climate-neutral continent by 2050. The “Fit for 55” package, introduced in July 2021, sets a target to reduce emissions by 55% by 2030 compared to 1990 levels. This package includes significant legislative measures affecting maritime transport, such as the Fuel EU Maritime Regulation and the Alternative Fuels Infrastructure Regulation (AFIR), which mandate reduced GHG emission intensity and the provision of On-shore Power Supply (OPS) and LNG bunkering facilities in ports. These regulations, effective from January 2025 and by 2030, respectively, exemplify the EU’s proactive stance on decarbonizing the maritime sector and enhancing port sustainability.

In light of these significant challenges, this paper seeks to explore key issues and strategies. The research questions proposed are:

• Which ports are considered mega ports?
• How important is climate change for mega ports?
• What primary strategies are employed by ports worldwide to mitigate their environmental impact and align with global climate goals?
• To what extent are the main strategies for Climate Change Mitigation (CCM) implemented within mega ports?
• What are the main strategies for Climate Change Adaptation (CCA) in ports?

Therefore, the overarching objective of this paper is to analyze the role of mega ports in climate change mitigation and adaptation and to offer relevant insights for both academia and industry stakeholders. This study delves into the specific environmental challenges faced by mega ports, specifically in terms of GHG emissions, and evaluates the effectiveness of current mitigation strategies. By synthesizing empirical data and case studies from mega ports worldwide, the research aims to provide an understanding of how these strategic hubs can contribute to global climate goals while maintaining operational efficiency and economic competitiveness.

This paper is written in the framework of the project #2021-026-3-600 “The role of mega ports in climate change”, which is financed by Division VI “Chemistry and the Environment” of the International Union of Pure and Applied Chemistry (IUPAC). The main tasks of the project are the critical review of the current knowledge and understanding of port activities and operations that cause GHG emissions, the overview of ports’ environmental management practices to address climate change and options for GHG mitigation, and the collaborative approach between the port, city, and the stakeholders.

2. Methodology

To effectively address the research questions and achieve the objectives of this paper, a structured research pathway has been outlined. This pathway comprises the following steps:

• Definition of mega port concept (Section 3.1): This involves a thorough examination of existing definitions of mega ports. This research mainly included published papers on the subject, port websites, port reports, and official documents of international associations. Additionally, an analysis of their primary characteristics has been conducted to establish an accepted definition tailored to this research.
• Identification of worldwide mega ports (Section 3.1): Based on the established definition, a comprehensive list of mega ports worldwide has been compiled based on the existing data published by the World Shipping Council. This list forms the foundational basis for subsequent analysis.
• Identification of environmental priorities of mega ports (Section 3.2): Utilizing data from the Self-Diagnosis Method (SDM) [2], the main environmental priorities of the classified mega ports have been characterized. The SDM is a survey developed within the ECOPORTS project, funded by the European Commission (GRD2-2000-30195), that lasted from 2002–2005. This project helped to grow environmental awareness among European ports, establishing for the first time a level playing field between European ports in relation to the environment. It also contributed to the development of several environmental management tools, such as SDM [19]. This tool is a concise checklist of the elements that a port should have to achieve an effective Environmental Management System (EMS). It also includes a checklist of environmental priorities for ports. Using this information, it has been possible to identify the mega ports’ environmental priorities and compare them with the top ten environmental priorities of the EU port sector.
• Research on proactive measures in the port sector (Section 4.1): A comprehensive review of proactive measures within the port sector aimed at reducing the impact of port activities on climate change has been conducted through an extensive literature review. This included a revision of more than 50 documents, taking into consideration papers in scientific journals, port sector journals, environmental reviews, and many others.
• Definition of main Climate Change Mitigation (CCM) strategies (Section 4.2, Section 4.3, Section 4.4, Section 4.5, Section 4.6, Section 4.7 and Section 4.8): From the previous research, it has been possible to define CCM strategies for reducing environmental impact and enhancing sustainability within mega ports.
• Creation of a CCM strategies checklist (Supplementary Materials): A checklist of CCM strategies has been formulated to assist mega ports in reducing their GHG emissions effectively. It consists of a table with the names of the ports listed vertically and the strategies for GHG reduction listed horizontally. In this way, it is very easy to cross each variable against the other.
• Analysis of mega ports’ compliance with CCM strategies (Supplementary Materials): The methodology employed involved scrutinizing each one of the mega ports against the seven proposed strategies and analyzing their compliance with each indicator. This process required exploring the available information on port websites, published annual or environmental reports, and relevant data in the scientific literature to assess the extent to which classified mega ports comply with proposed CCM strategies. The sources utilized in the research for each port are documented in Table S1 of Supplementary Materials.
• Presentation of research findings (Section 5): Research findings are presented in tabular format to summarize the percentage of acceptance, non-acceptance, or unconfirmed information for each CCM strategy.
• Identification of resilience measures for Climate Change Adaptation (CCA) (Section 6): Potential resilience measures that mega ports can adopt to effectively mitigate the effects of climate change are identified based mainly on academic papers discussing these topics.

3. Mega Ports Concept and Environmental Priorities

3.1. Definition of Mega Port Concept and Identification of Mega Ports

The expansion of ports into massive dimensions has given rise to the definition of the so-called “mega ports”. They are characterized by their extremely high cargo capacity, extensive product handling capabilities, and considerable geographical extension. The term “mega port” is used to describe an exceptionally large and strategically significant seaport that serves as a major hub for international trade and shipping activities. These ports typically have extensive infrastructure, handling a substantial volume of cargo, accommodating large vessels, and playing a crucial role in the global supply chain.

In the existing literature, there are different definitions of a mega port. According to Merk [20], a mega port is characterized by three aspects: the quantity of cargo it manages, its economic significance, and the scale of land and water areas it occupies. Saigon Newport also affirmed these criteria as the three essential characteristics attributable to mega ports [21]. These descriptions are not necessarily discrete. For instance, certain ports may manage substantial cargo volumes without generating equivalent economic value, especially if they do not have trade clusters, industrial estates, or thriving waterfronts connected to the port.

It is worth noting that in today’s world, the significance of a port transcends mere cargo handling statistics, extending to its contribution to the global energy transition. Smaller ports traditionally deemed less significant due to their maritime throughput are now gaining prominence as they embrace their pivotal role in the energy sector, for instance, in facilitating offshore wind projects. The size of a port no longer solely determines its importance; rather, its involvement in renewable energy initiatives plays a crucial role in shaping its relevance and impact on both local and global scales.

However, with no standardized volumes of cargo for mega ports found in the existing literature, this study has defined the concept of mega ports as those that manage more than 5 million TEUs annually. This classification corresponds with the top thirty world container ports, as outlined in

Table 1. Top container ports with more than 5 million TEUs/year [22].

Pos.	Port	Country	TEUs *	Pos.	Port	Country	TEUs *
1	Shanghai	China	43.21	16	Los Angeles	U.S.A.	9.61
2	Singapore	Singapore	36.31	17	Tanjung Pelepas	Malaysia	9.50
3	Ningbo-Zhoushan	China	27.65	18	Hamburg	Germany	8.86
4	Shenzhen	China	26.81	19	Long Beach	U.S.A.	8.15
5	Guangzhou Harbor	China	22.57	20	Keihin Ports	Japan	7.99
6	Busan	South Korea	21.69	21	Dalian	China	7.98
7	Qingdao	China	20.66	22	Laem Chabang	Thailand	7.97
8	Hong Kong, S.A.R.	China	18.88	23	New York-New Jersey	U.S.A.	7.58
9	Tianjin	China	17.40	24	Suzhou	China	7.19
10	Rotterdam	The Netherlands	14.54	25	Ho Chi Minh City	Vietnam	6.98
11	Jebel Ali, Dubai	United Arab Emirates	14.33	26	Colombo	Sri Lanka	6.93
12	Port Klang	Malaysia	13.32	27	Tanjung Priok, Jakarta	Indonesia	6.69
13	Antwerp	Belgium	11.34	28	Yingkou	China	5.83
14	Xiamen	China	10.99	29	Valencia	Spain	5.49
15	Kaohsiung, Taiwan	China	10.12	30	Piraeus	Greece	5.10

* Million Twenty-foot Equivalent Units (TEUs)/year, corresponding to the average 2017–2021.

, based on the calculated average 2017–2021 data provided by the World Shipping Council [22].

3.2. Environmental Priorities of Mega Ports

In order to identify the environmental priorities of mega ports, as aforementioned, the results of the Self-Diagnosis Method (SDM) questionnaire [23] were used (access to the EcoPorts database was provided by ESPO). Based on the responses of ports to the 2023 SDM, the authors have prepared a ranking of the Top 10 environmental priorities of mega ports worldwide (left column in

Table 2. Top environmental priorities of mega ports and EU ports 2023.

Priority	Mega Ports *	EU Port Sector [24]
1	Climate change	Climate change
2	Air quality	Air quality
3	Water quality	Energy efficiency
4	Port development (water-related)	Noise
5	Port development (land-related)	Water quality
6	Relationship with the local community	Ship waste
7	Noise	Relationship with the local community
8	Garbage/Port waste	Port development (land-related)
9	Ship waste	Garbage/Port waste
10	Dust	Port Development (water)

* Based on the responses of classified mega ports to the SDM.

). In addition, these results are compared with priorities identified for the overall EU port sector, published in the ESPO Environmental Report 2023 [24].

The results presented indicate that both mega ports and the EU port sector prioritize climate change and air quality as their top two environmental concerns. This alignment suggests a common recognition of the urgency to address these global and regional challenges. However, there are other differences in subsequent priorities. For mega ports, water quality and port development (water and land-related) are ranked third, fourth, and fifth, respectively, reflecting their focus on managing direct environmental impacts and expansion projects. Conversely, the EU port sector places energy efficiency and noise at higher priorities, indicating a broader concern with operational efficiency and noise pollution. Further divergences are seen in the relationship with the local community, where mega ports rank higher than their EU counterparts. Ship waste management is also a shared concern, though ranked differently.

With climate change standing out as a top priority for both mega ports and the EU port sector, the subsequent section focuses on potential mitigation strategies potentially implemented in mega ports.

4. Strategies for Climate Change Mitigation (CCM) in Mega Ports

4.1. Research on Proactive Measures in Mega Ports

In this section, an extensive examination was undertaken to review proactive measures within the port sector aimed at mitigating the impact of port activities on climate change. This thorough review encompassed a wide array of strategies adopted by mega ports globally, including innovative technologies, policy initiatives, and collaborative efforts focused on reducing GHG emissions and promoting environmental stewardship. Addressing GHG emissions in mega ports necessitates a multifaceted approach, integrating technological innovation, regulatory frameworks, and industry collaboration.

The strategies for GHG reduction cover various aspects, including those directly within the domain of the port authority and those where the port authority can influence other stakeholders, such as shipping companies. Mega port authorities, serving as central coordinators of maritime activities, possess considerable influence over the environmental impact of shipping within their jurisdictions. This underscores their multifaceted role in shaping the behavior of shipping companies and guiding them toward practices conducive to mitigating climate change impacts.

Following the review, seven key strategies were identified, visually summarized in Figure 1, and detailed in Section 4.2, Section 4.3, Section 4.4, Section 4.5, Section 4.6, Section 4.7, Section 4.8.

4.2. Alternative Fuels Supply

Facilitating the availability and utilization of alternative fuels is crucial for reducing GHG emissions in mega ports. These ports can actively collaborate with energy providers to increase the availability of low-sulfur fuels and transition to cleaner energy sources. The annual energy demand of maritime transport is 3300 TWh, and only a mere 1% of the currently operating vessels utilize alternative fuels, primarily in the categories of short-sea shipping and passenger vessels [25]. Nevertheless, in the present scenario, 12% of newly constructed ships are equipped to operate using alternative energies [26].

Numerous marine fuel options are currently under investigation and research, including Liquefied Natural Gas (LNG), hydrogen, ammonia, synthetic fuels, and biofuels. These alternatives are expected to contribute to the decarbonization of their entire life cycle, “from well to propeller”. The fundamental risk posed is the potential absence of a market for certain investments or the risk of them becoming outdated before the payback period has elapsed [27]. Consequently, ports are finding it increasingly challenging to adapt to these solutions or determine the most suitable investments.

For this reason, the industry must inevitably cooperate and invest in Research and Development (R&D) to achieve the transition of the global fleet. This calls for energy companies, engine manufacturers, shipowners, and stakeholders from onshore sectors to come together, defining technical requirements and priorities for fuel-related R&D. Coordination on how to progress is crucial for a collective and effective approach.

Of all the existing alternatives today, LNG is probably the most relevant. Although it may not address all long-term issues, LNG can serve as a short to medium-term alternative contributing to decarbonization [28] since it is 20–25% less carbon-intensive than heavy fuel oil [29]. In 2023, 42% of European ports offered LNG bunkering within their facilities, an increase of 11% compared with 2021 [24]. It may be justified by the publication of the EU Alternative Fuels Infrastructure Regulation (AFIR), as it obliges the TEN-T Core Network of ports to be equipped with LNG refueling points by 2025. In addition, in 2023, 15% of European ports currently have ongoing LNG bunkering infrastructure projects under development, and another 21% are planning to undertake this development during the next two years [24]. A dual transition with significant investments is anticipated: the first from petroleum derivatives to LNG and the second from LNG to zero-emission fuels [30].

4.3. On-shore Power Supply (OPS)

The vast majority of ships, including cargo vessels, bulk carriers, container ships, ferries, and cruise liners, operate with their engines running while docked in ports, to sustain the electricity and cooling services required onboard. This is not the case for recreational boats, as they have access to a connection to the electrical grid on the docks [31].

Taking this into account, another way in which mega ports can assist ships in reducing their GHG emissions is through the provision of On-shore Power Supply (also known as cold ironing), involving the supply of electrical power (preferably from renewable sources) to vessels moored in port. This approach would replace the consumption of fossil fuels, allowing the shutdown of main engines and auxiliary generators and reducing the GHG and pollutants emissions (NO_x, SO_x, or particles), as well as noise [32].

Mega port authorities have the option to invest in the necessary infrastructure, including connection points at berths. In addition, collaborating with private entities, such as shipping companies and energy service providers, fosters the development of shore-side power projects. Public-private partnerships can accelerate the implementation of this technology, combining resources and expertise.

The development of cold ironing for supplying electricity to ships faces various standardization challenges that need resolution, including issues such as electricity billing, insufficient grid capacity and availability, and the lack of viable business model frameworks resulting in high costs with minimal returns on investment. For these reasons, a majority of OPS facilities installed in Europe have received support from public financing, covering up to 50% of the costs [33].

4.4. Environmentally Differentiated Port Fees

Mega port authorities can implement environmentally differentiated port fees, where ships with lower emissions are rewarded with reduced fees. Reductions in port fees can also be granted, for instance, to limit the speed of vessels in specific navigation areas. This economic incentive encourages shipping companies to invest in cleaner technologies and practices, aligning financial motivations with environmental responsibility.

The latest ESPO Environmental Report [24] revealed that 63% of EU ports are currently offering special rates for ships that are environmentally friendly. This represents a significant increase of 10% in just two years. Additionally, the report points out that 38% of ports are planning to introduce specific environmental tariffs within the next two years, reflecting an 8% rise during the same period. This information highlights a positive trend in European ports, as they actively encourage and support environmentally sustainable practices in the maritime industry.

The provision of green discounts by port authorities on fees for specific types of vessels can be perceived as an independent and voluntary choice made by company leadership in alignment with their planning, local imperatives, and economic constraints. Port fees constitute a significant portion, up to half, of port revenues, making them a vital income source for port management entities. Moreover, green discounts may also mirror non-economic objectives pursued by the port, including factors related to reputation and competitiveness [27].

4.5. Low Emission Zones (LEZ) and Berth Standards

To further influence shipping companies, mega port authorities can designate Low Emission Zones (LEZ) or set berth standards that dictate the environmental performance expected from vessels while at berth. This proactive approach establishes a framework for responsible behavior and encourages shipping companies to invest in cleaner technologies.

On the one side, LEZ are designated areas within port facilities where specific emissions standards are enforced to limit the impact of air pollutants and GHG [34]. The primary objectives include improving air quality, protecting public health, and reducing the overall carbon footprint associated with port operations. Ports define and enforce specific emission criteria for vessels, vehicles, and equipment operating within the LEZ. Criteria may include limits on nitrogen oxides (NO_x), sulfur oxides (SO_x), particulate matter, and other pollutants. Compliance is mandatory for all entities operating within the designated zone [35]. Ships that do not meet these standards typically cannot enter the LEZ. However, they can fit within limits by adopting cleaner technologies such as using low-sulfur fuels, installing exhaust scrubbers, or switching to electric or hybrid power while in port, which are all measures to improve air quality.

On the other side, ports are establishing berth standards that outline environmental performance criteria for visiting vessels. These criteria may encompass limits on GHG emissions, air pollutants, and noise levels during a vessel’s stay at the berth. The standards serve as a benchmark for evaluating the environmental impact of ship operations while docked [36].

4.6. Implementing an EMS with GHG Reduction Targets

Implementing a robust Environmental Management System (EMS) standard is crucial for mega ports striving to enhance sustainability and address climate change challenges. This approach provides a structured framework for selecting, monitoring, and managing environmental aspects and impacts associated with port operations. While mega ports, like any other structure or activity, are required to follow local, national, and international environmental regulations, an EMS goes beyond mere compliance. By adhering to an EMS standard, mega ports can systematically identify and mitigate environmental risks, continually improve their environmental performance, and set higher standards for sustainability. This not only ensures compliance with regulations but also demonstrates a proactive commitment to environmental responsibility, positioning the port as a leader in sustainable practices and enhancing its reputation among stakeholders [37].

Setting objectives and targets on Significant Environmental Aspects (SEAs) within an EMS serves as a roadmap for achieving desired environmental outcomes [38]. These targets provide quantifiable benchmarks for measuring progress and fostering a culture of continuous improvement within mega ports. Regular reviews and updates to environmental management processes ensure alignment with best practices and technological advancements in sustainable operations focused on GHG reduction [39].

Moreover, adherence to an EMS standard facilitates the integration of climate change adaptation measures into port planning, enhancing resilience to climate-related challenges. Additionally, maintaining an EMS standard enhances the reputation of mega ports among stakeholders (such as shipping companies, port employees, regulatory bodies, local communities, environmental organizations, and investors), fostering confidence in their environmental commitment. This positive reputation can lead to business advantages and support from the broader community.

4.7. Smart Port Technologies and Digitalization

On average, vessels spend up to 9% of their time waiting at anchorages, contributing to inefficiencies in maritime operations. Additionally, 15% of the world fleet’s marine fuel consumption occurs during periods spent in port, at anchor, and when vessels operate at very low speeds [40]. These statistics highlight the importance of addressing inactive periods, both at anchorages and in port, as they significantly impact fuel consumption, emissions, and operational efficiency in the global maritime industry.

Mega ports are increasingly embracing Smart port technologies and digitalization to enhance operational efficiency, reduce environmental impact, and optimize performance. A key aspect of this digital transformation is the implementation of the “Just-In-Time” (JIT) operation, which focuses on scheduling vessel arrivals to reduce idle times and minimize waiting times at berth, thereby reducing associated GHG emissions [25]. According to the IMO [40], JIT operations have a high potential to reduce energy consumption and emissions in the maritime transport sector.

Smart Port Technologies utilize real-time data to dynamically schedule vessel arrivals and departures, optimizing schedules based on factors such as weather conditions, berth availability, and cargo handling capacity to align with JIT principles. This ensures vessels arrive precisely when needed, minimizing unnecessary inactive times [41].

Furthermore, integrating smart technologies in automated cargo handling and terminal operations enhances the performance of modern ports. Automation of processes, including container handling systems, robotic cranes, and autonomous vehicles, streamlines operations, accelerates cargo handling and reduces delays. This, in turn, increases overall port efficiency, reduces vessel berthing time, lowers fuel consumption, and aligns with sustainability goals in the maritime industry. Additionally, shorter berthing times allow ships to sail at lower speeds, further reducing emissions, fuel consumption, and costs. When vessels are scheduled to arrive “Just-In-Time”, they can avoid rushing to reach the port, enabling them to travel at more fuel-efficient speeds. This practice, known as “slow steaming”, significantly cuts down on fuel use and emissions. Lower fuel consumption also translates to cost savings for shipping companies. Moreover, improved scheduling and reduced idle times enhance operational productivity across the supply chain by ensuring smoother and more predictable logistics operations, minimizing delays, and optimizing resource utilization [25].

4.8. Renewable Energy Generation

Mega ports require significant energy, historically sourced from fossil fuels, to facilitate various activities such as cargo handling, storage (especially for refrigerated goods), internal transport, and lighting. Therefore, effective energy management is increasingly becoming a fundamental aspect of terminal operations. The electrification of cargo handling equipment, including cranes and loaders, as well as the port vehicle fleet, reduces reliance on fossil fuels, decreases emissions during port operations, lowers operational costs, and mitigates noise levels.

Many forward-thinking mega ports are adopting renewable energy generation as a key strategy to reduce GHG emissions. By using natural resources such as sunlight, wind, or water, as well as integrating renewable energy technologies, ports aim to power their operations and even contribute surplus energy back to the grid [42].

For example, mega ports are implementing on-site solar photovoltaic (PV) systems, strategically placing solar panels on terminal buildings, warehouses, and open areas to capture solar energy. These installations not only generate clean electricity but also reduce reliance on conventional grid power, resulting in a significant decrease in associated carbon emissions. Examples of mega ports using solar energy are the ports of Singapore [43], Los Angeles [44] and Hamburg [45]. Additionally, ports are utilizing wind energy by installing onshore and offshore wind turbines in windy coastal areas to convert wind energy into electricity for powering port operations [46]. Some examples of ports using wind energy are Rotterdam [47] and Antwerp [48].

Likewise, coastal ports are exploring tidal and wave energy as alternative renewable power sources. By strategically deploying devices to harness energy from tidal movements and ocean waves, ports tap into a constant and predictable renewable energy source, contributing to a diversified and resilient energy portfolio [49,50].

The diverse strategies proposed for enhancing the sustainability and efficiency in mega ports also offer a comprehensive roadmap for the shipping transportation industry. Emphasizing alternative fuels like LNG and other low-emission options addresses both immediate and long-term decarbonization goals, although careful consideration of market viability and investment risks is necessary. The integration of On-shore Power Supply (OPS) systems can significantly cut emissions while ships are docked, with public-private partnerships being vital to overcoming financial and standardization challenges. Environmentally differentiated port fees and Low Emission Zones (LEZ) provide economic incentives for adopting cleaner technologies, aligning financial interests with environmental goals. Implementing Environmental Management Systems (EMS) with clear GHG reduction targets ensures continuous improvement and regulatory compliance, enhancing port reputation and stakeholder trust. Smart port technologies and digitalization, including Just-In-Time operations, reduce idle times and fuel consumption, driving operational efficiencies and sustainability. Finally, generating renewable energy onsite furthers the transition away from fossil fuels, exemplified by successful implementations in ports worldwide.

Following the analysis of these seven CCM strategies, extensive research was undertaken to assess their implementation levels within the classified mega ports, as detailed in the subsequent section.

5. Results and Discussion on the Implementation of CCM Strategies among Mega Ports

To evaluate the degree of implementation of these seven strategies within the designated mega ports, comprehensive research was conducted. This research aimed to assess how effectively these strategies are being put into practice within these ports. By examining the current status of implementation, the research aims to identify areas of success and areas needing improvement, providing valuable insights for refining strategies and fostering continuous improvement in environmental performance.

The research findings for each mega port are presented in Table S1 of the Supplementary Materials. This table provides, for each port, the bibliography used, documenting the sources utilized in the research.

Table 3. Percentages of implementation of CCM strategies in mega ports *.

Strategy	YES (%)	NO (%)	Not Found (%)
Alternative fuel supply	63.3	6.7	30.0
On-shore Power Supply (OPS)	80.0	0.0	20.0
Env. differentiated port fees	36.6	56.7	6.7
Low Emission Zones (LEZ)	73.3	0.0	26.7
GHG reduction targets	100.0	0.0	0.0
Digitalization systems	66.7	0.0	33.3
Renewable energy generation	53.3	10.0	36.7

* These percentages are based on the results presented in Table S1 of the Supplementary Materials.

summarizes an overview of the outcomes, describing the percentage of acceptance (YES), non-acceptance (NO), or unconfirmed information (Not found) for each of the seven CCM strategies explained earlier.

The comprehensive research undertaken to evaluate the degree of implementation of CCM strategies within mega ports revealed an admirable level of commitment to reducing environmental impact in terms of GHG reduction. For instance, strategies such as setting GHG reduction targets and providing On-shore Power Supply (OPS) demonstrate widespread acceptance and successful integration across the assessed ports, with 100% and 80% verified implementation rates, respectively.

Also, the adoption of best practices extends to the establishment of Low Emission Zones (LEZ), with 73.3% of mega ports taking part in that initiative. In general, these results demonstrate the strong commitment within the port industry to reducing GHG emissions and adopting environmentally friendly practices.

While alternative fuels are being adopted by 63.3% of ports, a significant 30% are yet to confirm their implementation. The research demonstrates that the indicator Renewable energy generation has room for improvement, since there is a confirmed acceptance of 53.3%, but still a significant 36.7% remain pending confirmation.

Finally, despite the overall positive outlook, the research also highlights a specific area of concern: the existence of Environmental differentiated port fees, with only 36.6% of ports affirmatively confirming their implementation, while a significant 56.7% exhibit negative responses. Overcoming these challenges will necessitate collaborative efforts among port authorities, stakeholders, and policymakers to develop innovative solutions and incentivize sustainable practices.

The results of this study have significant implications for the maritime transportation sector. The high adoption rates of OPS and GHG reduction targets indicate that these strategies are viable and effective measures for ports aiming to reduce their environmental footprint. This success can serve as a model for other ports and stakeholders in the sector, highlighting the importance of regulatory frameworks and incentives that support the adoption of these strategies. However, the lower implementation rates of environmentally differentiated port fees suggest a need for further investigation into the barriers hindering their adoption. Addressing these barriers may involve developing standardized guidelines and providing financial incentives to encourage ports to adopt differentiated fee structures based on environmental performance.

For shipping transportation companies, prioritizing investments in technologies and practices that provide both environmental and economic benefits will be crucial. Collaboration across the industry, from energy providers to port authorities, can facilitate shared advancements and cost efficiencies. Additionally, staying ahead of regulatory trends and utilizing financial incentives for green practices will position companies competitively in an increasingly eco-conscious market.

As mentioned earlier, ports both contribute to, and are impacted by, climate change, necessitating adaptation to its consequences. Thus, after identifying what ports are doing to reduce emissions, the following section discusses strategies for adaptation.

6. Strategies for Climate Change Adaptation (CCA) in Ports

Ports are highly vulnerable to the impacts of climate change since they are literally on the front line in the face of rising sea levels [51]. The increased frequency and intensity of extreme weather events (e.g., extreme winds, high waves, storms, floods, or overflow) directly impact navigation, infrastructure, and port and transportation operations [13].

The concept of a port as resilient infrastructure refers to both its digital and physical components, capable of adapting to changes (e.g., in climate and weather conditions) and meeting demands (e.g., from maritime transport and land logistics), ensuring the long-term sustainability of a port and its operations while harmonizing with local communities, nature, and heritage [25].

According to the ESPO environmental review [24], while fewer than half of the ports (47%) encountered operational challenges linked to climate conditions, a substantial proportion (76%) integrated climate change adaptation considerations into the planning and execution of new infrastructure projects. This section provides a set of strategies used by ports for the CCA.

To address the vulnerability of ports to climate change-related effects, a proactive approach involves implementing adaptation and resilience measures, such as the ones identified in

Table 4. Proposed measures to mitigate climate change effects in ports [13,51,52,53,54,55].

Measure	Description
Risk assessments and vulnerability studies	Undertaking risk assessments and vulnerability studies is a key starting point since identifying potential climate stressors enables precise planning and targeted mitigation measures.
Port personnel training	Measures aimed at improving the skills, knowledge, and capabilities of port personnel to effectively address and respond to the evolving challenges associated with climate change. This also involves developing emergency response protocols and conducting regular drills.
Infrastructure upgrades	Investing in climate-resilient infrastructure, such as elevated quays, reinforced berths, and flood protection systems, helps ports to resist the impacts of sea level rise and storms.
Smart technologies	Incorporating smart technologies into port infrastructure ensures adaptability to changing climate conditions. For instance, automated flood barriers, sensor-equipped quays, and climate-controlled storage facilities contribute to a climate-responsive and resilient port environment.
Durable materials	Selecting materials that can resist environmental stressors, including saltwater corrosion and extreme weather, ensures the durability of port structures.
Innovative engineering solutions	Employing innovative engineering solutions, such as floating infrastructure and modular designs, accommodates changing sea levels and facilitates efficient adaptation.
Integrated coastal management	Collaborative efforts between port authorities, local governments, and environmental agencies are essential for implementing integrated coastal management strategies. These strategies consider the interrelation of port operations with broader coastal ecosystems.
Integration of nature-based solutions	Technological considerations should extend to the integration of nature-based solutions, influencing the inherent resilience of natural ecosystems. For instance, restoring mangrove ecosystems along coastal areas helps mitigate the impacts of storm surges and erosion since mangroves act as natural barriers, enhancing the resilience of port environments.
Real-time monitoring and early warning systems	Deploying early warning systems and real-time monitoring technologies helps ports track environmental conditions, anticipate potential risks, and respond to extreme weather events, enabling timely evacuation and risk mitigation.
Research and innovation	Continuous research and innovation are essential to staying ahead of evolving climate risks. Implementing cutting-edge technologies and staying informed about climate projections contribute to informed decision-making.

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The measures to enhance port resilience against climate change require a comprehensive approach, starting with risk assessments to identify potential stressors and inform on targeted mitigation strategies. Training port personnel ensures that they are equipped to handle climate challenges, while infrastructure upgrades and the use of durable materials strengthen physical defenses against impacts. Integrating smart technologies and innovative engineering solutions, like floating infrastructure, enhances adaptability. Collaborative, integrated coastal management and the inclusion of nature-based solutions, such as mangrove restoration, support ecosystem resilience. Real-time monitoring and early warning systems enable proactive responses to extreme weather, and ongoing research and innovation ensure ports stay ahead of evolving risks.

As noted above, the urgency of strengthening ports’ resilience and adaptation to projected future changes is paramount. Immediate action is necessary to safeguard the functionality of ports, protect coastal communities, and uphold the global supply chain. By embracing adaptive measures, investing in climate-resilient infrastructure, and fostering collaborative approaches, ports can navigate the complex challenges posed by climate change and emerge as robust and sustainable nodes in the maritime landscape.

7. Conclusions

Seaports serve as critical nodes in the global trade network, facilitating the movement of goods and fostering economic development. Mega ports, defined in this paper as those handling more than 5 million TEUs per year are characterized by extensive infrastructure and cargo handling capabilities and face intensified environmental challenges due to their scale and significance in global trade. The paper lists the top 30 container ports worldwide, which corresponds to the proposed definition of mega ports.

As mega ports emerge as pivotal hubs, balancing economic growth with environmental conservation becomes imperative. In particular, the paper identifies climate change as the top environmental priority of mega ports worldwide, as it is for the overall EU port sector. Achieving a sustainable balance between economic prosperity and environmental preservation is essential for the long-term resilience and viability of mega ports in the face of evolving global challenges, especially climate change.

The main existing strategies for CCM in ports are described in this paper, offering a comprehensive overview of their implementation across mega ports worldwide. The results demonstrate an overall commitment of mega ports to mitigate their environmental impact and align with global climate goals. For instance, there is widespread acceptance and successful integration of strategies along mega ports, such as setting GHG reduction targets (100%) and providing on-shore power supply (OPS) (80%). Despite the overall positive outlook, challenges remain, particularly in areas such as the implementation of environmentally differentiated port fees (36.6%) and renewable energy generation (53.3%).

This research contributes to the existing body of knowledge by providing insights into the implementation of CCM strategies in mega ports and the challenges they face. By identifying areas with lower implementation rates and emphasizing the need for collective action, the study offers practical recommendations for improving sustainability practices in the port industry. The findings can inform future research on climate change adaptation and resilience measures in port infrastructure and operations.

Despite the positive outcomes observed in the study, certain limitations should be acknowledged. The research focused primarily on the implementation of CCM strategies and may not have captured all aspects of climate change adaptation in mega ports. Additionally, the study’s reliance on publicly available data sources may have limited the depth of analysis in certain areas. Future research could explore the long-term effectiveness of CCM strategies, the integration of new technologies, and the socio-economic impacts of climate change initiatives in mega ports.

This study highlights the importance of collaborative efforts among port authorities, stakeholders, and policymakers in driving innovation and sustainability in port management practices. By advocating for supportive policies, regulations, and funding initiatives, policymakers can create an enabling environment for the effective implementation of CCM strategies in mega ports. Furthermore, engaging with local communities and fostering public awareness can enhance the social acceptance and impact of sustainability initiatives within port operations. By building on the research findings and addressing the identified limitations, stakeholders can work towards a more sustainable and climate-resilient future for mega ports worldwide.