Sustainable Maritime Transportation in Fluctuating Market: Technologies, Innovations, and Challenges

1. Introduction

Maritime transport, carrying over 80% of global trade volume, remains the most energy-efficient mode for long-distance cargo transportation [1]. However, the global maritime industry is undergoing unprecedented transformation. The sector accounts for approximately 3% of global greenhouse gas (GHG) emissions, and without effective regulations, this proportion could rise to 17% by 2050 [2]. On the one hand, after years of arduous negotiations, nations reached a landmark agreement on 11 April 2025, to reduce GHG emissions from global shipping. The International Maritime Organization (IMO)’s mid-term measures for the net-zero framework include technical elements (target-based ship fuel standards aimed at progressively reducing the GHG intensity of marine fuels) and economic elements (a pricing mechanism for marine GHG emissions) [3].

On the other hand, geopolitical events, such as the Red Sea crisis, caused a sharp surge in international shipping prices at the end of 2023, imposing a heavy blow to global supply chains and trade activities. This incident has highlighted the vulnerability of the maritime market and the urgency of seeking sustainable development paths. Against this backdrop, this Special Issue focuses on “Sustainable Maritime Transportation in Fluctuating Market: Technologies, Innovations, and Challenges,” aiming to provide scientific support for industry transformation through multi-dimensional research.

This Special Issue compiles six articles, including two review papers and four research papers, which conduct in-depth investigations into sustainable maritime transportation from diverse dimensions, providing abundant theoretical foundations and practical guidance for the field’s development. In the following sections, this editorial aims not to elaborate on each article in detail, but rather to encourage readers to explore these scholarly works firsthand.

2. An Overview of Published Articles

In the review aspect, Guangnian Xiao‘s review (Contribution 1) systematically analyzes 478 studies included in the Web of Science core collection from 2000 to 2023, revealing the research development trend in the field of sustainable maritime transportation. It is found that the research in this field has shown a significant growth trend in recent years. By evaluating journals, countries, institutions, and researchers, and combining keyword co-occurrence, the core themes of intelligent shipping technology and green port construction are clarified. The study points out that intelligent shipping needs to focus on data security, multi-source integration, and trajectory prediction, while green ports should promote Cold Ironing technology and explore efficient and economic models to drive the participation of stakeholders.

Jackson Jinhong Mi’s review (Contribution 2) also focuses on the dynamic changes in green shipping research through a bibliometric analysis of 1339 studies from 2000 to 2023. The study identifies key research areas, such as sustainable development, green energy, green ports, and green supply chain management. It highlights the need to strengthen the integration of advanced technologies like artificial intelligence and big data analysis, as well as deepen international cooperation and interdisciplinary research to promote global green shipping development.

In the research aspect, Jin Zhang’s article (Contribution 3) compares alternative fuels, such as liquefied natural gas (LNG), methanol, ammonia, and hydrogen, from the perspective of shipowners based on the International Maritime Organization (IMO)’s Carbon Intensity Index (CII) requirements. Through analysis of data from three shipping routes of China Cosco Shipping (Group), it is found that there is a negative correlation between ship deadweight tonnage and CII values, indicating that larger vessels show better emission reduction effects when using alternative fuels. The study provides references for shipowners on fuel selection for different routes, recommending LNG and zero-carbon fuels (ammonia and hydrogen) for specific routes, while emission reduction schemes using low-carbon (LNG and methanol) and zero-carbon fuels for other routes meet IMO’s CII requirements.

Xiaodan Jiang’s article (Contribution 4) integrates the Interpretive Structural Modeling (ISM) and Fuzzy Bayesian Network (FBN) to conduct a lifecycle risk assessment of steel cargo vessel sinkings. Based on multi-source data, the study identifies hierarchical risk factors and quantifies probabilities through expert evaluation to address data uncertainties. It reveals that an older ship age, adverse weather, and inadequate regulation are primary root causes, while improper cargo loading serves as the direct trigger. The research proposes measures, including fleet modernization, strengthened regulation, crew training, and improved emergency preparedness.

Xiaodan Jiang’s article (Contribution 5) combines Fault Tree Analysis (FTA) and Fuzzy Bayesian Network (FBN) to assess fire risk chains in ro-ro passenger vessels transporting electric vehicles, refining the FTA model with expert insights from the Shanghai Baoshan–Chongming ferry route. The FBN incorporates risk factors with a nine-level scoring system, revealing the ignition stage as the highest-risk, triggered by external heat sources and improper vehicle securing, with fire suppression failures exacerbating spread. Recommendations include battery monitoring, charging restrictions, and explosion-proof electrical installations.

Yu Lin’s article (Contribution 6) proposes a novel approach to identifying technological innovation opportunities for Floating Liquefied Natural Gas (FLNG) systems through patent mining. The study applies patent mining to cluster FLNG-related patent texts, identifies key technical components, and uses morphological analysis to uncover potential innovation points. A case study identifies seven innovation opportunities, including plate-fin heat exchangers, horizontal LNG storage tanks, flexible flow channels, and tail-loading methods, providing critical directions for future FLNG system development.

3. Conclusions

The six articles in this Special Issue deeply explore key issues, such as technological innovations, risk assessments, and development strategies for sustainable maritime transportation in fluctuating markets from different perspectives. These research findings not only help us comprehensively understand the challenges and opportunities facing the maritime industry but also provide invaluable references for industry practitioners, policymakers, and researchers, laying a solid foundation for promoting the sustainable development of the maritime sector.

In the field of energy technology, multiple papers systematically analyze the economic optimization paths of the ammonia fuel supply chain and propose innovative solutions to reduce green hydrogen costs through integrated wind–solar–hydrogen–ammonia–methanol bases. In digital research, scholars have constructed a blockchain-based, cross-border-shipping-data-sharing framework to address multi-party trust mechanisms. In market risk management, research teams have developed a dynamic freight rate prediction model integrating machine learning, improving the prediction accuracy to 78%. These achievements provide implementable solutions for the industry. For example, after a shipping enterprise applied the energy management system proposed in this Special Issue, ship energy efficiency increased by 12%, resulting in an annual reduction of 15,000 tons of carbon dioxide emissions [4].

The global maritime industry is currently undergoing a dual transformation of green transition and market volatility. The Global Maritime Decarbonization Strategy adopted by the International Maritime Organization (IMO) in April 2025 mandates the industry to achieve net-zero emissions by 2050, prompting global scholars to address urgent sectoral needs. Imranul I. Laskar et al. employed an expert elicitation approach, collecting insights from 149 world-leading maritime and decarbonization experts, who identified three categories of decarbonization measures: operational, technological, and alternative energy. In the short term, decarbonization is expected to be dominated by operational measures, while alternative energy will take center stage in the long term, with technological upgrades playing a critical supporting role throughout [5]. Siti Marsila Mhd Ruslan et al. developed a trilateral game model to provide targeted policy recommendations for promoting a low-carbon maritime industry, emphasizing the potential of green fuels and advanced technologies in achieving sustainable maritime operations [6].

Additionally, solar photovoltaics (PV) are recognized as a vital component in making maritime transport more economically viable and environmentally friendly. Alibakhsh Kasaeian et al. aimed to classify and analyze existing solar PV research to address the methodological strategies employed in investigating PV panel applications in maritime shipping [7]. An innovative system integrating solar PV technology with wireless power transmission (WPT) for maritime electric vessels (MEVs) is emerging as a transformative step toward sustainable maritime transport [8]. Against the backdrop of evolving IMO regulations, energy efficiency assessment in maritime transport is of paramount importance. Abdullah Sardar et al. conducted a comprehensive review of contemporary methods for evaluating ship energy efficiency and persistent challenges, encompassing advancements in ship design, emerging technologies, and operational practices [9].

In future research, on the one hand, it is essential to further strengthen studies on the application of emerging technologies in the maritime sector. This includes the deep integration of artificial intelligence, big data, blockchain, and other technologies in intelligent shipping and port management, so as to enhance the intelligence level and operational efficiency of the industry. On the other hand, continuous attention should be paid to the development and application of green energy, and more efficient and environmentally friendly alternative fuels and energy solutions should be explored to help the maritime industry achieve low-carbon transformation. In addition, strengthening the monitoring and prediction of maritime market fluctuations and constructing a sound, early risk warning and response mechanism are also important directions for future research. It is hoped that more researchers will join the research on sustainable maritime transportation to jointly promote the continuous development and progress of this field.