Search Results (33)

The liner shipping industry is thriving in the low-carbon transition, and optimizing operational strategies for liquefied natural gas (LNG) dual-fuel ships has become a research hotspot. This research examines the impacts of the carbon tax, emission control area (ECA) policies, fuel price discounts and methane slip rate on fuel management strategies. Firstly, to reduce liner operating costs and adhere to ECA policies, this study develops a basic optimization model. Further, the model is extended to take into account the impact of fuel price discounts. Secondly, by linearizing multiple nonlinear terms, the operational strategies are obtained. Thirdly, taking a real vessel sailing between the Far East and Northwest Europe as a case study, this study identifies the ports for LNG and very low sulfur fuel oil (VLSFO) bunkering, determines the bunkering amounts and calculates the planned speeds. Furthermore, sensitivity analyses are conducted on fuel price difference, carbon tax rate and methane slip rate. Results show that fuel price difference, carbon tax rate, methane slip rate and fuel price discount exert a significant impact on ship operational decisions. To ensure the effectiveness of maritime decarbonization regulations, authorities should monitor ship engines with high methane slip rates. This study offers important references for shipping enterprises to meet ship emission policies and simultaneously cut operational costs. Full article

Climate change has exacerbated the need for transitional shifts within high-impact sectors, notably maritime transport, which facilitates nearly 90% of global trade. In response, the International Maritime Organization (IMO) has implemented stricter environmental regulations under MARPOL Annex VI, which includes, among other things, the designation of Emission Control Areas (ECAs) and Particularly Sensitive Sea Areas (PSSAs). These regulatory instruments have prompted the uptake of new technologies, such as scrubbers, LNG propulsion, and low-sulfur fuels to mitigate emissions in these zones. However, emerging evidence has raised environmental concerns about these solutions which may offset their intended climate benefits. This study investigates the hypothesis that ECAs and PSSAs act as catalysts for maritime environmental advancements through a systematic mapping of 76 peer-reviewed articles. Drawing on data from Scopus and Web of Science, the study analyzes trends in technological advances, publication timelines, geographic research distribution, and the increasing role of decision-support tools for regulatory compliance. Findings show increased academic outputs particularly in China, North America, and Europe, and suggest that achieving effective emissions reduction requires globally harmonized policies, bridging research practice gaps, and targeted financial support to ensure sustainable outcomes throughout the sector. The study suggests that for ECAs and PSSAs to deliver truly sustainable outcomes, global regulation must be supported by empirical performance assessments, environmental safeguards for compliance technologies, and targeted support for developing maritime regions. Full article

Ship emissions represent a significant challenge to environmental sustainability and public health. The widely implemented Emission Control Area (ECA) policy aims to mitigate these emissions; however, existing research often overlooks inland and underdeveloped coastal regions. This study evaluates the impact of China’s Domestic Emissions Control Area (DECA) policy on SO₂ and PM_2.5 air concentrations in three inland cities along the Yangtze River and three underdeveloped coastal cities since its inception in 2018. Employing regression discontinuity (RD) and difference-in-differences (DID) methodologies, this analysis seeks to provide a comprehensive understanding of the DECA’s effects on air quality and its implications for sustainability in these areas. This study revealed that DECA policies resulted in significant improvements in both SO₂ and PM_2.5 concentrations, contributing directly to environmental sustainability and potential public health co-benefits in inland urban areas as well as underdeveloped coastal cities. In the case of inland cities, the daily average concentrations of SO₂ in Yichang and Taicang decreased by 5.3% and 18.9%, respectively, while the average daily concentrations of PM_2.5 saw reductions of 21.9% and 13.9%, respectively. Among the underdeveloped coastal cities, the average daily concentration of SO₂ in Haikou, Danzhou, and Sanya declined by 1.6%, 20.2%, and 21.2%, respectively; additionally, the average daily concentrations of PM_2.5 in Danzhou and Sanya decreased by 13.8% and 9.5%, respectively. The effectiveness of this policy exhibited geographical variation within inland cities and was influenced by urban development indicators in coastal areas. These findings not only underscore the success of the DECA policy in enhancing air quality but also highlight its role in advancing sustainable development goals. They provide essential evidence for formulating effective and sustainable emissions control strategies applicable to similar inland regions and underdeveloped coastal settings worldwide. Full article

The expansion of sugarcane production has led to increased nitrogen (N) fertilizer use, contributing to greenhouse gas emissions and environmental concerns. Optimizing N management is crucial for sustainable agriculture. Soil apparent electrical conductivity (EC_a) has emerged as a valuable tool for mapping soil spatial variability and yield potential, potentially guiding more efficient fertilization strategies. This study evaluated sugarcane yield and N responsiveness across two areas with distinct soil types over two crop cycles. Experimental plots were classified into high (HC) and low (LC) EC_a zones, with randomized blocks receiving four N rates and a control. Higher yields were generally observed in HC plots, except for the second ratoon in area 2 (Ultisol). HC plots required lower N rates to achieve maximum yield compared to LC plots. In area 1 (higher clay content), optimal N rates were lower than in area 2 (lower clay content), indicating that yield potential is linked to soil attributes and spatial variability. Although EC_a alone may not define precise N doses, it effectively identifies zones with different yield potentials, supporting site-specific N management. These findings highlight the potential of EC_a to improve nitrogen use efficiency and contribute to more sustainable sugarcane production. Full article

Maritime regulators are closely monitoring the progression of green shipping, and liner companies are seeking strategies to meet tough ship emission rules. To reduce the operating cost while conforming to the increasingly strict environmental regulations, the study first constructs a mixed-integer nonlinear optimization model. Subsequently, the nonlinear parts in the objective function and constraints are transformed into linear forms. Thereafter, the model is applied to the Asia–Europe route of the CMA CGM Shipping Company to find the planned speeds and bunkering strategies for container liners sailing in expanded emission control areas (ECAs) that will be implemented in the future. Finally, a sensitivity analysis is performed to examine the influence of bunker tank capacity and fuel price difference on the operating cost, carbon dioxide emission, bunkering strategy and planned sailing speed. The study contributes to determining the optimal tank capacity and developing bunkering strategies at different fuel price differences. With stricter policies, operators must strategically choose refueling ports, adjust refueling amounts, and optimize planned sailing speeds based on ship and route data. The proposed approach provides a solution to the contradiction between compliance with environmental regulations and cost-effectiveness of shipping companies and is of great significance for promoting the sustainable development of the waterway transportation industry. Full article

The maritime shipping sector needs to transition towards a low- or zero-emission future to align with the 1.5 °C temperature goal and the recently adopted and revised greenhouse gas (GHG) strategy at the International Maritime Organization (IMO). A significant research gap exists in understanding how socio-economic and socio-political processes can lead to the adoption of alternative marine fuels that will be essential in meeting the aforementioned goals. The aim of this paper is to use a case study of an existing transition to understand how diffusion takes place, specifically how the adoption of liquified natural gas (LNG) in Norway has unfolded and what lessons can be learnt from this process. To answer this question, a combination of semi-structured interviews with key maritime stakeholders and documentary evidence was collected covering the period from 1985 to 2015. The collected data were analysed through a content analysis approach applying the multilevel perspective (MLP) as a heuristic. The qualitative results paint an interesting picture of the changing attitudes towards LNG as a marine fuel in Norway. In the early years, the adoption of LNG was primarily driven by air pollution and political considerations of using Norwegian natural gas, which over time, evolved into a more focused maritime paradigm painted through the lens of the Norwegian maritime industry under wider regulatory developments such as emission control areas (ECAs). By the 2010s, these drivers were superseded by GHG considerations such as methane slip concerns and a less favourable natural gas market leading to a slowdown of LNG adoption. These findings provide valuable insights for understanding future adoption dynamics of alternative zero-emission fuels, particularly in relation to the role of strong technology champions, institutional modification requirements, and starting conditions for a transition. Full article

In the post-pandemic era, the complexity of the international shipping situation, such as environmental policies, port congestion, and local conflicts, poses challenges to the stability of liner shipping, which requires strict adherence to schedules. This paper addressed the issue of schedule recovery for liner ships operating under Emission Control Areas (ECAs) regulations in the face of disruptive events. It established a bi-objective nonlinear programming model based on recovery costs and delay severity and designed a bi-objective particle swarm optimization algorithm based on two traversal of voyage leg path selection and port skipping decisions of feasible solutions to solve it. The effectiveness of the algorithm was validated through a case study of a 6000 TEU liner ship, summarizing the correlation laws of operational decisions such as port skipping, voyage leg path selection, and speed adjustment, and proposing the optimal recovery strategy for liner ships under long-term ECA constraints while ensuring short-term schedule resilience. The findings demonstrate that, in compliance with emission restrictions, ships operating within ECA are required to slow down to mitigate costs. In contrast, ships operating outside of ECA regions must accelerate their pace to adhere to established shipping schedules. Full article

The implementation effectiveness of ship emission control area (ECA) policies can be effectively evaluated using econometric models. However, existing studies mainly focus on changes in SO₂ concentrations in the air. In order to comprehensively assess the impact of ECA policies on air quality, this study takes Ningbo Port in China as an example and uses a regression discontinuity (RD) model to analyze the influence of ship emissions around the wharf on concentrations of SO₂, NO₂, and particulate matter (PM) in the air. The results indicate that individual ships’ activities within the monitoring area (within 300 m) make a relatively small contribution to the concentration of SO₂ in the air and do not form a significant breakpoint. However, there is a noticeable breakpoint in the concentration of NO₂ around the monitoring point as the ship approaches. At the same time, the variation range of PM_2.5 is significantly greater than that of PM₁₀, which aligns with the characteristics of PM emitted by ships. The experimental results have passed three robustness tests, demonstrating that the current policy on ship ECAs has a positive limiting effect on SO₂ emissions and, to some extent, reduces PM emissions. However, further reductions in ship emissions may require more restrictions in nitrogen oxide emissions. Full article

Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL Convention), adopted in October 2008, was dedicated to addressing environmental issues caused by ships, especially in ports, inland waterways, and some sea areas with concentrated routes and high navigational density. This study utilizes a regional-level ship dataset to assess the influences of emission-control areas (ECAs) on the ecological shipbuilding industry by fitting the policy utility through the synthetic control method and testing robustness via the difference-in-differences method. The outcomes of this study show that the cumulative new orders for eco-designed ships in China, The Netherlands, Republic of Korea, the UK, and the USA increased by 3401, 81, 234, 549, and −1435, respectively, after the implementation of ECAs. Compared to the implementation of ECAs, the increases were about 32%, 20%, 41%, 66%, and −83%, respectively. Full article

Emissions of maritime transport have been a critical research topic with the substantial growth in the global shipping industry, encompassing both the expansion of the world fleet and the increased distances it has been covering recently. The International Maritime Organization (IMO) has enforced some regulations to mitigate ship Greenhouse Gas (GHG) emissions, which affect vessels’ operational practice, and further affect service reliability. In this paper, some compliance methods (two-speed strategy, fuel switching, and LNG) against Emission Control Areas (ECAs) at the operational level are examined regarding if and how they impact the liner shipping schedule and service reliability; meanwhile, uncertain weather conditions and port times, as the main uncertain factors, are also involved. Then, a bi-objective fuzzy programming model is formulated and solved by the augmented $\epsilon$-constraint approach, which generates a set of Pareto solutions by balancing the economic and environmental sustainability. Some findings can be concluded through the experimental results, including that, firstly, to meet uncertain weather conditions at sea requires strong robustness; secondly, ECA regulations can negatively affect the liner shipping service level; moreover, slow steaming is an immediate and effective measure to reduce GHG emissions; and, furthermore, ship routing choice could have a significant influence on ship emissions and service reliability. Full article

Shipping emissions contribute significantly to air pollution at the local and global scales and will do so even more in the future because global maritime transport volumes are projected to increase. The Mediterranean Sea contains the major routes for short sea shipping within Europe and between Europe and East Asia. For this reason, concern about maritime emissions from Mediterranean harbours has been increasing on the EU and IMO (International Maritime Organization, London, UK) agenda, also supporting the implementation of a potential Mediterranean Emission Control Area (MedECA). Many studies are concerned with the impact of ship emissions in port cities. Studies of the contributions of ship emissions to air quality at the local scale include several monitoring and modelling techniques. This article presents a detailed review of the contributions of ship emissions of NO₂, SO₂, PM₁₀, and PM_2.5 on air quality in the main ports in the Mediterranean area. The review extracts and summarises information from published research. The results show a certain variability that suggests the necessity of harmonisation among methods and input data in order to compare results. The analysis illustrates the effects of this pollution source on air quality in urban areas, which could be useful for implementing effective mitigation strategies. Full article

In this study, nondominated sorting genetic algorithm II (NSGA-II) was used to minimize the cost and carbon emissions of a liquefied natural gas (LNG) dual-fuel ship for a given route. This study considered the regulations of emission control areas (ECA) and the European Union (EU) Emissions Trading System (ETS) to determine the optimal speed and LNG/oil ratio for the ship. NSGA-II used the arrival time at each port and the LNG usage ratio for each voyage leg as its genes. The time window for arrival, the fuel cost, and potential EU carbon emission regulations were used to estimate the cost of the considered voyage. Moreover, fuel consumption was determined using historical data that were divided by period, machinery, and voyage leg. The results indicated that the optimal speed and fuel ratio could be determined under any given fuel and carbon price profile by using NSGA-II. Finally, the effects of regulations and carbon price differences on the optimal speed and fuel ratio were investigated. The cost minimization solution was susceptible to being affected by the regulations of ECAs and the EU ETS. The speed profile of the cost minimization solution was found to have a tendency to travel at faster-than-average speeds outside ECAs and non-EU regions, and travel slower in ECAs and EU regions. Meanwhile, the selection of fuel type showed that 100% traditional fuel oil in all regions, but with sufficiently high EU carbon permit cost, tends to use 100% LNG in EU regions. Full article

Global concerns regarding air quality have over the past decade led to the introduction of regulations by the International Maritime Organisation curbing the emissions of sulphur and nitrogen oxides (SO_x, NO_x). These limits were implemented initially in so-called “emission control areas”, defined where the density of shipping activity combines with large coastal population centres such as northwest Europe or eastern USA. However, any legislation requires a scientifically robust and rigorous monitoring program to ensure compliance and prove attribution to an individual vessel. We argue the case for adherence to the mantra “faster, better, cheaper”, where widespread adoption of independent low-cost solutions of onboard, in-stack sensors, combined with existing, globally ubiquitous satellite-based “automatic identification system” (AIS) data telemetry, provides an excellent solution to the affordable compliance and attribution conundrum for shipping companies and enforcement agencies alike. We present data from three field-campaigns which have significantly advanced the concept of onboard real-time monitoring of atmospheric ship emissions. Full article

Various port cities and authorities have established emission control areas (ECAs) to constrain ships’ fuel usage in a specified offshore geographical range. However, these ECA policies involve high costs and have low monitoring and regulation enforcement efficiencies. In this study, a meeting model was used to investigate the drone-scheduling problem by considering the simultaneous movements of drones and ships. Set-covering integer linear programs were developed to formulate the assignments of drones to ships, and a model and solution algorithm were devised to determine the moving times and meeting positions for particular drones and ships. The proposed models and algorithms were employed and verified in experiments. The flying times for the datasets with three drone base stations were shorter than those with two. More drones resulted in shorter flying distances. The use of the meeting model enabled the acquirement of shorter flying times and distances than when it was not used. The datasets with more ships had longer flying times and distances, with almost linear relationships. The sensitivity of the effect of varying 5% of the ships’ speeds on the flying time metrics was less than 1%, affecting the flying distance by about 4–5%. Accelerating the drones was more effective towards optimizing the drones’ flying distances than times. Numerical studies showed that the consideration of simultaneous movements in the model allowed for a reduction in the drones’ flying distances and increased efficiency. Based on the modeling and experimental studies, managerial implications and possible extensions are discussed. Full article

In recent years, liner-shipping companies have faced a traditional trade-off between cost and emission (CO₂ and SO_X) reduction. This study considers this element to construct a liner-shipping network design model which includes a package-cargo transport plan, route allocation, and route design. The objective is to maximize profit by selecting the ports to be visited, the sequence of port visits, the cargo flows between ports, and the number/operating speeds of vessels. In addition, emission control areas (ECAs) exist in the liner network. With reference to the idea of the column generation algorithm, this study proposed a heuristic algorithm based on empirical data through a real case calculation and selected the optimal scheme, which is in-line with both economic and environmental benefits. The results show that the model and optimization method are feasible and provide an effective solution for the liner network design of shipping companies, while also considering environmental factors. In addition, the effects of the number of ECAs, inter-port origin-destination (OD) demand, freight rate, fuel price, and carbon prices on the design of transport networks are discussed to provide a reference for the operation of shipping companies and government decision-making. Full article