Main ecological problems in sea transport. General characterization of environmental problems

Avoiding food loss and waste may counteract the increasing food demand and reduce greenhouse gas (GHG) emissions from the agricultural sector. This is crucial because of limited options available to increase food production. In the year 2010, food availability was 20% higher than was required on a global scale. Thus, a more sustainable food production and adjusted consumption would have positive environmental effects. This study provides a systematic approach to estimate consumer level food waste on a country scale and globally, based on food availability and requirements. The food requirement estimation considers demographic development, body weights, and physical activity levels. Surplus between food availability and requirements of a given country is considered as food waste. The global food requirement changed from 2,300 kcal/cap/day to 2,400 kcal/cap/day during the last 50 years, while food surplus grew from 310 kcal/cap/day to 510 kcal/cap/day. Similarly, GHG emissions related to the food surplus increased from 130 Mt CO2eq/yr to 530 Mt CO2eq/yr, an increase of more than 300%. Moreover, the global food surplus may increase up to 850 kcal/cap/day, while the total food requirement will increase only by 2%-20% by 2050. Consequently, GHG emissions associated with the food waste may also increase tremendously to 1.9-2.5 Gt CO2eq/yr.

Composting is an environmentally friendly method of managing organic waste, but it has a substantial downside in the form of greenhouse gases (GHGs) emissions such as: carbon monoxide (CO), nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2). Organic waste makes up a total of 67% of total waste released daily in Kenya, while cow dung is a readily available resource. The aim of this study was to assess the dynamics of the emissions of GHGs specifically CH4 and CO2 from organic waste in an in-vessel aerated composting system. The feedstock was a mixture of cow dung and food waste materials and was composted for a total of sixty days. Five treatments: T0 = 100% cow dung (CD), T1 = 75% CD + 25% food waste (FW), T2 = 50% CD + 50% FW, T3 = 25% CD + 75% FW and T4 = 100% FW + 0% CD were set up in a complete randomized design (CRD) layout. GHGs emissions were collected using a plastic gas pack from each treatment weekly from the 2nd week to the 8th week of the composting process and measured using gas chromatography methods. The GHGs emission gradually reduced as composting progressed. The average carbon dioxide equivalent (CO2e) for the entire period from treatments T0, T1 and T2 were 1.282, 4.322 and 2.596 kgCO2e/ton respectively; these were higher compared to, T3: 0.380 and T4: 0.534 kgCO2e/ton. ANOVA analysis indicated that there were significant differences in GHGs emission between treatments, p<0.05. Tukey’s HSD affirmed that treatments T0, T1 and T2 were significantly different from each other and from treatments T3 and T4. Treatments T3 and T4 were not significantly different from each other. The C:N ratio at end of the decomposition process ranged between 26:9 and 22:9, which is higher compared to the recommended 15:1 for agricultural production. Treatment T3 emitted the least GHGs to the environment, thus, a combination ratio of 25% CD + 75% FW is recommended which is within EPA recommended range of 0.1 to 0.5 kgCO2e/ton of composted wet waste.

Climate variability and food waste treatment: Analysis for bioenergy sustainability

_ Maritime transport accounts for around 3% of global anthropogenic greenhouse gas (GHG) emissions (Well-to-Wake). These GHG emissions must be reduced by at least 50% in absolute values by 2050 to contribute to the ambitions of the Paris Agreement signed in 2015. Switching to zero-carbon fuels made from renewable sources (hydro, wind, or solar) is seen by many as the most promising option to deliver the desired GHG reductions. However, renewable energy is a scarce resource that gives a much larger GHG reduction spent within other sectors. This study explores how to reach the IMO 2050 GHG targets exclusively through energy efficiency measures. The results indicate that by combining wind-assisted ship propulsion (WASP) with a slender hull form, fuel consumption and GHG emissions can be reduced by 30–35%, at a negative abatement cost for speeds exceeding 8 knots. Where the cost saving increases with the speed because at higher speeds, the fuel accounts for a higher share of the total cost, which implies that the cost saving goes from zero at 8 knots, to 5% reduction at 11 knots average speed to 14% reduction of total cost with 15 knots average speed. In comparison, GHG reductions through zero-carbon fuels will increase transport costs by 50–200%. Introduction From the first days of our civilization, sea transport has enabled regional and global trades. Today, sea transport accounts for 80% of the global trade measured in ton-miles (UNCTAD 2021) and 3% of greenhouse gas (GHG) emissions measured Well-to-Wake (Lindstad et al. 2021). More than 40% of this sea trade is performed by dry bulkers, making them the real workhorses of the sea. Even though sea transport is energy efficient compared to other transport modes, all sectors need to reduce their GHG emissions by at least 50% in absolute values by 2050 to contribute to the Paris Agreement (UNFCCC 2015). According to Bouman et al. (2017), the desired energy and GHG reductions can be achieved through: Design and other technical improvements of ships; Operational improvements; Fuels with zero or low GHG footprints; or a combination of these.

Assessing the effect of the aquaculture industry, renewable energy, blue R&D, and maritime transport on GHG emissions in Ireland and Norway

The shipping industry, particularly containerized cargo transport, plays a vital role in global trade, but it is also a significant contributor to greenhouse gas (GHG) emissions. With increasing pressure to reduce carbon footprints and achieve sustainability targets, the U.S. maritime sector is seeking innovative solutions to lower its environmental impact. Optimizing fuel usage, improving operational efficiencies, and adopting alternative fuels are essential strategies to decarbonize maritime transport. However, these complex challenges require sophisticated tools for simulating and analyzing different fuel and routing strategies. The US Department of Energy, Advanced Research Projects Agency - Energy funded a project to focuses on developing an advanced decision-support tool to optimize fuel deployment and intermodal freight routing for domestic container shipping in the U.S., aiming to reduce GHG emissions and improve operational efficiency. This project aims to develop an advanced decision-support tool that leverages modeling and simulation to optimize fuel deployment and intermodal freight route planning for domestic container shipping across U.S. maritime corridors. The tool's central goal is to simulate and assess vessel operations, considering both environmental impact and operational efficiency, with a focus on reducing greenhouse gas (GHG) emissions through intelligent fuel selection and optimized routing strategies. The project will integrate traditional oil-based vessel technologies with alternative/Low emission fuels, specifically methanol and ammonia/hydrogen, to evaluate these technologies' potential for decarbonizing the maritime sector. The modeling scope encompasses several critical aspects of container shipping operations: it will simulate container and containership movements across key U.S. maritime routes, including both open sea and inland waterways (e.g., from Los Angeles to Seattle). The simulation will track vessel movements in real-time, incorporating key operational events such as departures, arrivals, refueling, and port dwell times. The model will identify and analyze a range of domestic vessel types, initially using baseline information on oil-powered ships and comparing them with vessels using alternative fuels. This comparison will allow for an evaluation of energy consumption, operational efficiency, and emissions reductions achievable with different fuel mixes. A key feature of the model will be its ability to estimate energy consumption and emissions under various operating conditions. The model will take into account a broad range of factors, such as cargo weight, vessel type, sea currents, wind conditions, and route specifics to generate highly accurate simulations of energy usage and emissions per voyage. By using advanced modeling techniques, the tool will create a detailed reduced-order model, informed by real-world operational data, which can be generalized and applied across various domestic corridors and routes. This will allow for scalable insights and flexible application, making the tool useful for a variety of real-world shipping scenarios. The role of advanced modeling and simulation is crucial in enabling the detailed analysis required to understand complex maritime operations. The model will simulate dynamic operational events (such as docking, refueling, or delays) and intermodal transport interactions, optimizing freight routing across different transport modes (water, rail, and truck) to minimize overall GHG emissions. This approach allows for a comprehensive, whole-system analysis that considers both direct emissions from maritime transport and indirect emissions from associated modes of transport. Moreover, the model will interface with external systems simulators, to incorporate data on port-to-port container origin-destination (OD) flows, port storage, and dwell times. These external inputs will be integrated into the model to ensure that port operations, cargo handling, and intermodal logistics are optimized for efficiency and emissions reduction. This integration of multiple data sources and transport modes will enable the simulation to reflect the complexities of the real-world intermodal network, offering insights on how best to allocate freight across water, rail, and road to achieve the lowest possible emissions. Through the use of advanced modeling and simulation, the tool will generate actionable insights to guide policy makers, shipping operators, and environmental regulators in their efforts to decarbonize U.S. domestic shipping. The ability to simulate and compare different fuel types, vessel configurations, and routing strategies will help stakeholders make data-driven decisions that balance economic feasibility with environmental sustainability. Ultimately, the tool will help identify pathways to reduce the carbon footprint of domestic container shipping, offering a roadmap for adopting cleaner, more efficient maritime transport practices while improving operational performance. By enabling the detailed modeling and simulation of complex maritime systems, this project will contribute significantly to the development of sustainable maritime transport policies and technologies, providing a critical resource for advancing the transition to a low-carbon economy in the U.S. shipping sector.

Waste generation nowadays is rising in the world and it seems hard to prevent it. Municipal Solid Waste (MSW) has been a major problem worldwide, especially in the fast growing cities and towns in the developing countries. This study aims to estimate the cost benefit and mitigation of greenhouse gases (GHGs) by converting the on-campus food and green waste generated in Universiti Teknologi of Malaysia (UTM) campus to compost. This study calculated the costing which includes the transportation, operating and equipment costs if green and food waste were converted into compost. The analyses were made with the basis of the pilot scale operation in Phase I operation. Extrapolation was made to project the further four phases of composting with higher amount of waste to estimate the potential profit. The results obtained from this study indicated that composting has the potential to generate a significant profit of Malaysia Ringgit (MYR)1.6 M/y based on 2,700 t/y of food and green waste composted. At the same time, the total solid waste supposedly to be sent to the landfill can be reduced by at least 47 %. Moreover, this study revealed that the composting process is able to reduce the GHGs emission rate by 90 %, i.e. the GHGs produced by the composting process is shown to be only 10 % of the total GHGs produced by landfill dumping given the same amount of solid waste to be disposed at the landfill site.

The effects of recycling loops in food waste management in Japan: Based on the environmental and economic evaluation of food recycling

Application of AHP and VIKOR methods under interval type 2 fuzzy environment in maritime transportation

In this study, it is substantiated that the process of globalization leads to the world economy acquiring the characteristics of a complex multi-level system, which makes it possible to use the properties of systems as tools for researching the effects of negative factors and threats to the development of the world economy and maritime transport as subsystems of the world economy. It was established that not only the rise in prices on the world's leading stock exchanges Using the systems theory methods but also the freight cost of dry cargo ships is a significant influencing factor on food prices for the whole world. It has also been established that since the cargo traffic of food with a substantial level of processing to countries where, due to the level of development of their economy, there are mostly no opportunities for processing products, this affects the increase in the cargo traffic of container transport in global sea transportation. The synergistic nature of the impact of negative factors on the worldwide economy and the maritime transport industry has been outlined. It is singled out that the synergistic negative effect led to a chain reaction to the change of international sea transport routes. The assessment of the effectiveness of management actions of the industry management on external challenges and threats was carried out. It is pointed out that the direction of the global maritime transport industry needs to dynamically adjust the operation of logistics networks to respond effectively to the growing needs of the world market. It is also indicated that the need for more efficiency and capacity of the port infrastructure still predominantly affects container transportation due to the growing demand for the volume of cargo transportation. It is emphasized that the established definition of the world transport system needs to be sufficiently corrected. The conducted research found that the world transport system, under the influence of the globalization of the world market and the internationalization of the cargo transportation process, acquires transnational features and becomes a global structure, working increasingly in the interests of the world market. Keywords: globalization, internationalization, maritime transport, crises, risks, threats, efficiency of industry management.

The management and prevention of food losses and waste in low- and middle-income countries: A mini-review in the Africa region

Environmental impact of sewage sludge co-digestion with food waste and fat-oil-grease: Integrating plant-wide modeling with life cycle assessment approach

Waste-to-Renewable Natural Gas (RNG) offers a promising solution to alleviating waste management challenges by converting waste into renewable fuels. This process can significantly reduce greenhouse gas (GHG) emissions, as demonstrated through a comprehensive life cycle analysis. Biogas upgrading is essential to enhance the methane concentration, though it could be energy-intensive and susceptible to methane slippage. Four commonly adopted biogas upgrading technologies, including pressure swing adsorption, membrane separation, chemical absorption, and water scrubbing, are considered. Our study evaluates the life cycle GHG emissions of RNG production from major sources of waste in the U.S. including wastewater sludge, food waste, landfill gas, dairy cow manure, and swine manure. Meta-analysis was conducted to assess methane slippage and energy consumption of biogas upgrading and associated GHG emissions, while accounting for potential avoided emissions from conventional waste management, which vary widely (ranging from −481.0 to 101.8 g CO2-eq/MJ). Under default upstream assumptions, representative carbon intensity of RNG varies from about −125 g of CO2-eq/MJ (dairy cow manure) to about 41 g of CO2-eq/MJ (wastewater sludge). We also explored RNG applications in producing hydrogen, ammonia, and compressed/liquefied forms. These findings highlight the potential of RNG and RNG-derived fuels to reduce GHG emissions and bolster the U.S. energy supply.

With the prosperity and development of the Maritime Silk Road, China's maritime industry has reached a new height. While the maritime transport industry has been vigorously developed, it has also brought great challenges to safe navigation. To realize intelligent navigation, effectively prevent maritime collision accidents, and improve navigation safety, a structural model of intelligent navigation obstacle avoidance platform based on Internet of Things technology is first proposed. Then the research combines the analytic hierarchy process, artificial neural network and BP neural network algorithm, and introduces environmental factors to design an optimized intelligent navigation obstacle avoidance algorithm, so that the algorithm can make real-time intelligent adjustment strategies according to the changes of the actual environment. Finally, the collision risk at the location of the research ship is judged, and the priority list of obstacle avoidance is constructed by the risk value between different ships and the research ship, providing reference for the pilot. The research results show that the prediction accuracy of I-INOA algorithm is 97.83%. In the two obstacle avoidance experiments, the decision-making efficiency of the four ships based on I-IONA algorithm is the highest, which is 1. In practical application, the priority list of obstacle avoidance is P, O and S2. In conclusion, I-INOA algorithm has better performance and practicability, enabling the research ship to respond more intelligently and quickly.

The shipping industry urgently requires new ways to mitigate its greenhouse gas emissions. To achieve this, literature has identified the necessity for integrating technical and operational measures, which require organization through management strategies. In recent years, Just-in-time (JIT) has been discussed as a potential solution to cut fuel consumption by slowing down ships and having them arrive just-in-time at ports, instead of waiting at anchor for berth. Analyzing this option requires defining the unit of change, a task that can benefit from institutional rhetoric to provide structure, highlight institutionalized myths, and identify potential avenues for implementing change. This study takes an empirical approach, incorporating extensive interviews and field observations. Through this, it becomes possible to identify four arguments against the use of JIT and two counterarguments in its favor. The concepts of trust and distrust become useful constructs in this argumentation concerning control and external circumstances. This study contributes to the advancement of sustainable practices in the maritime shipping industry by shedding light on JIT as a widely discussed fuel-efficiency strategy that demands further investigation.