مقاله انگلیسی رایگان در مورد تحلیل سیستم های حمل و نقل دریایی – الزویر 2017

The fifth assessment report published by the Intergovernmental Panel on Climate Change indicates that international and coastal shipping accounts for nearly 10% of global transport sector CO2 emissions [1] or 2% of CO2 emissions from fuel combustion [2,3]. According to the third International Maritime Organization (IMO) study on carbon emissions [4], maritime transport emits around 1000 million tonnes of CO2 annually and is responsible for about 2.5% of global CO2 emissions. Depending on future economic and energy developments, maritime transport carbon emissions are predicted to increase between 50% and 250% by 2050. A combination of operational and technological measures can help reduce ship’s energy and hence carbon emissions by up to 75% [5]. Among the list of ten most effective measures in reducing energy intensity, and hence carbon emissions, speed reduction has ranked top of the list [6]. Studies in the literature generally employs life cycle analysis (LCA) or other analytical methods to explore the decarbonization potential of maritime transport or shipping. Existing studies on shipping tend to focus either exclusively on just the marine vessel or to provide a system view of the maritime freight over the vessel’s lifetime. Those focusing on the marine vessel are further divided into studies on the complete life cycle of the vessel from manufacturing to end-of-life scrapping [7], shipbuilding [8], vessel operation [9,10], docking at ports [11], and ship scrapping and recycling [12–16]. These studies can provide insights on specific stages of a larger maritime transport system, but they are unable to provide a holistic understanding of the life cycle system of shipping. Those examining the larger system of maritime freight are further divided by focus areas and methods. Some studies focus on examining technical and operational measures for reducing carbon emissions such as [17–20]. Other studies focus on the development and/or use of LCA software to study the environmental impacts of shipping such as [21,22]. Relatedly, some studies tend to focus on the issues related to LCA methods, such as adaptation of LCA methodology to suit maritime transport, system boundaries selection, and life cycle inventories (LCIs) [23]. Although the existing literature has somewhat covered most aspects of LCA studies on shipping, the number of LCA studies on maritime transport is far smaller as compared to the number of LCA studies on energy systems. That has led to even smaller number of LCA studies addressing the critical issues related to system and boundary formulations to ensure consistent and unbiased results. The scarce number of LCA studies is likely caused by the fact that all stages of shipping have already been studied in quite some detail. Furthermore, it is conceptually intuitive and has been demonstrated by existing studies that the shipping stage accounts for the majority of the life cycle carbon emissions. Since fuel typically accounts for around 40% of the total cost in shipping, freight business operators have a strong incentive to reduce transport speed [24]. However, the metrics used for evaluating the decarbonizing potential of speed reduction have not been thoroughly evaluated from a life cycle standpoint. Due to the lack of studies focusing on system, boundary and input-output definitions, many other similar issues as “speed reduction” require further independent assessment using alternative LCA methods. More importantly, the scarce number of LCA studies on shipping also highlights the need for further developments in LCA methodologies for analysis of systems providing services.