Impact of emission allocation in maritime transportation

Abstract

The rapid growth in the maritime sector has raised concern about its environmental impact. It is essential and important to improve the environmental performance of maritime transportation without increasing cost. An emission allocation scheme is a prerequisite for the correct measurement of emissions, serving as a basis for the improvement. It can be described as the distribution of the emissions from transport activities to different elements of the transport chain (e.g., legs, vehicles) at different cargo aggregation levels. However, most of the main global emissions auditing standards or standard-like reports do not have a detailed discussion on emission allocation. In the field of maritime transportation, the focus is on the ferries and RoPax vessels, which represent a small part of global transport. The emission allocation regarding a return route, repositioning, or container shipping is still unresolved. It shows that emission allocation is a young and challenging discipline, especially at the cargo shipment level. Thus, in this thesis, we focus on emission allocation and its impact in maritime transportation. The work from this thesis shows that although the emission allocation is still in its infancy, it has a significant impact on environmental performance measurement. Emission allocation can provide information on the responsibility of different players with respect to emission reduction. It also provides insights for policy makers to device rules for calculating emission inventories, which can encourage collaboration and shared transport in complex, multi-stakeholder networks. Furthermore, by allocating the emissions to a specific cargo transport unit, the same basis for each transport mode can be achieved. This makes the measurement, comparison and benchmarking of the environmental performance in multimodal transport possible. Underlying principles an allocation scheme needs to fulfil are useful to support a selection of a proper emission allocation scheme in maritime transportation. Moreover, we suggest that the alternative allocation schemes adhering to the principles should be developed in different cases in maritime transportation according to the characteristics of network structure and cargoes. In this thesis, the cases based on a repositioning network and intermodal transport network are used to demonstrate how and why different schemes need to be considered. A simulation-based design of experiment method is applied to capture the behaviour of complex transport networks in these examples and also to analyze and optimize the results for furtherer performance improvement. The main contributions of this thesis can be summarized as: - A set of general principles an emission allocation scheme needs to fulfil in maritime transportation A set of emission allocation schemes which can be applied for different cases in maritime transportation including container shipping and repositioning transport network -The identification of, and insights into, the impact of emission allocation schemes on the environmental performance measurement - The application of a simulation-based design of experiment (DOE) method combined with optimization to improve the performance of maritime transportation efficiently