11. Critical Analysis of Air Emissions from Ships: Lifecycle Thinking and Results

The authors have incorporated the life cycle thinking approach in their research activities during the past few years with the aim to conduct environmental assessments of ship air emissions from a life cycle perspective. This chapter presents some illustrative findings from this work. These include a presentation of a life cycle ship framework which considers the ship as a system that may be detailed into sub-systems for which: (a) inputs, (b) processes, and (c) outputs, are identified and elaborated. Important ship life cycle stages are built-in in this model; namely the shipbuilding stage, ship operation including major maintenance activities, and finally the stage of ship dismantling/recycling. This chapter also presents illustrative numerical results of a Life Cycle Assessment study conducted for important air emissions occurring throughout the life cycle of an ocean going ship. Finally, the chapter discusses the main difficulties observed during the period of experimenting with the Life Cycle Assessment method and some limitations of this method to sufficiently cover the case of shipping. The main issues discussed in this context are: the adaptation of the methodology to maritime transport scenarios, the system boundaries selection, the establishment of life cycle inventories and the availability of data and most importantly the impact assessment step of Life Cycle Assessment which (for the case of ships) has shown to have more difficulty and wider uncertainty than any other step of the method.