Exploring the sectoral level impacts and absolute emission changes of using alternative fuels in international shipping

The shipping sector is required to reduce fuel sulphur content to 0.1% in Emission Control Areas by 2015 and to 0.5% globally by 2020. At the same time there is regulation and a need to address NOx and PM emissions at a localised level and increasing pressure to address the sector’s rising CO2 emissions, which is a major contributor to global climate change. A measure to address these challenges is to switch from the use of heavy fuel oil to alternative fuels that are able to address local pollutants and carbon emissions in parallel. This paper aims to explore the wider impacts of decisions on the choice of fuel undertaken at ship level. This is achieved by incorporating into shipping tool deployed in this study (GloTraM) the upstream and operational emissions for a range of alternative fuels, and test running them with a series of future scenarios. Key research questions include: (1) what are the total CO2 emissions when GloTraM is run with upstream emission factors added?; (2) what impact do these emissions have on the amount/type of fuels used in the sector?; (3) What are the nonGHG emissions and how significant are they compared to CO2 emissions? A life cycle approach is used to generate the upstream, i.e. well-to-tank emissions, accounting for the emissions associated with the processes used to grow and/or manufacture, distribute and dispose of an alternative fuel. The functional unit is tonne of CO2 per tonne of fuel delivered (to the vessel). These emissions are then incorporated alongside the operational emissions, which have been taken from the IMO’s 3rd GHG study. The results of the study provide a better understanding of the magnitude of total emissions from international shipping and the wider system level implications of fuel switching decisions.