A perspective on the role of multi-criteria decision-making in assessing the sustainability of alternative shipping fuels

According to the fourth “International Maritime Organization greenhouse gas study”, the combustion of fossil fuels such as heavy fuel oil in the shipping sector was responsible for 2.9% of global anthropogenic greenhouse gas emissions in 2018. These emissions can potentially be reduced through alternative fuels with low or zero-carbon footprints. Of issue, however, is the high financial investment and lead in time for development of facilities to produce these fuels, and the assessment of which of the fuel systems should be prioritised. Multi-Criteria Decision Making (MCDM) methods can aid decision-makers in comparing alternative fuels from technical and sustainability perspectives. MCDM provides methodologies to deal with multiple, often conflicting, criteria with varying degrees of importance. This paper provides a perspective on the use of the MCDM methods for comparing alternative shipping fuels. The work indicates that: 1) future research must use Life Cycle Assessment for a more holistic approach to assessing the environmental impact of each fuel; 2) process simulation software can be used to develop the data required for comparing different fuel production pathways; 3) objective weighting methods can be used more in future research; 4) input from port stakeholders must be considered in future research; and 5) to generate a robust comparison, infrastructural requirements must be considered.