The impact of the 2020 global sulfur cap on maritime CO2 emissions

Purpose As of January 1, 2020, the upper limit of sulfur emissions outside emission control areas decreased from 3.5% to 0.5%. This paper aims to present some of the challenges associated with the implementation of the sulfur cap and investigates its possible side effects as regard the drive of the International Maritime Organization (IMO) to reduce carbon dioxide (CO2) emissions. Even though it would appear that the two issues (desulfurization and decarbonization) are unrelated, it turns out that there are important cross-linkages between them, which have not been examined, at least by the regulators. Design/methodology/approach A literature review and a qualitative risk assessment of possible CO2 contributors are presented first. A cost-benefit analysis is then conducted on a specific case study, so as to assess the financial, as well as the environmental impact of two main compliance choices, in terms of CO2 and sulfur oxide. Findings From a financial perspective, the choice of a scrubber ranks better comparing to a marine gas oil (MGO) choice because of the price difference between MGO and heavy fuel oil. However, and under different price scenarios, the scrubber choice remains sustainable only for big vessels. It is noticed that small containerships cannot outweigh the capital cost of a scrubber investment and are more sensitive in different fuel price scenarios. From an environmental perspective, scrubber ranks better than MGO in the assessment of overall emissions. Research limitations/implications Fuel price data in this paper was based on 2019 data. As this paper was being written, the COVID-19 pandemic created a significant upheaval in global trade flows, cargo demand and fuel prices. This made any attempt to perform even a rudimentary ex-post evaluation of the 2020 sulfur cap virtually impossible. Due to limited data, such an evaluation would be extremely difficult even under normal circumstances. This paper nevertheless made a brief analysis to investigate possible COVID-19 impacts. Practical implications The main implication is that the global sulfur cap will increase CO2 emissions. In that sense, this should be factored in the IMO greenhouse gas discussion. Originality/value According to the knowledge of the authors, no analysis examining the impact of the 2020 sulfur cap on CO2 emissions has yet been conducted in the scientific literature.