Proposal and analysis for effective implementation of new measures to reduce the operational carbon intensity of ships

The Carbon Intensity Indicator (CII) requirements for international shipping regulate total annual carbon dioxide emissions (by transport work proxy using the ship's Deadweight Tonnage (DWT) instead of the actual cargo carried). It limits the accurate calculation of operational efficiency and causes an overestimation of the operational energy efficiency of international shipping. Due to lack of research on the International Maritime Organization's (IMO) CII requirements (energy efficiency based on actual cargo), the effects of CII requirements were investigated by contrasting the CII values based on DWT and actual cargo carried from data provided by the European Union Monitoring, Reporting and Verification. Results demonstrated that the CII calculated using actual cargo carried differed from that calculated using DWT by an average of 30%. Thus, future data collection must be based on actual cargo volume to apply IMO CII criteria more precisely, intuitively, and consistently.