The Energy Efficiency Existing Ship Index (EEXI) applies technical standards to cut CO2 emissions by ships from 1 January 2023 based largely on the Energy Efficiency Design Index (EEDI) levels adopted by the International Maritime Organization for newbuildings in 2020. Compliance with EEXI will mostly be via engine or shaft power limitation restricting the maximum power that can be achieved.


The Carbon Intensity Indicator (CII) will regulate existing ships above 5,000 gt from an operational perspective. CII is worked out by taking a ship’s annual emissions from fuel used, and dividing that by its capacity (deadweight or gross tonnage), multiplied by annual distance travelled in nautical miles.