This policy briefing explores the feasibility of improving the International Maritime Organization’s Carbon Intensity Indicator through developing a separate at port metric. It suggests that determining an appropriate at port metric would need to reflect the wide range of activities and conditions experienced by different vessel types and in different locations. This could be mainly achieved through consideration of an appropriate “useful work” definition.

Highlights:

  •  The cargo-carrying capacity and distance travelled used in CII do not reflect vessels’ at port activities
  •  Contracts between shipowners, operators, and charterers may not support CII rating improvements
  •  At port CII metric potentially valuable but limited by practical complexities
  •  Develop at sea CII metric first and further research how the at port part could work
  •  A review of the “useful work” definition should be undertaken for the various at port activities by vessel type
  •  As low(er) carbon fuels are adopted, other emissions – such as methane and nitrous oxide – and on a whole life cycle (“well-to-wake”) basis should be included in CII

 

Suggested citation:

Shi, Y., Copeland, C. L., & Moutzouris, I. (2026). Carbon Intensity Indicator (CII): Exploring the potential for an at port metric. Zenodo. https://doi.org/10.5281/zenodo.20056634