Published January 16, 2026 | Version v1

IMO Short-term Measures: A Review of the Carbon Intensity Indicator (CII)

  • 1. ROR icon City St George's, University of London
  • 2. ROR icon Durham University

Description

The Carbon Intensity Indicator (CII) is one of the short-term measures introduced by the International Maritime Organization
(IMO) to reduce greenhouse gas emissions from shipping. This policy brief reviews the measure and provides
improvement recommendations, focusing on how emission standards at sea and at port should be dealt with.

Key Highlights:

  • CII is currently insufficient for capturing emissions accurately at sea and at port and incentivising emission reduction
  • A range of revision options could be considered such as excluding port emissions, adjustments for time at port, or separate metrics for at sea and at port
  • Other areas that could be considered include allowance for actual cargo, well-to-wake emissions, and pilot fuel

Recommended revision for CII is to use separate metrics for at sea and at port emissions.

Files

Clean_Maritime_Research_Hub_CII_PolicyBrief_16Jan26.pdf

Files (1.5 MB)

Additional details

Funding

Department for Transport
Engineering and Physical Sciences Research Council
EP/Y024605/1