IMO Carbon Intensity Indicator (CII)

What Is the IMO Carbon Intensity Indicator (CII)?

The Carbon Intensity Indicator (CII) is a rating system introduced by the International Maritime Organization (IMO) that measures how efficiently a vessel transports cargo or passengers relative to the CO2 it emits, assigning each ship an annual efficiency rating from A (best) to E (worst).

How Does CII Work?

A vessel's CII is calculated based on its actual fuel consumption and cargo-carrying activity over the year, then compared against a reference efficiency standard set by the IMO. Ships rated D or E for multiple consecutive years must submit corrective action plans to improve their rating, potentially requiring operational or technical changes.

Why CII Matters for Shippers

As CII enforcement affects vessel operations and, over time, capacity and routing decisions by carriers, shippers may see indirect effects like preferential deployment of higher-rated vessels or operational speed adjustments to meet ratings. It's part of a broader trend of maritime emissions regulation that shippers should expect to influence freight costs and vessel scheduling over time.