Amendments to the International Convention for the Prevention of Pollution from Ships (MARPOL) Annex VI entered into force on 1 November 2022. Developed under the framework of the Initial IMO Strategy on Reduction of GHG Emissions from Ships agreed in 2018, these technical and operational amendments require ships to improve their energy efficiency in the short term and thereby reduce their greenhouse gas emissions.

From 1 January 2023 it will be mandatory for all ships to calculate their attained Energy Efficiency Existing Ship Index (EEXI) to measure their energy efficiency and to initiate the collection of data for the reporting of their annual operational carbon intensity indicator (CII) and CII rating.

What are the new mandatory measures?

As a stimulus to reduce carbon intensity of all ships by 40% by 2030 compared to 2008 baseline, ships will be required to calculate two ratings: their attained Energy Efficiency Existing Ship Index (EEXI) to determine their energy efficiency, and their annual operational Carbon Intensity Indicator (CII) and associated CII rating. Carbon intensity links the GHG emissions to the amount of cargo carried over distance travelled.

When do the measures come into force?

The amendments to MARPOL Annex VI are in force from 1 November 2022. The requirements for EEXI and CII certification come into effect on 1 January 2023. This means that the first annual reporting will be completed in 2023, with initial ratings given in 2024.

The measures are part of IMO's commitment under its 2018 Initial Strategy on Reduction of GHG Emissions from Ships to reduce carbon intensity from all ships by 40% by 2030 compared to 2008.

What is a Carbon Intensity Indicator rating?

The CII determines the annual reduction factor needed to ensure continuous improvement of a ship's operational carbon intensity within a specific rating level.  The actual annual operational CII achieved must be documented and verified against the required annual operational CII. This enables the operational carbon intensity rating to be determined.

How will the new ratings work?

Based on a ship's CII, its carbon intensity will be rated A, B, C, D or E (where A is the best). The rating indicates a major superior, minor superior, moderate, minor inferior, or inferior performance level. The performance level will be recorded in a "Statement of Compliance" to be further elaborated in the ship's Ship Energy Efficiency Management Plan (SEEMP).

A ship rated D for three consecutive years, or E for one year,  will have to submit a corrective action plan to show how the required index of C or above will be achieved. Administrations, port authorities and other stakeholders as appropriate, are encouraged to provide incentives to ships rated as A or B.

 A ship can run on a low-carbon fuel clearly to get a higher rating than one running on fossil fuel, but there are many things a ship can do to improve its rating, for instance through measures, such as:

1.hull cleaning to reduce drag;

2.speed and routeing optimization;

3.installation of low energy light bulbs; and

4.installation of solar/wind auxiliary power for accommodation services.

How will the impact of the new regulations be assessed?

IMO's Marine Environment Protection Committee (MEPC) is to review the effectiveness of the implementation of the CII and EEXI requirements by 1 January 2026 at the latest and develop and adopt further amendments as required.

The review paragraph says: Regulation 28 Operational carbon intensity:

...

Review 

11 A review shall be completed by 1 January 2026 by the Organization to assess: 

.1 the effectiveness of this regulation in reducing the carbon intensity of international shipping;

.2 the need for reinforced corrective actions or other means of remedy, including possible additional EEXI requirements;

.3 the need for enhancement of the enforcement mechanism;

.4 the need for enhancement of the data collection system; and

.5 the revision of the Z factor and CIIR values. 

Source: IMO