The Carbon Intensity Indicator (CII) is a measure of how efficiently a ship transports goods or passengers and is given in grams of CO2 emitted per cargo-carrying capacity and nautical mile. The ship is then given an annual rating ranging from A to E, whereby the rating thresholds will become increasingly stringent towards 2030. The CII applies to all cargo, RoPax and cruise ships above 5,000 GT.
The yearly CII is calculated based on reported IMO DCS data and the ship is given a rating from A to E. For ships that achieve a D rating for three consecutive years or an E rating in a single year, a corrective action plan needs to be developed as part of the SEEMP and approved.
The CII applies to all ships above 5,000 GT of the following ships types: bulk carriers, gas carriers, tankers, container ships, general cargo ships, refrigerated cargo carriers, combination carriers, LNG carriers, vehicle carriers, Ro-Ro cargo vessels, Ro-Ro passenger vessels and cruise ships.
The basic CII is calculated as CO2 emitted per cargo-carrying capacity and nautical mile. The CII calculation will be further improved through correction factors in a separate guideline that will be developed next year.
For the time being, using actual cargo carried instead of capacity (i.e. the EEOI) can only be reported on a voluntary basis and not for the purpose of the CII rating.
For different ship segments, the CII is based on different ways of measuring the carbon footprint of the transport work. The Annual Efficiency Ratio (AER) and capacity gross ton distance (cgDist) are two such CIIs using different units. AER (emission per dwt-mile) is used for segments where the cargo is weight critical, and cgDist (emissions per gross ton-miles) for volume-critical cargo.
AER (emission per dwt-mile) and cgDist (emissions per gross ton-miles) are supported by data elements reported through the IMO DCS system. The IMO DCS system does not collect the cargo data required to calculate the EEOI (emission per tonne-mile). Therefore, the EEOI is not an option to use for the CII today. However, it will be possible to voluntarily report cargo data and report the EEOI for those who wish to do so.
The CII requirements will take effect from 2023. An enhanced SEEMP with an implementation plan for achieving the required CII needs to be approved and kept on board. The SEEMP will be subject to company audits, although the guidelines for the audit are still to be developed.
The EEXI is a one-time certification equivalent to the EEDI (Energy Efficiency Design Index) phase 2 or 3 concerning design parameters of the vessels. The CII is an operational indicator and will be assessed annually from 2023 with yearly stricter emission limits. The EEXI and CII are applicable to the same ship types.
The difference is that CII ratings will apply to ships 5,000 GT and above regardless of propulsion type.
The CII is based directly on the fuel consumption, which is influenced by how a specific ship is operated in combination with its technical efficiency and fuel. Its value will be affected by the type of fuel used, the efficiency of the vessel and operational parameters such as vessel speed, cargo transported, weather conditions and the general condition of the vessel (e.g. biofouling).
An owner can control the CII by optimizing operations and ensuring vessels are in a good condition. Charterers will have a major influence over the CII of the ships they charter by selecting the speed. It will be beneficial for owners/operators to continuously monitor the CII performance of the vessel to avoid having to take drastic measures unexpectedly. DNV can assist in monitoring the CII through the Emissions Insight Service.
As an RO (Recognized Organization), DNV currently verifies DCS emission reports and SEEMPs on behalf of flag states. We expect that this will also apply to the annual CII rating and the enhanced SEEMP. The monitoring and rating of emissions are shared with our customers through the Emission Insight Service (DNV class services).
Our independent advisory team can assist with consultancy services related to measures for compliance and strategic approaches for the selection and implementation of relevant measures.
Find more information on our CII service page.
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