The International Maritime Organization’s Marine Environment Protection Committee has agreed to establish an intersessional working group to address concerns over the IMO Net-Zero Framework, following its 84th session held in London from 27 April to 1 May 2026.

Nearly 100 delegations participated in discussions on the adoption of mid-term measures to address greenhouse gas emissions from ships, with multiple proposals tabled on how to advance negotiations. The committee agreed to schedule two intersessional meetings — from 1 to 4 September and 23 to 27 November — ahead of its 85th session scheduled for 30 November to 3 December.

Member states will be able to submit new amendments and adjustments to draft amendments previously approved. A one-day expert workshop on chain of custody models, which track fuel origin and movement across the supply chain, will also be held.

Closing the meeting, IMO Secretary-General Arsenio Dominguez said: “We are back on track, but we have to rebuild trust. I encourage you to maintain this momentum through your intersessional work and to prepare submissions that can bring the membership together.”

The committee will resume its second extraordinary session on 4 December 2026, subject to confirmation by the 85th session.

North-East Atlantic emission control area

MEPC 84 adopted a resolution designating the North-East Atlantic as a new emission control area for nitrogen oxides, sulphur oxides and particulate matter. The ECA will come into effect on 1 September 2027.

The new ECA prohibits ships from using fuel with a sulphur content greater than 0.10% m/m, or achieving equivalent emission reductions using approved technology. It requires all ships constructed after a certain date to comply with NOx Tier III limits as specified in Regulation 13 of MARPOL Annex VI.

For ships constructed on or after 1 January 2027 and operating in the North-East Atlantic emission control area, a ship is defined as constructed on or after 1 January 2027 if the building contract is placed on or after 1 January 2027, or, in the absence of a building contract, the keel is laid or the ship is at a similar stage of construction on or after 1 July 2027, or delivery is on or after 1 January 2031.

The North-East Atlantic emission control area includes the exclusive economic zones and territorial seas, extending up to 200 nautical miles from the baselines, of Greenland, Iceland, the Faroe Islands, Ireland, and the mainland of the United Kingdom, France, Spain and Portugal.

Data collection and reporting

Amended Regulation 27 of MARPOL Annex VI will enter into force on 1 September 2027 and will provide for the collection, management and controlled sharing of ship fuel oil consumption data through the IMO Ship Fuel Oil Consumption Database.

The IMO grants administrations, or organisations authorised by them, access to all reported data for their respective ships for previous calendar years. Parties to MARPOL Annex VI will be granted access to a non-anonymised dataset covering all ships subject to the regulation, for analytical and consideration purposes.

Multiple engine operational profiles

MEPC 84 adopted revised definitions, certification documentation and NOx engine test cycles under MARPOL Annex VI to clarify how marine diesel engines are tested and certified, including when multiple engine operational profiles are used.

Amendments to the International Air Pollution Prevention Certificate include new rows added to the supplement to allow recording of compliance using NTC 8 (Multiple Engine Operational Profiles).

EEDI for dual-fuel engines

MEPC 84 adopted amendments to the 2022 Guidelines on the Method of Calculation of the Attained Energy Efficiency Design Index, together with new 2026 Guidelines on survey and certification of the EEDI.

The revised guidelines clarify how the attained EEDI should be calculated for ships equipped with dual-fuel main and/or auxiliary engines, including LNG-fuelled engines, and how compliance is to be surveyed and certified.

CII calculations

MEPC 84 adopted amendments to the 2024 Guidelines for the development of a Ship Energy Efficiency Management Plan in relation to increased granularity of data submitted annually to the IMO Data Collection System.

The committee also adopted amendments to the 2022 Guidelines on operational carbon intensity indicators and the calculation methods. The amendments state that transport work, for now, continues to be defined as the product of a ship's capacity (deadweight tonnage or gross tonnage as applicable) and the total distance travelled (both under way and not under way) in a given calendar year.

Biofuels guidance

MEPC 84 approved a revised MEPC circular containing interim guidance on the use of biofuels under Regulations 26, 27 and 28 of MARPOL Annex VI.

The revised guidance clarifies that, for biofuels blended with fossil fuel, the CO₂ emission conversion factor should be calculated as a weighted average based on the mass of the fuels blended, rather than on an energy basis.

Biofuels, or the biogenic components within biofuel blends, that are not certified as "sustainable" or do not meet the well-to-wake emission factor criteria set out in the Guidelines on life cycle GHG intensity of marine fuels should be assigned a conversion factor equal to that of the equivalent fossil fuel type.

For the purpose of consistent annual reporting to the IMO Data Collection System, the revised guidance on biofuels will apply from 1 January 2027.

Methane and nitrous oxide emissions

The 2023 IMO Strategy on reduction of GHG emissions from ships specifies that the IMO should work to reduce emissions of methane and nitrous oxide, both of which are greenhouse gases.

MEPC 84 adopted three guidelines: 2026 guidelines for test-bed and onboard measurements of methane and/or nitrous oxide emissions from marine diesel engines; new guidelines for engine load monitoring and calculation of emission values; and new guidelines for continuous emission monitoring systems used to quantify methane and/or nitrous oxide emissions from marine diesel engines.

MEPC 84 agreed that, for now on a voluntary basis, actual tank-to-wake emission values for methane and nitrous oxide emissions may be quantified using engine load monitoring in conjunction with the 2026 guidelines for test-bed and onboard measurements, and/or continuous emissions measurement systems using the new CEMS guidelines.