Technical Notices

IMO MEPC 83: Brief Summary on the key outcomes

The 83rd session of the International Maritime Organization’s Marine Environment Protection Committee (MEPC 83) was held from 7 to 11 April 2025.

The session focused on advancing measures for greenhouse gas (GHG) emissions reduction, marine pollution control, and overall environmental sustainability within the maritime sector. The IMO Net-zero Framework is the first in the world to combine mandatory emissions limits and GHG pricing across an entire industry sector.

Key Outcomes

1-Mid-Term GHG Reduction Measures
-Approval of draft amendments to MARPOL Annex VI (new Chapter 5), introducing accessibility of the IMO Net-Zero Framework with mandatory fuel GHG intensity limits and a pricing mechanism.
-Under the draft regulations, ships will be required to comply with:

1/Global fuel standard: Ships must reduce, over time, their annual greenhouse gas fuel intensity (GFI) – that is, how much GHG is emitted for each unit of energy used. This is calculated using a well-to-wake approach.

2/Global economic measure: Ships emitting above GFI thresholds will have to acquire remedial units to balance its deficit emissions, while those using zero or near-zero GHG technologies will be eligible for financial rewards.

-Formal adoption expected in October 2025, with tentative entry into force on 1 March 2027.

IMO Net-Zero Fund
-The IMO Net-Zero Fund will be established to collect pricing contributions from emissions. These revenues will then be disbursed to:

1/Reward low-emission ships;

2/Support innovation, research, infrastructure and just transition initiatives in developing countries;

3/Fund training, technology transfer and capacity building to support the IMO GHG Strategy; and

4/Mitigate negative impacts on vulnerable States, such as Small Island Developing States and Least Developed Countries.

2-Short-Term GHG Measure Enhancements
-Adoption of updated CII reduction factors for 2027–2030 (targeting 21.5% reduction by 2030 from 2019 baseline).
-Revised SEEMP guidelines including updated terminology and provisions for expanded CII metrics.

3-Data Collection & Transparency
-Draft amendments to MARPOL Annex VI approved to enhance transparency of fuel consumption data (non-anonymized for flag states, anonymized for public).

4-Onboard Carbon Capture and Storage (OCCS)
-Approval of a draft regulatory work plan to guide OCCS integration aboard ships, with development scheduled through 2028.

5-Air Pollution Control
-Amendments to the NOₓ Technical Code adopted, addressing multi-profile engine certification and modification processes (entry into force: 1 March 2027).
-Adoption of new guidelines for Selective Catalytic Reduction (SCR) systems.

6-Marine Plastic Litter & Biofouling Management
-2025 Action Plan adopted to tackle plastic litter from ships, including control measures for plastic pellet transport.
-Agreement to develop a legally binding framework on biofouling to limit invasive aquatic species spread.

7-Ballast Water Management Convention Review
-Continued review efforts focusing on system performance under challenging water quality conditions and improved record-keeping protocols.

8-Emission Control and Sensitive Areas
-Approval of the North-East Atlantic as a new ECA (SOₓ, NOₓ, PM).
-Preliminary approval for designating new Particularly Sensitive Sea Areas (PSSAs) along the Pacific coast of South America.

Conclusion
MEPC 83 reaffirmed the IMO’s strategic direction toward climate-resilient, environmentally responsible shipping. The outcomes reflect growing international consensus on accelerated decarbonization, data transparency, and ecosystem protection.