The International Maritime Organization (IMO) has made impressive strides toward regulating greenhouse gas (GHG) emissions from international shipping, with key developments coming out of its 2030 checkpoint of its 2023 Strategy on Reducing GHG Emissions from Ships. This strategy sets indicative targets of at least 20% (and ideally 30%) reduction from 2008 levels by 2030; 70% reduction (strive for 80% reduction by 2040); and net zero by around 2050 relative to 2008 levels.
MEPC 83 Approves Draft Net Zero Regulations
At its 83rd Session (MEPC 83) from 7-11 April 2025, the International Marine Environment Protection Committee approved draft amendments to MARPOL Annex VI known as the IMO Net-Zero Framework. These measures serve as industry's first binding regulations combining mandatory fuel standards with GHG pricing mechanisms in one package.
This framework targets vessels over 5,000 gross tonnage, which account for 85% of international shipping's CO2 emissions. Ships must comply with a greenhouse gas fuel intensity (GFI) standard using a well-to-wake approach, which helps decrease GHG emissions per unit of energy over time. Vessels exceeding thresholds will acquire remedial units while those using zero or near-zero technologies earn credits or rewards.
Arsenio Dominguez, Secretary-General of the IMO, applauded MEPC 83's collaborative spirit by noting its key role in accelerating zero emission fuels and supporting an equitable transition process. MEPC 83 regulations will form new Chapter 5 of MARPOL Annex VI which have already been ratified by 108 parties representing 97% of global merchant tonnage.
Timeline and Implementation Pathway.
After MEPC 83 approval, the draft text will be circulated among member states for review. Formal adoption will occur at an extraordinary MEPC session (MEPC/ES.2) scheduled in October 2025 with tacit acceptance taking effect by spring 2027; compliance begins 1 January 2028 to enable shipowners to update Ship Energy Efficiency Management Plans (SEEMPs).
Spring 2026's MEPC 84 will approve implementation guidelines. The initial compliance year aligns with 2028, supporting the 2030 target of 20-30% emissions cuts. This builds on measures like phase 3 Energy Efficiency Design Index (EEDI) enhancements which have advanced newbuild efficiency by 30% relative to 2014 baselines.
MEPC 83 Supportive Measures
MEPC 83 addressed broad environmental priorities by adopting a 2025 Action Plan against marine plastic litter and progressing Ballast Water Management Convention reviews. Furthermore, they designated North-East Atlantic as an Emission Control Area as well as two Particularly Sensitive Sea Areas off South America's Pacific coast as Emission Control Areas and Particularly Sensitive Sea Areas respectively.
Draft Work Plan advanced regulatory frameworks for Onboard Carbon Capture and Storage (OCCS) systems as a complementary step toward net zero carbon emissions, further underscoring IMO's comprehensive approach to marine protection and decarbonization.
Industry and Global Implications
The net-zero framework incentivizes sustainable fuels, with credits tradable or contributed directly to an IMO Net-Zero Fund as offsets. Furthermore, seafarer training and safety for alternative fuels is prioritized, providing for equitable transition.
Finland's government announced in April 2025 a series of provisional agreements designed to reduce maritime emissions, promote global uptake of low-carbon technologies and help the shipping sector meet Paris Agreement-aligned goals as it transitions. These verifiable milestones position shipping for success.