IMO Environmental Regulations (MARPOL Annex VI & GHG Strategy)
Status: Upcoming — Major mid-term GHG measures are expected to be adopted in 2025, with global carbon pricing for shipping on the horizon.
What Is It?
The International Maritime Organization's environmental regulatory framework is undergoing its most significant transformation in decades. Building on the existing MARPOL Annex VI provisions for energy efficiency (EEDI/EEXI) and operational intensity (CII), the IMO adopted a revised GHG Strategy in July 2023 (MEPC.377(80)) with significantly enhanced ambitions: reaching net-zero GHG emissions from international shipping close to 2050, with indicative checkpoints of at least 20% reduction by 2030 and at least 70% by 2040 compared to 2008 levels.
To deliver on this strategy, the IMO is developing a comprehensive basket of mid-term measures expected to be adopted in 2025 and enter into force around 2027. The leading candidates include a global maritime fuel standard (similar in concept to FuelEU Maritime but applied worldwide) and an economic measure — either a GHG levy, an emissions trading system, or a feebate mechanism — that would put a price on maritime GHG emissions at the international level. The Marine Environment Protection Committee (MEPC) is negotiating the design of these instruments, with the level of the GHG price and the stringency of the fuel standard as key points of discussion.
In parallel, the IMO's existing framework continues to evolve. The EEXI (Energy Efficiency Existing Ship Index) requirement entered into force in 2023, requiring existing vessels to meet minimum technical efficiency standards. The comprehensive review of the CII framework is scheduled for 2026, with potential revisions to the rating methodology, correction factors, and reduction trajectory. Additionally, the IMO's lifecycle GHG assessment guidelines (LCA guidelines) adopted in 2024 establish the well-to-wake methodology that will underpin the forthcoming global fuel standard.
Who It Affects
IMO environmental regulations under MARPOL Annex VI apply to all ships of 400 gross tonnage and above engaged in international voyages (for energy efficiency requirements, the threshold is 5,000 GT for CII). The forthcoming mid-term GHG measures are expected to apply to vessels of 5,000 GT and above, mirroring the scope of the existing CII and EU MRV frameworks. Unlike EU regulations which apply based on port calls, IMO measures apply globally to all international shipping regardless of trading area, making them the broadest-reaching maritime environmental regulations in development. Flag states bear responsibility for enforcement, with classification societies acting as recognized organizations for technical verification.
Key Dates
EEXI requirement enters into force — existing ships must meet technical efficiency standards
Revised IMO GHG Strategy adopted at MEPC 80 — net-zero close to 2050 target
IMO lifecycle GHG/carbon intensity guidelines for marine fuels adopted at MEPC 81
Expected adoption of mid-term GHG measures (fuel standard + economic element) at MEPC 83
Projected entry into force of IMO mid-term GHG measures
First indicative checkpoint — at least 20% GHG reduction vs 2008 baseline
Requirements
- Comply with EEXI technical efficiency requirements for existing vessels through power limitation, energy efficiency technology, or other approved measures
- Maintain CII operational efficiency ratings and implement corrective action plans for vessels rated D (3 years) or E (1 year)
- Prepare for the forthcoming global maritime fuel standard by assessing fleet readiness for well-to-wake GHG intensity requirements
- Develop SEEMP Part III with energy efficiency improvement plans aligned with the IMO GHG Strategy trajectory
- Monitor developments in IMO mid-term GHG measures and assess financial exposure to a potential global carbon pricing mechanism
- Adopt IMO lifecycle GHG assessment guidelines for evaluating the well-to-wake emissions of alternative marine fuels
- Ensure technical documentation and class approvals are in place for any EEXI compliance measures implemented (e.g., EPL, shaft power limitation)
Penalties & Non-Compliance
Currently, non-compliance with EEXI results in the inability to obtain or renew the International Energy Efficiency Certificate (IEEC), effectively preventing the vessel from trading internationally. CII non-compliance triggers corrective action plan requirements as described separately. The penalties for the forthcoming IMO mid-term GHG measures are still under negotiation, but the economic element is expected to create a material financial incentive through either direct GHG pricing (with discussion ranging from $20-150 per tonne of CO2) or a feebate mechanism that rewards over-compliance and penalizes under-compliance. The fund generated by any levy mechanism is proposed to support developing nations' maritime decarbonization efforts and accelerate the availability of alternative marine fuels globally.
How CyberSmart Helps
These modules help you prepare for the evolving IMO regulatory framework.
Prepare for the IMO's next chapter
See how CyberSmart positions your fleet ahead of global carbon pricing, fuel standards, and enhanced efficiency requirements.