MEPC 83, MEPC 84: What the IMO's New Carbon Framework Means for Shipowners

Merchant shipping · Regulation · Decarbonization

April 2025. The Marine Environment Protection Committee of the International Maritime Organization (MEPC 83) adopts, after years of negotiations, the world's first carbon pricing mechanism for the shipping sector. A historic first in international maritime transport.

A few days later: the United States sabotaged the negotiations. Pacific island nations abstained. China, Brazil, and Saudi Arabia defended an alternative approach based on carbon credits.

April 2026. MEPC 84 convened in London, from April 27 to May 1. The net-zero framework (net-zero emissions by 2050) has still not been formally adopted. But the technical texts are progressing. And Arsenio Dominguez, IMO Secretary-General, summed up the week's mood in a measured phrase:

"We are back on track, but we have to rebuild trust."

For shipowners, captains, and fleet managers, the question is no longer whether carbon regulation will apply. It already does — partially. Its progressive tightening is now mapped out through 2030 and beyond.

The real question lies elsewhere: are you able to produce, voyage by voyage, the data this compliance will require?

What MEPC 83 Actually Adopted

MEPC 83 (April 7–11, 2025) approved what the IMO calls the Net-Zero Framework: the world's first system combining binding emissions limits with a greenhouse gas pricing mechanism across an entire industry sector.

This framework rests on two pillars:

1. A GHG Fuel Intensity standard (GFI). Each vessel must progressively reduce the carbon intensity of its energy consumption, measured in GHG emissions per unit of energy used — from well to wake. Thresholds tighten year after year.

2. An economic GHG pricing mechanism. Ships exceeding the permitted thresholds will be required to pay a financial contribution. Those using zero-emission fuels will be rewarded through a credit mechanism. Projections suggest additional costs could reach up to $500 per tonne of conventional fuel exceeding the base targets by 2035.

These measures will apply to vessels over 5,000 GT, which account for 85% of total CO₂ emissions from international shipping. Entry into force: March 2027. First effective reporting year: 2028.

MEPC 84: A Week of High Tension in London

Few observers expected a full agreement at the close of MEPC 84, and the session indeed exposed deep fractures — alongside some concrete progress.

A Secretary-General Calling for Dialogue

Opening the proceedings, Arsenio Dominguez urged delegations to "find convergences." "Let's listen to each other. There is no need to argue," he said, referencing the particularly turbulent discussions of autumn 2025. Trust between member states had been seriously undermined by previous episodes.

He also noted that measures already in force are producing measurable effects: the carbon intensity of international maritime transport has reportedly fallen by more than 38% since 2008. A positive signal — but insufficient in light of the 2050 targets.

US Opposition: A Major Stumbling Block

The most significant shift in context: the United States' stance. The Trump administration now openly opposes any form of global carbon pricing in shipping, favoring an incentive-based approach instead. Washington also argues that the IMO is placing too much weight on alternative fuels that are not yet sufficiently mature.

This position reinforces the already critical stances of several hydrocarbon-producing countries, notably Saudi Arabia. Attention also falls on major flag states — Liberia, Panama — whose support will be essential to building a credible compromise. Facing them, a broad coalition — the European Union, United Kingdom, Australia, and Canada — maintains its backing for the pricing mechanism.

Technical Progress Made

Despite the political tensions, several technical advances were formally agreed at MEPC 84:

• Alternative fuel certification: procedures for certifying zero- and low-carbon fuel supply chains are progressing — essential for shipowners to rely on these fuels with internationally recognized guarantees.

• Methane and nitrous oxide measurement: new guidelines approved for tracking CH₄ and N₂O emissions from marine engines — two greenhouse gases with a global warming potential far exceeding that of CO₂.

• Onboard carbon capture: guidelines on onboard capture systems were adopted, following a technology-neutral approach.

• CII tightening: Carbon Intensity Indicator reduction factors are being raised, from 11% in 2026 to 21.5% in 2030.

• Wind-assisted propulsion: wind propulsion assistance technologies were highlighted as a complementary lever for emissions reduction.

The next session — MEPC 85, December 2026 — should be decisive. Without an agreement by then, the full framework's entry into force in 2027 will be at risk.

What This Means for Shipowners: Data at the Heart of Compliance

The message from MEPC 84 is clear for the sector: even if the regulation is not yet set in stone, the compliance timeline is moving forward. Future compliance will rest on data — voyage by voyage, vessel by vessel, fleet by fleet.

For CII — already mandatory for vessels over 5,000 GT: fuel consumption by type, distance traveled, engine hours, cargo carried depending on vessel type.

For GFI — from the 2028 reporting year: carbon intensity of fuels used (well-to-wake), certification of alternative fuel origins, CH₄ and N₂O emissions in addition to CO₂, aggregated data per vessel and per fleet.

For the ZNZ reward mechanism: documented proof of zero or near-zero emission fuel use, certifiable traceability voyage by voyage.

Data is no longer a back-office topic. It sits at the core of regulatory compliance and, soon, at the core of the economics of operating a vessel.

Why Many Operators Are Not Yet Ready

A significant number of shipowners — particularly in coastal shipping, inland waterways, and working vessel fleets — do not yet have a system capable of producing this data reliably, automatically, and in a certifiable way.

The data exists onboard, but it is scattered: entered manually in engine room logs, exported as PDFs, stored without usable structure. Automatic collection is perceived as something reserved for large shipping companies — wrongly so: the technologies available today allow an operator with a few vessels to connect their fleet to a management tool without disproportionate investment.

With 2028 as the first mandatory reporting year, some operators feel the topic can wait — but that's taking a serious risk. The 2027 data will be foundational for the 2028 certification. And setting up a reliable data collection system takes time.

What to Do Operationally Right Now

Without waiting for 2028, several actions are essential for shipowners who want to get ahead of carbon compliance:

• Centralize consumption data collection — every voyage documented with fuel type, quantity, distance, and engine hours, in a structured, exportable format.

• Calculate and track CII voyage by voyage — even for fleets below the 5,000 GT threshold, knowing your carbon intensity is an indispensable management baseline.

• Document fuel origins — if you already use biofuels, LNG, or methanol, keep your supply certificates. They will be essential to benefit from future reward mechanisms.

• Build a consolidated fleet view — reporting will not be limited to the vessel level. A multi-vessel operator must be able to aggregate emissions across the entire fleet.

What the BoatOn Book Can Do Today

BoatOn Book natively integrates a carbon footprint tracking module, fed by operational data collected automatically or entered in the electronic logbook:

• Voyage-by-voyage tracking: fuel consumption, distance, engine hours recorded at every navigation and automatically centralized in the logbook.

• Automatic CO₂ emission calculation: based on real consumption data, per vessel and per fleet, with no manual re-entry.

• Customizable dashboards: a consolidated view of fleet carbon intensity, with export capabilities for regulatory and internal reporting.

• Onboard data connectivity: via AIS, Qondor beacons, or onboard protocols (NMEA 0183, NMEA 2000, J1939), data can be collected with no human intervention.

• Timestamped traceability: every entry is stored and certifiable — a solid documentary basis for upcoming audits and inspections.

The IMO regulatory framework is taking shape. The timeline will not keep shifting indefinitely. Shipowners who put their data infrastructure in place in 2026 and 2027 will be the ones entering 2028 with a head start.