The IMO Net-Zero Framework, explained: targets, the two-tier carbon price and what to do before March 2028

The IMO Net-Zero Framework is the first attempt to give the entire global fleet a single greenhouse-gas rulebook with money attached. It combines a fuel-intensity limit with a sector-wide carbon price, written as amendments to MARPOL Annex VI, covering all ocean-going ships above 5,000 GT — the fleet responsible for more than 85% of shipping’s emissions. Approved at MEPC 83 in April 2025 and delayed once since, it now heads to an adoption vote on 4 December 2026, with the earliest entry into force on 1 March 2028.

The mechanism looks complex from the outside. Underneath, it is one sentence: measure the GHG intensity of the energy your ship uses; beat the target, earn credits; miss it, pay by the tonne — at one of two prices.

The GFI: one number per ship

The framework’s core metric is the GHG Fuel Intensity (GFI): grams of CO₂-equivalent per megajoule of energy used on board, measured well-to-wake — upstream fuel production included, not just the funnel. Every ship’s attained GFI is compared against a reference value of 93.3 gCO₂eq/MJ, representing the 2008 baseline.

From there, two target lines descend year by year:

• The base target — the floor every ship must clear. For 2028 it sits 4% below the reference.
• The direct compliance target — the stricter line the framework actually wants ships on. For 2028, 17% below the reference.

Both tighten annually on a trajectory aligned with the IMO’s net-zero-by-or-around-2050 strategy. The two-line design is deliberate: it separates “falling slightly short” from “not trying,” and prices them differently.

Three positions, three outcomes

Every ship lands in one of three positions each year:

1. Below the direct compliance target — over-compliance. The ship earns surplus units that can be banked for later years or transferred, which for the first time gives efficient tonnage a tradable asset rather than a certificate.
2. Between the direct and base targets — the moderate gap. Covered by acquiring Tier 1 remedial units at $100 per tonne CO₂eq.
3. Above the base target — the expensive gap. Covered by Tier 2 remedial units at $380 per tonne CO₂eq — a price set to make persistent high-intensity operation visibly uneconomic.

The deficit arithmetic is direct: (attained GFI − target GFI) × energy used in the year. Two ships with identical trades and different fuel strategies can sit on opposite sides of a seven-figure annual difference — which is why the framework, if adopted, reaches into fuel procurement, charter party negotiations and newbuilding specifications at once. Revenues flow into an IMO Net-Zero Fund, with rewards earmarked for zero- and near-zero-emission fuels and support for developing states.

The timeline that matters

Date	What happens
April 2025	Framework approved at MEPC 83 as draft MARPOL Annex VI amendments
October 2025	Adoption postponed; talks moved to 2026
4 December 2026	Extraordinary session votes on adoption (subject to MEPC 85 confirmation)
1 March 2028	Earliest entry into force if adopted

A vote is a vote — December could adopt the framework as approved, amend the sequence, or stall again. What December cannot change is the direction: every scenario on the table involves per-vessel intensity measurement with commercial consequences.

Where it lands on top of EU ETS and FuelEU

For ships trading to Europe, the NZF would be the third instrument on the same fuel decision. EU ETS prices emissions on European voyages today; FuelEU Maritime already regulates GHG intensity with its own penalty and pooling mechanics; the NZF would add a global intensity price on top. They measure related but not identical things, on different scopes, with different money. How Brussels adjusts its instruments against a global price is one of the genuinely open questions after December — and a topic we will keep covering as primary texts appear.

What to do before March 2028

The preparation that pays off under every scenario is not a fuel bet — it is data discipline:

1. Keep fuel and energy data per vessel, auditable, now. Attained GFI is computed from the same consumption records that already feed CII, EU ETS and FuelEU. If those records are clean, every future compliance position is arithmetic. If they are not, every instrument becomes an estimate argued with a verifier.
2. Know your intensity position before the regulation asks. A fleet that can state its attained intensity per vessel today can price the 2028 exposure in an afternoon — and negotiate charters accordingly.
3. Put 4 December 2026 on the board calendar. Not because the vote needs watching for its drama, but because fuel procurement and fixture decisions made in 2027 will be priced against its outcome.

Apeks view — The two-tier price is the framework’s most consequential design choice: $100 buys tolerance for transition, $380 makes standing still expensive. Owners who treat this as an environmental debate will meet it as a cost surprise; owners who treat it as a data-discipline problem will meet it as a spreadsheet. The second group sets the charter terms.