Scope 3 emissions accounting is becoming the great leveller. For decades, a European receiving freight from Asia saw the exporter report higher CO₂ emissions. Now, the rectification of this arrangement has meant shipping’s customers are financially liable for Scope 3 emissions.

Some major shippers and charterers are seeking greater visibility over how ships perform during voyages and becoming active participants in ship efficiency and voyage optimisation.

They are also starting to advertise shipping’s carbon reduction wins as their own.

Data released this month showed that Sea Cargo Charter (SCC) signatories, who together represent about 14% of shipping trade, were able to improve their trajectory relative to the IMO’s year-on-year climate goals, from 12.2% behind in 2024 to 11.6% behind in 2025.

“Sea Cargo Charter signatories did not let their decarbonisation efforts slip over what was an incredibly tumultuous period for the sector,” said James Lewis, and Cargill Ocean Transportation Head of Operations and chair of the Sea Cargo Charter. Lewis added, however, that a global IMO regulation would be needed.

“This ability to keep scores stable is not guaranteed in the future,” he added. “Although signatories remain committed to their decarbonisation efforts, the IMO’s climate alignment goals will become progressively further out of reach without the tangible incentives and level playing field that a global regulatory framework would deliver.”

Any reduction in the carbon cost of shipping goods is an improvement for Scope 3 emissions profiles. But it should be unsurprising that the carbon emission reductions recorded by the SCC arose largely as a result of speed optimisation, weather routing and live performance monitoring. These technologies can produce substantial results often without the need for major hardware to be installed on a vessel.

But adding an additional challenge to overcoming the charter-owner split-incentive problem, when it comes to retrofits, financing can be difficult for owners to access for an asset that is already built, possibly halfway through its operating life, and still saddled with some level of debt.

“To allow shipowners to finance different parts they install on a ship, separately – you would really have to change the entire structure of global finance,” a financier stated on the sidelines of London International Shipping Week. “Banks are nervous and are stuck in limbo.”

Hence, efforts are underway to support retrofits via other routes. Rather than waiting for shipowners to propose efficiency measures and as part of its Ecoshipping Programme, Brazilian mining giant Vale led a project to install five Norsepower rotor sails on a 325,000dwt very large ore carrier (VLOC), in partnership with its owner Pan Ocean.

Vale estimated efficiency gains of up to 8% and annual emissions reductions of approximately 3,400 tonnes of CO₂ equivalent per vessel.

Vale has since expanded its commitment to wind-assisted propulsion. In 2024, a capesize bulk carrier operating under contract for the miner was retrofitted with rotor sails, becoming the first vessel of its type to adopt the technology. The installation is expected to reduce fuel consumption and greenhouse-gas emissions by between 6% and 10% when combined with voyage optimisation measures.

In another example early last year, Mærsk unveiled an ambitious plan to part-fund retrofits for some 200 of its 389 chartered-in vessels, benefiting some 50 shipowners. In each case, half the cost is provided by Mærsk, and the rest is provided by the owner.

The money is going toward affixing new propellers and pre-swirl devices, waste heat recovery, new bulbous bows, and increasing cargo capacity through raising lashing bridges. Some 1,500 projects are already completed, with 1,000 more due by 2027.

Mærsk later revealed it would deprioritise work with those owners that refused to upgrade.

Our medium- and long-term chartered fleet makes up a significant proportion of our operations as well as of our total fuel consumption,” said Mærsk. “The model is a win-win… we can reduce both emissions and fuel costs, while the owners get the long-term value of a modernised vessel.”