Microsoft and NORDEN Complete First RSB-Verified Maritime Book and Claim Transaction

Microsoft and Danish shipping company NORDEN have completed a pilot transaction that marks the first verified maritime emissions reduction delivered by a shipping carrier through the Roundtable on Sustainable Biomaterials, or RSB, Book & Claim Registry.

The transaction builds on a collaboration announced by Microsoft and NORDEN in 2025 and represents an effort to establish a more standardized system for companies seeking to reduce greenhouse gas emissions associated with ocean freight.

Under a book-and-claim system, the environmental attributes associated with sustainable fuel use can be separated from the physical fuel itself. A company can therefore finance the use of sustainable fuel elsewhere in the transport system and receive the associated verified emissions reduction claim, even if the fuel is not physically used on the vessel carrying its goods.

This approach is designed to address one of the main barriers to decarbonizing global freight: sustainable marine fuels remain limited in availability and are not distributed evenly across ports and shipping routes.

The latest transaction is the first in which a maritime carrier has issued and delivered verified emissions reductions through the RSB Book & Claim Registry. Microsoft is also the first company to use the RSB system to make such a claim for shipping-related emissions.

Building on the Companies' Earlier Shipping Pilot

Microsoft and NORDEN began working together on maritime supply chain emissions in 2025.

That initial program was expected to reduce Microsoft's maritime Scope 3 emissions by nearly 10,000 metric tons of carbon dioxide equivalent over three years. NORDEN said it used certified waste-based biofuel across several voyages, with the fuel providing estimated life-cycle greenhouse gas reductions of approximately 80% to 90% compared with conventional fossil marine fuels.

The resulting emissions reductions were then allocated to Microsoft using a book-and-claim approach rather than requiring the biofuel to be consumed specifically by ships carrying Microsoft-related cargo.

According to NORDEN, the original pilot included independent verification and followed a framework developed by the Smart Freight Centre to support traceability and reduce the risk of inaccurate emissions claims.

The new development takes that model further by integrating the transaction into RSB's formal Book & Claim Registry.

RSB Expands its Framework Into Maritime Transport

RSB launched its Book & Claim system initially with a strong focus on sustainable aviation fuels. The organization has increasingly expanded the framework toward other hard-to-abate sectors where direct access to renewable fuels can be constrained.

Its registry allows sustainability attributes associated with certified renewable fuels to be separated from the physical product and converted into transferable units. Eligible account holders can then transfer and retire these units to support sustainability claims.

The registry is intended to create a controlled chain-of-custody mechanism while reducing risks such as double counting, in which more than one company claims the same environmental benefit.

For the Microsoft transaction, NORDEN became the first maritime operator to obtain RSB Book & Claim trader certification. That certification is required for companies issuing and selling verified emissions reductions through the registry.

RSB and NORDEN worked together to adapt an existing framework originally developed for aviation to accommodate maritime carriers and shipping-related transactions.

Following the pilot, RSB said it intends to update its Book and Claim Chain of Custody procedure to support broader adoption across maritime transport.

Addressing Difficult Scope 3 Emissions

The model could be particularly relevant for companies whose climate inventories include significant emissions from outsourced freight.

Transport emissions generated by third-party logistics providers typically fall within Scope 3 rather than a company's direct operational emissions. Businesses often have less control over these sources because carriers determine vessel selection, routing and fuel procurement.

Book-and-claim mechanisms can give cargo owners an alternative to waiting for sustainable fuels to become available on every route they use.

For Microsoft, reducing value-chain emissions forms part of a wider target to become carbon negative by 2030. The company has committed to cutting Scope 3 emissions by more than half from a 2020 baseline while reducing Scope 1 and Scope 2 emissions to near zero.

The maritime transaction therefore provides a potential mechanism for addressing one relatively difficult part of Microsoft's supply chain footprint.

It does not, however, eliminate the need to reduce physical emissions from shipping. Book and claim systems depend on actual lower-carbon fuel being consumed somewhere within the relevant transport system, while credible accounting systems are required to ensure that the same reduction is not claimed more than once.

Shipping Faces a Major Fuel Transition

The pilot also comes as the shipping sector faces increasing pressure to replace conventional fossil fuels.

The International Maritime Organization's 2023 greenhouse gas strategy calls for international shipping to reach net-zero greenhouse gas emissions by or around 2050. It also includes indicative checkpoints for total emissions reductions of at least 20%, while striving for 30%, by 2030 compared with 2008 levels.

By 2030, zero or near-zero greenhouse gas emission technologies, fuels and energy sources are expected to account for at least 5% of international shipping's energy use, with an ambition to reach 10%.

Alternative fuels are expected to play a central role, but scaling them requires investment in production, bunkering infrastructure and long-term demand.

Book and claim systems could support that process by allowing corporate buyers to create demand for sustainable fuels even when their own shipping routes do not yet have access to them.

Implications for Cargo Owners and Shipping Companies

For cargo owners, the Microsoft-NORDEN pilot demonstrates a possible method of financing maritime decarbonization while addressing reported supply chain emissions.

For shipping companies, the model could create an additional revenue stream connected to sustainable fuel investments. Carriers using qualifying renewable fuels could potentially separate the fuel's emissions attributes from the physical shipment and transfer those attributes to companies seeking verified Scope 3 reductions.

The effectiveness of the model will depend heavily on the quality of certification, emissions accounting, chain-of-custody procedures and rules governing corporate claims.

RSB has continued updating its book and claim framework as the market develops. Its Book & Claim Manual establishes rules governing issuance, management and retirement of sustainability attributes, while its registry procedures are designed to support traceability and credible claims.

NORDEN said it now plans to work with additional customers and partners to scale the solution, with the longer-term objective of making verified emissions reductions available as a more standard component of ocean freight services.

If similar systems gain broader industry acceptance, book and claim could help connect corporate demand for lower-emission logistics with sustainable fuel projects that would otherwise struggle to find buyers.

The Microsoft pilot is still an early example, but its significance lies in moving maritime book and claim from a bilateral corporate experiment toward a standardized registry-based mechanism that could potentially be used across a wider range of international supply chains.

Source: www.esgtoday.com