Bridging the gap to maritime net zero

How do we bridge regulatory ambition with practical implementation? And in a world of regional schemes like the EU ETS and voluntary tools like Book & Claim (B&C), where does innovation fit? Drawing from recent analyses, including September 2025 report on Carbon3's synergy with MEPC 83, this article explores how Carbon3 not only complements these frameworks but accelerates equitable, scalable decarbonization.

Carbon3 for MEPC 83

MEPC 83's outcomes are bold: a two-tier GHG levy, $100/tCO2 for emissions between compliance & base targets, and $380/tCO2 for emissions above base targets, alongside a fuel standard mandating progressive GHG intensity reductions via low-carbon options like biofuels and e-fuels. Revenues from the levy will fund equitable transitions, including subsidies for developing nations. However, success hinges on infrastructure. Building bunkering facilities and scaling e-fuel production demands hundreds of billions in capital, far beyond what the levy alone can muster.

Carbon3 positions itself as financial infrastructure, and can help IMO MEPC succeed by integrating with IMO's Data Collection System for seamless verification, enabling trading of Surplus Units (SUs) from overcompliance, and distributing levy burdens across Scopes 1-to-3 stakeholders; all of this is possible with Carbon3's inset credits as a instrument. Unlike traditional offsets, Carbon3 keeps impacts embedded, turning compliance into profit for shippers, cargo owners, and investors. Without such tools, delays could jeopardize 2030 goals.

Carbon3 and Book&Claim

While MEPC 83 enforces global standards, voluntary mechanisms like Carbon3 and B&C drive private action. B&C is a chain-of-custody methodology that "books" sustainability attributes at production, and allows "claiming" elsewhere without physical delivery, ideal for aviation and emerging in maritime under FuelEU Maritime. Carbon3 builds on insetting principles but evolves into a full marketplace: credits represent current or future verified reductions traded on open markets to drive incentives, co-financing and de-risking of sustainability initiatives and new infrastructure projects. B&C handles attribution; Carbon3 adds liquidity. In terms of core focus, B&C emphasizes the attribution of fuel attributes without physical linkage through certification-based processes, while Carbon3 prioritizes tradable insets for chain-wide reductions with trading and financing.

Economically, B&C offers scalability with low logistics costs and new revenue for producers, but it has static claims that limit monetization and fragmented pricing; conversely, Carbon3 provides high liquidity via pre-purchase and arbitrage to de-risk new infrastructure investments. From a sustainability perspective, B&C boosts fuel demand signals and equitable access for small operators, yet its physical disconnect may slow uptake and remains fuel-centric; Carbon3 ensures additionality and integrates the whole Scope 1, 2 and 3 spectrum of stakeholders to participate physically and/or financially.