Skip to content

The Carbon Credit Gap

Ships Can Earn Credits for Switching Fuels — But Not for Capturing Emissions

Key Finding

Verra's CCS methodology framework (VM0049) contains zero modules for maritime capture and zero modules for mineralization storage. Meanwhile, the fuel-switching methodology for shipping (M0191) is at final Verra review. This means the voluntary carbon market is about to create a credit pathway for fuel switching — a strategy with significant ILUC integrity concerns — while at-berth capture, which has zero ILUC exposure, has no equivalent pathway.

The VM0049 Gap

Verra's modular CCS methodology (VM0049) currently includes five active modules:

Module Function Maritime Application
VMD0056 Direct Air Capture None — covers atmospheric capture only
VMD0057 CO2 Transport Potentially applicable to port-to-storage logistics
VMD0058 Geological Storage Not applicable — maritime uses mineralization, not injection
VMD0059 Additional tools No maritime-specific provisions
VT0012/VT0013 Calculation tools Generic, not calibrated for maritime parameters

Missing:

  • Maritime at-berth capture module — quantifying CO2 captured from vessel auxiliary engines using barge-mounted or dock-side systems
  • Mineralization storage module — quantifying permanent storage of CO2 as calcium carbonate through calcium looping

The CCS+ Initiative, which coordinates VM0049 module development, has zero maritime members. The initiative is led by South Pole and Perspectives Climate Group, with focus areas in industrial point-source capture and geological injection. Maritime capture is simply not on their roadmap.

The Fuel-Switching Problem

Verra methodology M0191 (fuel-switching for shipping) is at final review stage. When approved, it will enable vessels using alternative fuels — including biofuels — to generate Verified Carbon Units.

This creates a perverse market dynamic:

The ILUC Integrity Gap

ICCT's March 2026 analysis of IMO Net-Zero Framework biofuel provisions found that biofuel indirect land use change (ILUC) emissions could exceed 2008 baseline levels by 2035.1 Key findings:

  • Cumulative ILUC: approximately 950 Mt CO2e through 2035
  • Annual ILUC emissions could surpass the biofuel sector's direct emission reductions
  • The IMO's Net-Zero Framework projects $11.4–12.1 billion in annual revenue from carbon pricing (2028–2035) — much of which would flow to biofuel-based compliance

This means fuel-switching credits carry a fundamental integrity risk: the net climate benefit depends on assumptions about land use change that are difficult to verify and may not hold.

At-Berth Capture Has Zero ILUC Exposure

At-berth emissions capture physically removes CO2 from the exhaust stream and permanently mineralizes it as calcium carbonate. There is no fuel substitution, no supply chain dependency on agricultural commodities, and no indirect land use change. The captured carbon is measurable, verifiable, and permanent.

This makes at-berth capture credits a potentially higher-integrity asset class than fuel-switching credits — but only if a methodology exists to issue them.

Technology: Commercially Deployed, Not Theoretical

The integrated at-berth capture system combining criteria pollutant removal with CO2 capture has been independently verified and commercially demonstrated:

  • Performance verified at 99% PM, 95% NOx, up to 95% CO2, and 90% sulfur removal — independently verified by Yorke Engineering LLC under CARB and South Coast AQMD oversight2
  • Integrated emissions + CO2 capture demonstrated at the Port of Long Beach in April 2025 by STAX Engineering and Seabound on the Wallenius Wilhelmsen ro-ro carrier Talisman, with CO2 captured at approximately 80% efficiency and permanently mineralized as calcium carbonate. CARB and South Coast AQMD co-funded the demonstration.3
  • Deployed on a commercial vessel (UBC Cork, 5,700 GT cement carrier) as of February 2026, with captured carbon offloaded at the Port of Brevik, Norway for use in cement production

The technology works. The carbon market pathway does not yet exist.

Methodology Development Underway

EcoAsset Lab is developing concept frameworks for two new methodology components intended for Verra submission:

Module A: Maritime At-Berth CO2 Capture

  • Quantification framework for CO2 captured from vessel auxiliary engines
  • Applicable to barge-mounted and dock-side capture systems
  • Includes project emissions deductions for system energy consumption
  • Conservative default factors for capture efficiency variance across vessel classes

Module B: Mineralization Storage

  • Quantification and permanence framework for calcium looping storage
  • CO2 chemically bound as calcium carbonate (limestone) — thermodynamically stable at ambient conditions
  • Addresses Verra's measurement uncertainty concerns with mass-balance verification
  • Includes lifecycle assessment of sorbent (lime) production, including emerging "green lime" pathways

Target submission: 2026 (pending Verra Methodology Idea Note window)

The Window

The voluntary carbon market is at a decisive moment for maritime capture. M0191 (fuel switching) will be approved soon, establishing the precedent that shipping activities can generate VCUs. The question is whether capture — the higher-integrity pathway — gets its own methodology before the market consolidates around fuel switching.

The Methodology Idea Note window is the first-mover opportunity. After that, the timeline for methodology approval typically extends 12–18 months, with first credit issuance possible by 2028–2029.

Collaboration

Technology operators, port authorities, carbon market participants, and methodology developers interested in supporting or contributing to this filing should contact us.

  1. International Council on Clean Transportation, "IMO Net-Zero Framework biofuel provisions and indirect land use change implications," Brief ID 541, March 2026. Published at theicct.org. ↩

  2. Yorke Engineering LLC, independent verification of STAX Engineering barge-mounted emissions capture systems under CARB and South Coast AQMD oversight, March–April 2025. ↩

  3. STAX Engineering and Seabound, "Successfully Demonstrate First-Of-Its-Kind Integrated Emissions and Carbon Capture Solution," April 2025; independent verification by Yorke Engineering LLC. ↩