Captain Drawdown’s daily logbook on every CDR story, paper, and expert voice — so you don’t have to read them all.
The maritime decarbonization story this week is that DNV verified a 98% capture rate on a Carbon Ridge onboard unit, and shipping press, LinkedIn, and several procurement desks are quoting it as if maritime CDR just shipped. It hasn’t. The number is real. The framing is wrong. And the gap between those two facts is exactly the accounting trap that will detonate maritime MRV (measurement, reporting, verification) in 2027.
The consensus. Onboard carbon capture is decarbonizing shipping. Class society verifies 98% efficiency, owners install the kit, fuel stays cheap, and the sector buys time on its IMO trajectory. The Carbon Ridge announcement was reported almost universally this way. Marketers and a few buyers are already calling these tonnes “removal.”
Steel-man. It is a real engineering result. A 98% capture rate at the funnel, verified by a serious classification society, is hard. If the downstream chain closes - port offload, CO2 carrier, geological injection - this is a credible pathway for residual maritime emissions that batteries and ammonia cannot touch this decade. Onboard CCS belongs in the toolkit. Nobody serious disputes that.
The break. The 98% is a point-of-capture efficiency. It is not a cradle-to-permanent-storage figure. The 3rd Edition State of Carbon Dioxide Removal is explicit: capture without verified permanent storage does not count as removal. Onboard CCS with offload-to-storage chains currently has no published end-to-end MRV protocol. The funnel number is being conflated with a removal number, and those are different categories of object.
Supporting evidence the consensus glosses.
First, the storage side is only now being built. MISC and K Line just secured a second Northern Lights charter for a CO2 carrier. The boats to move captured shipboard CO2 to wells are pre-revenue. You cannot credit a tonne as removed before the chain that removes it exists.
Second, storage is the binding constraint, not capture. The European Commission’s own assessment confirms EU CO2 storage capacity falls short of the 2030 target. Crediting funnel-efficiency tonnes against a storage shortfall manufactures phantom inventory.
Third, the atmospheric physics is sharpening, not softening. The new Nature Geoscience paper on stratospheric cooling and amplified radiative forcing quantifies that vented or re-released CO2 has non-linear consequences on decadal timescales. As David Ho (@davidho.bsky.social) put it, the processes setting the vertical profile of stratospheric cooling “were not fully understood… until now.” The 2% slipping the funnel plus any venting before injection is not a rounding error. It is a forcing term.
Where the consensus is partially right. Onboard CCS is genuinely useful for hard-to-abate residual maritime emissions, which is what CDR is for in the first place. The technology works. The class verification is meaningful. The mistake is the boundary, not the kit.
Implication. If you are buying maritime credits or writing MRV in 2026, the Carbon Ridge cycle is your test case. Robert Höglund (@roberthoglund.bsky.social) recently argued net zero has to be “a commitment to act on the system, not just account for emissions.” Onboard CCS sold as removal, before the storage chain closes, is the accounting-only failure mode he is warning about. It is forestry’s wrong-boundary mistake in a new hull.
Procurement teams should demand chain-of-custody mass balance from stack to injection, not funnel efficiency. Watch whether Isometric, Puro.earth’s CRCF program, or DNV itself publishes a maritime onboard CCS methodology requiring end-to-end measurement, and whether the first Northern Lights offload from a captured cargo arrives with a verifiable mass balance attached. Until then, 98% is an engineering result. It is not a tonne. The durability hierarchy still rules: capture without verified storage is not removal, no matter who is holding the certificate.
Citations
- Carbon Herald — Carbon Ridge announcement
- Stateofcdr — 3rd Edition State of Carbon Dioxide Removal
- Carbon Herald — second Northern Lights charter for a CO2 carrier
- European Commission — [European Commission’s own assessment](https://ec.europa.eu/transparency/documents-register/detail?ref=COM(2026)
- Nature — Nature Geoscience paper on stratospheric cooling and amplified radiative forcing — research paper
- Bluesky — @davidho.bsky.social — Bluesky post
- Bluesky — @roberthoglund.bsky.social — Bluesky post