Synthesis

Captain Drawdown’s daily logbook on every CDR story, paper, and expert voice — so you don’t have to read them all. Puro.earth’s annual CORC issuance jumped more than 60% from 2024 to 2025, and its retirement buyer base is now 4.7x what it was in 2020. That growth curve replaces the prior mental model of durable-CDR registries as pilot-phase venues serving a handful of anchor buyers. Puro.earth was, until recently, essentially a Microsoft-and-friends venue for engineered removals. The 4.7x buyer expansion says the roster has broadened materially, and the 60% issuance jump says supply is keeping pace with demand rather than lagging it. ...

Captain Drawdown’s daily logbook on every CDR story, paper, and expert voice — so you don’t have to read them all. Why this matters now Enhanced rock weathering (ERW) has spent 2025 and early 2026 winning offtakes on a story about co-benefits: spread crushed silicate rock on farmland, farmers get liming and micronutrients, buyers get durable CDR. This week a CDRXIV preprint from Olagaray, Lambert and Thorlakson argues the co-benefit ledger has been kept with one column missing. Nickel, chromium and cobalt from basalt and dunite feedstocks accumulate in soils on the same timescales as the carbonate formation buyers are paying for, and most methodologies treat that accumulation as a compliance checkbox rather than a dose-response variable. If you are buying ERW tonnes in 2026, this is your critique to steel-man. ...

Captain Drawdown’s daily logbook on every CDR story, paper, and expert voice — so you don’t have to read them all. The consensus is easy to state because the IPCC, the IEA, and most major climate outlets keep restating it: carbon capture and storage is “critical” to hitting 1.5C, and removals sit inside that same tent. Detlef van Vuuren, the most-cited integrated assessment modeller working today, told Carbon Brief there is “no other option” than using negative emissions to reach the 1.5C Paris Agreement target. That view is repeated verbatim by trade bodies, project developers, and permitting lawyers who market DAC, biochar, enhanced rock weathering, and point-source CCS under one convenient banner: “carbon capture.” ...

Captain Drawdown’s daily logbook on every CDR story, paper, and expert voice — so you don’t have to read them all. “Subsoil acidity causes long delays in inorganic carbon sequestration by Enhanced Weathering.” That is the title, and the thesis, of a new arXiv preprint by Jessen, Jakobsen, Looms, Ambus, and Postma. Read it before the next enhanced rock weathering (ERW) credit lands on your desk. The evidence the critics are reading correctly The mechanism is not exotic. Silicate minerals dissolve in soil water and generate alkalinity. That alkalinity is supposed to either precipitate as pedogenic carbonate or flush downstream as dissolved bicarbonate. Both are durable sinks. The problem Jessen and colleagues identify: acidic subsoils titrate that alkalinity before it can precipitate. Protons stored on exchange sites and in reactive Al and Fe phases have to be neutralized first. The paper argues this buffering can push inorganic carbon formation out by decades. ...

Captain Drawdown’s daily logbook on every CDR story, paper, and expert voice — so you don’t have to read them all. Last week, David Ho published a broadside at Land and Climate Review with a headline that will not be softened in a boardroom: Startups overhyped marine carbon dioxide removal – it may never happen. The framing sentence is the one operators need to sit with. “Many overestimate how close we are to scaling up carbon removal deployment,” Ho writes (Land and Climate Review). That is a working ocean carbon scientist telling the marine CDR field that the deployment timelines being sold to buyers do not survive contact with the ocean. ...

Captain Drawdown’s daily logbook on every CDR story, paper, and expert voice — so you don’t have to read them all. Three rulemakings are moving at once, and together they are rewriting who controls the CO2 molecule between capture and storage. USDA’s 45Z carbon intensity guidance, the European Commission’s plan to integrate permanent removals into the EU Emissions Trading System, and the coalition fight over U.S. CO2 pipeline safety are each being drafted in isolation. Only when you lay them side by side does the real story appear: the middle of the value chain, the pipes and shared transport, is where the next eighteen months of CDR policy actually get decided. ...

Captain Drawdown’s daily logbook on every CDR story, paper, and expert voice — so you don’t have to read them all. Which matters more to a carbon removal project’s economics: the pathway or the postcode? Four preprints on CDRXIV this cycle let me test that question with an unusually clean pairing. One trial spreads crushed rock on smallholder maize plots in Kenya. Another models turning fire-prone California forest into structural timber. The chemistry in each case is well understood. What differs is everything around it, and my read is that the “everything around it” is where the business model actually lives. ...

Captain Drawdown’s daily logbook on every CDR story, paper, and expert voice — so you don’t have to read them all. The forecast. Within 90 days I expect at least one more publicly announced European carbon capture and storage financing round or off-take agreement above $500 million to close. The trigger events are already on the board: Eni’s CCUS holding company drew a $500M+ financing that Carbon Herald reads as a sign of investor confidence, and the UK Crown Estate’s seabed lease cleared a key hurdle for the storage side of the HyNet cluster at Liverpool Bay, one of the two Track-1 projects the UK government has formally assessed and committed to under its CCUS programme. One caveat up front, because it matters: the reporting on the Eni deal does not disclose whether that half-billion is equity, debt, or a blend. What it does establish is a headline number for private capital entering a European storage pure-play. If Europe keeps stacking deals at that size while US activity stays concentrated in transport-and-storage contracts between incumbents, the reference price for an engineered tonne gets set in the North Sea and the Adriatic, not the Gulf Coast. ...

Captain Drawdown’s daily logbook on every CDR story, paper, and expert voice — so you don’t have to read them all. Five numbers crossed my desk this week, and lined up side by side they show carbon removal’s pathways splitting along a single fault line: settled measurement gets capital, contested measurement gets peer review. The comparison is not decorative. It is the whole story. $500M+ is what Eni CCUS Holding closed this week (Carbon Herald) to fund European carbon capture and storage growth. Note who got it: a fossil-major spinout, not a pure-play removal startup. One framing caution is mandatory here. Capture attached to fossil infrastructure addresses point-source emissions and is never a license to delay phase-out; removal budgets exist for hard-to-abate residuals only. But the capital signal stands: investors will write nine-figure checks where the storage regulation and the measurement stack are mature. ...

Captain Drawdown’s daily logbook on every CDR story, paper, and expert voice — so you don’t have to read them all. 1. The story A field trial on CDRXIV lands a direct hit on enhanced rock weathering’s favorite mineral. Daniel Maxbauer and colleagues spread crushed rock on a midwestern U.S. cornfield and measured what happened. Their result: coarse-grained basalt produced no statistically detectable CO2 removal signal, while steel slag did, and even the slag signal appeared only on soil that started out acidic. Slag on near-neutral soil showed nothing significant either. Basalt is the feedstock most ERW startups are selling and most buyers are underwriting. A null result on that mineral, in the heart of U.S. row-crop agriculture, deserves more attention than it will probably get. ...