CDR

This chart is a stacked bar count of every company in the CDR Directory, grouped along the x-axis by removal pathway (direct air capture, enhanced weathering, biochar, ocean alkalinity, and so on), with each bar segmented by business focus: pure-play producers, brokers and marketplaces, and firms where CDR is a side business bolted onto a different core model. The total height tells you which pathways are crowded with company formation. The segment mix tells you something a raw count hides: whether a pathway’s apparent size is built on operators actually delivering tonnes, on intermediaries reselling them, or on incumbents whose CDR line is a minor adjunct. Two pathways with identical totals can have very different underlying economies once you see the split. ...

Captain Drawdown’s weekly Sunday selection — 15 candidate stories considered, 6-9 picked. Each link carries our 1-2 sentence take so you don’t have to click everything to know what’s there. The week’s signal sits at the intersection of policy plumbing and capital flows: jurisdictions are linking compliance markets while private registries and ocean-CDR vendors raise rounds that bet on those markets actually clearing. Meanwhile, the methodology frontier keeps creeping into stranger biology — fungi-mediated soil carbon credits being the latest test of what measurement, reporting, and verification (MRV) can credibly underwrite. ...

Take on a podcast episode from Reversing Climate Change, originally published Thu, 25 Ju. Listen: https://podcasters.spotify.com/pod/show/reversingclimatechange/episodes/405-Does-Managed-MRV-imply-the-existence-of-Unmanaged-MRV--w-Varsha-Ramesh-Walsh--Offstream-e3l8cev TL;DR Offstream is repositioning from a DMRV (digital monitoring, reporting, verification) software vendor to “Managed measurement, reporting, and verification (MRV)” — they do the work, not just provide a dashboard. Useful naming of an under-articulated category. Walsh’s claim: the head-of-MRV in-house hire is often more expensive than outsourcing the whole function. Plausible for small biomass developers, untested at scale. Most operational data in carbon projects still passes through a human at some point — bills of lading, odometer photos, clipboard entries. Honest admission worth hearing from a vendor. Thesis: every owner of a physical asset eventually becomes a carbon project developer. Big swing; light on the path to get there. Long surveillance-capitalism tangent eats ~20% of the runtime. Skippable. Ross Kenyon hosts Varsha Ramesh Walsh, cofounder/CEO of Offstream, on episode 405 to explain why Offstream stopped trying to be pure software and embraced what Walsh calls “Managed MRV” — a services-plus-platform model targeting biomass-based durable CDR developers (biochar, lumber mills with waste streams) and increasingly 48E ITC tax-credit work. ...

Take on a podcast episode from Interchange Recharged, originally published Tue, 24 Fe. Listen: <> TL;DR Hyperscaler power demand has flipped carbon capture from a regulation-driven to a buyer-led market in ~18 months. Plausible, and consistent with the Meta/Hyperion-type deals. ION claims natural gas + capture + storage lands at ~31 kgCO2/MWh — competitive with solar+storage on a lifecycle basis. Aggressive; rests on a 0.75% methane leakage assumption that is below US field averages. Cost adder: ~$20–25/MWh for retrofits, $16–18/MWh for new builds, inclusive of transport and storage. Useful number if it holds. ION’s pitch on its amine solvent: doesn’t degrade in oxygen, so 99% capture is achievable without the usual exponential energy penalty. Worth probing. Execution risk — getting power purchase agreements to final investment decision — is now the binding constraint, not policy or tech. 45Q stayed at $85/t under the current administration. Bridget van Dorsten hosts Tim Vail, CEO of ION Clean Energy, for a fairly technical hour on post-combustion capture at natural gas plants serving AI data centers. The framing is unapologetically pro-gas-plus-capture as a “clean firm” option alongside nuclear and geothermal — if you want a skeptical take on that premise, this isn’t it, but if you want the seller’s most coherent version of the argument with actual numbers, it’s here. ...

Take on a podcast episode from The Academic Minute, originally published Thu, 25 Ju. Listen: https://www.academicminute.org/p/petra-fromme-arizona-state-university TL;DR Petra Fromme (Arizona State University) describes nanoscale imaging of moisture-swing sorbents for direct air capture — material rearranges with humidity, controlling CO₂ uptake/release. Core claim: a porous resin sorbent performs especially well because its internal structure lets gases move more freely. Useful but unquantified — no kg CO₂/m³, no cycle data. Method angle (nanoscale imaging of structural changes under humidity swings) is the genuinely novel bit, not the moisture-swing concept itself (Klaus Lackner territory). Three-minute segment. Zero numbers on capacity, cost, durability, or scale. Treat as a research-direction pointer, not a result. Worth it only if you specifically track sorbent materials science for passive/moisture-swing direct air capture. This is a three-minute Academic Minute segment with Petra Fromme, Regents Professor of Chemistry and Biochemistry at Arizona State University, on academicminute.org. She’s pitching work done with graduate student Gayatri Yoga Ganeshan on moisture-swing sorbents for direct air capture — materials that grab CO₂ when air is dry and release it when air is humid, avoiding the thermal or pressure swing energy penalty. ...

This violin plot sorts every pure-play CDR company in the Directory by its pathway (columns) and its headcount (vertical axis, log scale from 1 to 100+). Each dot is one company, coloured by its current liveliness tier — Active, Moderate, Suspect, or Likely Dead. The grey shape behind each column is the size distribution: where it bulges, that’s where most companies in that pathway sit. The value here is comparative. A raw company list tells you who exists; this view tells you where the weight sits. Pathways with most dots stacked at the bottom are dominated by sub-10-employee firms — many small entrants, few that have grown. Pathways with dots reaching up the column have produced operators that scaled past the founder-and-a-few-engineers phase. Colour (not vertical position) is what tells you the health story: red dots high up the column mean a sizeable operator went quiet; red dots on the floor are the long tail churning as it always has. ...

Afforestation, reforestation and the wider “land sink” bucket Afforestation — planting trees where there were none in recent history — and its close cousin reforestation (replanting where forest was recently cleared) remain the largest single category of carbon removal sold today, by both tonnes issued and dollars transacted. The pitch is straightforward: trees pull CO₂ out of the air through photosynthesis and lock a fraction of it into wood, roots and soil organic matter for as long as the forest stands. The complications are equally straightforward: forests burn, get cut, get sick, and the carbon goes back. For a senior buyer comparing pathways, the central question is not whether trees sequester carbon — they obviously do — but how durable, additional and well-measured a given project actually is, and how that compares to engineered alternatives at 10–100× the price per tonne. ...

Take on a YouTube video from Dirk Paessler, originally posted 2026-06-22. Watch the source: https://www.youtube.com/watch?v=mE7n4WhDXH8 TL;DR Lucilla Boito (likely Hamburg/UHH group based on the feedstock list) ran sequential chemical extractions on enhanced weathering soil samples to track where cations actually end up. Four operationally-defined pools tested: exchangeable, carbonate, oxide/hydroxide, clay. Useful framing for anyone modeling residence time. Steel slag (40 t/ha) drove calcium up across nearly all pools; dunite drove magnesium across all pools; diabase showed up in three of four for Ca. Results track feedstock XRF composition. Caveat flagged by speaker: only n=2 per treatment, no statistics. Treat as directional. Sodium and potassium showed up in carbonate pools where they shouldn’t chemically exist — a useful reminder that sequential extractions dissolve primary minerals too, not just the named pool. Video here. This is a CDR Symposium 2026 talk by Lucilla Boito on sequential extraction results from a multi-feedstock, multi-soil enhanced rock weathering (ERW) experiment. The core question: when basalt, diabase, dunite, steel slag, or bassanite (“Eifelgold”) weather in soil, which operationally-defined pool do the released cations end up in — exchangeable, carbonate, oxide, or clay — and does the answer depend on soil type? ...

Each dot on this scatter is a single CDR pathway - direct air capture, enhanced rock weathering, biochar, ocean alkalinity, mineralization, and the rest. The horizontal axis counts how many companies are working that pathway; the vertical axis sums the employees across those companies. Linear scales on both, so distance on the page matches distance in the numbers. What this view reveals that a headcount table cannot is the shape of the industry. A pathway sitting high and to the right is crowded with firms and staffed deeply. One sitting high but to the left is a pathway dominated by a few large companies. Low and to the right means many small teams chasing the same idea. The spread between these corners is the story of where capital and talent have actually landed, versus where the field is still a cottage. ...

Take on a podcast episode from Reversing Climate Change, originally published Thu, 18 Ju. Listen: https://podcasters.spotify.com/pod/show/reversingclimatechange/episodes/404-When-will-insetting-work-for-carbon-dioxide-removal-w-Tom-Mills--Stripe-Climate-Fellow-former-e3kugqp TL;DR Tom Mills (ex-Stripe Climate Fellow, now at Mati Carbon) argues insetting durable CDR into ag supply chains is harder than the industry assumes — useful reality check. Coffee is the first ag value chain where biochar insetting actually pencils, driven by EUDR pressure, unmixed supply chains, and willing-to-pay CPGs. Plausible. GHG Protocol forces removals onto a separate ledger from scope 3 reductions — a structural block on insetting demand that’s underdiscussed. Important. “Supply shed” remains undefined; practitioners are setting norms by just doing it. Honest, slightly alarming. Real insetting business model = stacking non-carbon benefits (yield, pesticide residue, nitrate leaching, biofortification), not selling the ton. Worth the hour for value-chain folks. Ross Kenyon hosts Tom Mills — former Stripe Climate Fellow, now at enhanced rock weathering developer Mati Carbon (XPRIZE Carbon Removal grand prize winner) — on episode 404 of Reversing Climate Change. Mills spent his fellowship year on a single question: when does embedding biochar and enhanced rock weathering into Global South ag supply chains actually work? The honest answer is “not yet, and here’s why.” ...