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 connecting thread this week is accountability — who checks the numbers, and what happens when they don’t hold. Two governments faced scrutiny over how removal money and removal policy actually get executed, two registries and frameworks opened up their accounting logic for inspection, and a stack of new bench science quietly explained why several pathways are slower or messier than the pitch decks suggest. If you only have ten minutes, read the policy pair; if you’re building or buying, the methodology cluster is where the money will move.
Policy & public money
- LinkedIn (Carbon Gap) — UK GGR Review — Government response — The UK response to the independent GGR review is the clearest signal yet on whether engineered removals get a real demand-side mechanism (ETS integration, business models) or stay in pilot purgatory. Worth reading alongside the review itself: the UK remains the only major economy with a semi-articulated plan to fold removals into a compliance market on a stated timeline.
- Carbon Herald — Lawmakers Accuse DOE Of Illegally Using Carbon Capture Funds To Subsidize Coal — Beyond the legal question, this is reputational damage the CDR field can’t afford: every dollar of capture appropriations repurposed to prop up coal makes the “CCS/CDR is a fossil lifeline” critique harder to rebut in the next budget cycle. Watch whether DAC hub money gets pulled into the same fight.
Methodology & measurement fights
- Carbon Herald — Verra Looking For Feedback On A Major Revision To Its VM0044 Biochar Methodology — Biochar is still the workhorse of actually-delivered durable CDR (routinely the large majority of tonnes delivered, per CDR.fyi), so a major VM0044 revision affects real supply, not roadmaps. Also a competitive story: Verra tightening here is partly a response to Puro having captured most of the durable biochar market.
- EarthArXiv — Atmospheric Mineral Carbonation and the Case against Ca(OH)₂ Dispersal: A Four-Barrier Feasibility Analysis — A useful negative result: the chemistry of aerial lime dispersal is sound, but the paper argues the pathway fails on kinetics, energy, logistics, and exposure risk — the kind of structured takedown the field needs more of before ventures form around chemically plausible but practically dead ideas.
Bench science: where the rate limits actually are
- sciencedaily.com — How to solve a bottleneck for CO2 capture and conversion — Integrated capture-to-conversion systems have historically been hostage to feedstock concentration swings; the MIT group’s nanofiltration buffer decouples the electrochemistry from that variability, which matters more for real-world operation than headline efficiency numbers do.
- npj Materials Sustainability — Aqueous matrix and limiting factors in steel slag carbonation under elevated CO2 at ambient conditions — Steel slag is one of the few alkaline feedstocks available at tens of megatonnes per year with negative disposal costs, but this work confirms the kinetics are less forgiving than mass-balance estimates assume — directly relevant to anyone pricing industrial-byproduct weathering credits.
- Zenodo — Local Mass-Transfer Boundary Conditions Control Basalt Carbonation Pathways during CO2 storage — Pore-scale heterogeneity in basalt carbonation determines whether mineralization seals storage capacity shut or keeps it open — a first-order question for scaling the Carbfix-style in-situ storage model beyond its current well-characterised sites.
The dominant signal: the field’s infrastructure of trust — registries, government programs, feasibility gatekeeping — is under active renovation, and mostly for the better. Conspicuously absent this week: any notable purchase or offtake announcement, a reminder that the demand side remains the quietest corner of the market.