Market averages for one tonne of CO₂e, 2025–26: $6 for avoided deforestation, over $500 for direct air capture.1 Same tonne, same atmosphere, same certificate format. The spread is not a discount — it is a different object, and choosing between them is the first honest decision anyone has to make.
Avoided-deforestation (REDD+) credits pay a landowner not to cut. The tonne is counted against a baseline of what would supposedly have happened otherwise — a counterfactual nobody can observe. A synthesis of six independent ex-post evaluations covering 44 projects found they claimed 10.7 times more avoided deforestation than the evidence supports; the projects mostly did reduce deforestation, just far less than they sold. Project proponents contest the method, and that dispute is itself unresolved.
Reforestation is real removal and it dominates issuance: around 7.5 million ARR credits in 2025, more than all long-duration removal credits ever issued by the same registries. But biological carbon can come back out — one fire season, one drought, one change of owner. It is storage with a cancellation clause, and registry supply looks larger than it is: of 773 listed ARR projects, only 158 have issued anything.
Soil-carbon credits come with genuine agronomic co-benefits — water retention, resilience, yield. The problem is measurement: demonstrating a change in soil stock takes years of sampling across heterogeneous ground, and the signal is small against the noise. We found no public price index for it, which is why this panel shows none. Thin, bilateral trading is a finding about the method, not a gap in our research.
Biochar fixes carbon into a stable solid, quantified at the kiln rather than estimated across a landscape. It is the dominant durable pathway by contracts — nearly five times more unique buyers than the next method — and it survives being checked. Note the disagreement underneath the average: the Puro CORC biochar index printed $143 in July 2025, while suppliers surveyed said they need $187 to make a reasonable profit.
Enhanced rock weathering converts CO₂ into dissolved bicarbonate — effectively permanent. The durability is not in question; how much actually weathered, how fast, and how much you may count is exactly what the field is still standardising. Suppliers surveyed in 2025 said they need $349/t to be profitable while buyers called $271/t expensive — the gap is the state of the method, priced.
Direct air capture is unambiguous: molecules pulled from the atmosphere and put underground, metered end to end. It is also scarce and priced accordingly. Buyers surveyed put the “good value” point at $458/t in 2025 and expect roughly a 41 % fall by 2030 — which means buying it today is partly buying the scale-up of an industry that does not exist yet at meaningful size.
The measurement is not finished and will not be for a while. Waiting for it would be the comfortable option. It is also not finished as a decision: we have not chosen a supplier, bought anything, or set a date. This section says where that stands rather than announcing a policy we cannot yet stand behind.
A shipped Drop is estimated at ~38 g CO₂e, plausible band 15–120 g, location-based, ISO/IEC 21031 boundary. That is a first-cut figure from assumed activity, not from telemetry, and its largest input is still an assumption rather than a measurement. Buying removals is a decision we have not made yet. No supplier is chosen, no purchase has been made, no date is set, and the ledger below is empty. We deliberately do not set a removal quantity against that estimate here: a removal purchase does not undo an emission, and the comparison people want to draw between the two is the one this page refuses to make. We would rather show you an empty table than imply a retirement that has not happened.
Buying the $6 tonne would make a removal cost €0.006 per Drop and be worth about that under scrutiny. The whole point of the exercise is that receipts survive being checked, so the criterion we are working to is a form of carbon that can be checked — measured at the point of capture rather than estimated across a landscape, and retired with a registry serial. Which method meets that bar is exactly what we have not settled. No supplier has been selected and no purchase has been made. A removal without a retirement serial is a receipt for a promise.
It is not a neutrality claim, and we will not make one. A measured footprint and a removal purchase are two separate facts and we keep them on separate lines — fusing them into a causal sentence is precisely what Directive (EU) 2024/825 blacklists from 27 September 2026, and what the BGH found misleading in Katjes. Reduction and compensation are not equivalent. Reduction comes first.
Our music and image providers do not publish which country their servers run in, and we have not found it in their documentation. Until that is resolved, grid intensity stays at a 100–700 gCO₂e/kWh band — the widest single term in the estimate. Writing to both providers is on the list; whatever comes back, including silence, gets published here.
Overshooting is a stopgap, not an answer. It buys time to narrow the band; it does not narrow it. The work that counts is getting the estimate from ×/÷8 to ×/÷3 — and the fastest route there is two disclosures we do not control.
A claim that carbon was removed is worth exactly as much as the registry serial behind it. Each purchase will appear here with supplier, tonnage, price paid, the Drops it covers and a link to the retirement record on the registry — checkable by anyone, without asking us.
Mirrored on bdrop.studio alongside the artist payout record, so the carbon receipts and the artist receipts are checked the same way and in the same place.
Knowing how to pay for a tonne is the easy half. The hard half is knowing how many tonnes you owe. Drag the assumptions and watch the honest answer stretch.
Sylvera, carbon offset pricing (2026 update): average transacted price by method — REDD+ $6, ARR $22, biochar $177, ERW over $200, DAC over $500. Averages across a wide distribution; regional spreads are large (African afforestation $37 vs Asian $14).
sylvera.comCDR.fyi × OPIS, Bridging the Gap: Durable CDR Market Pricing Survey (Jan 2025), 97 suppliers and 25 purchasers: biochar $187 profitable vs $155 “expensive”; ERW $349 vs $271; DACCS “good value” $458, expected to fall ~41 % by 2030. Puro.earth CORC biochar index $143 (Jul 2025).
cdr.fyiNature Communications (2026), synthesis of six ex-post evaluations across 44 REDD+ projects: most reduced deforestation, but claimed 10.7× more than independent estimates justify. Original: West et al., Science (2023). Contested by Mitchard et al. (2023), who argue the comparison uses ex-ante baselines rather than issued credits. We cite both.
science.org · ade3535Wu et al. (2026), Joule: frontier models (>200 B parameters) on H100 nodes, median 0.31 Wh/query, IQR 0.16–0.60 — the ×/÷ 1.94 band used here. ARR issuance figures: Berkeley Carbon Trading Project Voluntary Registry Offsets Database (v2026-06).
cell.com/jouleThe durability / affordability / verifiability bars are our own qualitative reading of the literature, not a score any registry issues. The ordering is defensible; the exact lengths are a judgement. Treat them as a way to compare methods against each other and nothing more.
The explorer is a derivation, not a measurement: spend → GPU-seconds → watt-hours → grams, at 700 W (H100 SXM TDP), 75 % utilisation and PUE 2.4 for a non-hyperscale host, plus a flat 25 Wh allowance for everything that is not the accelerator — orchestration, storage, transport — which at the default settings is the majority of the total and does not move when you drag the dials. Its headline input, the per-generation cost, is an assumed $0.08 rather than a figure off a bill, and that assumption is why the band is this wide. It exists to show how far an answer moves when assumptions move. It is replaced by bdrop.studio telemetry in the next entry, or it comes down.
Grid intensity, data-centre energy and per-prompt figures used across mint trees are sourced in the research log. Prices are market averages from 2025–26 and move; each is dated at its source. Corrections welcome and published with attribution.