Captain Drawdown’s daily logbook on every CDR story, paper, and expert voice — so you don’t have to read them all.
A biochar CORC transaction reportedly cleared at under $100 per tonne of CO2 this week.
The print came from Carba, sold to U.S. Bank, and was flagged by Kevin Lee Caster (@kevinleecaster.bsky.social on Bluesky): “As I understand it, Carba sold the biochar based CORCs to U.S. Bank for less than $100/tonne of CO2. I’m disappointed that the biochar will not be used as a soil amendment as that can help increase s[oil].”
The reference point it undercuts is the roughly $150/tCO2e figure that a Research and Markets biochar outlook this month describes as the stabilised level for durable removal credits, with high-integrity permanent tonnes earning a premium on top (GlobeNewswire). Same commodity class, roughly a one-third gap between one reported print and one published benchmark.
How was it measured? It wasn’t, in any formal sense. The $100 figure is a secondhand report from a knowledgeable observer on Bluesky, not a registry-disclosed clearing price or a broker index. The $150 figure is a market research estimate, not a traded index either. Both numbers are useful, and neither is audited. That is the state of biochar price discovery right now.
The implication for the sector is narrower than a single anecdote can carry, but it is worth stating. Biochar accounted for about 86% of delivered global carbon removal tonnes in 2024 (Biochar Today), and reported biochar demand has reached 2.99 million tonnes (CarbonCredits.com). So where biochar credits clear matters more for realised CDR revenue than where DAC or ERW headlines suggest. If some transactions are landing near $100 while headline benchmarks sit near $150, developer revenue models pegged to the benchmark will overshoot, and buyer procurement teams pegging bids to the benchmark may be overpaying relative to what at least one peer accepted.
The caveat, which is where the prior version of this post overreached, is that one reported transaction does not redraw the market. Supercritical reports that 81% of high-quality 2026 biochar supply was already committed by July via long-term offtake (Biochar Today). Scarce premium tonnes are locked up. A sub-$100 print likely reflects a specific tier: a specific vintage, registry, feedstock, and end-use. Caster’s own note that the char will not be used as a soil amendment is part of the price story. What a buyer pays reflects what a buyer is buying, and biochar is not one product.
The number to watch next is the second data point. If Climate Week NYC or NACS 2026 surfaces additional transaction-level biochar prices, and especially if registries or brokers begin publishing cleared prices segmented by tier rather than a single aggregate, the shape of the actual price distribution becomes legible. Until then, treat both the $100 print and the $150 benchmark as endpoints of a range, not as competing truths. For context on why biochar sits alongside, not against, other durable pathways, see Why Carbon Removal Needs More Than Trees.
Citations
- Bluesky — @kevinleecaster.bsky.social on Bluesky — Bluesky post
- Globenewswire — GlobeNewswire
- Biochartoday — Biochar Today
- Carboncredits — CarbonCredits.com
- Biochartoday — Biochar Today