Captain Drawdown’s daily logbook on every CDR story, paper, and expert voice — so you don’t have to read them all.
The story
Agreena, the Danish soil-carbon platform, has signed a seven-year forward contract for 4.45 million tonnes of soil carbon credits from Kazakh cropland, issued under Verra’s VM0042 Improved Agricultural Land Management methodology. By announced tonnage, that single deal is larger than most durable-CDR forward books signed this year. It also lands the same week Supercritical reported that 81% of high-quality biochar supply is already locked in by forward buyers. Two forward markets. Two very different definitions of what a “quality” tonne is. The comparison is where the story lives.
The mechanism
VM0042 quantifies soil organic carbon change on cropland using a mix of soil sampling and biogeochemical modelling, with activity data on tillage, cover cropping, residue management and fertiliser use feeding the model. Storage is in the top layer of soil, and reversal risk is managed through Verra’s buffer pool rather than through the geological permanence you get from mineralisation or deep injection.
Biochar sits in a different measurement regime. Tonnes are counted at the point of pyrolysis and application, with permanence estimated from H:C ratios and modelled decay curves. Buyers get a physically produced, mass-balanced tonne with a century-scale permanence claim.
Both pathways rely on models. The honest distinction is not “measured versus modelled.” It is which variables the model has to predict, and over what timescale reversal can happen.
The market angle
The volumes tell the tier story more clearly than any framing I can add. Agreena has booked 4.45 million tonnes on one contract. The biochar market Supercritical is tracking is measured in the tonnes buyers can still get their hands on, with most of the vetted supply already committed. Neither party has publicly disclosed the Kazakh contract’s price per tonne, and I will not guess at it. What I can say is that soil credits under VM0042 have historically traded well below engineered-removal prices, and the volume-versus-price shape of these two markets is not converging.
For a corporate buyer running a mixed portfolio, that gap is now a procurement question. If you can source millions of avoidance-adjacent removal tonnes on one contract, and only thousands of biochar tonnes across a whole vetted supply set, your scarcity signal on the durable side gets sharper, not weaker.
The policy context
The Agreena deal arrives just after Verra’s VCS v5 was recognised as CCP-eligible by ICVCM, the integrity threshold many durable-CDR buyers had been citing as a reason to stay away from VCS-issued credits. That recognition does not collapse the tier boundary between nature-based and engineered removals. It does remove one of the cleaner rhetorical justifications for treating VCS tonnes as categorically outside a serious net-zero claim.
Buyers who used ICVCM as a filter now have to argue on methodology substance rather than on registry brand.
What experts are saying
David Ho puts the tier boundary in one line: “I love trees but they’re not durable CDR” (David Ho, @davidho.bsky.social). Soil organic carbon sits in the same permanence bucket as trees. It can be lost to a tillage decision, a drought, or a change of farm operator. VM0042’s buffer pool is designed to absorb that risk at portfolio level, not to make any individual tonne behave like mineralised carbon.
Zeke Hausfather offers the scale check: “We might ultimately spend 10% to 20% of our resources on removals and 80%-90% on mitigation. I’d suggest 99% on mitigation / 1% on removals is reasonable today” (Zeke Hausfather, @zekehausfather.com). Against that frame, 4.45 million tonnes of soil credits over seven years is a large deal for the soil sector and a small one against the residual-emissions problem CDR exists to close. Removal never substitutes for cutting fossil emissions at source.
The counter-argument
The case against reading too much into the comparison is straightforward. A soil tonne and a biochar tonne are different products. Buyers who signed the Kazakh forward are almost certainly not the same buyers competing for biochar allocations from Supercritical’s tracked suppliers. Nature-based credits under VM0042 are often used against Scope 3 land-sector claims where a biochar tonne would be an awkward fit anyway.
The scepticism cuts the other way too. Model-quantified soil organic carbon at continental cropland scale is exactly the accounting surface that has drawn the sharpest MRV critiques, and buffer pools sized to today’s reversal understanding may not hold under warming-driven soil moisture regimes.
Verdict
The Agreena contract does not merge the durable and nature-based tiers. It does force procurement teams with mixed portfolios to write down, in their claim ledgers, why a VM0042 tonne is or is not fungible with a biochar or DAC tonne in their net-zero accounting. That written answer is what will show whether the tiers are converging on substance or just on press-release volume.
Two disclosures would move the story forward. First, the name of the offtake counterparty. Second, how that counterparty categorises the tonnes internally against any durable removals it is also buying. Until then, the biggest soil-carbon forward of the year and the tightest biochar forward book of the year are running on parallel tracks that occasionally look like the same railway. For a longer treatment of why permanence framing matters when comparing pathways, my primer on enhanced weathering walks through the durability question in a different pathway with the same accounting structure.
Citations
- Verra — VM0042 Improved Agricultural Land Management methodology
- Carbon Herald — Supercritical reported that 81% of high-quality biochar supply is already locked in
- Verra — Verra’s VCS v5 was recognised as CCP-eligible by ICVCM
- Bluesky — “I love trees but they’re not durable CDR” — Bluesky post
- Bluesky — @davidho.bsky.social — Bluesky profile
- Bluesky — “We might ultimately spend 10% to 20% of our resources on removals and 80%-90% on mitigation. I’d suggest 99% on mitigation / 1% on removals is reasonable today” — Bluesky post
- Bluesky — @zekehausfather.com — Bluesky profile