The Science Based Targets initiative published its long-delayed Corporate Net-Zero Standard in June. From 2027, a new recognition programme lets companies account for emissions they haven't cut yet. From 2035, large companies must start buying carbon removals, beginning around 1% of their footprint and rising every year after.
Marcela Vera, manager of carbon project development at ClearBlue Markets, has spent the months since watching how companies are responding, and whether they're engaging because the rules now require it or because they've chosen to get ahead of them. "Many companies will only do what they're required to do from a compliance standpoint, but there are others who are committed to setting and meeting internal voluntary targets," she says. "Those that are today developing a pipeline of projects and partnerships will be the ones to guarantee compliance in the future."
Voluntary rules are borrowing from compliance
The bigger shift this year, in Vera's view, isn't that voluntary and compliance markets are meeting in the middle. It's that voluntary credits are increasingly being held to standards a government wrote, not a registry. "This has been the biggest change of the last year," she says. The European Commission has proposed Article 6 of the Paris Agreement as the quality bar for credits that European airlines buy and cancel under CORSIA, aviation's offsetting scheme. The rules are strict enough that airlines could find almost no eligible supply in Phase 1, and the market reacted before the proposal was even finalized: CORSIA-eligible prices rose roughly 30% within a week. Buyers with no aviation obligation at all have started using Article 6 eligibility as their own quality floor, borrowing a compliance-market bar for a voluntary purchase.
The same pull is visible outside Europe. Vera points to Colombia, where government appetite for a domestic compliance market has shifted noticeably in the past year, driven partly by new ministers with carbon-market backgrounds. Article 6.4, the UN-run crediting mechanism, is expected to issue its first credits before the end of 2026. In each case, the direction of travel is the same: voluntary supply reorganizing itself around rules built for compliance markets, not the two systems folding into one.
Same tonne, wildly different price, and nature-based credits show it most
Quality has improved and pricing has become more visible, but companies still aren't buying much more. "There is no such thing as 'the carbon price' anymore," Vera says. Over one week in August, biochar credits traded around $122 a tonne while REDD+ credits, forest-protection credits and the oldest, largest category of nature-based supply, traded around $5.70. Same tonne of CO2e on paper, more than twenty times the price.
That divergence shows up inside a single quality scale, too. The Calyx-ClearBlue Price-Integrity Index, which prices credits by GHG-integrity rating rather than by market average, put the highest-rated tier (AAA-A) at $8.83 a tonne in August against $6.54 for the lowest (C-D), a 35% premium that has held steady through the year even as prices across all three tiers eased slightly. The index has grown almost as fast as the scrutiny driving it: 274 projects covered at its February 2025 launch, 455 by the end of July. Buyers aren't paying more for carbon broadly, they're paying a defined premium for a specific, ratable tier of it, and treating the rest as close to unsellable.
Nature-based projects are absorbing most of that repricing because they're where quality has been hardest to prove. Registries are responding: Verra's newer VM0048 methodology moves to jurisdiction-wide deforestation baselines rather than developer-selected reference areas, and newer entrants such as Equitable Earth have launched methodologies built around independent, ongoing monitoring rather than per-credit fees. The market's own language is shifting alongside the methodologies, from "permanence," which implied a guarantee, to "durability," which treats forest carbon as a risk to be managed rather than a fact to be certified. The Integrity Council for the Voluntary Carbon Market is revising its Core Carbon Principles around that distinction now.
Why demand hasn't caught up, and what to do instead of waiting
Demand hasn't disappeared, it's gotten more selective. Buyers followed through on 6.3% fewer carbon credits in 2025 than the year before, Marcela says, and the shortfall isn't really about interest, it's about documentation. Teams that used to close on a project deck now want the underlying data before they sign off.
Supply is tightening at the same time. ClearBlue Market's Voluntary Carbon Markets Weekly Report put issuances at about 124 million credits for the year-to-date, down roughly 7.4% year over year, while retirements are down 4.5% at 117 million. That's a market where supply is pulling back faster than demand is cooling, not one where both sides are shrinking together, and it's the kind of gap that should support prices for the credits buyers actually want.
For nature-based projects specifically, answering those three questions increasingly means going to the field, not a desk. ClearBlue's own project development team spent ten days in Colombia's Orinoquia region earlier this year gathering more than 40,000 observations on trees, plants, birds, reptiles and mammals for a biodiversity credit baseline, the kind of ground-level work that durability and reversal-risk debates have made unavoidable for anyone underwriting a forest or land-use project today.
Vera's advice to companies deciding what to do next is the same whether the credit is a removal, a REDD+ tonne or a biodiversity unit: "Wait for a price you can calculate. Look at your 2035 removal requirements, work backwards, and build a portfolio as early as you can. Do not treat the voluntary market as separate from your compliance obligations."
A version of this article first appeared as an interview with Environmental Finance as part of their annual Voluntary Markets Rankings announcement on September 22. ClearBlue Markets won Best Advisory/Consultancy for the fifth year running. Read about it here.
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Source for the durability/ICVCM framing: Nature-based solutions: 4 predictions for 2026 (Trellis)