The Red Flags
We scanned every rated project for named integrity failures. Most of the market's risk is systemic, but a tail of projects carries specific, avoidable red flags.
Based on CarbonDecode's ratings of 12,040 projects · registry data as of 2026-08 · 6 min read
- — 71% of rated projects (8,520) carry at least one integrity flag.
- — Most of that risk is systemic, not one-off: over-crediting risk (type) alone touches 42% of the market.
- — The flags that should actually stop a purchase are project-specific (reversals, missing buffers, stalled verification), and they cluster in a smaller tail.
- — A clean grade is not a clean bill of health: read the flags, not just the letter.
Most risk is systemic
When we scan every scorecard for named integrity flags, the most common ones are about a project's category rather than the project itself. Whole classes of credits carry structural over-crediting and additionality risk, and that shows up on a large share of the market at once.
This is the honest, uncomfortable baseline: the biggest integrity problems in the voluntary market are priced into entire project types. That's useful: it tells a buyer where not to look first, but it isn't what separates a good project from a bad one within a category.
The flags that should stop a purchase
The signals that actually distinguish projects are evidence-based and specific, drawn from a project's own buffer, vintage, verification, and retirement record. They are rarer, and that's precisely why they matter: a project carrying one of these is telling you something its grade alone may not.
| Red flag | Severity | What it means | Projects |
|---|---|---|---|
| Uncovered reversal | critical | A reversal occurred beyond what the buffer pool covers, stored carbon was lost. | 30 |
| Inactive status | high | The project is flagged inactive in the registry. | 839 |
| No buffer pool | high | A reversible project with no buffer-pool contribution recorded. | 377 |
| Buffer released for reversal | high | Buffer credits were drawn down to cover a reversal event. | 22 |
| Late to verify | medium | Verification cadence has slipped, issued tonnes outrunning independent checks. | 882 |
| Thin buffer pool | medium | Buffer holdings are a small fraction of issuance for a reversible project. | 147 |
| Low retirement | low | Large issuance with little retired, a possible quality overhang. | 543 |
| Stale vintages | low | Pre-2016 credits carry elevated over-crediting doubt under older methodologies. | 365 |
Note the top of the table: the highest-severity flags, uncovered reversals, drawn-down buffers, no buffer at all, are the rarest, but they represent carbon that was claimed and then lost, or was never protected. In a portfolio, one of these outweighs a dozen cosmetic concerns.
A clean grade is not a clean bill of health
Only 30 projects carry a critical flag, and that is exactly why the flag layer matters: it surfaces the serious failures that a headline grade can average away. The grade tells you where a credit sits; the flags tell you what to check before you trust it.
How flags are assigned
Flags are named, severity-ranked rules in our scoring rubric. Systemic flags come from project-type priors; project-specific flags fire on a project's own registry record, buffer adequacy, reversal events, vintage age, verification cadence, and retirement ratios. Data derives from public registry records (the Berkeley Carbon Trading Project) and the registries themselves. See the full methodology →
Check the flags before you buy
Every project's flags, grade, and evidence, free to browse, or pull the data programmatically.