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 11,649 projects · registry data as of 2026-06 · 6 min read
- — 71% of rated projects (8,326) 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 two most common are not about any single project — they're about its category. 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. | 832 |
| No buffer pool | high | A reversible project with no buffer-pool contribution recorded. | 369 |
| 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. | 530 |
| Stale vintages | low | Pre-2016 credits carry elevated over-crediting doubt under older methodologies. | 359 |
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 — reassuringly few — but that is exactly why the flag layer matters: it surfaces the rare, 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.