What is non-permanence, and why does it only affect land projects?
Non-permanence is the risk that carbon stored in a natural reservoir — trees, vegetation, soil, or a geological formation — is released back to the atmosphere. A release of that kind is called a reversal. It is specific to storage-based projects because the carbon is being held somewhere it can be lost, rather than simply never emitted.
A renewable energy project that displaces coal generation cannot un-displace it; the reduction happened and is over. A forest can burn, be cleared, or die of disease twenty years after the credits were sold. That asymmetry is why land-based crediting needs a mechanism that avoided-emission crediting does not.
How does the VCS buffer pool work?
Verra withholds a share of every AFOLU project's credits into a shared buffer pool rather than issuing them to the project. The pool functions as collective insurance: when a reversal occurs at any contributing project, buffer credits equal to the loss are cancelled from the pool, so the tonnes claimed by buyers remain backed.
- Buffer credits are held and managed by Verra, not by the project.
- The withheld share is set by the project's assessed non-permanence risk rating, so a riskier project contributes more.
- On a reversal, buffer credits equal to the loss are cancelled.
- At the end of a project's final crediting period, all of its buffer credits are cancelled.
The practical consequence for a developer is that the credits a project can sell are always fewer than the tonnes it sequesters, and how many fewer is a function of how risky the project looks on paper. Reducing assessed risk is therefore a direct commercial lever, not merely a compliance exercise.
How is the risk rating calculated?
Risk is assessed under Verra's AFOLU Non-Permanence Risk Tool, at version 4.2 of 12 October 2023. The tool organises assessment into three categories — internal risks, external risks and natural risks — and the factors within them are added together to produce a total risk rating, which determines the buffer contribution.
| Category | Broadly covers |
|---|---|
| Internal risks | Project management, financial viability, technical capacity, land tenure and longevity of the activity |
| External risks | Community engagement, political and regulatory conditions, and pressures arising outside the project |
| Natural risks | Fire, pest and disease, extreme weather, geological events, and — since version 4.1 — future climate change and sea-level rise |
Several of these are things a project can actually change. Secure land tenure, documented community agreement, a funded management plan and a credible fire response all reduce assessed risk and therefore increase issuable credits. This is the clearest case in the VCS where good project design pays back in units.
When does risk make a project ineligible?
There is a ceiling. If a project's assessed non-permanence risk warrants a buffer reserve greater than the highest withholding percentage available for its project type, the project is not eligible for crediting under the VCS at all.
This is worth knowing before site selection rather than after. A project in a location with insecure tenure, high fire exposure and weak governance may not simply be expensive to credit — it may be uncreditable. Running the risk assessment early, on paper, is much cheaper than discovering the answer during validation.
What does this mean for monitoring?
The buffer mechanism only works if reversals are detected and reported. A project that loses carbon and does not report it is not quietly getting away with it; it is failing a reporting obligation, and Verra can place buffer credits on hold where minimum monitoring standards are not met.
Detecting loss across a project area, promptly and with evidence, is a monitoring problem before it is a reporting one — and it is one satellite observation is well suited to, because change detection over time is exactly what it does. See forest carbon monitoring, and the VCS document library for the Loss Event Report Template a reversal is reported in.