# How long must a tree, soil or wetland carbon project keep monitoring reversals under the Integrity Council for the Voluntary Carbon Market (ICVCM) rules, and how big is the buffer?

Canonical: https://senseible.earth/answers/ccp-permanence-forty-years-monitoring-and-buffer

For conservation and avoided conversion (for example avoided deforestation), forests, soil carbon and wetlands, a program shall require monitoring for at least forty years from the start of the first crediting period, or until the end of the crediting period if later. A pooled buffer holds at least twenty percent of credits, or an amount proportional to reversal risk.

## Which projects this covers (criterion 9.1)

The framework treats storage and protection of carbon in biogenic reservoirs as material reversal risk: conservation and avoided conversion, agriculture soil carbon sequestration, forestry sequestration (improved forest management, afforestation or reforestation, agroforestry) and wetland and marine ecosystem restoration or management. Credits may only be approved under the Core Carbon Principles (CCP) if all the permanence requirements are met.

Biochar, displacement of non-renewable biomass, geological storage, enhanced weathering, mineralisation and carbon dioxide in concrete are on a separate list, where the program shall assess reversal risk and have measures where risk is material.

## The rules for reversals

1. The program (or the project owner, as the program requires) cancels one credit for each tonne of CO2 equivalent reversed.
2. Monitoring and compensation for at least forty years from the start of the first crediting period, or to at least the end of the crediting period, whichever is later.
3. The owner monitors and reports reversals for the whole period and compensates avoidable reversals; no further credits are issued until avoidable reversals are compensated.
4. If avoidable reversals are not compensated, the pooled buffer reserve is drawn on. Stopping monitoring and verification is treated as an avoidable reversal.
5. The reversal risk is estimated with a public methodology, and the program defines clear criteria for whether a reversal is avoidable or unavoidable.

## The buffer

The pooled buffer reserve shall hold at least twenty percent of the credits issued to the contributing projects, or credits proportional to the reversal risk over the whole period that also account for the risk that owners do not compensate avoidable reversals. The program makes the buffer contents public, including origin by activity type and vintage.

## How this sits with Verra's tool

Verra's own risk-rating tool, covered on the linked pages, sets a buffer share by project score. The framework lets a program choose either a buffer of at least twenty percent or one sized to the project's reversal risk, so Verra's rating-based share can differ from twenty percent.

## Monitoring end date and a twenty percent buffer

- First crediting period starts 1 April 2027 and lasts ten years, to 31 March 2037
- Forty years from the start: 31 March 2067, which is later than 31 March 2037, so monitoring runs to 31 March 2067
- Credits issued: 100,000. Buffer under the twenty percent option: 100,000 x 20% = 20,000 credits

Dates and the credit count are an example. A program that uses the risk-proportional option can hold more or less than twenty percent.

## What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, which a land project can use for its own vehicle and pump fuel. Tree and soil carbon, and the issuing of credits, sit outside it.

- [How much of my credits go into the buffer pool](https://senseible.earth/answers/how-much-of-my-credits-go-to-buffer-pool)
- [Non-permanence risk rating for forestry and agroforestry](https://senseible.earth/answers/afolu-non-permanence-risk-rating)
- [Reversal risk by storage type](https://senseible.earth/answers/capture-and-storage-credits-reversal-risk-by-storage)
- [Carbon credits for Indian businesses](https://senseible.earth/carbon-credits)

Sources: [Integrity Council for the Voluntary Carbon Market, Core Carbon Principles Assessment Framework, Section 4, January 2024, version 1.1 (criteria 9.1 to 9.4)](https://icvcm.org/wp-content/uploads/2024/02/CCP-Section-4-V1.1-FINAL-15May24.pdf)

Last reviewed 2026-11-05. Based on Assessment Framework version 1.1 (January 2024). The Integrity Council's August 2026 rule architecture says Interpretations and Technical Notices may affect how criteria are assessed, so check icvcm.org for any in effect before you rely on a detail.