> For the complete documentation index, see [llms.txt](https://open-carbon-protocol.gitbook.io/ocp-methodology-requirements/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://open-carbon-protocol.gitbook.io/ocp-methodology-requirements/sections/8.-permanence.md).

# 8. Permanence

The impact of CO2 and other greenhouse gases in the atmosphere lasts a long time - CO2 can stay in the atmosphere for 300-1000+ years \[[source](https://climate.nasa.gov/news/2915/the-atmosphere-getting-a-handle-on-carbon-dioxide/#:~:text=Carbon%20dioxide%20is%20a%20different,timescale%20of%20many%20human%20lives.)]. ‘Permanence’ and ‘durability’ are sometimes used to refer to the same concept, but ‘durability’ covers both the planned duration storage + reversal risk before that deadline, while ‘permanence’ has traditionally only covered reversal risk more broadly. Projects must assure that the carbon reduced/removed will stay out of the atmosphere ‘permanently’ - which is considered 100+ years, or have monitoring and mitigation processes in place in case of reversals.

For some sectors, reversal is either impossible or unlikely. Other sectors are less likely to be able to ensure permanent storage or reductions, especially nature-based-solutions (NBS). These risk levels for current OCP methodologies and sectors, as well as non-OCP NBS sectors are outlined below. *This table will continue to be updated as new OCP methodologies are developed.*

| No Risk of Reversal                                                                                                                             | Low-Medium Risk of Reversal                                                                                                     | Higher Risk of Reversal                                                                                                                                                                            |
| ----------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| <p><strong>Refrigerant Gas Destruction</strong> <br><br>100% permanence since gas molecules are destroyed in an irreversible physical event</p> | <p><strong>Oil & Gas Well Management</strong> <br><br>Low risk of physical plug leaking, especially within first few months</p> | <p><strong>IFM, ARR, REDD+</strong> <br><br>Risk of natural hazards (extreme weather, wildfires) or human hazards (mismanagement, reverting to previous land use) </p>                             |
|                                                                                                                                                 |                                                                                                                                 | <p><strong>Regenerative Agriculture</strong><br><br>Risk of natural hazards (extreme weather, wildfires) or human hazards (mismanagement, reverting to non-regenerative agricultural methods) </p> |

### Permanence & Reversal Risk Assessment

**All methodologies must include instructions for conducting an assessment of permanence risk, including risk of reversals.** This must include all potential causes and their scale, and likelihood of occurring based on the project type. The methodology must describe how these risks are monitored throughout the crediting period.\
\
Methodologies must assess permanence risk using the following common taxonomy, as applicable to the activity type:

1. **Physical or operational risks** (e.g. equipment failure, degradation, or loss of control);
2. **Economic or behavioral risks** (e.g. changes in incentives leading to abandonment, re-extraction, or rebound effects);
3. **Regulatory or policy risks** (e.g. changes in law or enforcement affecting continued mitigation);
4. **Counterfactual substitution risks** (e.g. activity displacement that undermines credited outcomes).

Methodology developers must explicitly identify which risk categories are relevant for projects using the methodology, and justify their inclusion or exclusion.

### Risk Mitigation

Methodologies must also include a risk mitigation strategy that outlines mechanisms to reduce the reversal risks outlined. This must include appropriate safeguards, such as buffer pools or insurance, to address underperformance or reversals. High-risk events must have defined remediation plans, which may involve restoring carbon stocks, drawing from the buffer pool, or canceling credits. The OCP has partnered with the carbon insurance carbon kita.earth, who will join every panel (as a non-voting platform partner) to assess reversal and other risks, and guide suggested buffer pool contributions based on the methodology. Each methodology is different but all must be aligned with ICVCM best practices.

These risk mitigations will involve setting [post-crediting monitoring requirements](/ocp-methodology-requirements/sections/9.-monitoring.md#post-crediting-monitoring-requirements), which are set at a sector/methodology level on the OCP. Additionally, any identified reversal risk that can be proactively mitigated must have an identified procedure for mitigation in the project proposal document.

Materiality of reversals is determined at the OCP level. A reversal is considered material when the cumulative magnitude of the reversal reaches or exceeds five percent (5%) of the total credited emission reductions or removals issued to the project.

Accordingly:

* Any single reversal event or cumulative series of reversal events amounting to 5% or more of credited outcomes shall automatically trigger a mitigation response;
* Repeated or cumulative small reversals below 5% shall be tracked and aggregated over time for the purposes of assessing materiality;
* Methodology-defined thresholds for minor events shall not preclude program-level intervention where the cumulative 5% threshold is reached or where integrity risks are identified.

Reversals below the 5% threshold do not automatically require mitigation but must be documented, disclosed, and considered in ongoing risk assessment.

Project developers are required to notify the program as soon as possible and no later than 5 working days after becoming aware of the reversal event, as per [OCP Terms of Service](https://pilot.ocp.earth/terms-and-conditions).

A diagram or figure explaining how permanence is ensured is encouraged for this section.

<br>


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://open-carbon-protocol.gitbook.io/ocp-methodology-requirements/sections/8.-permanence.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.