Why the UN Wants a Reversal Buffer on Article 6.4 Cookstove Credits

Cookstove credits look like a simple avoided-emissions product, but the UN’s Article 6.4 body may rule this week that the carbon these stoves protect can be lost again. The Supervisory Body of the Paris Agreement Crediting Mechanism (PACM) meets for the 23rd time in Bonn from 5-9 October 2026, and Argus scenarios put the possible credit cuts at between 6% and 60%.

This would be the first time a major crediting programme applies reversal-risk buffer rules to cookstoves. Developers, buyers and civil society are all pressing the Supervisory Body before it decides.

For you, the question is how the Article 6.4 cookstove credits you buy or develop might change in supply, cost and quality.

You will come away with a clear picture of how the buffer works, how big the cuts could be, and what happens if the decision slips.

Why does the UN say cookstove credits carry reversal risk?

A credit for a cleaner stove is really a credit for standing trees. Clean-cooking projects earn credits by reducing the harvesting of above-ground woody biomass, which keeps carbon stocks in the surrounding landscape intact, according to the UNFCCC note.

That is where the vulnerability sits. Preserved carbon can be lost again through natural events such as wildfires and drought, or human-induced ones such as land conversion to agriculture or mining.

The Methodological Expert Panel (MEP) treats reversal risk as separate from over-crediting. They are different integrity problems and need different fixes.

The MEP’s position Addressing reversal risk is needed for integrity and consistency across activity types.

Two terms matter for what follows. The fraction of non-renewable biomass (fNRB) is the share of harvested wood that cannot regrow sustainably, and it sets the baseline for a cookstove’s claimed savings. A buffer pool is an account that receives a share of credits to cover possible future losses.

The draft methodologies measure risk over a 100-year assessment using a Reversal Risk Assessment tool (A6.4-MEP014-A07), building on the Reversal Standard (A6.4-STAN-METH-007). Information note A6.4-MEP016-A04, updated on 17 September 2026, confirms that a corresponding fraction of credits would go to a buffer pool. The MEP says emission reductions and reversals come from the same carbon reservoirs.

If you buy or develop these credits, the UN is treating the claim as one that could be undone. That changes what counts as a fully issued credit.

How does the buffer pool work, and what does it cost developers?

The mechanism is simpler than the politics around it. Each step below happens at issuance, and none requires ongoing monitoring.

1. The developer assesses risk using the tool’s default values.
2. The reversal factor (F_buffer,i,t) is calculated for each fuel type.
3. That factor is applied to the share of reductions tied to woody biomass and subtracted from credits due.
4. The subtracted credits are cancelled in the buffer account by the registry administrator.
5. The developer is issued the remainder.

The result is a one-time discount, not a pool of tradable credits held in escrow. Developers would not monitor forests. Jurisdiction-specific defaults would sit at the same geographic level as fNRB, with separate natural and human-induced assessments.

The MEP says defaults avoid new monitoring and post-crediting duties. Alternative monitoring under the Reversals Standard, which applies where developers lack control over the stocks, may add costs.

The UNFCCC information note presented to the Supervisory Body sets out how jurisdiction-specific default values would be used and how a share of credits would move into the buffer pool, so you can see the proposed mechanics before any decision is made.

Öko-Institut describes the general Article 6.4 design: reversals trigger cancellation from the buffer, avoidable reversals within participants’ control require replenishment, and unavoidable ones do not. Columbia’s Center on Global Energy Policy (2025) calls buffer pools and insurance standard reversal tools, with contribution ratios adjusted to keep pools capitalised.

Where stacking bites

Older CDM-style cookstove methodologies typically applied a standard leakage deduction of about 5% with no dedicated permanence mechanism. The new reversal deduction would sit alongside more conservative uncertainty treatment and fNRB revisions.

For a developer, the question is not the size of one deduction. It is the combined effect of all of them on credits received per project.

How big could the cuts be, and what happens to prices?

The scale depends on where a project sits. Country defaults vary widely, and the human-induced factor the MEP proposed is 20-45%.

Default values by country

Natural reversal-risk defaults run from under 4% in Somalia to over 36% in Timor-Leste. Major cookstove markets fall between.

Argus illustrated the effect on 18 September 2026. A charcoal-to-electricity activity would see about a 6% cut in credits at a 10% reversal scenario, while a fuelwood-efficiency activity would lose about 60% at a 50% scenario.

These are scenarios, not forecasts, and no aggregate sector-wide estimate was found. Treat the range as the outer bounds of a debate, not a prediction.

What prices say so far

• Fastmarkets assessed Sub-Saharan Africa CCP-labelled cookstove credits at $15/tCO2e on 26 May 2026.
• The same assessment was $13.50 in the week to 29 September 2026.
• Non-CCP legacy credits were offered at $3 or less.
• CORSIA Phase 1 credits were assessed at $10.55 on 27 May 2026.

The CCP premium reflects higher production costs from tighter fNRB rules. If you buy these credits, the gap over legacy credits shows quality is already priced in, and further issuance cuts would push unit costs up, not down. The MEP itself acknowledges UN units may need higher prices.

The gap between CCP-labelled and legacy credits is one example of how quality gets priced in, and the same logic shapes carbon market pricing in compliance systems, where volume records can still hide weak price signals.

Who is pushing back, what else was considered, and how does this compare with other programmes?

Both camps have a serious argument, and the MEP’s own rejected options show why the choice is hard.

The case for the buffer

The Carbon Credit Quality Initiative (CCQI) classes efficient cookstoves as carrying material non-permanence risk. Citing its May 2022 work, Carbon Market Watch notes that CDM, Verra and Gold Standard have no specific approach to compensating reversals. ICVCM-approved methodologies mainly tightened fNRB, and no other programme uses Article 6-style buffer pools.

The case against

Climate Change News reported on 8 September 2026 a coordinated push to weaken the rules. At an IETA webinar on 29 September 2026, Pedro Barata of EDF warned of over-indexing integrity, and developers urged postponement.

Ritika Tewari of the Project Developer Forum warned that the volume reduction could be devastating for the sector.

Developers neither control nor monitor the stocks. The Mærsk Mc-Kinney Møller Center for Zero Carbon Shipping argues reversal risk is already baked into conservative fNRB estimates, so a buffer should not be additive. Pascal Siegwart of TotalEnergies says stacked discounts could halt new investment and favours science-based fNRB and stronger monitoring.

Safeguards scrutiny runs in parallel, including an 89-organisation coalition letter and July 2026 allegations about the Myanmar project. Details of both were not found.

Alternatives the MEP weighed

The Clean Cooking Alliance’s CLEAR report (June 2025) proposes conservative baselines and monitoring instead. Each option trades one risk for another, so judge a position by which risk its speaker is prioritising.

What happens if the Supervisory Body delays the decision?

The Supervisory Body asked for more analysis in July 2026, and stakeholders say they only just received the explanatory note. A postponement is therefore plausible, but it would not end the argument.

• 5-9 October 2026: Supervisory Body meeting in Bonn.
• 9-20 November 2026: COP31 in Antalya, Turkey.
• February 2027: the next Supervisory Body meeting (SBM 24).

The Supervisory Body does not meet during COP. Even so, the CMA reviews its annual report and gives guidance, so a delay could shift the debate into politics.

If the Supervisory Body postpones, the argument may move into politics, where carbon pricing mechanisms and trade frameworks are already colliding and where integrity standards increasingly carry diplomatic weight.

Scenario: decision adopted

Credits would carry the buffer deduction, and the stacking question becomes a live project-economics issue. The MEP acknowledges stricter rules might push developers to other frameworks, though it argues exemption would undermine consistency.

Scenario: postponed

Rules stay unresolved through a long gap. A delay means uncertainty, not relief, so plan for both outcomes.

No quantified analysis of supply, pricing or developer migration was found, so any firm forecast would be guesswork.

What to watch as Article 6.4 cookstove rules take shape

The dispute pits conservative integrity against credit supply, and neither side is simply right. Reversal risk is real, yet stacked deductions could choke the projects the rules aim to protect.

Three things deserve your attention:

1. The Bonn outcome, which was not known at the time of writing.
2. Whether any softening alternative, such as a phased buffer, is adopted.
3. Movements in CCP and legacy credit prices.

If you develop or buy these credits, model your exposure under both a full buffer and a delay.

This article is for informational purposes only and should not be considered financial advice. Investors should conduct their own research and consult with financial professionals before making investment decisions. These statements are speculative and subject to change based on market developments and regulatory decisions.