By El Hadji Mbaye Diagne and Simon Fellermeyer, Co-Chairs of the Article 6.4 Methodological Expert Panel

The removal of carbon emissions from the atmosphere is central to meeting the targets set by the Paris Agreement. Yet ensuring that these removals deliver lasting benefits is far from straightforward.

According to climate science, as assessed by the IPCC, reaching global net zero requires that any remaining emissions be balanced by carbon removals that are durably stored. For climate integrity, one tonne claimed must equal one tonne proven, not only today but over the decades to come.

As members of the Article 6.4 Supervisory Body and co-chairs of its Methodological Expert Panel (MEP), we are focused on setting robust standards for this new UN carbon market. The confidence of countries, investors, and the public depends on it.

At the heart of that confidence lies a difficult challenge: addressing the risk that carbon once removed or stored could be released back into the atmosphere. This “reversal risk” must be managed with enough precision and discipline that the credits issued under the Paris Agreement Crediting Mechanism (PACM) remain trustworthy over time.

Implementing the removal standard

Earlier this year, the Supervisory Body tasked the MEP with implementing the removal standard adopted at COP29 in Baku.

This guiding standard is important, as it sets requirements for crediting activities that remove greenhouse gases from the atmosphere or reduce emissions where reversal risk exists, including rules for monitoring, reporting, and managing non-permanence to ensure environmental integrity.

Our recommendation to the Supervisory Body, in the form of a draft reversal standard, does not invent new requirements; it operationalises what countries have already agreed. The guiding principle is straightforward: credits can only be issued when measures are in place to fully address the risk of non‑permanence, ensuring that any potential reversals are effectively managed.

The removal standard requires monitoring to continue after the end of the crediting period to assess whether any reversals have occurred and confirm the continued storage of greenhouse gases. Monitoring may cease only when that risk is fully addressed or demonstrably negligible. To manage risk, the removal standard recognises a set of tools – buffer pools, insurance, and third‑party guarantees – that can be deployed individually or in combination, depending on the profile of a given activity.

The approach is technology and sector neutral. What matters is not the label attached to a mitigation solution, but its risk characteristics and the adequacy of the safeguards around it.

Understanding the draft reversal standard

In developing the draft reversal standard, we have tried to balance three imperatives: ensuring environmental integrity, supporting countries in accounting for emissions and removals, and giving investors clarity and predictability.

This has involved extensive discussion, technical analysis, and careful review of more than 1,200 stakeholder contributions. Suggestions which conflicted with the removal standard itself could not be incorporated as these would have undermined the coherence of the framework agreed by countries at COP29.

Key updates since the MEP’s call for public input in July 2025 include:

• A materiality threshold for reversals, allowing very small releases that naturally recover within the monitoring period to be excluded from reporting.
• Greater flexibility on reporting timelines, including automatic extensions and more lenient options for requesting deadline extensions.

Long‑term monitoring obligations can be demanding. The draft reversal standard acknowledges this reality while preserving environmental integrity. If monitoring stops and a non-negligible reversal risk remains, projects must remediate potential reversals by replacing credits as an interim approach. This requirement is stringent but reflects the realities of climate science while the Supervisory Body and the MEP explore further remediation procedures.

Managing residual risks and maintaining neutrality

We are continuing work on paragraph 62 of the removal standard. This includes exploring measures such as insurance, third-party guarantees, or monetary reserves to address reversals. The aim is to provide practical options for managing residual risks after the crediting period, even when negligible risk cannot be demonstrated.

Neutrality across mitigation solutions remains a core tenet. All projects must undertake risk assessments that inform what is reserved in pooled insurance or similar arrangements, and all must fully address any reversal that occurs.

Different activities face different risk profiles; the standard adapts to that reality without compromising the integrity of credited outcomes.

Why this matters for credibility

Durable removals and safeguarded reductions are a prerequisite for credible climate action and a functional crediting system. The revised draft reversal standard is intended to deliver that credibility – anchored in science, consistent with guidance on removals agreed by countries, and attentive to practical realities.

As the Supervisory Body prepares to review the proposal, we encourage stakeholders to focus their comments on how suggested changes align with the provisions of the removal standard, particularly regarding paragraph 28 on post-crediting period monitoring obligations.

We are grateful to the experts who contributed to this work and invite all stakeholders to continue engaging constructively in the consultation process. To support this, we have extended the input period ahead of the next Supervisory Body meeting, allowing ample time to review the draft standard. In parallel, a webinar on Sep. 18 will explain the process behind developing the current draft and clarify its key elements.

Ultimately, the credibility of the PACM depends on our collective commitment to standards that ensure that one tonne truly equals one tonne, not just today but for generations to come.

El Hadji Mbaye Diagne and Simon Fellermeyer co-chair the Article 6.4 Methodological Expert Panel and sit on the Article 6.4 Supervisory Body, which is tasked with operationalising the Paris Agreement Crediting Mechanism.

Any opinions expressed in this commentary reflect the views of the authors and not of Carbon Pulse.