By Dr. Guy Pinjuv and Peter Ellis
For all the attention on carbon market integrity, one of the most important processes this year is unfolding in a corner of the UN climate system that few people follow closely and even fewer find easy to access: the Article 6.4 mechanism under the Paris Agreement. Yet between April and October, a series of technical and governance decisions could determine whether carbon markets can deliver climate ambition at scale.
That matters because Article 6.4 will not just set the rules for the Paris Agreement Crediting Mechanism (PACM), but will also set a precedent across a much broader front in both the compliance and voluntary realms. And this year, the agenda includes a range of issues that go directly to the future of removals, natural climate solutions (NCS), and jurisdictional-scale approaches. Below, we highlight three to pay attention to.
The first is a concept note that determines whether and how Article 6.4 standards – such as the additionality, leakage baselines standards – would apply to so-called “large-scale crediting programmes”. This sounds dry, but the stakes are high. For anyone interested in how REDD+ and other NCS interventions might connect to the Paris architecture, this is one of the key places to watch. The Methodological Expert Panel (MEP) is expected to open a call for public input during either its April or June meeting, with a draft moving up to the Supervisory Body in the second half of the year. The approaches developed through this process are likely to set important precedents for future large-scale crediting, including jurisdictional models, and could therefore materially shape the eventual pathway for J-REDD+.
The second is a concept note describing the risk-remediation measures available under the PACM: financial and market tools that can manage non-permanence risk such as insurance, guarantees, permanence monetary funds, buffer approaches, replacement obligations, and related instruments. This is not a side issue. This concept note could set the tone for the future, deciding whether Article 6.4 treats reversal risk as something to be managed intelligently, or as a reason to narrow the field of eligible climate solutions. This is highly consequential for NCS because it will shape which reversal-risk tools are recognised, how they can be used, and whether they offer a credible pathway for nature-based activities to qualify. The decisions made here could determine whether Article 6.4 accommodates a diverse set of interventions, or instead sidelines many NCS, sharply constraining the level of ambition the mechanism can support.
The third is the reversal risk assessment tool. The reversal risk assessment tool will be a decisive element of the framework, as it will effectively determine how risk is quantified across activities and methodologies. In doing so, it could exclude NCS from the market altogether or impose buffer pool contribution requirements at levels that make such projects economically unviable. The stakes are therefore exceptionally high. Given these implications, it is essential that the tool be scientifically rigorous, transparently constructed, and grounded in a broad base of interdisciplinary expertise. This will help ensure that risk is characterised accurately and without systematic bias, and that resulting requirements are both environmentally credible and operationally feasible.
The timeline for these three issues is moving quickly: a call for public input is expected to be announced at the upcoming meeting of the MEP in June at the latest, which we anticipate will be followed by a three-week submission window, before the MEP forwards its recommendation to the Supervisory Body, for consideration by the Supervisory Body during its meeting in July or October. We plan to share a fuller assessment of the implications once our expert teams have had the opportunity to review the materials in detail.
Taken together, these three workstreams amount to more than an administrative calendar. They are the beginnings of a policy choice.
Will Article 6.4 be designed around a false binary in which only the most durable options are treated as truly credible? Or will it reflect a more practical and scientifically grounded portfolio approach, one that recognises different climate solutions offer different combinations of durability, readiness, cost, scalability, and co-benefits?
It should be the latter.
No serious climate strategy can afford to sideline large-scale, near-term mitigation options while waiting for a single ideal solution to emerge. Natural climate solutions are available now, can operate at meaningful scale, and when well designed, often deliver biodiversity, water, resilience, and livelihood benefits alongside mitigation. Engineered removals will also be essential, particularly over the long term. But the climate challenge does not present us with the luxury of sequencing action so slowly that only one class of solution is allowed to matter at a time.
That is why the debate needs to shift from “permanent versus non-permanent” to durability, risk management, and scale.
The relevant policy question is not whether every tonne can be guaranteed for centuries under every circumstance. In most domains of public policy, society does not manage risk by insisting on impossible absolutes. It quantifies risk, prices it, mitigates it, monitors it, and creates compensation mechanisms when things go wrong. Climate mitigation should be no different.
Article 6.4 now has a chance to embody that logic. A well-designed system can recognise that storage duration exists on a spectrum; that reversal risk varies by context; and that risk remediation measures such as buffer pools, insurance, permanence monetary funds, replacement obligations, and stronger monitoring can materially improve integrity. In other words, risk is a design problem, not an excuse for exclusion.
This is also why the Article 6.4 calendar deserves more attention than it is getting. These debates are not happening in isolation. They are landing as Europe works through post-2030 climate policy decisions, including the role of removals and international credits, and California continues implementing SB 905. The ICVCM will pick up this discussion under its permanence working group and SBTi for its corporate claims framework. The arguments made in one arena about durability, eligibility, and risk tools will not stay there.
For policymakers, market participants, and civil society, the takeaway is simple: do not sleep on the technical calendar. April, June, July, and October are not just meeting dates. They are pressure points in the design of a market architecture that will help determine whether Article 6.4 can support a broad, high-integrity portfolio of climate action.
The Paris goals will not be met by betting on only one kind of solution. Article 6.4 should be built to reflect that reality: yes to integrity, yes to risk management, and yes to a portfolio approach that scales what can deliver now while building what the future will require.
Dr. Guy Pinjuv is a Senior Advisor for Carbon and MRV at Conservation International and Peter Ellis is the Global Director of Natural Climate Solutions Science at The Nature Conservancy.
Any opinions expressed in this commentary reflect the views of the authors and not of Carbon Pulse.
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