Photo: Maíra Erlich
Article 6.4 is the Paris Agreement’s carbon crediting mechanism. Standards set core requirements; tools and guidance implement them; activity-specific methods calculate and monitor benefits. Technical experts recommend decisions to the Supervisory Body, which oversees the mechanism. Decisions in 2026–2027 will determine whether these pieces enable the full portfolio of climate solutions – including forest protection, restoration and other nature-based activities – while maintaining environmental integrity.
The stakes extend beyond individual technical decisions. As a UN-backed framework, Article 6.4 could influence expectations across other carbon markets and shape access to climate finance, particularly for developing countries with significant opportunities in land use and rural energy. Delivering on that potential requires strong safeguards alongside rules that credible activities can meet in practice. Overlapping requirements, even when individually well intentioned, can unintentionally limit participation or make activities financially unviable. Drawing on current science and the experience of implementers, host countries and affected communities can help ensure the mechanism supports a broad portfolio of solutions and delivers measurable climate and sustainable development benefits.
2026 immediate priority: the Reversal Risk Assessment Tool
This tool assesses the risk of losing credited climate benefits through what are known as “reversals”. It determines credits set aside in a shared reserve, called a buffer pool, to cover losses and whether reversal risk is low enough to end monitoring after crediting stops.
Why it matters for nature. The model cited in the tool represents robust science that makes a serious contribution to the field. However, reliance on a single model that cannot alone determine absolute reversal risk in different geographies around the globe is problematic. A better approach would be to reflect a broader scientific evidence base, including multiple models and datasets, combining formal evidence review, multi-model comparison and site-specific assessments. Initially intended for cookstoves that reduce unsustainable biomass use, the tool could set a precedent for nature as the expert panel has expressed in the past that this tool could be adopted for other sectors. If the model overstates reversal risk in a specific location, that would lead to inaccurately high buffer pool contributions that could make nature-based activities unviable. Substantial revision is needed; or, if adopted as is, it should explicitly rule out serving as a template for nature-based activities without further changes. Rule clarity on reversal risk also matters for market function. Corporate buyers cannot commit procurement volumes against requirements that remain undefined. Finishing these rules unlocks the demand that nature-based activities need to reach scale.
Also on near-term radar. Work on Programmes of Activities (PoAs) standard also remains near-term. This standard updates the rules for grouping multiple projects under one Programme of Activities in the Paris Agreement’s carbon crediting mechanism, allowing new projects to join over time and share approaches to monitoring and earning credits. It could help smaller, dispersed nature projects – such as forest restoration across communities – grow in scale, support their transition from the previous UN carbon market system (CDM), and inform future rules for larger forest protection programmes. The proposed revisions mostly target non-renewable biomass programmes, so they don’t automatically fit other types, especially nature-based ones, which would need extra adjustments like program-level additionality, dynamic baselines, and tiered project eligibility. This matters because these large-scale crediting programs carry over from the old CDM system, and even though a separate paper on large-scale programs (including JREDD+) is coming next year, how the current revision is handled could set a precedent.
2027 next steps
Managing carbon losses. The Remedial Actions concept note is postponed to 2027. It explores insurance, guarantees and dedicated funds as alternatives or complements to credit reserves (buffer pools) and routes to ending post-crediting monitoring while ensuring longer durability. For nature, where reversal risks cannot be eliminated, these options can make long-term obligations manageable, and 6.4 should promote their development.
Calculating credits. Revisions to the Setting the baseline standard will address downward adjustments to reference emissions levels. Nature needs approaches suited to forest protection and restoration that keep estimates conservative without unnecessarily eroding credit volumes and financial viability.
Displaced emissions. The Addressing leakage standard will clarify how rules apply to larger programmes and projects within them. This matters for aligning forest projects with national or regional accounting. The requirement to consider international leakage is not itself up for review; practical, science-based implementation is needed to avoid additional barriers.
Larger programmes and grouped projects. The Large-scale crediting programmes concept note will consider whether jurisdiction-wide and sector-wide programmes can qualify, including forest conservation and restoration under JREDD+. Related work on the Article 6.4 activity standard for programmes of activities could set a precedent for large-scale crediting that will be important for crediting of J-REDD+ programmes (see above).
Showing benefits would not otherwise occur. Reviews of the Demonstration of additionality standard and Common practice analysis tool may adapt these tests for larger programmes. For government-led forest conservation and restoration, tests need to account for policy and governance actions and establish meaningful comparisons with other activities.
Monitoring after crediting. The Addressing non-permanence and reversals standard may introduce common monitoring periods or low-risk thresholds. Indefinite or 100-year obligations would exceed many land agreements, raising costs and deterring nature investment; practical experience should guide revisions.
Safeguards and participation. The revised Sustainable development tool is likely to reach the Supervisory Body only in 2027, with implications for community rights, benefit-sharing and biodiversity. Revisions to the Direct communication with stakeholders procedure can improve Indigenous Peoples’ and local communities’ participation, consultation time and transparency about how comments are considered. While the revisions help reduce integrity and implementation risks, further safeguards are needed. Specifically, the tool should strengthen stakeholder consultation and benefit-sharing mechanisms, and clarify key definitions and assessment procedures.
Already agreed foundations (not comprehensive)
Calculating credible benefits. The Demonstration of additionality standard and Common practice analysis tool test whether benefits would occur without the mechanism for project-scale activities. For nature, requirements such as going beyond legal obligations affect which activities can qualify. The Setting the baseline standard requires an initial 10% downward adjustment to reference emissions levels and a further 1% annually thereafter, on top of the conservative baselines already required under previous decisions. These additional adjustments risk reducing credit volumes to a point where nature projects are no longer financially viable under PACM.
Forest protection and displaced emissions. The Addressing leakage standard requires forest protection projects to fit within national or jurisdictional programmes, supported by national reference levels, plans, monitoring and safeguards systems. This ties project eligibility to host-country readiness. Methods must consider emissions displaced elsewhere, including across borders; while important, limited data and unclear procedures for assessing international leakage could create barriers for nature.
Safeguards and long-term responsibility. The Sustainable development tool supports ecosystems’ protection, including biodiversity and water, stakeholders consultation, and livelihoods; revisions to the tool are in train and there are recommendations for improvement, including strengthening stakeholder consultation and including specific provisions to benefit-sharing mechanisms. The Requirements for activities involving removals standard and the Addressing non-permanence and reversals standard extend monitoring beyond crediting, with approved minimum periods and low-risk thresholds. Monitoring may end after the minimum period if risk is sufficiently low or adequate measures (buffers pools, guarantees, insurance, permanence fund, etc.) address losses. For nature, fire and other risks make these solutions critical to avoid prohibitive monitoring costs after the crediting period ends, when there are no more revenues to finance it. Implementation guidance is still in development.