In a Nutshell

Article 6.4 of the Paris Agreement establishes the Article 6.4 mechanism, a market-based instrument that countries can voluntarily use to trade credits from emission reduction and removal projects. Under the mechanism, reducing emission levels in one country can be used by another country to fulfill its climate target, Nationally Determined Contribution (NDC).

Often seen as a tool to help countries achieve their climate targets cost-effectively, its real goal is to bring about higher ambition – enabling countries to do more than they could without using it. It’s built to incentivise and facilitate the participation of authorised public and private entities by crediting their emission reduction and removal activities. The projects need to deliver an overall mitigation in global emissions.

It’s a centralised UN crediting mechanism governed by Article 6.4 Supervisory Body. Being a successor of the Clean Development Mechanism (CDM) under the Kyoto Protocol, it will operate under the Paris Agreement, where all countries have climate targets. This means that the host countries need to know that they can still meet their climate targets when selling credits via the Article 6.4 mechanism, and double counting of the same emission reductions or removals must be avoided through the double-entry bookkeeping for emissions accounting (“corresponding adjustments”).

Among its other work in setting up the instrument, the Supervisory Body is preparing the foundation for how the Article 6.4 mechanism will apply to removals. There is a growing ecosystem of novel removal methods, and many of these are poised to be used by countries in their climate targets. Given the lack of broadly accepted international accounting rules for a range of removal methods, the decisions taken under Article 6.4, and the methodologies approved under it, are bound to have an outsized impact on carbon markets globally.

What's on the Horizon?

  • The Article 6.4 Supervisory Body has prepared recommendations on methodologies and removals. These recommendations have been sent for approval and were reviewed at the Conference of the Parties serving as the meeting of the Parties to the Paris Agreement (CMA5 – during COP28). If the recommendations are approved, Article 6.4 will become operational in principle. More recommendations from the SB will be needed to make Article 6.4 fully operational.
  • The Subsidiary Body for Scientific and Technological Advice (SBSTA) is preparing recommendations on including emission avoidance and conservation enhancement activities in the scope of Article 6.4 mechanism, authorisation of credits, and connection between registries for adoption at CMA5 (during COP28).

 Getting the Article 6.4 mechanism up and running will take a few years. 

Deep Dive

How will it work? 

The Article 6.4 Supervisory Body is responsible for establishing guidance and procedures, approving methodologies, registering projects, issuing credits, and more.

Methodologies may be developed by project participants, host countries, stakeholders, or the Supervisory Body.

The credits are called the Article 6.4 Emission Reductions (A6.4ERs). These are used for both emission reductions and carbon removal. The host country will have to authorise A6.4ERs and account for these by applying corresponding adjustments unless the A6.4 ERs contribute to the national target in the host country (mitigation contribution A6.4ERs). 

Removal activities get a maximum of 15-year crediting periods, renewable twice. The mechanism credits emission reductions and removals by public and private sector actors.

2% of Article 6.4 credits are subject to cancellation (“Overall Mitigation in Global Emissions” clause), 5% of credits are dedicated to the Adaptation Fund (“Share of Proceeds for Adaptation”) and other fees for registration, inclusion, issuance, renewal, and post-registration apply as well (“Share of Proceeds for Administrative Expenses”).  

Many other details are yet to be ironed out, listed in the “Open elements” section below. 

How will removals be covered? 

Whilst the mechanism covers emission reductions and removals, it will likely focus on emission reductions in the coming decade, with interest in removals growing as climate targets get closer to net zero and beyond. 

The Supervisory Body has been tasked with preparing a general framework for including the full spectrum of carbon removal methods under Article 6.4, called “recommendations”, to be approved at CMA5 during COP28.  

For the first time, novel carbon removal methods will be tackled under the Paris Agreement, and the recommendations will set a precedent by establishing broad removals-specific rules under the UN crediting mechanism. 

Open elements 

Two separate ongoing work streams are ironing out the details of the mechanism – (1) the Supervisory Body and (2) the Subsidiary Body for Scientific and Technological Advice (SBSTA) where international climate negotiations under the Paris Agreement are ongoing on the technical elements. 

The Supervisory Body has a busy work program for 2023 and has been tasked to prepare several deliverables for adoption for CMA5 (during COP28). This includes recommendations on methodologies (baseline, monitoring methodologies, methodology development process, review), recommendations on activities involving removals (monitoring, reporting, accounting for removals and crediting periods, addressing reversals, avoidance of leakage), transitioning the Clean Development Mechanism into the Article 6.4 mechanism, developing accreditation standard, and designing project activity cycle.

SBSTA is negotiating recommendations on including emission avoidance1 and conservation enhancement activities in the scope of Article 6.4 mechanism, authorisation of credits by host countries, and work on the registry. These discussions are very technical, have continued throughout the Bonn Climate Conference in June 2023, and will be submitted for adoption at CMA5 during COP28.

1 Emission avoidance in this context mainly refers narrowly to reducing emissions from deforestation and forest degradation (REDD+ projects), not to be confused with how the term “emission avoidance” is used in the voluntary carbon markets where some stakeholders use it as a blanket term for emission reductions and avoidance. 

How can stakeholders engage with the Article 6.4 process?   

Documents for stakeholder input will be published at least a week before each Supervisory Body meeting. Any organisation can provide written input before meetings, but only UNFCCC-accredited observer organisations can attend the Supervisory Body meetings. Everyone can follow the live stream and watch recordings of past sessions.


Meeting number  Meeting dates  Deadline for registering as an observer  Deadline for submitting public comments on the meeting agenda 
SB 006  10-13 July 2023  19 June  3 July 
SB 007  11-14 September 2023  21 August  4 September 
SB 008  10 October to 2 November 2023  9 October  23 October 

In June 2023, the UNFCCC launched a dedicated Article 6.4 newsletter covering the latest news, calls for inputs and other announcements from the Supervisory Body. 

The negotiations under SBSTA take place in 2-week sessions twice a year during the Bonn Climate Conference and COP. 



12 December 2015
4 November 2016
November 2021
November 2022
19 November 2022 - 15 March 2023
7-10 March 2023
16 March - 11 April 2023
18-25 May 2023
31 May - 3 June 2023
5-15 June 2023
5-19 June 2023
23 June 2023
10-13 July 2023
11-14 September 2023
Until 19 September 2023
30 October - 2 November 2023
Before SBSTA29/COP28
18 November 2023
30 November - 12 December 2023
12 December 2015

The Paris Agreement is adopted

4 November 2016

The Paris Agreement enters into force 

November 2021

CMA3/COP26 Glasgow – Adoption of the rules, modalities and procedures for Article 6.4 mechanism 

November 2022

Adoption of guidance on Article 6.4, elaborating on key processes and principles, providing SBSTA to work on remaining elements, and mandating the Supervisory Body to operationalise the mechanism 

19 November 2022 - 15 March 2023

Request for submissions by Parties and admitted observer organisations to submit their views on activities involving removals via the submission portal

23 June 2023

Article 6.4 Supervisory Body stakeholder webinar

Until 19 September 2023

Public consultation on the three SBSTA working areas on Article 6.4 (inclusion of emission avoidance and conservation enhancement, registries, authorisation of credits) 

Before SBSTA29/COP28

Technical expert dialogue on the three SBSTA working areas on Article 6.4 (inclusion of emission avoidance and conservation enhancement, registries, authorisation of credits) 

18 November 2023

The SB has approved the long-awaited recommendations on activities involving carbon dioxide removal and Article 6.4 mechanism methodologies.

30 November - 12 December 2023

CMA5/COP28 in Dubai.The Article 6.4 Supervisory Body’s recommendations on removals and methodologies have been sent for approval to CMA5. 

Unofficial Title

Article 6.4



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