The IPCC's work is guided by a set of principles and clear procedures for all the main activities of the organization. This page serves as a repository for all official procedural documents guiding IPCC activities.
The IPCC's processes and procedures are constantly being reviewed and updated to ensure that they remain strong, transparent and reliable. For recent changes to IPCC procedures and related information see the Review of Processes and Procedures page that covers all the recent changes to IPCC procedures approved by the Panel in the period 2010-2012.

The document Principles Governing IPCC Work lays down the role of the IPCC, its organization, participation in it and its key procedures, and establishes comprehensiveness, objectivity, openness and transparency as guiding principles of IPCC Work. The IPCC is open to member countries of the UN and WMO. All major decisions about the organization and its work are taken by the Panel during the Plenary Sessions.

The Principles Governing IPCC Work provide detailed rules and procedures in the following appendices:

Appendix A
... is about the "Procedures for the preparation, review, acceptance, adoption, approval and publication of IPCC Reports"

Including: Annex 1 - Tasks and Responsibilities for Lead Authors, Coordinating Lead Authors, Contributing Authors, Expert Reviewers and Review Editors of IPCC Reports and Government Focal Points; Annex 2 - Procedure on the Use of Literature in IPCC reports; and Annex 3 - IPCC Protocol for Addressing Possible Errors in IPCC Assessment Reports, Synthesis Reports, Special Reports and Methodology Reports
Appendix B
... covers "Financial Procedures for the Intergovernmental Panel on Climate Change (IPCC)"
(explanatory notes to the Financial Procedures for the IPCC)

Appendix C
... contains the "Procedures for the Election of the IPCC Bureau and any Task Force Bureau"

In order to set priorities and guide decisions on whether to prepare Special Reports, Methodology Reports and Technical Papers, the IPCC has adopted the "Decision Framework and Criteria for Special Reports, Methodology Reports and Technical Papers".

The IPCC also has a "Conflict of Interest Policy" , and an "IPCC Policy and Process for Admitting Observer Organizations".


Preparation of the IPCC Reports


The writing and review of IPCC reports and other publications is done in accordance with the "Procedures for the preparation, review, acceptance, adoption, approval and publication of IPCC Reports" contained in Appendix A to the Principles Governing IPCC Work.
These procedures, which were initially adopted by the 15th Session of the IPCC in 1999 and have been regularly reviewed and revised since then, provide detailed procedures for the preparation of the various types of IPCC material namely:

A.  IPCC Reports which include Assessments, Synthesis and Special Reports and their Summaries
      for Policymakers and Methodology Reports. 
B.  Technical Papers which are based on the material already in the Assessment, Synthesis and Special
      Reports and their Summaries for Policymakers and Methodology Reports. 
C.  Supporting Materials which consist of workshop proceedings and materials from expert meetings which
      are either commissioned or supported by the IPCC; software or databases to facilitate the use of IPCC
      Methodology Reports; and guidance materials to guide and assist in the preparation of comprehensive
      and scientifically sound IPCC Reports and Technical Papers.

The procedures address all steps leading to the preparation of IPCC material starting with the scoping process, nomination process and selection of authors, preparation of drafts by the writing teams, the review by experts and governments and finally the approval, adoption and acceptance process in plenary sessions. They also contain definitions of IPCC terms and its main bodies and a description of tasks of authors, reviewers, review editors and government focal points.

Summary description of the IPCC writing and review process


Each IPCC Report is preceded by a scoping meeting that develops its draft outline (and explanatory notes as appropriate). Based on the report of the scoping meeting, the Panel decides whether to prepare a report and agrees on its scope, outline and work plan including schedule and budget.
Authors are chosen from lists drawn up by member governments, observer organizations and the Bureaux (Co-Chairs and Vice-Chairs) of the Working Group or Task Force producing the report. The Bureau of the Working Group or Task Force selects the authors from these lists and from other experts known through their publications and work.

The composition of the group of Coordinating Lead Authors and Lead Authors for a chapter, report or summary reflects the range of scientific, technical and socio-economic expertise; geographical representation, ensuring appropriate representation of experts from developing and developed countries and countries with economies in transition; a mixture of experts with and without previous experience in the IPCC; and gender balance. Scientists who are nominated but not selected as authors are invited to register as expert reviewers for the report.
A first draft of the report is prepared by the authors based on available scientific, technical and socio-economic information. The role of the IPCC is to assess all relevant scientific information. Priority is given to peer-reviewed scientific, technical and social-economic literature. The IPCC recognizes that non-peer reviewed literature, such as reports from governments and industry can be crucial for IPCC assessments, and the appropriate use of such literature expands the breadth and depth of the assessment by including relevant information. Use of this literature brings with it an extra responsibility for the author teams to ensure the quality and validity of cited sources and information.
In preparing an IPCC report, Lead Authors should clearly identify disparate views for which there is significant scientific or technical support. Contributing Authors may be invited to submit further material.
Review is an essential part of the IPCC process to ensure objective and complete assessment of the current information. In the course of the multi-stage review process - first by experts and then by governments and experts - both expert reviewers and governments are invited to comment on the accuracy and completeness of the scientific, technical and socio-economic content and the overall balance of the drafts. The circulation process among peer and government experts is very wide, with hundreds of scientists looking into the drafts to check the soundness of the scientific information contained in them. The Review Editors of the report (normally two per chapter) make sure that all comments are taken into account by the author teams. Review comments are retained in an open archive on completion of a report.
After the first order draft has been reviewed by experts, authors prepare a second order draft of the report and a first draft of its Summary for Policymakers (SPM). The second order draft of the report and the first draft of the SPM are subject to simultaneous review by both governments and experts. Authors then prepare final drafts of the report and SPM. These are distributed to governments who provide written comments on the revised draft of the SPM before meeting in plenary to approve the SPM and accept the report.
All IPCC reports must be endorsed by a Working Group and the Panel meeting in Plenary Session. There are three levels of endorsement:
1. "Approval" means that the material has been subjected to detaied line by line discussion and agreement. It is the procedure used for the Summary for Policymakers of the Reports.
2. "Adoption" is a process of endorsement section by section. It is used for the Synthesis Report and Overview Chapters of Methodology Reports.
3. "Acceptance" signifies that the material has not been subject to line by line nor section by section discussion and agreement, but nevertheless presents a comprehensive, objective and balanced view of the subject matter.
For the treatment of suspected errors in Assessment, Special and Methodology Reports see Error Protocol section.
Simplified procedures apply to Technical Papers, which are based on material already in other IPCC reports. They are initiated in response to a formal request from the UNFCCC or its subsidiary bodies and agreed by the Bureau, or as decided by the Panel. A team of Lead Authors selected by the Working Group/ or Task Force Bureaux prepares a draft that is circulated widely to experts and governments for a simultaneous government and expert review. With the assistance of at least two Review Editors per Technical Paper, Lead Authors revise the draft and submit it for final government review. Lead Authors then finalize the Paper based on the comments received during the final government review in consultation with the IPCC Bureau which functions as an Editorial Board. If necessary and as determined by the IPCC Bureau, the Technical Paper would include in a footnote differing views, based on comments made during the final government review that were not otherwise adequately reflected in the Paper.

IPCC Framework and Criteria for Special Reports, Methodology Reports and Technical Papers

The Panel adopted a framework and set of criteria for establishing priorities for Special Reports, Methodology Reports and Technical Papers for the period of the Fourth and Fifth Assessments. The aim is to ensure efficient use of resources while addressing user needs. This framework is to be applied in accordance with the Principles Governing IPCC Work and is meant to guide, but not prescribe, future decisions by the Panel regarding its work programme; decisions whether to initiate a new report will be considered on a case by case basis. The framework is reviewed after every assessment cycle and is therefore not part of Appendix A to the Principles Governing IPCC Work.
For more information please see: "Decision Framework and Criteria for Special Reports, Methodology Reports and Technical Papers".
At its Forty-First Session (Feb 2015), the Panel took a number of decisions concerning the period of the Sixth Assessment. With respect to the IPCC products and their timing, please refer to: Decision IPCC/XLI-4, Future Work of the IPCC.

How has the IPCC writing and review process been strengthened in recent years?

In addition to already existing procedures regarding the writing and review of IPCC reports, and in response to an independent review of IPCC processes and procedures by the InterAcademy Council (IAC), changes have been made on matters such as the use of literature in IPCC reports (see Annex 2 of Appendix A), the role of Review Editors, and consideration of the range of scientific, technical and socio-economic views (also see Appendix A). Additional guidance has been provided to AR5 authors on the consistent treatment of uncertainties. These efforts have further strengthened and clarified the IPCC's strict procedures for the preparation and review of IPCC assessment reports. For more information see Review of Processes and Procedures.

IPCC Error Protocol

The IPCC decided in May 2011 to adopt an IPCC Protocol for Addressing Possible Errors in IPCC Assessment Reports, Synthesis Reports, Special Reports or Methodology Reports. This Protocol is the new Annex 3 of Appendix A.
In case of a suspected error in an IPCC report, please send a mail to containing the following information:
  Complete name,

Funding and Financial Procedures of the IPCC

The IPCC is funded by regular contributions from its parent organizations WMO and UNEP, and voluntary contributions from its member countries and the UNFCCC. The WMO also hosts the IPCC Secretariat, and the WMO and UNEP provide one senior staff member each for the IPCC Secretariat. Information about contributions received and expenditures incurred is provided by the Secretariat to the Panel. It is contained in the document on programme and budget. The annual budget is decided by the Panel at its plenary sessions.
Thanks to the contributions received, the IPCC Trust Fund, which is administered under the Financial Regulations of the WMO, supports IPCC activities, in particular the participation of developing country experts in the IPCC, the organization of meetings as well as publication and translation of IPCC reports. During the 34th Session of the IPCC held in Kampala on 18-19 November 2011, the Panel revised the IPCC Financial Procedures to ensure consistency with International Public Sector Accounting Standards (IPSAS).
Governments provide further substantial in-kind support for activities of the IPCC, in particular by hosting Technical Support Units, supporting the participation of experts from their respective countries in IPCC activities, and by hosting meetings.
For more information please see: "Financial Procedures for the Intergovernmental Panel on Climate Change (IPCC)" [English - Arabic - Chinese - French - Russian - Spanish].

Election of the Bureau

The IPCC Bureau and any Task Force Bureau (currently the Task Force on National Greenhouse Gas Inventories) is elected by the Panel according to principles laid down in Appendix C to the Principles Governing IPCC Work on Procedures for the Election of the IPCC Bureau and any Task Force Bureau . The Bureau is elected for a term of about five to six years. It corresponds to the cycle for the preparation of an Assessment Report. According to the Principles Governing IPCC Work, a Bureau shall reflect balanced geographic representation with due consideration for scientific and technical requirements. Bureau Members should be highly qualified experts in the field.
Following the review of IPCC processes and procedures carried out by the InterAcademy Council (IAC) in 2010 the Panel has taken a number of decisions including on terms of office and terms of reference for the IPCC Bureau. For more information on the relevant decisions taken by the Panel in 2010-2012 with respect to the Bureau, please see IPCC Review of Processes and Procedures.
For more information on the election of members of the Bureau, please see "Procedures for the Election of the IPCC Bureau and Any Task Force Bureau".

Conflict of Interest Policy

The role of the IPCC demands that it pay special attention to issues of independence and bias in order to maintain the integrity of, and public confidence in, its products and processes. It is essential that the work of the IPCC is not compromised by any conflict of interest for those who execute it.
Following recommendations from the InterAcademy Council (IAC), in 2011 the IPCC decided to adopt and implement a Conflict of Interest (COI) Policy that applies to all individuals directly involved in the preparation of IPCC reports, including senior IPCC leadership (IPCC Chair and Vice-Chairs), other Bureau and Task Force Bureau members, authors with responsibilities for report content, review editors and staff of the Technical Support Units. The overall purpose of this policy is to protect the legitimacy, integrity, trust, and credibility of the IPCC and of those directly involved in the preparation of reports, and its activities. The staff of the IPCC Secretariat is subject to the disclosure and ethics policies of WMO and UNEP.
For the purposes of the IPCC COI Policy, circumstances that could lead a reasonable person to question an individual's objectivity, or whether an unfair advantage has been created, constitute a potential conflict of interest. These potential conflicts are subject to disclosure.
A COI Committee was established comprising all elected members of the Executive Committee and two additional members with appropriate legal expertise appointed by WMO and UNEP. The Panel approved the Methods of Work of the COI Committee during its 35th Session (Geneva, 6-9 June 2012) and amended it at its 44th Session (Bangkok, 17-20 October 2016). The amended COI form was approved by the Panel at its 44th Session.
The approved IPCC Conflict of Interest Policy is available here in all UN languages.





Observer Organizations

Any non-profit body or agency, whether national or international, governmental or intergovernmental, which is qualified in matters covered by the IPCC, may be admitted as an observer organization. An "IPCC Policy and Process for Admitting Observer Organizations" has been established for the purpose, and the admittance is subject to acceptance by the Panel.
Representatives of observer organizations may attend sessions of the IPCC and the plenary sessions of the IPCC Working Groups.
Observer organizations are also invited to encourage experts to participate in the expert review and government/expert review stage of IPCC reports. These experts participate in the review process in their own name and not on behalf of the Observer Organization. Organizations which already have an observer status with the WMO or with the UN are considered as observers of the IPCC if they so request, and subject to acceptance by the Panel. UN bodies and organizations are admitted as observers if they so request. The IPCC has at present 29 observer organizations among UN bodies and organizations, and 87 non-UN observers (see list of IPCC observer organizations).

IPCC Communications Strategy

At its 33rd Session in May 2011, the Panel adopted the Guidance on IPCC Communications Strategy following recommendations from the InterAcademy Council in August 2010 to develop a communications strategy. The Panel adopted the IPCC Communications Strategy at its 33rd Session in June 2012.
Drawing from lessons learnt through the communication of the Fifth Assessment Report and recommendations of the IPCC Expert Meeting on Communication (February 2016), the Panel revised the IPCC Communications Strategy at its 44th Session in October 2016.