GENEVA, 6 July – Registration is now open for experts to review the First Order Draft of the Working Group I contribution to the IPCC Seventh Assessment Report (AR7). The Working Group I contribution to AR7 is assessing the latest physical science basis of climate change, including observed and projected large-scale climate changes, climate processes and feedbacks, and regional climate information.
The expert review, the first of multiple review stages, will run from 10 August to 2 October 2026.
Interested experts are invited to register here by 23:59 CEST on 25 September 2026.
“The strength of IPCC assessments relies on the breadth and quality of expert input from all regions of the world. We therefore encourage relevant experts worldwide to engage and contribute to this review. The review process is key to ensure that the report reflects the most robust and up-to-date scientific understanding of physical science of climate change” said Robert Vautard, one of the Co-Chairs of IPCC Working Group I
During the review, experts are invited to comment on the accuracy, balance, clarity and comprehensiveness of the report. They may suggest improvements to the presentation of information, including figures and tables, identify relevant scientific literature with full citations, propose revisions, and recommend ways to improve the clarity and conciseness of the text while preserving its scientific integrity.
“Expert review is a cornerstone of the IPCC assessment process. The diverse knowledge, perspectives and expertise provided by reviewers help strengthen the scientific quality, policy relevance and credibility of our reports. We warmly encourage experts to engage with the IPCC in this important effort” said the other Working group I Co-Chair Xiaoye Zhang.
IPCC reports undergo several stages of review, first by experts and subsequently by governments and experts. Experts who provide comments on the First Order Draft will also be invited to review the Second Order Draft. All expert reviewers will be acknowledged in the published report.
More information on the role of an expert reviewer is available in Annex 1 of Appendix A to the Principles Governing IPCC Work.
Additional information on the expert review process is available in this guide for expert reviewers.
Information on participation by country and region, including the number and origin of registered experts, is available here.
For more information, contact:
IPCC Press Office, Email: ipcc-media@wmo.int;
Andrej Mahecic, +41 22 730 8516; Werani Zabula, +41 22 730 8120.
Notes for editors
What is the IPCC?
The Intergovernmental Panel on Climate Change (IPCC) is the UN body for
assessing the science related to climate change. It was established by the
United Nations Environment Programme (UNEP) and the World Meteorological
Organization (WMO) in 1988 to provide political leaders with periodic
scientific assessments concerning climate change, its implications and risks,
as well as to put forward adaptation and mitigation strategies. In the same
year the UN General Assembly endorsed the action by the WMO and UNEP in jointly
establishing the IPCC. It has 195 member states.
Thousands of people from all over the world contribute to the work of the IPCC.
For the assessment reports, experts volunteer their time as IPCC authors to
assess the thousands of scientific papers published each year to provide a
comprehensive summary of what is known about the drivers of climate change, its
impacts and future risks, and how adaptation and mitigation can reduce those
risks.
The IPCC has three working groups: Working Group I, dealing
with the physical science basis of climate change; Working Group II, dealing
with impacts, adaptation and vulnerability; and Working Group III,
dealing with the mitigation of climate change. It also has a Task Force on
National Greenhouse Gas Inventories that develops methodologies for
measuring emissions and removals.
IPCC assessments provide governments, at all levels, with scientific
information that they can use to develop climate policies. IPCC assessments are
a key input into the international negotiations to tackle climate change. IPCC
reports are drafted and reviewed in several stages, thus guaranteeing
objectivity and transparency.
About the Seventh Assessment Cycle
Comprehensive scientific assessment reports are published every 5 to 7 years.
The IPCC is currently in its seventh assessment cycle, which formally began in
July 2023 with the elections of the new IPCC and Task Force Bureaus at the
IPCC’s Plenary Session in Nairobi.
At its first Plenary Session in the seventh assessment cycle – the 60th Plenary Session in Istanbul, Türkiye, in January 2024 – the Panel agreed to produce in this cycle the three Working Group contributions to the Seventh Assessment Report (AR7), namely the Working Group I report on the Physical Science Basis, the Working Group II report on Impacts, Adaptation and Vulnerability and the Working Group III report on Mitigation of Climate Change. The Synthesis Report of the Seventh Assessment Report will be produced after the completion of the Working Group reports and released by late 2029.
During its 62nd Plenary Session held in Hangzhou, China, in February 2025, the Panel has agreed on the outlines of the three Working Group contributions to the Seventh Assessment Report (AR7).
At the Panel’s most recent Plenary Session in Lima, Peru, in October 2025, member governments agreed on the scientific content of the 2027 Methodology Report on Carbon Dioxide Removal Technologies, Carbon Capture, Utilization and Storage. There, the Panel also agreed on the 2026 workplan for the three Working Group contributions to the Seventh Assessment Report.
The Panel decided already during the previous cycle to produce a Special Report on Climate Change and Cities and a Methodology Report on Short-lived Climate Forcers during AR7.
At the IPCC’s 61st Plenary Session held in Sofia, Bulgaria, from 27 July to 2 August 2024, the Panel agreed upon the outlines for the Special Report on Climate Change and Cities scheduled for approval and publication in March 2027 and for the 2027 IPCC Methodology Report on Inventories for Short-lived Climate Forcers scheduled for publication in the second half 2027.
In addition, a revision of the 1994 IPCC Technical Guidelines on impacts and adaptation as well as adaptation indicators, metrics and guidelines, will be developed in conjunction with the Working Group II report and published as a separate product.
IPCC’s latest report, the Sixth Assessment Report, was completed in March 2023 with the release of its Synthesis Report, which provided direct scientific input to the First Global Stocktake process under the United Nations Framework Convention on Climate Change at COP28 in Dubai.
For more information visit www.ipcc.ch.