GENEVA, May 8 – The Intergovernmental Panel on Climate Change (IPCC) has opened registration for governments and experts to serve as Expert Reviewers on the Second-Order Draft (SOD) of the Special Report on Climate Change and Cities.
Following the Third Lead Author Meeting this January, authors of this Special Report have processed comments from expert reviewers of the First-Order Draft and prepared a second draft, which will open this week for governments and experts worldwide to review and provide comments.
“Our authors have worked hard to process the tens of thousands of comments received in our First-Order Draft to present a Second-Order Draft that accounts for the suggestions, perspectives and expertise of urban and climate experts around the world,” said Winston Chow, Co-Chair of Working Group II.
”We are proud to present this new draft and would like government representatives and more experts to come forward to review and help us refine the report to one that supports and inspires decision-making on climate action in cities around the world”.
The review of the Second-Order Draft is the next step in the IPCC’s rigorous multiple-stage review process. This is an essential part of the IPCC process to ensure a comprehensive, objective and transparent assessment of the current state of knowledge of the science related to climate change. Reviews are critical in preparing IPCC reports as they ensure that the report is scientifically rigorous, includes the widest range of perspectives, and remains relevant to the urgent challenges urban areas and communities face in a warming world and changing climate.
This Second-Order Draft will also include the first draft of the Summary for Policymakers (SPM), a key product that encapsulates the report’s findings and is aimed at informing policymakers shaping climate action worldwide.
Following receipt of the review comments, author teams will prepare final drafts of the full report and SPM, taking into account review comments received. The final draft of the report will be distributed to governments for a final round of written comments on the SPM, before governments meet in plenary session to approve the SPM line by line and accept the underlying report.
Scheduled for release in March 2027, the Special Report on Climate Change and Cities will be the first IPCC report published in the seventh assessment cycle. It is also the only special report in the current cycle. The report aims to provide a timely assessment of the latest science related to climate change and cities, including climate impacts and risks, as well as adaptation and mitigation options.
All review comments submitted by experts or governments are addressed by the authors. The comments and the authors’ responses, together with the drafts, are published after the report is finalized.
Interested experts can register for participation in the review here. The registration of experts closes on 26 June 2026.
The SOD of the IPCC Special Report on Climate Change and Cities is available for Expert Review from 8 May to 3 July 2026.
During the Expert Review from October to December 2025, the First-Order Draft of the Special Report on Climate Change and Cities received more than 32,000 comments from 1,365 registered Expert Reviewers around the world
For more information about the Expert Review or to speak to relevant IPCC Working Group Co-Chairs, please contact Woo Qiyun, Senior Communications Manager, IPCC Working Group II Technical Support Unit, media@ipccwg2.org .
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.