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 the IPCC Special Report on Climate Change and Cities 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 .

This media release was first published on the IPCC website. You can view the original release here.

_{Cover image: Flooding in Kolkata, India. Image by Dibakar Roy.}