Professor will contribute to the IPCC Seventh Assessment Report

Published 19-08-2025

Professor William Colgan has been appointed a lead author of chapter 4 of the IPCC Seventh Assessment Report.

A person is sitting in a digged out area of ice putting small cores of ice in bags.
William Colgan, Professor in Glacier Dynamics during fieldwork in Greenland. (GEUS)

William Colgan is a lead author of chapter 4 on Physical Science Basis 'Advances in process understanding of Earth system changes' in Working Group 1.

“It is an honour to be appointed, and now have the chance to contribute to such important work. UN members need good climate advice now, more than ever. I look forward to collaborating with so many dedicated researchers and scientists around the planet,” says William Colgan, Professor in Glacier Dynamics.

Professor Colgan will be in great company alongside the other lead authors from Working Group 1 from Denmark: 

  • Riikka Rinnan, University of Copenhagen, lead author on Chapter 4: 'Advances in process understanding of Earth system changes', and:
  • Shuting Yang, DMI, lead author on Chapter 8: 'Abrupt changes, low-likelihood high impact events and critical thresholds, including tipping points, in the Earth system'.

Together, the lead authors are tasked to ensure that the report will delivers on the topics agreed upon by the member governments in 2024. The topics are divided into three working groups:

  • Working Group I will do a report on the Physical Science Basis,
  • Working Group II will do a report on Impacts, Adaptation and Vulnerability, and
  • Working Group III is tasked to create a report on Mitigation of Climate Change.

William Colgan and Riikka Rinnan are two of 16 authors leading Chapter 4 of the Physical Science Basis, 'Advances in process understanding of Earth system changes', which focuses on how our understanding of the climate system has changed since the last IPCC assessment report.

The Synthesis Report of the Seventh Assessment Report will be produced after the completion of the Working Group reports and released by late 2029. The Lead Authors will meet regularly over the next four years, both online and in person, to coordinate the work of summarizing the state of our global climate, as well as our adaptation and mitigation possibilities.

A portrait of a person.

Willian Colgan, Professor in Glacier Dynamics (GEUS).

William Colgan
Professor
Glaciology and Climate
Malene David Jensen-Juul
Special Consultant
Press and Communication