News Reaction
IPCC to Include SRM in Next Assessment Report
In late February, the IPCC met in China to develop chapter outlines for the 7th Assessment Report (AR7). We asked experts for their reaction to the inclusion of sunlight reflection methods (SRM), also known as solar geoengineering, in AR7, whether this development will make a difference in the field, and what challenges IPCC authors will face in this process.
Photo: IISD/ENB | Anastasia Rodopoulou
The Intergovernmental Panel on Climate Change (IPCC) failed to reach agreement on the timing of its 7th Assessment Report (AR7) during a contentious meeting from 24 February to 1 March 2025 in Hangzhou, China.
It did, however, agree on the outlines of its three Working Group reports, and decided to include analysis of SRM in the reports by Working Group I (the Physical Science Basis) and Working Group II (Impacts, Adaptation, and Vulnerability).
IPCC assessment reports, which have been published every 5–7 years since 1990, provide the closest thing to an international consensus on the state of climate change and play an important role in helping governments determine policy responses. Notably, the United States was absent from the session for the first time in IPCC history.
Delegations from around the world called for discussion of SRM scientific and geopolitical risks and uncertainties in the report. The way AR7 characterises SRM will likely set the tone for future discussions.
We asked experts to share their thoughts on how the IPCC plans to address SRM and what the main challenges will be.
Michael Diamond
Assistant Professor of Meteorology and Environmental Science
Florida State University
It is clearer than ever that we are not going to prevent warming above the Paris Agreement’s ambitious 1.5°C limit through decarbonization of the economy alone, and keeping warming below 2°C looks unlikely as well. The world will need to look seriously into ideas like removing carbon dioxide from the atmosphere directly and reflecting sunlight back to space, in addition to deep decarbonization of the economy, if we want to keep open the possibility of limiting warming or cooling down after a temporary temperature overshoot. I am therefore very pleased to see the IPCC dedicate a chapter to this important topic in the Working Group I report. The risks of sunlight reflection methods will also be addressed within the Working Group II report, where they should be weighed alongside the risks of unabated warming to provide society with the best information it needs to make decisions.
Michael Diamond is an Assistant Professor at Florida State University, studying how interactions between clouds and tiny atmospheric particles influence Earth’s climate. He is also interested in how climate science can and should be used to inform policy.
Thelma Krug
Chair of the Global Climate Observing System
World Meteorological Organization
The assessments made by the authors and included in the IPCC reports on SRM are extremely relevant, as they convey the state of the knowledge on SRM until the cut-off date established by the IPCC. Although the information provided is extremely helpful, by the time the reports are made available, they are already outdated, given the speed at which novel knowledge is presently generated on SRM, particularly in the Global North.
Thelma Krug is the Chair of the Steering Committee of the Global Climate Observing System (GCOS) under the World Meteorological Organization. She represented Brazil for more than 15 years in negotiations at the UNFCCC and served as Vice-Chair of the IPCC from 2015 to 2023.
Alfonso Fernández
Full Professor of Physical Geography
Universidad de Concepción
The summary for policymakers is the thing that most people read, and it gets a lot of editing, not just from scientists, but also from governmental actors and policymakers. That could be contentious depending on who is in charge. More than the reports themselves – like Working Group I or II, which are mostly scientific – the summaries are what most people use for teaching, for policymaking, et cetera. Language tends to shape reality, so it’s essential that the summary for policymakers minimizes wording biases and focuses on clear, straightforward explanations of the science of SRM.
Alfonso Fernández is a broadly-trained geographer based at Universidad de Concepción in Chile, studying climate changes, mountain environments, and glaciers. His work interweaves a range of techniques such as remote sensing, hydroclimatic modelling, and geodesy.
The views expressed by Perspective writers and News Reaction contributors are their own and are not necessarily endorsed by SRM360. We aim to present ideas from diverse viewpoints in these pieces to further support informed discussion of SRM (solar geoengineering).
