This newsletter provides solar geoengineering / solar radiation management coverage free of charge and advertising. We rely on donations from readers like you to keep going. Please donate now to support our work.
TOP 10 SRM UPDATES FROM SEPTEMBER 2025
POLAR GEOENGINEERING RESEARCH
A recent article by Siegert et al. in Frontiers in Science evaluated several proposed polar geoengineering methods, concluding that they would be infeasible, environmentally risky, “unimaginably expensive,” and a “dangerous” distraction from decarbonization. The authors advised against continued research into these interventions, sparking wide debate within the research community.
In response, Frontiers published multiple commentaries presenting contrasting views - from Mike Hulme supporting the paper’s conclusions, to Frans Berkhout emphasizing governance and policy complexities, Aarti Gupta’s call for an international non-use agreement on solar geoengineering, Sophie Crump’s focus on integrating Inuit perspectives into geoengineering policies, and John Moore’s case for continued geoengineering research under a “compassionate harm-reduction” framework, which he further elaborated on in a podcast. The paper received broad media coverage, and inspired an open letter signed by over 100 scientists advocating responsible investigation of climate intervention approaches. Frontiers in Science also hosted a live discussion with the lead authors of this paper, with the recording to be released soon.
GLOBAL CONFERENCE ON PREVENTING 2°C BY 2040
The Healthy Planet Action Coalition will host an online conference, The Global Heating Emergency | Preventing 2°C by 2040: What’s the Plan?, on October 15–16, 2025. Scientists, policymakers, and citizens will discuss why global heating is accelerating and how to prevent surpassing 2°C by 2037. The free event aims to mobilize global action for an integrated climate plan.
TU DELFT FUNDS MCB ENGAGEMENT PROJECT
Annelot Broerze, PhD researcher in Atmospheric Science & Climate Intervention at TU Delft, has received a Seed Fund grant for her project “Brighter Clouds, Cooler Future?” - an interactive installation designed to gauge public acceptance of Marine Cloud Brightening research. The installation will engage audiences at venues from festivals to ministries, fostering dialogue on climate action and small-scale field trials. The Climate Action Seed Fund by TU Delft is also currently open for proposals. The deadline is 01 December 2025.
REFLECTIVE SEEKS FEEDBACK ON SAI UNCERTAINTY DATABASE
Reflective has published a preliminary version of its Uncertainty Database for Stratospheric Aerosol Injection, inviting expert input by October 15. The database aims to map key physical uncertainties, assessing both their degree and potential consequences, to guide future SRM research priorities. Shared early to ensure community collaboration, the initiative seeks to refine understanding of critical unknowns in SAI deployment and modeling.
UK AND EU OUTLINE THEIR STANCE ON SRM
The UK government has rejected proposals to deploy SRM over Antarctica, citing environmental risks and treaty concerns. Responding to the Environmental Audit Committee, ministers said Antarctica was “not the place for experimentation.” While opposing deployment, the UK will continue funding £56.8 million in geoengineering research, including small-scale SRM trials in 2026 across the UK, US, Canada, and Australia. In a parallel report, the European Union warned that geoengineering’s benefits remain uncertain and could be exploited by malicious actors, stressing the need for strict global governance.
DOGE SUBCOMMITTEE HEARING ON SRM
The House Oversight Subcommittee on Delivering Government Efficiency, led by Rep. Marjorie Taylor Greene, held a hearing titled “Playing God with the Weather — A Disastrous Forecast” to discuss solar geoengineering and weather modification. Greene claimed such programs could alter weather and harm communities, calling for restrictions. Witnesses offered conflicting views: Dr. Michael MacCracken, a climate scientist, defended continued research and transparency, while others argued for an international ban, warning of unpredictable risks. Major outlets such as E&E News, Wired, and ABC News reported that the hearing blurred the line between science and conspiracy, mixing unverified claims about cloud seeding and contrails with legitimate debate on geoengineering governance and climate risk management.
CAMBRIDGE TO HOST AUTUMN CLIMATE REPAIR LECTURES
The Centre for Climate Repair at Cambridge has announced its Autumn Lecture Series, running from October 16 to November 27, exploring innovations to cool the planet. The lineup includes “Do the numbers add up?”, a talk on climate justice in COPs, and more. Open to the public, events will be held at Cambridge’s engineering and mathematics departments.
SRM MESSAGING AND CLIMATE ACTION
Cambridge University Press published an article exploring how public attitudes toward climate action respond to information about solar geoengineering. Surveying 2,509 U.S. adults, researchers found that balanced messaging about solar geoengineering did not diminish support for decarbonization policies. Instead, it often strengthened perceptions of climate urgency and the need for emissions cuts. The authors conclude that moral-hazard concerns should not deter responsible research communication.
NUFFIELD SRM ETHICS PROJECT
The Nuffield Council on Bioethics launched a project to identify the ethical considerations and health-related impacts associated with Solar Radiation Management and make recommendations for the governance of research and development. The project will be delivered in two phases, and findings will be published by early 2027.
AFRICA MUST LEAD SOLAR RADIATION MANAGEMENT GOVERNANCE
Nature Climate Change published a commentary urging Africa to take a leading role in the governance of SRM technologies. Authored by Kwesi Akumenyi Quagraine, Babatunde J. Abiodun, and Samuel Essien-Baidoo, the piece emphasizes that SRM decisions made elsewhere could significantly impact Africa’s climate. To ensure these technologies align with principles of justice and local priorities, the authors advocate for Africa’s active participation in SRM research, governance, and public engagement.
For a full recap of last month’s updates, check out our weekly summaries: WEEK 1 | WEEK 2 | WEEK 3 | WEEK 4
And here’s a quick short overview:
RESEARCH PAPERS
ScienceDirect - Afro-Asian Climate Response to Future Solar Radiation Management | Authors: Tolulope E. Adeliyi, Akintomide A. Akinsanola, Thierry N. Taguela
MDPI - Preliminary Structural System Design for Planetary Sunshade | Authors: Joel Town, Nishanth Pushparaj and Chantal Cappelletti
ScienceDirect - Responsible research for space-based climate geoengineering | Authors: Rob Bellamy
Cambridge University Press - Balanced Messaging about Solar Geoengineering does not Reduce Average Support for Emissions Reductions | Authors: Damian Antoan, Nicholas Chiang, Spencer Dearman, Santiago Espejel, Manarldeen Fajors, et al.
IOP Science - Potential effects of stratospheric aerosol injection on the mean and extreme climate of South America | Authors: Carla Gulizia, Ramiro I Saurral and Ines A Camilloni
Engineered Science Publisher - Glacier Defense: A Material Science Proposal | Authors: Qingchun Zhang, Zhang Chen, Qian Zhang and Yanfeng Gao
Cambridge University Press - Solar Geoengineering Governance: A Fragmented Institutional Landscape Covering Multi-Dimensional Impacts | Authors: Dana Ruddigkeit, Heleen Bruggink and Aarti Gupta
EGUsphere - Enhancing Volcanic Eruption Simulations with the WRF-Chem v4.8 | Authors: Alexander Ukhov, Georgiy Stenchikov, Jordan Schnell, Ravan Ahmadov, Umberto Rizza, Georg Grell, and Ibrahim Hoteit
Taylor & Francis - Climate engineering in The Ministry for the Future and Termination Shock | Authors: Matt Morgenstern
Communications Earth & Environment - Divergent impacts of climate interventions on China’s north-south water divide | Authors: Xiao Zhang, Yuanchao Fan, Jerry Tjiputra, Helene Muri & Qiao Chen
Royal Society of Chemistry -Effervescent nozzle design to enable outdoor marine cloud brightening experimentation | Authors: Luke P. Harrison, Chris Medcraft, and Daniel P. Harrison
Frontiers - Safeguarding the polar regions from dangerous geoengineering: a critical assessment of proposed concepts and future prospects | Authors: Martin Siegert, Heïdi Sevestre, Michael J. Bentley, et al.
Frontiers - A new paradigm from the Arctic - Viewpoint Article | Authors: John C. Moore, Marc Macias-Fauria, Michael Wolovick
Frontiers - The false promises of polar geoengineering (research) - Editorial Article | Authors: Mike Hulme
Frontiers - Polar geoengineering: not so simple - Viewpoint Article | Authors: Frans Berkhout
European Geosciences Union - Measurement report: Aerosol vertical profiling over the Southern Great Barrier Reef using lidar and MAX-DOAS measurements | Authors: Robert G. Ryan, Lilani Toms-Hardman, Alexander Smirnov, Daniel P. Harrison, and Robyn Schofield
ScienceDirect - Collective climate geoengineering futures through a global participatory technology foresight exercise | Authors: Benjamin K. Sovacool, Laurence L. Delina, Ben Martin
ResearchSquare - Solar geoengineering impacts on precipitation under projected climate change in Pakistan - Preprint | Authors: Hassaan Sipra, Muhammad Latif, Nabeel Ahmed, Athar Hussain
SSRN - Sky Wars: Escalation Pathways in the Age of Solar Geoengineering - Preprint | Authors: Gideon Futerman, Peter Rautenbach
Authorea - Wind-Driven Circulation Feedbacks Offset Tropical Geoengineered Sea Salt Emissions - Preprint | Authors: Cindy Wang, Leo J. Donner, Naser G. A. Mahfouz
ResearchGate - Solar Geoengineering Likely up to 14 Times More Efficient than CDR: Albedo Misrepresentations in Climate Forcing and Governance - Preprint | Authors: Alec Feinberg
ARXIV - A Planetary Cooling Hose - Preprint | Authors: Roderick A. Hyde
EGUsphere - Uncertainties of SAI efficiency and impacts depending on the complexity of the aerosol microphysical model - Preprint | Authors: Simone Tilmes, Daniele Visioni, Ilaria Quaglia, Yunqian Zhu, et al.
SSRN - Multi-Risk Governance of Solar Radiation Modification - Preprint | Authors: Jonathan B. Wiener, Tyler Felgenhauer, Mark Borsuk
A fragmented institutional architecture with extensive coverage of SRM impact areas
(Source)
THESES
UC San Diego - Modeling the far-reaching climate responses of regional geoengineering proposals | Authors: Wan, Jessica Shen Yi
Middlebury - Geoengineering: Planet Politics and the Price We Pay | Authors: Rosella Graham
Groen Kennisnet - Identifying Drivers of the Acceptance and Rejection of Geoengineering: A Meta-Analysis | Authors: Jager, P.B. de
Smartie Kiu - The Science of Climate Engineering: Risks and Benefits | Authors: G Mwende Wairimu
ProQuest - Conditions Leading to Extrinsic and Intrinsic Ecosystem Change Across Large Ensembles of Climate Futures | Authors: Daniel M Hueholt
REPORTS
CCAN, DSG & EDF - Solar Geoengineering Research: Next Steps for the Climate Movement - Workshop Outcomes Report
European Commission - Strategic Foresight Report 2025 - Resilience 2.0: Empowering the EU to thrive amid turbulence and uncertainty
UK Parliament - The UK and the Antarctic environment: Government Response
WEB POSTS
Communications Earth & Environment - Pathways for prevention of cascading tipping points
Mongabay - Scientists weigh giant sea curtain to shield ‘Doomsday Glacier’ from melting
CIEL - The Risks of Geoengineering on Biodiversity
Repair - Geoengineering as a climate crutch-In response to urgent need for climate mitigation reformation and the indispensability of geoengineering under current insufficient efforts
David Suzuki Foundation - Costly geoengineering schemes could stall real solutions
Science - Could a giant dam save the Atlantic currents that keep Europe warm?
Sifter - Dimming the sun, refreezing the ice: VCs flirt with geoengineering
Research Money - Canada needs research to inform policy-making on deploying solar geoengineering to reduce global warming
Science Focus - These are science’s boldest ideas to cool our heating planet
Planetary Sunshade - United Nations: Official Report on Capping Climate Change from Space
Arctic Today - Abrupt changes in Antarctic call for emissions cuts, not geoengineering: Commentary
WMKY - Officials urge Kentucky state legislature to pass an act to prohibit geoengineering
SRM360 - No, Polar Geoengineering Has Not Been Debunked
New World Journal - Securing the ‘great white shield’? Climate change, Arctic security and the geopolitics of solar geoengineering
Public News Service - Scientists discuss solutions at New York City Climate Week
News24 - Can geoengineering save us from a climate catastrophe?
Inside Climate News - UN Sessions on Solar Geoengineering Trigger Unease
David Keith - Preserving Earth’s Reflectivity: Supplementary Comments on “A Responsible Way to Cool the Planet”
Axios - Climate scientist discusses “chemtrails” conspiracy theories
Scottish Government - Solar geoengineering plans: EIR release
EOS - Geoengineering Fears on Display at Congressional Hearing
Scottish Government - Advanced Research and Innovation Agency’s (ARIA) Exploring Climate Change Programme: EIR release
CNA - Commentary: Sea curtains and glass beads? Zany climate ideas show how far off track we are
WIRED - The DOGE Subcommittee Hearing on Weather Modification Was a Nest of Conspiracy Theorizing
AEI - Statement of Dr. Roger Pielke Jr. to the Subcommittee on Delivering on Government Efficiency (DOGE) of the Committee on Oversight and Accountability of the United States House of Representatives
The Epoch Times - Experts Urge Government Ban on Solar Geoengineering
New World Journal - Securing the ‘great white shield’? Climate change, Arctic security and the geopolitics of solar geoengineering
Works in Progress - Sunscreen for the planet
TCD - Lawmakers take controversial action after discussing ‘chemtrail’ conspiracy theory: ‘That’s not natural’
CCAN - Reflecting Sunlight Away From Earth: A Plan B for Climate Change?
Axios - How extreme weather fuels interest in geoengineering
Nature Climate Change - Africa must lead the governance of solar radiation management
The Telegraph - Dimming the sun ‘could disrupt weather patterns’
SRM360 - From Climate Despair to Advocating for Climate Intervention Research
The Guardian - Underwater curtains and reflective beads are ‘unrealistic and dangerous polar geoengineering ideas’
The Conversation - High-tech plans to save polar ice will fail, new research finds
Eco Business - Explainer: Could making ocean clouds shinier cool the planet?
Operation Arktis - Dear polar scientists, engage with climate reality
Aninvest - Navigating Climate Risks: Strategic Divestment from Geoengineering to Proven Decarbonization Technologies
EurekAlert - Frontiers Forum Deep Dive series: Well-publicized polar geoengineering ideas will not help and could harm, warn experts
Jus Corpus - Climate Geoengineering and The Legal Vacuum: Should India Regulate Solar Radiation Management?
Bloomberg - UK Rejects Plan to Deflect Sun’s Rays to Curb Climate Change
Climate Repair - Relative risks and fuller strategies: should we research geoengineering?
E&E News by Politico - ‘Disastrous Forecast’: Marjorie Taylor Greene hearing targets geoengineering
News Break - Aerosol Sprays to Dim the Sun? Geoengineering Moves From Sci-Fi to Reality
SCIAM - Scientists Clash over whether Polar Geoengineering Is a Dangerous Gamble
Financial Post - UK Rejects Plan to Deflect Sun’s Rays to Curb Climate Change
The Washington Times - DOGE subcommittee to hold hearing on weather modification, ‘geo-engineering’
TCD - Scientists issue warning against dangerous schemes proposed in the Arctic: ‘Fringe ideas’
ARC - Vanishing Arctic Ice: Why Responsible Research into Arctic Stabilization is Now Essential
The New York Times - Turns Out Air Pollution Was Good for Something
ABC News - Fact-checking what lawmakers said during congressional weather modification hearing
PROJECTS
Nuffield Council on Bioethics - Nuffield Council on Bioethics begin work to explore the ethical considerations and health-related impacts of Solar Radiation Management
Delft University of Technology - Brighter Clouds, Cooler Future? An interactive installation to measure public acceptance of climate intervention research by Annelot Broerze
Share Solar Geoengineering Updates
JOB OPPORTUNITIES
Imperial College London - Research Associate or Assistant in Simulating Stratospheric Plumes
The Degrees Initiative - Policy Engagement Manager | Remote, based in either the UK or Asia | Deadline: 19 October 2025
ARIA - Communications & Engagement Lead: Future Proofing our Climate & Weather
UPCOMING EVENTS
09 October | United States - Expanding the Toolbox for a Safe, Equitable Climate Future by Manny’s
Saturdays 11 October - 22 November 22 | Online & In-person - An Intro to Climate Systems Engineering by Members of the Climate Systems Engineering Initiative (including David Keith, Tiffany Shaw, and B.B. Cael)
14 October | Online - Exploring governance analogues for SRM research by Co-Create
15-16 October | Online - Conference: The Global Heating Emergency Preventing 2°C by 2040: What’s the Plan? by Healthy Planet Action Coalition
16 October | UK - Discover Climate Repair: another kind of climate action by Centre for Climate Repair
17 October - Introducing SkyScroll by Planetary Sunshade Foundation
21-22 October | Helsinki, Finland - Workshop: The Future of climate intervention research - an early career gathering by Alliance for Just Deliberation on Solar Geoengineering
23 October | Helsinki - ATLAS25: Risk Management of Earth System Tipping Points by Operaatio Arktis
24 October | Finland - Climate Reckoning: Dr James Hansen & Clare Farrell on where we really stand by Operaatio Arktis
31 October - Online | Introducing: Sunshade Temperature mitigation using Asteroids and Rings system by Planetary Sunshade Foundation
3-7 November | Pune, India - 11th WMO Scientific Conference on Weather Modification
14 November - Online | Planetary Sunshade Foundation - annual update by Planetary Sunshade Foundation
15-19 December | New Orleans, Louisiana - 2025 American Geophysical Union Meeting
9-13 March 2026 | Kyoto, Japan - CMIP Community Workshop (CMIP26)
21-26 June 2026 | United States - Gordon Research Conference - Bridging Observations, Models, and Impacts in Solar Radiation Modification Research
Solar Geoengineering Events Calendar
PODCASTS
Entanglements by Undark - Should We Change Our Planet’s Climate...On Purpose?
BBC Rare Earth - Engineering the Planet
Catalyst with Shayle Kann - Geoengineering, nuclear, power prices, and more
Shocked - Geoengineering
Beyond the Ice - Why is everyone talking about geoengineering? | Professor Dame Jane Francis
YOUTUBE VIDEOS
Healthy Climate Initiative - Climate Intervention and Role of Civil society | Operaatio Arktis
UNEP - Multistakeholder Workshop on Solar Radiation Modification
MEER SRM - MEERtalk September 2025 - Mike Tidwell
Healthy Climate Initiative - Restoring a Healthy Climate: Nature Inspired Interventions to Reduce Global Warming and Restore Hope
Chesapeake Climate Action Network - Solar Geoengineering Research: Next Steps for Civil Society
Arctic Reflections - How And Why Dutch Start up Arctic Reflections Aims To Thicken 100,000km2 Of Arctic Ice
MEER SRM - Risk Realism: Cooling a Livable Planet w/ David Spratt
Healthy Planet Action Coalition - Ocean Nanobubbles and Buoyant Flakes
Climate Chat - ‘A Responsible Way to Cool the Planet’?!
GOP Oversight - Playing God with the Weather – A Disastrous Forecast
Remove and Reflect Podcast - A New Paradigm From the Arctic: Harm Reduction and Geoengineering
eCornell - Geoengineering: The Science and Myths of Climate Intervention
Healthy Climate Initiative - HCI Short Film
Instituto Clima e Sociedade - Solar Radiation Modification Seminar
Westminster College - 2025 Hancock Symposium-Hassaan Sipra ‘10: “Intervening in the Sky”
Healthy Planet Action Coalition - Brian Soden - Climate Geoengineering: A Bad Idea Whose Time Has Come?
Sky News - New report reopens controversy over so-called geoengineering
WION - Geoengineering Plan Sparks Debate | WION Climate Tracker
Wilkes Center - Ben Bromley: Dust as a Solar Shield
Follow us on:
Twitter | Bluesky | LinkedIn | Substack | Google Group | Podcast 1 | Podcast 2
Support us here:
While all content on Solar Geoengineering Updates is free for everyone, We urge those who can to become paid subscribers. Your support empowers this important work and helps us spread the message far and wide.
Share Solar Geoengineering Updates
