1. This Week’s Top SRM Highlights
2. Research Papers
3. Open Letter
4. Reports
5. Web Posts
6. Projects
7. Upcoming Events
8. YouTube Videos
Subscribe to stay informed on solar geoengineering tech and support our independent reporting through a paid subscription.
Donate < $10
Get 20% off a group subscription
Follow us on:
Twitter | Bluesky | LinkedIn | Google Group | Podcast
Research Paper: Marine cloud brightening mitigates the warming induced by the aerosol reductions toward carbon neutrality (Communications Earth & Environment)
Preprint: Stratospheric aerosol forcing for CMIP7 (part 2): Volcanic sulfur dioxide emissions (EGUsphere)
Co-sign an Open Letter: Supporting Applied-Science Testing and Piloting of Near-term Global Climate Cooling Approaches (HPAC)
Funding Announcement: Ocean Visions Awards New Funding for Research on Novel Approaches to Protect and Restore Arctic Sea Ice (Ocean Visions)
Mission Spotlight: EarthCARE tracks how ship emissions transform clouds (Eesa)
Call to Ban “Non-existent” SRM: Bill would empower EPA to root out climate tampering (E&E News by Politico)
Upcoming Event: The unknowability of solar geoengineering and why it matters by OCRN Annual Lecture (University of Oxford)
Video: Greg Slater Update on a Proposal for a First Antarctic SAI Test (Healthy Planet Action Coalition)
Read on to unpack more updates:
Solar Geoengineering: Protecting Democratic Deliberations in a Contested Information Environment
Authors: Trish Lavery
Synopsis: Solar geoengineering aims to reflect sunlight and limit warming but is increasingly targeted by disinformation and conspiracy narratives. Its technical complexity and governance uncertainty make it vulnerable to exploitation by malign actors as a hybrid threat. This article outlines how such campaigns could distort democratic debate and proposes a strategic communications framework to safeguard evidence-based deliberation without advocating for or against deployment.
Marine cloud brightening mitigates the warming induced by the aerosol reductions toward carbon neutrality
Authors: Yang Yu, Yang Yang, Hailong Wang, Lynn M. Russell, et al.
Synopsis: This study simulates marine cloud brightening (MCB) to counter warming from declining anthropogenic aerosols under SSP1-1.9. Seeding sea salt in four eastern Pacific regions (2020–2100) stabilizes global temperature and precipitation near 2020 levels, driven by aerosol–cloud interactions. Yet regional warming persists in Europe, the U.S., and northeastern China, partly due to AMOC changes, underscoring location-sensitive risks and the need for cautious design.
Aerosol-Cloud Interactions: Overcoming a Barrier to Projecting Near-Term Climate Evolution and Risk
Authors: Ulas Im, Bjørn H. Samset, Athanasios Nenes, Jennie L. Thomas, et al.
Synopsis: Aerosol–cloud interactions (ACI) remain one of the largest uncertainties in climate science, shaping radiative forcing, cloud behavior, and precipitation. Poor observational and modeling constraints limit projections of near-term warming, carbon budgets, extremes, and climate interventions. This perspective calls for advances in satellites, in situ data, high-resolution models, and machine learning to better quantify ACI and strengthen climate risk assessment and policy guidance.
Drivers of reduced permafrost cooling efficacy of equatorial stratospheric aerosol injection in the Eastern Arctic compared to a moderate emission pathway - Preprint
Authors: Isaline Businger, Rhonda Müller, Raleigh Grysko, Jacqueline Oehri, Jin-Soo Kim, Gabriela Schaepman-Strub
Synopsis: The Arctic is warming ~4× faster than the global average, threatening permafrost stability. Analysis of the GeoMIP6 G6sulfur SAI experiment shows that while aerosol injection lowers radiative forcing and slows permafrost loss relative to SSP585, it alters circulation, clouds, and the NAO, reshaping thaw drivers. This produces deeper thaw in the Eastern Hemisphere and reduced thaw in the West, ultimately preserving less permafrost than SSP245.
Investigating the relationship between El Niño Southern Oscillation and cirrus clouds - Preprint
Authors: Ehsan Erfani
Synopsis: Cirrus clouds—high, ice-only clouds covering ~25% of Earth, strongly influence planetary heating by reflecting sunlight and trapping longwave radiation, yet their formation remains poorly understood. This study examines how the El Niño–Southern Oscillation (ENSO) alters cirrus properties over the Pacific and the Americas, using 30+ years of NASA satellite and reanalysis data to link cloud radiative effects, coverage, and height to shifts in convection, temperature, moisture, and winds.
Stratospheric aerosol forcing for CMIP7 (part 2): Volcanic sulfur dioxide emissions - Preprint
Authors: Thomas J. Aubry, Michael Sigl, Matthew Toohey, Man Mei Chim, Magali Verkerk, Anja Schmidt, and Simon A. Carn
Synopsis: This study presents a new volcanic sulfur emission inventory (1750–2023) for CMIP7, covering 463 eruptions that injected 428.2 Tg SO₂ into the upper troposphere–stratosphere. Built from satellite data and ice-core records, it improves representation of small-to-moderate eruptions often missing in earlier datasets. The inventory refines emission height and latitude estimates, highlights persistent uncertainties, and provides guidance for consistent use in climate and aerosol models.
Share Solar Geoengineering Updates
HPAC - Open Letter in Support of Applied-Science Testing and Piloting of Near-term Global Climate Cooling Approaches
Upon Further Reflection - Reflective Scientific Advisory Board: 2025 Meeting Report
Inevitable & Obvious - Why Countries Aren’t Ready for Climate Interventions Yet
SRM360 - Why Research Space-Based Sunlight Reflection?
Legal Planet - A Science-Policy Dialogue on SRM for Latin America
Impakter - Underwater Wall to Protect the ‘Doomsday Glacier’: Necessary Intervention or Costly Distraction?
Greg Steube - Rep. Steube Introduces Air Quality Act
E&E News by Politico - Bill would empower EPA to root out climate tampering
Keep Cool - From moral hazards to moral responsibilities
Lootpress - West Virginia Bill Would Prohibit Cloud Seeding
Des Moines Register - As an environmentalist, I urge Iowa to ban geoengineering
Eesa - EarthCARE tracks how ship emissions transform clouds
Wyoming Public Media - ‘Chemtrail’ legislation ban is nixed, but cloud seeding approval moves forward
Springer Nature Link - Global Environmental Politics
Ocean Visions Awards New Funding for Research on Novel Approaches to Protect and Restore Arctic Sea Ice
Ocean Visions announced funding for six research projects through our Arctic Sea Ice Restoration Research Fund to explore cutting-edge ideas aimed at slowing the loss of Arctic sea ice.
FUNDED PROJECTS
Share
19 February | University of Nottingham, UK - Cooling the Planet from Space: The Promise of Geoengineering
24 February | Online - Live Discussion: How Might Solar Geoengineering Affect Global Security? by SRM360 (NEW)
02 March | Online - MEERTalk with Robert Tulip by MEER SRM (NEW)
04 March | Oxford University - The unknowability of solar geoengineering and why it matters by OCRN Annual Lecture (NEW)
9-13 March 2026 | Kyoto, Japan - CMIP Community Workshop (CMIP26)
17-19 March | Tokyo, Japan - Sixteenth GeoMIP 2026 Meeting by Alan Robock and Daniele Visioni
18 March | University of Cambridge - Climate Repair: Hope or Hype? by Centre for Climate Repair
03-08 May | Vienna, Austria & Online - EGU26
13-15 May | University of Nottingham - IAA Planetary Sunshade Workshop by Planetary Sunshade Foundation
28 – 29 May | Belgium - International Forum on Solar Radiation Modification Research Governance by Co-Create
02-04 June | Rwanda - The IAF Global Space Conference on Climate Change 2026 - Uniting Space and Earth for Climate Resilience
20-21 June | United States - Bridging the Knowledge Gaps in Climate Engineering with Experiments, Models, and Observations by Gordon Research Seminar
21-26 June 2026 | United States - Gordon Research Conference - Bridging Observations, Models, and Impacts in Solar Radiation Modification Research
Solar Geoengineering Events Calendar
Add our Solar Geoengineering Events Calendar to your default calendar in 2 ways:
Sync specific event: Click the event → menu (≡) → Share → choose your calendar → Save.
Or sync all events: Menu (≡) → Preferences → iCalendar Feeds → Copy URL → Add to your calendar settings → Subscribe.
Emergency Geoengineering & the Virtues of Earth Stewardship by Allen Thompson | The Schweitzer Institute
“Geoengineering, especially solar radiation management (SRM), is increasingly discussed as a response to climate change. This paper argues that, while humans have a moral obligation to serve as planetary managers and can do so without hubris, virtuous Earth stewardship cannot include developing or deploying SRM. In response to the argument that SRM could be justified as a “lesser evil” in a climate emergency, it is argued that SRM could yield genuine moral dilemmas and thus is inconsistent with virtuous planetary stewardship.”
HCI Teaser Film | Healthy Climate Initiative | Healthy Climate Initiative
“A changing climate threatens our coasts, forests, and future—but there is hope. The Healthy Climate Initiative: Regenerating Our Future is a short film that tells the story of scientists, communities, and young leaders working together to cool the planet, restore ecosystems, and inspire collective action. From reforestation in rural villages to workshops at leading universities, HCI is building a movement for a safe and thriving future. Join us in regenerating our planet.”
Greg Slater Update on a Proposal for a First Antarctic SAI Test | Healthy Planet Action Coalition
“Greg Slater will be presenting an “Update On a Proposal For the ‘First Antarctic SAI Test’ (FAST)”. He will be discussing the need to have the first tests of SAI immediately (as in, 10 years ago, or tomorrow at the latest). He will make the case for immediate tests and also present his own set of test proposals.”
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.
Support This Newsletter
