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Research Paper: Defining Scales of Field Studies and Experiments to Assess Marine Cloud Brightening (AGU)
Preprint: SAI and L1 Space Sunshading Mass Requirements for Climate Mitigation: Fictitious Aerosol Disk Validation of SAI and Sunshade Formula Corrections (SSRN)
Blog: Ignorance Is Not an Option: Why NRDC Is Engaging on Solar Geoengineering (NRDC)
News: Hobbs vetoes Arizona bills on solar geoengineering, DPS funding and petition circulators (Havasu News)
Report: The National Security Case for U.S. Leadership In SRM Technology (ACCF)
Job Opportunity: Student Internship: Open Science for Reflective’s SAI Uncertainty Database (Reflective)
Call for Input: The Office of the United Nations High Commissioner for Human Rights has launched a call for input on climate-related technologies, including geoengineering, to assess their potential impacts on human rights (OHCHR)
Podcast: As interest in geoengineering grows, lack of oversight poses risks (Here & Now Newsroom)
Video: Geoengineering: Catalyst or Threat? (Arctic Circle)
Read on to unpack more updates:
Education Increases Solar Radiation Modification Literacy but Reinforces Caution: Evidence from a Pre–Post University Study
Authors; Pengyao Gao, Amanda Sie, Lili Xia and Chaochao Gao
Synopsis: This study evaluates how a university classroom module on SRM influenced student perceptions. Using pre–post surveys of 103 students, self-rated SRM knowledge increased significantly after instruction. While support for SRM research remained moderately positive, support for SAI deployment declined, and students shifted toward prioritizing low-carbon development. Results suggest that structured education increases understanding while encouraging more cautious views about SRM deployment, governance, and potential risks.
Geoengineering and Animal Ethics: The Case of Stratospheric Aerosol Injection
Authors: Leonie N. Bossert & Clare Palmer
Synopsis: This study examines the ethical implications of SAI specifically for wild animals, an area largely overlooked in SRM debates. It explores whether SAI could be considered inherently wrong from animal ethics perspectives and identifies key issues for moral evaluation, including limited empirical evidence on impacts, potential effects on animal welfare, and broader justice considerations that include non-human species.
Impact of stratospheric aerosol geoengineering on sea surface temperature in the angolan upwelling system
Authors: L.G. Mekonou-Tamko, C.Y. Da-Allada, F.F.B.K. Ayissi, J.H. Agada, E. Baloitcha, S. Tilmes
Synopsis: This study investigates how stratospheric aerosol geoengineering (SAG) affects sea surface temperatures (SST) in the Angolan Upwelling System under a high-emissions climate scenario. Simulations show global warming raises regional SST by about 1.65°C due to weaker vertical mixing and increased solar radiation. Under SAG, SST instead declines by roughly 0.35°C, mainly from stronger vertical mixing and reduced solar radiation. Remote wind forcing and coastal trapped waves also play a key role in driving SST changes in the region.
Effect of regional marine cloud brightening on land climate
Authors: Long Cao, Yu Fang and Jiu Jiang
Synopsis: This study uses the CESM Earth system model to assess land climate impacts of MCB. Seeding sea salt aerosols over 5% of susceptible ocean areas from 2031 stabilizes global temperatures near 1.5 °C under SSP2-4.5. MCB cools most land regions, reduces drought stress across 55% of land, and increases terrestrial productivity. However, abrupt termination causes rapid warming, up to four times faster than baseline, posing major ecological risks and highlighting governance challenges.
Sensitivity of projected Afro-Asian monsoon precipitation to solar radiation management
Authors: Tolulope E. Adeliyi, Akintomide A. Akinsanola
Synopsis: This study evaluates how SRM, specifically stratospheric aerosol injection (G6Sulfur) and solar dimming (G6Solar), affects Afro-Asian summer monsoon rainfall under the SSP5-8.5 scenario. Using GeoMIP CMIP6 simulations, results show SRM generally reduces heavy precipitation, precipitation variability, and extreme rainfall, while increasing consecutive wet days due to more light-to-moderate rainfall. SRM also alters monsoon timing and season length, and overall lowers population exposure to rainfall extremes, though some regions still face increased wet-day exposure.
Defining Scales of Field Studies and Experiments to Assess Marine Cloud Brightening
Authors: Sarah J. Doherty, Michael S. Diamond, Robert Wood, Haruki Hirasawa
Synopsis: SRM is being explored as a potential tool to reduce climate risks while greenhouse gas levels decline. However, knowledge of its effectiveness, impacts, and risks is limited, relying mainly on natural analogs and climate models. Researchers propose a framework for SRM field experiments, applied to marine cloud brightening (MCB), that defines study scale, uses stage-gates for progress decisions, and links experiments to clear scientific goals, detectability metrics, and impact assessments to support informed research and governance.
Impact of solar radiation management in anomalous atmosphere in Indonesia Case Study: The extreme rainfall of surigae tropical cyclone in papua province, indonesia
Authors: Hendri; Ahmad Faqih; Sorja Koesuma; Jassica Listyarini; Delfina Azzahra Kusuma
Synopsis: This study examines extreme rainfall linked to tropical cyclones in Papua, eastern Indonesia, focusing on Tropical Cyclone Surigae (April 2021). Using ERA5 data and Solar Radiation Management (SRM) model simulations, along with GeoMIP bias correction, researchers analyzed atmospheric dynamics during the event. Results show strong agreement between datasets and suggest a decrease in rainfall over eastern Indonesia during the cyclone. However, simplifications in GeoMIP, particularly in cloud–aerosol interactions and SRM assumptions, may lead to underestimation of precipitation impacts.
Spatiotemporal characteristics of aerosols and low clouds from MODIS and their implications for marine cloud brightening
Authors: Liya Niu, Chuanfeng Zhao, Haotian Zhang, Yongen Liang & Annan Chen
Synopsis: This study evaluates the global potential of marine cloud brightening using MODIS satellite data (2003–2024) to analyze relationships between aerosol optical depth, cloud droplet radius, cloud optical thickness, and cloud fraction. Results show strong regional variability, with the North Pacific in autumn displaying favorable cloud responses to aerosols. However, heterogeneous and sometimes decoupled cloud responses highlight uncertainties. The study emphasizes that MCB assessments must use dynamic sensitivity analyses rather than simple climatological screening to better understand aerosol–cloud interactions.
SAI and L1 Space Sunshading Mass Requirements for Climate Mitigation: Fictitious Aerosol Disk Validation of SAI and Sunshade Formula Corrections - Preprint
Authors: Alec Feinberg
Synopsis: This study compares mass requirements for three solar geoengineering approaches, L1 space sunshading, SAI, and Earth brightening. Correcting a geometric error in earlier L1 sunshade estimates reduces required disk area by 30–40×, and up to 1600× under an annual deployment framework. Even so, large masses are needed, with ~19,000 tonnes initially for L1 systems. Regionally targeted SAI requires about 1,000 tonnes of SO₂ per year, rising slightly over time, highlighting mass as a key feasibility constraint for solar geoengineering.
Solar Geoengineering Potential in Flood Assuagement in Four East African Cities - Preprint
Authors: Herbert O. Misiani, Betty N. Barasa, Franklin Joseph Opijah, Hussen S. Endris, Jully O. Ouma, Christopher Lennard
Synopsis: This study assesses whether SRM could reduce future rainfall-driven flood risks in four major cities in Eastern Africa. Using the Rainfall–Runoff–Inundation model with CHIRPS observations and climate simulations from WACCM6 and ARISE-SAI (SSP2-4.5), researchers simulated historical and future flooding. Results suggest stratospheric aerosol injection (SAI) could lower peak inundation depth and flood extent in areas of Dar es Salaam and Addis Ababa, reducing exposure of people and infrastructure. However, uncertainties remain due to rainfall modeling limits and reliance on a single hydrological framework.
Exploring divergent long-term stratospheric aerosol injection scenarios with the G2-SAI and ARISE-hybrid experiments - Preprint
Authors: Walker Raymond Lee, Simone Tilmes, and Ewa M. Bednarz
Synopsis: This study proposes a new G2-SAI experiment to better isolate climate responses to SAI. Using the CESM2 model with 150-year simulations, researchers test different aerosol injection strategies to control global temperatures. Results show that distinct injection patterns can produce similar temperature outcomes but very different Earth system responses, including impacts on the Atlantic Meridional Overturning Circulation (AMOC). The findings highlight the importance of long-term simulations and strategy design in evaluating the climatic effects of SAI.
Mitigating Non-stationarity in Machine Learning-Based Downscaling of Climate Projections - Preprint
Authors: Yue Wang, Daniele Visioni, Ben Kravitz, Douglas G MacMartin, Dhruv Balwada
Synopsis: This study examines how machine learning (ML) can downscale climate projections under future warming and SRM scenarios. A U-Net model trained on historical data performs poorly under changing climate conditions, with large increases in temperature error. Researchers introduce a preprocessing method using residual learning and pixel-wise detrending to reduce distribution shifts. The improved model cuts RMSE below 0.27 °C, outperforms standard methods, runs faster, and enables the first ML-based high-resolution downscaling of a GeoMIP SRM (G6sulfur) simulation.
Heinrich Böll Stiftung - Who Funds and Who Pays: The funding of solar geoengineering, 2020–2025
X - The Dose Makes the Poison
Inevitable & Obvious - The Generosity of Spirit - The type of leadership that climate stabilization will depend on
Clean Energy Wire - Foundation calls for rules to prohibit solar radiation management as global investments rise
University of Birmingham - Why cutting emissions still matters more than ever
CSEi - CSEi Announces Latest Research Awards
LinkedIn - Learning from one-another to govern research into the unknown: reflections ahead of the Co-CREATE Forum
NRDC - Ignorance Is Not an Option: Why NRDC Is Engaging on Solar Geoengineering
LinkedIn - Protecting American Weather Sovereignty - Strategies for a Safe and Secure Atmosphere for America
E&E News by Politico - US should lead on planet-cooling technology for national security, report says
Havasu News - Hobbs vetoes Arizona bills on solar geoengineering, DPS funding and petition circulators
ACCF - The National Security Case for U.S. Leadership In SRM Technology
Student Internship: Open Science for Reflective’s SAI Uncertainty Database at Reflective | San Francisco, CA
“Reflective is a climate research nonproft with the mission to equip the world with the data and tools needed to make informed decisions about sunlight reflection technologies, fast enough to matter.”
Call for Input - The Office of the United Nations High Commissioner for Human Rights has launched a call for input on climate-related technologies, including geoengineering (CDR & SRM), to assess their potential impacts on human rights | Deadline: 30 April 2026
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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
23 March | Boston - Unilateral Solar Geoengineering: A Scenario by Frederick S. Pardee School of Global Studies
24 March | Online - Live Discussion: Could Solar Geoengineering Prevent AMOC Collapse? by SRM360
25 March | Online - Deliberately Cooling the Planet. Could we? Should we? Would we? by RMetS
26 March | Online - Who Funds and Who Pays: The funding of solar geoengineering, 2020–2025 by HOME Alliance, the Heinrich Böll Foundation, and Geoengineering Monitor (NEW)
26 March | George Washington University - Plan C for Civilization, co-presented with the George Washington University and Planet Forward (NEW)
03-08 May | Vienna, Austria & Online - EGU26
13-15 May | University of Nottingham - IAA Planetary Sunshade Workshop by Planetary Sunshade Foundation
18 May | University of Chicago - Frontiers in Climate Systems Engineering by CSEi
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
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As interest in geoengineering grows, lack of oversight poses risks | Here & Now Newsroom
“A new report warns of a concerning lack of oversight into geoengineering, or weather manipulation.
Here & Now’s Peter O’Dowd speaks with Grist’s climate news reporting fellow Rebecca Egan McCarthy about the spread of geoengineering and how it can be used to fight climate change.”
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CSEi Seminar Featuring Holly Jean Buck (University of Buffalo) | UChicago Climate Systems Engineering initiative
“Title: The fantasy of “social tipping points” — and what it can teach us about incorporating social feedbacks into climate response strategies
This talk reviews these nascent frameworks and identifies limitations in how modelers approach the incorporation of social factors into solar geoengineering research, assessment, and governance. It connects these efforts to broader questions about how social dynamics are represented in mitigation science, discourse and policy. The talk then outlines an alternative approach to incorporating social dynamics into responding to climate change — one grounded in qualitative research and civic engagement.”
Geoengineering: Catalyst or Threat? | Arctic Circle
“PANELISTS
Dalee Sambo Dorough, Senior Scholar, University of Alaska Anchorage (UAA), USA
Shaun Fitzgerald, Director, Centre for Climate Repair, University of Cambridge, United Kingdom
Mark Symes, Programme Director, ARIA - Advanced Research and Invention Agency, United Kingdom”
Geoengineering: from controversy to conflict | Open University
“Geoengineering, a term encompassing a set of climate modification techniques to combat global warming, is increasingly present in scientific, media, and diplomatic circles. Its gradual development raises major controversies, particularly concerning the risks and justice issues raised by these techniques. Simultaneously, the lack of clear international regulation and the growing power of state and private actors fuel geopolitical tensions. Internationally, the controversial nature of geoengineering can thus become a real factor in international rivalries and conflicts. Marine de Guglielmo Weber, a researcher at IRSEM, will analyze these controversies and their security implications for the global climate regime. The Open University lecture and debate series, organized by CY Cergy Paris University, invites lecturers who are either faculty members at CY or researchers from outside the university.”
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