Weekly Solar Geoengineering Updates (12 January - 18 January 2026)
Weekly SRM roundup of research papers, web posts, events, jobs, projects, podcasts, videos and much more.
1. This Week’s Top SRM Highlights
2. Research Papers
3. Thesis
4. Projects
5. Reports
6. Web Posts
7. Job Opportunities
8. Call for Evidence
9. YouTube Videos
10. Upcoming Events
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Research Paper: Potential Impacts of Climate Interventions on Marine Ecosystems (AGU)
Preprint: Robust assessment of Solar Radiation Modification risks and uncertainties must include shocks and societal feedbacks (EGUsphere)
2025 SRM Year in Review: Solar Geoengineering in 2025: Rays of Hope, Clouds of Doubt (Solar Geoengineering Updates)
Job Opportunity: Executive Director (MEER)
Thesis: The Impact of IMO2020 on Droplet Number Concentration and Cloud Adjustments in the Southeast Atlantic Shipping Corridor (ProQuest)
Report: Parasol Lost: Recovery plan needed (Institute and Faculty of Actuaries)
Call for Evidence: Considering future generations, the environment and the interests of non-human species in the analysis of emerging technologies, including solar radiation modification (Nuffield Council on Bioethics)
Video: Doomsday Glacier and a Seabed Curtain (Climate Emergency Forum)
Read on to unpack more updates:
Authors: Ehsan Erfani and David L. Mitchell
Synopsis: This study assesses the climate intervention potential of cirrus cloud thinning (CCT) using satellite-based observations rather than conventional climate model assumptions. By leveraging CALIPSO retrievals and a radiative transfer model, it quantifies the radiative effects of cirrus clouds dominated by homogeneous versus heterogeneous ice nucleation across regions and surface types. Results show a wide range of possible outcomes, with both cooling and warming effects at the surface and top of the atmosphere, highlighting major uncertainties and the need for improved cirrus representation in climate models.
Authors: F. F. B. K. Ayissi, C. Y. Da-Allada, E. Baloïtcha, J. Agada, L. G. Mekonou-Tamko, S. Tilmes & E. Capo-Chichi
Synopsis: This study examines how stratospheric aerosol geoengineering (SAG) affects the seasonal variability of the ocean barrier layer (BL) in the northeastern Gulf of Guinea. Models reproduce observed BL patterns, with peak thickness in boreal autumn. Under global warming, barrier layer thickness increases markedly, by ~14% in autumn—driven mainly by higher river runoff and precipitation. Under SAG, BL thickening is much smaller (~2%) and linked to reduced freshwater inputs and ocean dynamics, indicating far weaker impacts than unabated warming.
Governing SRM Research for Legitimacy and Justice
Authors: Bennet Francis, Dominic Lenzi
Synopsis: As the US, UK, and EU advance solar geoengineering research, questions of governance have become increasingly urgent. This paper argues that existing research oversight institutions require innovation to meet emerging expectations of legitimacy and procedural justice. It contends that SRM research differs fundamentally from conventional climate science and more closely resembles other high-risk research domains, warranting specialised governance. The paper highlights challenges of global, intergenerational, and cross-community legitimacy, and emphasizes justice as recognition as a core requirement for credible SRM research institutions.
Authors: Shaun D. Fitzgerald, Albert Van Wijngaarden, Ramit Debnath & Zoe Fritz
Synopsis: Scientific discussions on climate engineering often face significant barriers, even within research and policy spaces. While public debate is important, this paper (comment) focuses on the specific challenges confronting scientific inquiry in this contested field. Drawing lessons from the history of controversial medical research, it suggests possible pathways forward, including the creation of formal oversight mechanisms, clearer boundaries for acceptable research, and the introduction of specialised review systems to support rigorous, responsible, and credible scientific engagement.
Potential Impacts of Climate Interventions on Marine Ecosystems
Authors: Kelsey E. Roberts, Tyler Rohr, Morgan R. Raven, Michael S. Diamond, et al.
Synopsis: As global temperatures continue to rise beyond the Paris Agreement targets, interest is growing in climate interventions such as carbon dioxide removal (CDR) and SRM. This review examines proposed marine-based CDR and SRM approaches and assesses their potential impacts on ocean ecosystems. While such interventions may reduce warming-related harms, they also carry risks for marine biodiversity, food webs, and ecosystem function. The study highlights key uncertainties, trade-offs, and knowledge gaps, underscoring the need for pathway- and region-specific assessments to prioritise low-risk options and avoid high-risk interventions.
Authors: Elliott Woodhouse
Synopsis: The Tollgate Principles call for geoengineering projects to respect environmental ethics, including “respect for nature,” drawing on the work of Paul Taylor. While Christopher Preston has argued that Taylor’s ethics presume against geoengineering due to a principle of non-interference, this interpretation overlooks Taylor’s own exemptions, especially the Principle of Restitutive Justice. Under strict conditions such as self-obviation, some geoengineering interventions may align with Taylor’s framework, suggesting the Tollgate Principles do not categorically rule out geoengineering.
Authors: Benjamin M. Sanderson, Susanne Baur, Carl-Freidrich Schleussner, Glen P. Peters, et al.
Synopsis: Conventional climate scenarios smooth over fast political and economic shocks, assuming slow climate responses to emissions. SRM breaks this logic by coupling rapid, sub-decadal climate responses to volatile human systems. This paper introduces the Solar Radiation Modification Pathway (SRMP) framework, outlining five typologies to capture event-driven risks such as termination shock, geopolitical conflict, and moral hazard. It shows why static SSP narratives are insufficient and argues that relying on idealised SRM scenarios risks producing a distorted and inadequate evidence base.
Authors: Tom Goren, Goutam Choudhury, and Graham Feingold
Synopsis: This study introduces a ternary-diagram framework to classify marine stratocumulus cloud morphologies based on cloud optical thickness. Applying satellite observations and large-eddy simulations, it shows that cloud evolution follows preferred pathways within this morphology space. Analysis of susceptibility to droplet number changes reveals that, for common morphologies, liquid water path and albedo effects largely cancel, while cloud fraction responses depend on precipitation regime. These results imply that marine cloud brightening effectiveness is strongly morphology-dependent and cannot be assessed with uniform assumptions.
Authors: Boss, Lili
Synopsis: This thesis examines aerosol–cloud interactions using shipping corridors as natural experiments to assess cloud sensitivity to aerosol perturbations and implications for marine cloud brightening. Focusing on the southeast Atlantic, it analyses MODIS satellite data before and after the IMO 2020 sulfur regulations, which reduced shipping aerosol emissions. Using a top-down kriging approach, results show declines in cloud droplet number concentrations and the Twomey effect, alongside changes in cloud fraction and liquid water path, highlighting how cleaner shipping alters cloud radiative responses.
University of Leeds - DOOC: Drone Observation Of Clouds and their role in weather and climate
Clouds strongly shape Earth’s climate and energy balance, yet long-term observations remain scarce. This project introduces a drone-based system for routine, in-situ cloud measurements, overcoming limits of aircraft, satellites, and balloons. By integrating a miniaturised cloud microphysics sensor with a commercial drone, it will deliver the first long-term vertical profiles of aerosol and cloud droplets up to 2 km. A three-month intensive campaign will support advances in cloud–radiation research, improve UK weather forecasting, and enable unique drone–satellite comparisons.
Institute and Faculty of Actuaries - Parasol Lost: Recovery plan needed
This report warns that global warming is accelerating faster than expected as “aerosol cooling” from air pollution, previously masking ~0.5°C of warming, rapidly declines, notably due to shipping regulations. It finds warming could reach 2°C before 2050, risking severe social and economic disruption. The report highlights rising risks of climate-driven inflation, financial instability, and “Planetary Insolvency,” and criticises economic models that have underestimated climate damages, delaying action.
Solar Geoengineering Updates - Solar Geoengineering in 2025: Rays of Hope, Clouds of Doubt
This report provides a comprehensive overview of Solar Geoengineering (SRM) in 2025, from funding and research breakthroughs to global debates, restrictions, media highlights, and more.
Cornell Chronicle – Scientists map key oceanic unknowns in climate interventions
Paul Gambill – You Can’t Focus Group Your Way to Permission
The Degrees Initiative – Latin American policymakers seek greater understanding of solar radiation modification
Politico (Opinion) – Betting on Climate Failure
The ARC – Thoughts on a safe climate future: Protecting against Arctic destabilization, a $70 trillion opportunity
SRM360 – What Does Trump’s Withdrawal From Climate Organisations Mean for SRM?
The Conversation – Climate engineering would alter the oceans, reshaping marine life – new study examines each method’s risks
Omnibus – Researcher in Geoengineering: A Worst-Case Scenario Has Now Become a Reality
HPAC – American Geophysical Union Poster – SAI Deployment and Risks to Human Civilization
EcoFlow – Geoengineering: Can Blocking Out the Sun Reverse Climate Change?
Executive Director at MEER | Remote
“MEER is pioneering globally scalable, surface-based cooling technologies to address one of the defining challenges of our time: extreme heat. Rooted in rigorous science, field-tested engineering, and deep commitment to climate justice, MEER works to reduce heat stress, rebalance Earth’s energy system, and expand planetary resilience.”
Call for Evidence – Considering future generations, the environment and the interests of non-human species in the analysis of emerging technologies, including solar radiation modification | Deadline: 15 March 2026
Doomsday Glacier and a Seabed Curtain | Climate Emergency Forum
“A bold new proposal aims to “hold back” the Doomsday Glacier. In this episode of the Climate Emergency Forum, Herb Simmens and Paul Beckwith speak with three leading voices behind the Seabed Curtain Project, which is exploring whether a seabed‑anchored curtain could slow the warm ocean water melting Antarctica’s Thwaites Glacier and delay up to several meters of global sea level rise.
The discussion also tackles governance, ethics, and geopolitics: who should decide if such a climate intervention goes ahead, how the Antarctic Treaty System and Arctic communities might be involved, and why the team hopes their research either proves a curtain unnecessary—or delivers a clear recipe for future decision‑makers if it becomes essential. Stay to the end for Herb’s roundup of recent climate headlines.”
“Marine cloud brightening (MCB) is a proposed solar climate intervention strategy that increases marine cloud reflectivity to cool Earth’s surface. While previous studies have examined its global temperature and precipitation effects, less is known about how MCB deployment strategy influences polar climate and sea ice.”
“Social-natural and indigenous-western science co-design of targeted interventions to conserve the cryosphere.”
Geo-Engineering with Stratospheric Sulfur Injection | Deep Tech Week
Lauren Zamora, UMD: To Arctic Clouds From Saharan Dust | Compass On Demand
“To Arctic Clouds From Saharan Dust: An Alumnus Career Retrospective”
Aerosol–cloud interactions are one of the largest sources of uncertainty in climate projections for the rapidly warming Arctic, particularly through their influence on the radiative properties of mixed‑phase clouds containing both liquid water and ice. In this talk, I will present a retrospective of my research on aerosol impacts on the environment, tracing a trajectory from PhD work at Rosenstiel on Saharan dust and atmospheric nutrient deposition to the ocean to my current focus on Arctic aerosol–cloud interactions. I will talk about how my training in marine and atmospheric chemistry with Dennis Hansell and Joe Prospero continues to inform my research approach. The presentation will focus primarily on recent developments in understanding Arctic aerosol-cloud interactions, including new satellite observational methods, community scientific priorities identified at a recent QuIESCENT international workshop, and new observations from NASA’s 2024 ARCSIX (Arctic Radiation-Cloud-Aerosol-Surface Interaction Experiment) field campaign. I will also discuss emerging satellite remote sensing approaches and recent work on polar mixed‑phase cloud thinning as a potential climate intervention strategy. I will conclude by briefly reflecting on career lessons learned that may be helpful for current graduate students, including managing research transitions, building diverse mentoring networks, and approaching complex scientific problems strategically.”
30 January | Online - Could solar geoengineering help protect coral reefs? by SRM360
9-13 March 2026 | Kyoto, Japan - CMIP Community Workshop (CMIP26)
03-08 May | Vienna, Austria & Online - EGU26
13-15 May | University of Nottingham - IAA Planetary Sunshade Workshop by Planetary Sunshade Foundation
17-19 March | Tokyo, Japan - Sixteenth GeoMIP 2026 Meeting by Alan Robock and Daniele Visioni
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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The observation about SSP scenarios being insufficient for SRM risk modeling is really sharp. I hadnt considered how rapid subdecadal climate levers would amplfy geopolitical volatility rather than smooth it out. Termination shock scenarios paired with volatile human decision-making create a totally different risk space than slow emissions trends.