SOLAR GEOENGINEERING WEEKLY SUMMARY (06 JANUARY 2024 - 12 JANUARY 2024)
Geoengineering News
SOLAR GEOENGINEERING WEEKLY SUMMARY (06 JANUARY 2024 - 12 JANUARY 2024)
2024 SRM YEAR IN REVIEW
Solar Geoengineering in 2024: Rays of Hope, Clouds of Doubt (Solar Geoengineering Updates)
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RESEARCH PAPERS
CAS-ESM2.0 Dataset for the G1ext Experiment of the Geoengineering Model Intercomparison Project (GeoMIP)
Cui, M., Ji, D., Moore, J. C., Zhang, H., Jin, J., Fei, K., ... & Zhang, D. (2025). CAS-ESM2. 0 Dataset for the G1ext Experiment of the Geoengineering Model Intercomparison Project (GeoMIP). Advances in Atmospheric Sciences, 1-14.
Abstract
Solar radiation modification, a scheme aimed at mitigating rapid global warming triggered by anthropogenic greenhouse gas emissions, has been explored through the G1ext experiment under the Geoengineering Model Intercomparison Project (GeoMIP) framework, utilizing the Chinese Academy of Sciences Earth System Model version 2 (CAS-ESM2.0). This paper briefly describes the basic configuration and experimental design of the CAS-ESM2.0 for G1ext, which involves a sudden reduction in solar irradiance to counterbalance the radiative forcing of an abrupt quadrupling of atmospheric CO2 concentration, running for 100 years. Preliminary results show that this model can reproduce well the compensatory effect of a uniform decrease in global solar radiation on the radiative forcing resulting from an abrupt quadrupling of CO2 concentration. Like other Earth system models, CAS-ESM2.0 reasonably captures variations in radiative adjustments, surface air temperature, and precipitation patterns, both globally and locally, under the G1ext scenario. The generated datasets have been released on the Earth System Grid Federation data server, providing insight into the potential efficacy and impact of solar geoengineering strategies.
South Asian Summer Monsoon under stratospheric aerosol intervention
Asutosh, A., Tilmes, S., Bednarz, E. M., & Fadnavis, S. (2025). South Asian Summer Monsoon under stratospheric aerosol intervention. npj Climate and Atmospheric Science, 8(1), 3.
Abstract
The South Asian summer monsoon (SAM) bears significant importance for agriculture, water resources, economy, and environmental aspects of the region for nearly 2 billion people. To minimize the adverse impacts of global warming, Stratospheric Aerosol Intervention (SAI) has been proposed to lower surface temperatures by reflecting a portion of solar radiation back into space. However, the effects of SAI on SAM are still very uncertain. Our study identifies the main drivers leading to a reduction in the mean and extreme summer monsoon precipitation under SAI. These include SAI-induced lower stratospheric warming and the associated weakening of the northern hemispheric subtropical jet, changes in the upper-tropospheric wave activities, geopotential height anomalies, a reduction in the strength of the Asian Summer Monsoon Anticyclone, and, to some degree, local dust changes. As the interest in SAI research grows, our results demonstrate the urgent need to further understand SAM variability under different SAI scenarios.
Impacts on Indian Agriculture Due To Stratospheric Aerosol Intervention Using Agroclimatic Indices
Grant, N., Robock, A., Xia, L., Singh, J., & Clark, B. (2025). Impacts on Indian agriculture due to stratospheric aerosol intervention using agroclimatic indices. Earth's Future, 13(1), e2024EF005262.
Abstract
Climate change poses significant threats to global agriculture, impacting food quantity, quality, and safety. The world is far from meeting crucial climate targets, prompting the exploration of alternative strategies such as stratospheric aerosol intervention (SAI) to reduce the impacts. This study investigates the potential impacts of SAI on rice and wheat production in India, a nation highly vulnerable to climate change given its substantial dependence on agriculture. We compare the results from the Assessing Responses and Impacts of Solar climate intervention on the Earth system with Stratospheric Aerosol Injection-1.5°C (ARISE-SAI-1.5) experiment, which aims to keep global average surface air temperatures at 1.5°C above preindustrial in the Shared Socioeconomic Pathway 2-4.5 (SSP2-4.5) global warming scenario. Yield results show ARISE-SAI-1.5 leads to higher production for rainfed rice and wheat. We use 10 agroclimatic indices during the vegetative, reproductive, and ripening stages to evaluate these yield changes. ARISE-SAI-1.5 benefits rainfed wheat yields the most, compared to rice, due to its ability to prevent rising winter and spring temperatures while increasing wheat season precipitation. For rice, SSP2-4.5 leads to many more warm extremes than the control period during all three growth stages and may cause a delay in the monsoon. ARISE-SAI-1.5 largely preserves monsoon rainfall, improving yields for rainfed rice in most regions. Even without the use of SAI, adaptation strategies such as adjusting planting dates could offer partial relief under SSP2-4.5 if it is feasible to adjust established rice-wheat cropping systems.
THESIS
Planetary Sunshade for Solar Geoengineering: Precursor Mission for Shading the Solar Radiation Reflected by the Moon
Abstract
Since the onset of industrial development in the eighteenth century, climate change has increasingly threatened natural ecosystems and human society, driving the urgent need for innovative, large-scale solutions to mitigate its impact. In particular, space-based geoengineering has emerged as a promising strategy, offering a global scale intervention. Among these methods, the Planetary Sunshade System, based on Solar Radiation Modification, aims to reduce the oncoming solar radiation, thereby mitigating the greenhouse effect and the rise of Earth's temperature. The main motivation behind this project lies in evaluating some of the critical technologies of a Planetary Sunshade System. In this perspective, a precursor mission demonstrator is designed. The mission scenario consists on deploying a solar-sail in proximity of the photo-gravitational equilibrium point L_1^*, where solar radiation pressure and gravitational pull balance. Using a CubeSat platform, chosen for its cost-effectiveness and rapid development cycle, the project aims to define optimal sizing and deployment parameters, including radius and mass, alongside essential supporting subsystems. The preliminary proposed design covers the mission analysis and deployment mechanism tested for structural resilience under operational stresses. The main contributions consist first on the CubeSat's mass optimization, considering typical solar-sail lightness parameters from the literature. Subsequently, the orbit design is performed in the Sun-Earth-Moon Bi-Circular Restricted Four-Body Problem framework by exploiting the solar radiation pressure through attitude control. Finally, the sail deployment mechanism is presented, focusing on mechanical, electrical, and physical considerations. The mechanical analysis evaluates maximum stresses, strains, and vibrational modes to ensure resonance frequencies remain well above the operating ones of the electric motor. The electrical system is designed to ensure efficient motor operation with minimal energy consumption. The deployment mechanism employs four tape-measure booms, and a 3.8:1 scale model of the sail has been constructed to verify it can deploy without tearing.
BOOK
Geoengineering and Climate Change: Methods, Risks, and Governance
About this book
This important and timely book assembles expert scientists from both sides of the debate to discuss Earth-based and space-based climate intervention technologies including the scale, deployment, risk management, and moral philosophy behind these technologies.
The role that geoengineering might play, within the context of global warming amelioration, has long been contentious. For all this, geoengineering is about getting down and dirty with respect to the issue of climate intervention. Often dismissed as an option of last resort, geoengineering is now emerging as a key component in humanity’s drive to bring the impacts of global warming under some form of mitigation and control. While geoengineering does not solve the fundamental problem of continued anthropomorphic carbon dioxide emissions, the root cause of global warming, it is an option that can effectively buy humanity some much-needed time. Time, that is, to act positively, and time to introduce meaningful emission reductions, and deploy large-scale sequestration technologies. Indeed, the failure to meaningfully corral greenhouse gas emission levels, and the slow development of large-scale carbon capture technologies, will, by the close of the 21st century, likely see global temperatures increase by at least 2 or 3 degrees above pre-industrial levels. What geoengineering can potentially do for us is to offset the more extreme climate change scenarios that are presently projected to come about. An integrated geoengineering program to cool Earth’s atmosphere, running in parallel with the development of sequestration technologies, and substantial emission reductions, can work to limit the worst effects of climate change that will, without geoengineering, surely come about. Geoengineering is not a neutral or benign action, however, and if it is to be deployed, then much more research, and field testing of ideas and technologies is urgently needed.
The authors in this book present a cross-section of philosophies, engineering approaches, and reactions to the idea of geoengineering. Through their words, the reader is introduced to the historical and contemporary debate concerning the potential deployment of geoengineering actions. Indeed, there are many ways in which geoengineering, as a grand worldwide initiative, or as a combined set of independent actions, might proceed in both the near, and the deep future, and here the reader is introduced to these topics by experts in their field.
SubscribedWEB POSTS
Could SAI Delay the Recovery of the Ozone Layer? (SRM360)
Blocking sun to fight climate change (The Financial Express)
Could SAI Replace the Lost Cooling Effect From Cleaning Up Air Pollution? (SRM360)
Marine Cloud Brightening (SRM360)
Chile team finds SRM shows potential to reduce glacier loss in the Andes (The Degrees Initiative)
JOB OPPORTUNITY
Vertical Legal Borrowing at University of Tasmania | Deadline to apply: 01 February 2025
"Project Title: Building international law from the bottom up: Vertical Legal Borrowing as a Pathway to Govern Climate Intervention Technologies
The aim of this PhD project is to evaluate how domestic law can provide lessons for international governance of climate intervention through a process of 'vertical legal borrowing.' Domestic governance provides opportunities for legal experimentation, where mechanisms can be tested and refined to inform the development of an international legal framework for climate intervention."
UPCOMING EVENTS
(NEW) 17th Symposium on Aerosol Cloud Climate Interactions | 12-16 January 2025 | New Orleans & Online
(NEW) Geoengineering: Should the world’s nations research ways to cool the planet? by CCAN | 15 January 2025 | Online
Solar Climate Intervention Virtual Symposia #15 | 17 January 2025 | Online
Solar radiation modification: What should Europe’s strategy be? by Scientific Advice Mechanism to the European Commission | 23 January 2025 | Online
(NEW) What if engineering could cool the planet by Centre for Climate Repair | 30 January 2025 | University of Cambridge
Solar Radiation Modification: What’s at stake for society? by Scientific Advice Mechanism to the European Commission | 03 February 2025 | Online
(NEW) What if we could make more ice by Centre for Climate Repair | 13 February 2025 | University of Cambridge
(NEW) What if clouds could be more reflectice by Centre for Climate Repair | 27 February 2025 | University of Cambridge
Climate Intervention: Distraction or Necessity? by Center for Climate Repair | 21 March 2025
2025 Solar Radiation Management Annual Meeting by Simons Foundation | 24-25 April 2025 | New York
The 2025 Degrees Global Forum | 12-16 May 2025 | Cape Town, South Africa
Artic Repair Conference 2025 by University of Cambridge & Center for Climate Repair | 26-28 June 2025 | Cambridge UK
Solar Geoengineering Events Calendar
YOUTUBE VIDEOS
Solar Radiation Modification: Ethics, Equity, and Governance Post-COP29 | Research Society of International Law
"In this episode, Maha Husain speaks with Hassaan Sipra, Director of Global Engagement at the Alliance for Just Deliberation on Solar Geoengineering (DSG). He shares insights into the science, ethics, and governance of solar radiation modification (SRM) and its implications for global climate policy."
AGU24 Roundtable: Experts discuss geoengineering ethics and COP29
"This media roundtable was recorded at AGU's 2024 Annual Meeting on 10 December 2024.
Join experts in climate science, ethics, and policy for a media roundtable on establishing a set of globally recognized ethical principles for climate intervention research.
At COP29, AGU’s delegation and its partners actively engaged with a diverse audience—including researchers, scientists, governments, nongovernmental organizations, philanthropic institutions, and the private sector—to promote and foster meaningful dialogue on the Ethical Framework Principles for Climate Intervention Research.
Released in October, the framework provides comprehensive guidelines to ensure climate intervention research is conducted responsibly, transparently, and equitably. The framework was facilitated by AGU and advised by a global panel of experts and draws on ethical precedents established in other emerging fields with unknown consequences, such as biomedical research and genetic engineering, to guide research, funding, and policy proposals."
Climate Engineering and the Napkin Diagram | Climate Emergency Forum
"In this panel discussion from COP29 in Baku, host Herb Simmens, and experts Hugh Hunt, and Paul Beckwith explore the controversial topic of Climate Engineering and the Napkin Diagram.
The conversation delves into the urgent need for a multi-faceted approach to combat climate change, including emissions reduction, carbon dioxide removal (CDR), and solar radiation management (SRM). The panelists argue that traditional methods alone may not be sufficient to address the rapidly escalating climate crisis.
Hugh Hunt, from the Center for Climate Repair at Cambridge University, introduces the Napkin Diagram, illustrating the potential role of SRM in mitigating temperature rise. Paul Beckwith, a prolific climate educator, emphasizes the acceleration of extreme weather events and the failure of natural carbon sinks, highlighting the critical need for innovative solutions. Both experts stress the importance of research into SRM techniques, despite the controversy surrounding them.
The discussion also touches on the challenges of introducing SRM into mainstream climate conversations, including political resistance and concerns about moral hazard. The panelists address the potential of SRM to mitigate risks associated with climate tipping points, such as the potential collapse of the Atlantic Meridional Overturning Circulation (AMOC). They conclude by advocating for more research and small-scale experiments to better understand the impacts and potential benefits of climate engineering techniques."
Draper Decentralized 01/07/25: MAKE SUNSETS | DraperTV
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Draper University was founded by venture capitalist Tim Draper with the mission to inspire people and accelerate ideas by igniting the entrepreneurial spirit globally. Come join 900+ alumni who have launched their own startups, raised $220+M in venture funding and who work with leading technology companies to foster innovation. Live and learn in Silicon Valley during the 5-week fully immersive program and go from human to hero."