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Smith, W. (2024). An assessment of the infrastructural and temporal barriers constraining a near-term implementation of a global stratospheric aerosol injection program. Environmental Research Communications.
Synopsis: Stratospheric aerosol injection could rapidly cool Earth in a climate emergency, but models overlook the lengthy preparation needed. Developing and certifying aircraft and infrastructure for deployment could take around 20 years. This delay highlights the impracticality of quick deployment, emphasizing the need for realistic planning in climate intervention strategies.
Low, S., Fritz, L., Baum, C. M., & Sovacool, B. K. (2024). Public perceptions on solar geoengineering from focus groups in 22 countries. Communications Earth & Environment, 5(1), 1-19.
Synopsis: This study maps the benefits, risks, and governance of stratospheric aerosol injection, marine cloud brightening, and a space-based sunshield through 44 focus groups in 22 countries. The findings reveal that while the global South shows more hope but diverse concerns, there is a worldwide preference for multilateral coordination and public engagement. However, skepticism remains regarding the effectiveness of multilateralism and public discourse in managing these technologies.
Sandro V., Sina K K., John A D., et al. Microphysical interactions determine the effectiveness of Solar Radiation Modification via Stratospheric Solid Particle Injection. ESS Open Archive.
Synopsis: SAI with solid particles could mitigate climate change with less stratospheric warming compared to SO2 injection. However, interactions like settling and coagulation of these particles have been overlooked. A global chemistry-climate model reveals that agglomeration reduces backscatter efficiency, mainly due to increased forward scattering and faster settling. Despite this, 150 nm diamond particles require lower injection rates and cause less stratospheric disruption than SO2. Yet, uncertainties about the feasibility of dispersing solid particles without agglomeration remain.
Jiang, J., Xia, Y., Cao, L., Kravitz, B., MacMartin, D. G., Fu, J., & Jiang, G. (2024). Different strategies of stratospheric aerosol injection would significantly affect climate extreme mitigation. Earth's Future, 12(6), e2023EF004364.
Synopsis: This study compares two SAI strategies: equatorial and multi-location SO2 injection. Both strategies reduce tropical hot extremes but lead to overcooling and decreased precipitation. In mid-to-high latitudes, they decrease cold extremes, suggesting residual winter warming. Multi-location injection shows less change in extremes compared to equatorial, indicating potential for mitigating climate change effects more effectively. Further research is needed to optimize SAI strategies for minimizing extreme climate events globally.
Wan, J. S., Fasullo, J. T., Rosenbloom, N., Chen, C. C. J., & Ricke, K. (2024). Targeted marine cloud brightening can dampen El Ni\~ no. arXiv preprint arXiv:2406.07853.
Synopsis: Marine cloud brightening, a proposed solar geoengineering approach, aims to mitigate climate extremes like El Niño-Southern Oscillation (ENSO) events. This study investigates its potential by simulating interventions during Australian wildfires and historical El Niño events. Results suggest that early and prolonged cloud brightening can induce La Niña-like conditions, counteracting El Niño impacts effectively. This approach, targeting climate variability, offers a promising complement to traditional climate risk mitigation strategies, such as ENSO forecasting, but requires further exploration and consideration of broader implications.
Parry, I., Ritchie, P., Boucher, O., Cox, P., Haywood, J., Niemeier, U., ... & Visioni, D. (2024). Solar Radiation Modification is projected to increase land carbon storage and to protect the Amazon rainforest.
Synopsis: SRM via SAI aims to cool the Earth but raises concerns about impacts on vegetation and rainfall patterns. This study uses five Earth System Models to simulate SAI effects, projecting increased global net primary productivity (NPP) (+15.6%) and land carbon storage (+5.9%) compared to a high emissions scenario (SSP585). Particularly in Amazonia, SAI leads to substantial NPP (+13.8%) and carbon storage (+8.6%) increases compared to both SSP245 and SSP585, suggesting SAI could mitigate climate risks like Amazon forest dieback and enhance atmospheric carbon sequestration.
Pamplany, A. (2024). Does Solar Geoengineering have any Scope in a Climate Emergency. American J Sci Edu Re: AJSER-188.
Synopsis: This paper reviews literature to analyze whether SRM can effectively avert a climate emergency. It finds a stark divide: proponents emphasize SRM's potential benefits, while opponents stress risks and argue for caution due to scientific uncertainties and ethical concerns. The debate underscores the need for specialized emergency-focused frameworks and greater involvement of emergency scientists in decision-making.
Wan, J.S., Chen, CC.J., Tilmes, S. et al. Diminished efficacy of regional marine cloud brightening in a warmer world. Nat. Clim. Chang. (2024).
Synopsis: MCB proposes to mitigate climate impacts by cooling atmospheric temperatures, focusing here on the North Pacific to alleviate extreme heat in the Western United States. Present-day simulations show significant reductions in heat exposure risk with MCB in remote mid-latitudes and nearby subtropics. However, projections for mid-century warming suggest diminished efficacy, potentially exacerbating heat stress globally. This decline in effectiveness may stem from complex interactions with the Atlantic Meridional Overturning Circulation, highlighting the need for adaptive strategies in climate intervention planning amid ongoing environmental change.
Morrison, A. L., Barnes, E. A., & Hurrell, J. W. (2024). Natural variability can mask forced permafrost response to stratospheric aerosol injection in the ARISE‐SAI‐1.5 simulations. Earth's Future, 12(6), e2023EF004191.
Synopsis: This study uses ensemble simulations to analyze SAI's impact on active layer depth and permafrost temperature in boreal regions. Results show that while SAI quickly diverges the forced response from non-SAI conditions, natural variability complicates detection of SAI effects, requiring over a decade for permafrost temperature and nearly 30 years for active layer depth. Variability also affects the likelihood of preventing permafrost tipping points, highlighting the need to account for natural variability in assessing SAI's effectiveness in stabilizing permafrost amid ongoing climate change impacts.
Henry, M., Bednarz, E. M., & Haywood, J. (2024). How Does the Latitude of Stratospheric Aerosol Injection Affect the Climate in UKESM1?. EGUsphere, 2024, 1-23.
Synopsis: This study compares SAI scenarios at different latitudes to assess their climate impacts. Injection at the equator leads to undesirable effects like residual Arctic warming, reduced tropical precipitation, and stratospheric heating. Subtropical injections (15° and 30° N/S) prove more efficient with fewer negative side effects, while a 60° N/S strategy requires slightly more aerosols for similar cooling but offers less stratospheric warming. The 30N+30S strategy emerges as a balanced option with potentially lower negative impacts, suggesting it merits further consideration for effective climate intervention strategies.
Williams, B. M., Shimamoto, M. & Graumlich, L. J., (2024) “An Ethical Framework for Climate Intervention Research: What It Is and Why You Should Care”, Zygon: Journal of Religion and Science 59(1), 82–96.
Synopsis: This overview discusses various geoengineering techniques aimed at mitigating climate impacts such as extreme weather and rising sea levels. It emphasizes the American Geophysical Union's (AGU) role in developing ethical frameworks to guide geoengineering research and fostering global engagement, including with faith community leaders. The article highlights ongoing debates and the need for careful consideration of ethical implications surrounding geoengineering interventions in the Earth's climate system.
Visioni, D., & Quaglia, I. (2024, January). Changes in shipping emissions as a natural analogue for Climate Intervention: detecting and attributing changes due to specific human activities as a testbed for future controversies. In 104th AMS Annual Meeting. AMS.
Synopsis: This study addresses the impacts of new International Maritime Organization (IMO) regulations reducing SO2 emissions on global climate dynamics and extreme events. It explores the potential consequences of reduced sunlight-reflecting aerosols on climate extremes like record-high temperatures and increased wildfire activity observed in recent years. The research uses observational data and simulations with the Community Earth System Model (CESM2) to analyze how removing aerosols from shipping affects surface and sea temperatures, as well as Earth's energy balance. Additionally, it simulates scenarios where aerosols are relocated to the stratosphere to assess their comparative regional climatic impacts and potential health benefits. This approach aims to inform discussions on climate intervention strategies, emphasizing the need for further research to reduce uncertainties and understand the comprehensive impacts of such interventions on both climate and public health.
Zhao, M., Cao, L., Visioni, D., & MacMartin, D. G. (2024). Carbon cycle response to stratospheric aerosol injection with multiple temperature stabilization targets and strategies. Earth's Future, 12(6), e2024EF004474.
Synopsis: This study investigates the impact of SAI simulations using the CESM2(WACCM6-MA) model on the global carbon cycle under the SSP2-4.5 CO2 concentration pathway. It examines how different SAI strategies and temperature stabilization targets affect the global carbon sink. Findings reveal that multi-location SO2 injection under various temperature targets (0.5°C, 1.0°C, 1.5°C) significantly enhances cumulative land and ocean carbon uptake compared to the SSP2-4.5 scenario. By 2069, SAI is projected to increase cumulative CO2 emissions slightly, implying a potential decrease in atmospheric CO2 under controlled emission scenarios. However, abrupt termination of SO2 injection could weaken the carbon sink and accelerate permafrost thaw, underscoring the need for gradual phase-out strategies to mitigate these impacts effectively.
Brody, E., Visioni, D., Bednarz, E. M., Kravitz, B., MacMartin, D. G., Richter, J. H., & Tye, M. R. (2024). Kicking the can down the road: understanding the effects of delaying the deployment of stratospheric aerosol injection. Environmental Research: Climate.
Synopsis: This study investigates the implications of delaying the start of SAI deployment under the SSP2-4.5 emissions pathway, targeting a global mean temperature increase of ~1.5°C above preindustrial levels. Using simulations from the CESM2-WACCM6 model, scenarios with SAI starting in 2035 versus a delayed start in 2045 are compared. Findings indicate that delaying SAI requires higher sulfur dioxide injection rates to achieve the same temperature target, due to increased energy absorbed by the Earth system during the delay period. Surface climate differences between the two start dates appear minimal in the short term (10-25 years post-delay), but longer-term impacts warrant further study. The study underscores the potential risks of irreversibilities and tipping points triggered by prolonged warming, which may not be fully captured in current models but could significantly alter outcomes in reality.
Grieger, K., Wiener, J. B., & Kuzma, J. (2024). Improving risk governance strategies via learning: a comparative analysis of solar radiation modification and gene drives. Environment Systems and Decisions, 1-14.
Synopsis: This Perspective compares stratospheric aerosol injection (SAI) and gene drive organisms (GDOs) as responses to environmental challenges. Both face risks from uncertainties and societal impacts but differ in deployment and reversibility. Recommendations include enhancing international governance for SAI and investing in economic research for GDOs, with insights from other emerging technologies' risk governance.
Quaglia, I., & Visioni, D. (2024). Modeling 2020 regulatory changes in international shipping emissions helps explain 2023 anomalous warming. EGUsphere, 2024, 1-19.
Synopsis: In response to anomalous summer temperatures in 2023, exacerbated by ongoing greenhouse gas-induced warming, this study investigates the impact of reduced sulfate emissions from international shipping since January 2020. Using updated Community Earth System Model (CESM2) simulations incorporating these emission changes, findings show a significant contribution to surface temperature anomalies. The study underscores the necessity of integrating realistic near-future changes in short-lived climate forcers into climate models like CMIP7 to enhance projections and understanding of short-term climatic shifts.
Smith, W. M. (2024). Comparison of marine cloud brightening in large eddy simulations (No. EGU24-4102). Copernicus Meetings.
Synopsis: The study addresses the challenges in modeling MCB due to scale disparities between microphysics and large-scale impacts. Utilizing Large Eddy Simulations (LES), specifically MONC and DALES models, the research aims to compare their outputs under MCB experiments. By integrating historic data and enhancing microphysical representation through coupled parcel models, the study seeks to improve understanding and comparability of MCB effects on cloud dynamics and radiation, crucial for assessing its potential as a climate intervention strategy.
Ayissi, F. F. B. K., Da-Allada, C. Y., Baloïtcha, E., Worou, L. O., & Tilmes, S. (2024). Changes in Coastal Upwelling in the Northern Gulf of Guinea under Stratospheric Aerosol Injection. Regional Studies in Marine Science, 103607.
Synopsis: This study assesses Stratospheric Aerosol Injection (SAI) impacts on coastal upwelling in the northern Gulf of Guinea using the GLENS model. Under global warming, boreal summer upwelling decreases by 6% along the coast, more in Ghana. SAI reduces upwelling by 5%, with less impact than warming due to weaker geostrophic flow effects. Minor upwelling increases under both scenarios due to Ekman transport.
"Our Institute (European Institute on Economics and the Environment) is always looking for bright researchers motivated to work on the defining issue of climate change. For this position we are encouraging applications by researchers interested in modelling and assessing the implications of climate engineering interventions, specifically either Carbon Dioxide Removal (CDR) or Solar Radiation Management (SRM), as possible additional strategies to conventional mitigation ones. We have a portfolio of international research projects on both removing CO2 and CH4 (e.g. UPTAKE, REPAIR), and on assessing solar radiation modification (e.g. CO-CREATE, RFF). We are looking from one to two candidates to work on either research strand, or possibly combine them. We are interested in the integration of all key aspects of climate engineering, from the technical side to its socio-economic repercussion and its governance."
University of Cape Town in South Africa have opened two 3-year postdoc positions to characterize the global and regional impacts and risks of SRM on agriculture and water resources:
Walker Lee on Marine Cloud Brightening Global Impact Modeling - HPAC | Robbie Tulip
"Walker Raymond Lee is a postdoctoral research associate at the National Center for Atmospheric Research in Boulder, Colorado. Walker's research explores the design space of climate intervention: what can climate models tell us about how different climate intervention strategies might affect the Earth system in different ways? In this talk he applies this research to Marine Cloud Brightening. From 2018-2023, Walker studied at Cornell University, where he compared simulations of stratospheric aerosol injection at various latitudes, altitudes, and seasons and used feedback control algorithms to determine whether and how different strategies could be used to prevent certain impacts from global warming. After completing his doctorate in 2023, Walker began as a postdoc at NCAR, where he is working to apply the same analysis to simulations of marine cloud brightening interventions."
Making sense of solar engineering | Latitude Media
"In this episode, Shayle talks to Dan Visioni (https://dan-visioni.github.io/) , a climate modeler who studies solar geoengineering at Cornell University’s Sibley School of Mechanical and Aerospace Engineering. They discuss what solar geoengineering might look like in the real world."
Can technology stop a hurricane? | YaleClimateConnections
"Climate change is fueling more intense and frequent hurricanes, posing greater risks to lives and communities. But could cutting-edge technology offer a solution? In this video, meteorologist Alexandra Steele talks with former hurricane hunter Jeff Masters and other experts about whether geoengineering or artificial intelligence could one day enable us to control hurricanes."
A rogue geoengineering startup sparks worry | Latitude Media
"Luke Iseman and Andrew Song are the co-founders of Make Sunsets, a startup claiming to be implementing solar geoengineering by launching weather balloons filled with SO2 into the stratosphere.
Their first experimental launch in the Mexican state of Baja resulted in a swift regulatory response from the Mexican government. But when they ran another test launch a few weeks ago just outside of Reno, Nevada, Luke invited Alejandro to meet them."
Solar Geoengineering: Ethics and Science | Harvard Climate Action Week 2024 | The Salata Institute at Harvard University
"Solar geoengineering refers to a strategy for reducing the impacts of climate change by reflecting some of the incoming solar radiation. Long considered too controversial to discuss in public, it has been getting more and more attention both within the scientific community and from the public at large, perhaps due to the growing awareness of climate change impacts as well as the scale of the challenge of decarbonizing the global energy system.
For nearly 20 years, Harvard has played a leading role in convening conversations surrounding this approach to managing climate change, as well as contributing important scholarship on new technological approaches, better understanding of the impacts, and debates surrounding its governance.
In this panel, leading scholars from atmospheric chemistry, climate physics and philosophy discussed the current state of our understanding of solar geoengineering, highlighting the main areas of uncertainty, and identified ways to move forward on solar geoengineering research while the debate intensifies on its possible deployment."
Board member Jackie Kado explains why she volunteers her time with Degrees | The Degrees Initiative
"Dr Jackie Kado is the Executive Director of the Network of African Science Academies (NASAC) and volunteers her time as a member of Degrees’ board of trustees. In this short interview she discuss her the work of the Degrees Initiative and what motivates her to work with the Degrees Initiative."
Thanks to Chlorine | ToSaveTheWorld
"David Henkel-Wallace, Franz Oeste, Clive Elsworth, Jeff Shrager, Peter Fiekowsky, and Rocio Herbert are all exploring the new discovery that clouds (the white ones that reflect sunlight back into space) also cool the planet in another way: by adding hydrochloric acid to the atmosphere, which has an independent cooling effect by destroying methane molecules. This may give us a new way of cooling the planet. Aele Buckley has a question."
Climate Change – Solar Geoengineering as a Solution? | Österreichisches Außenministerium
“This TechDiplomacyTalk aimed at deepening the understanding of solar geoengineering - technologies that cool the earth by reflecting sunlight back into space – and its associated ethical concerns, geopolitical implications and risks for the environment, biodiversity and humans. In the light of the risks, ongoing field tests and increasing private sector interest, the discussion focused on the need for global, science-based, and effective control and regulatory mechanisms for solar geoengineering. Three panellists participated in this TechDiplomacyTalk: Ambassador Salome Meyer, the Ambassador of Switzerland to Austria, Blaž Gasparini, climate physicist at the University of Vienna, specializing in the impact of clouds on climate, and Michel Tschirren, Head of the Global Affairs Section at Switzerland’s Federal Office for the Environment."
The Economics of Solar Radiative Management | Environmental Defense Fund
Solar Climate Intervention Virtual Symposium 11 (Dr. Claudia Wieners & Dr. Daniele Visioni) | Solar Climate Intervention Talks
"Solar Climate Intervention Virtual Symposium 11
Dr. Claudia Wieners (Utrecht University, Netherlands) : "Burning fossils like hell and cooling in 2080 – what could possibly go wrong? (Semi)-irreversible climate change under delayed stratospheric aerosol injection."
Dr. Daniele Visioni (Cornell University, USA) : "Assessing sunlight reflection methods on the international stage: what does it mean and where are we? A perspective between science and politics."
Shall We Whiten Clouds | ToSaveTheWorld
"Hugh Hunt, Daniel Rosenfeld, and Steven Rogak are all engineers who are eagerly studying the potential. use of salt water spray to whiten clouds and reflect sunshine back into space, thereby reducing global warming. Adele Buckley is an engineer who is skeptical about the value of trying to keep the Arctic frozen at this time."
Sharing Sámi Experiences: Indigenous Voices on Climate Intervention Research | SilverLining
"During the United Nations Permanent Forum on Indigenous Issues' Twenty-third Session, the Sámi Parliament of Finland, in partnership with Operaatio Arktis, SilverLining, and Green Africa Youth Organization, held "Sharing Sámi Experiences: Indigenous Voices on Climate Intervention Research," at the Permanent Mission of Finland to the UN.
Indigenous peoples are at the forefront of climate impacts, yet they possess invaluable traditional knowledge and practices through which they foster relationships with ecosystems. Indigenous knowledge also has the potential to contribute significantly to efforts seeking to address different facets of global warming– including climate intervention research.
This event highlights the critical importance of integrating Indigenous perspectives, knowledge, and participation into climate intervention research. At the same time, it underscores the urgent need to center Indigenous knowledge, perspectives, and rights in global efforts to address climate change.
The event aimed to provide a safer space for Indigenous voices, policymakers and climate scientists, as well as experts on climate intervention research and international governance, to discuss the scientific context of climate interventions and their potential roles in relation to 1.5°C of warming."
Inside the Extreme Plan to Refreeze the Arctic | WSJ Future of Everything | The Wall Street Journal
“A method normally used to create ice-skating rinks is now coming to the rescue of melting sea ice in the Arctic. Since satellite records began in 1979, summer Arctic sea ice has shrunk by around 13% per decade. Could making more ice be a potential solution to this issue?”
