SOLAR GEOENGINEERING WEEKLY SUMMARY (30 DECEMBER 2024 - 05 JANUARY 2024) Subscribe to our newsletter to receive monthly updates on Solar Geoengineering: Solar Geoengineering Updates <https://solargeoengineeringupdates.substack.com?utm_source=substack&utm_campaign=publication_embed&utm_medium=email> Monthly news summaries about solar geoengineering. Links to scientific papers, news articles, jobs, podcasts, and videos. <https://solargeoengineeringupdates.substack.com?utm_source=substack&utm_campaign=publication_embed&utm_medium=email> By Andrew Lockley <https://solargeoengineeringupdates.substack.com?utm_source=substack&utm_campaign=publication_embed&utm_medium=email>
Become a Paid Subscriber <https://solargeoengineeringupdates.substack.com/subscribe> ------------------------------ RESEARCH PAPERSNumerical Fit Modeling for Temperature Mitigation in Arid Cities <https://www.mdpi.com/2076-3417/15/1/285> Hoback, A. S. (2024). Numerical Fit Modeling for Temperature Mitigation in Arid Cities. *Applied Sciences*, *15*(1), 285. *Abstract* The purpose of the study is to develop a general method to predict local temperature changes from mitigating the urban heat island effect using local climate engineering. Specifically, the effects of a plume of calcite particles above cities have been found. Previous modeling work has been carried out with supercomputers, but those models have limited geographies and timelines. The main goal of this work is to produce a method that can be applied more generally and more quickly. This overcomes limited modeling data in arid regions. Arid cities show the most effective use of calcite plumes for local solar radiation management, but those areas have limited data. The new method is to use numerical fit techniques using actual weather data. The default heating and cooling rates are fit to historic rates, and then the radiative properties of the calcite are used to predict the change in the heat transfer rates. Air temperatures at a standard height of 2 m are predicted. The key findings are that the numerical fit gives comparable results to the full supercomputer model, but the numerical fit gives predictions of greater temperature change. This was explained as primarily due to how advection is handled differently by the methods. Adjustments in the methods are discussed so that the effect of advection is included. The conclusion is that numerical fit provides a method that can easily be applied to arid regions. Solar geoengineering research faces geopolitical deadlock <https://www.science.org/doi/10.1126/science.adr9237> McLaren, D., & Corry, O. (2025). Solar geoengineering research faces geopolitical deadlock. *Science*, *387*(6729), 28-30. *Abstract* As a powerful potential lever on global temperatures, solar geoengineering—or solar radiation modification (SRM)—comes with formidable environmental and political risks. Assessments of SRM acknowledge that future governance of “direction, ownership and control” [(1), p. 45] is no optional extra: Outcomes achieved in modeling studies presuppose governance “to restrain harmful or unjust use of SRM…and assess and minimize any countervailing harms” [(2), p. 6]. But, although research is deemed urgent, the “guardrails” and institutions needed remain moot (3) or are deferred for later (4). Tentative efforts toward international cooperation and oversight collapsed most recently in February 2024. Drawing upon observations of the United Nations Environment Assembly (UNEA), we set out how clashing geopolitical interests and diverging knowledge politics are making even research controversial. Although the differences seem irreconcilable, we suggest that apparent consensus around nondeployment of geoengineering could be seized upon to provide some hope for coordinated and responsible SRM research. Solar Geoengineering: Trials, Innovation, Investments and the Need for Governance <https://papers.ssrn.com/sol3/papers.cfm?abstract_id=5068179> Ramos, Y., & Santos, F. D. (2024). Solar Geoengineering: Trials, Innovation, Investments and the Need for Governance. *Innovation, Investments and the Need for Governance (December 22, 2024)*. *Abstract* Solar geoengineering has emerged as a potential tool to mitigate climate change by reflecting solar radiation back into space. The rapid development of technologies such as Stratospheric Aerosol Injection (SAI) and other Solar Radiation Management (SRM) methods has resulted in a growing number of patents, pilot projects, and private or state-driven investments. However, these advancements are often shrouded in secrecy, raising concerns about transparency, ethical responsibility, and the absence of inclusive governance frameworks. While geoengineering solutions may offer promise, the risk of exacerbating global inequalities-particularly for the Global Southremains significant. This paper examines current patents, investments, and trials in solar geoengineering, highlights their implications for international climate governance, and underscores the urgent need for a sound, ethical, and transparent global regulatory framework to ensure equity and accountability. Under a not so white sky: visual impacts of stratospheric aerosol injection <https://iopscience.iop.org/article/10.1088/1748-9326/ada2ae/meta> Lemon, A., Keith, D. W., & Albers, S. C. (2024). Under a not so white sky: visual impacts of stratospheric aerosol injection. *Environmental Research Letters*. *Abstract* Stratospheric aerosol injection (SAI) could change the sky's appearance. This could play a role in shaping public perception of SAI. Noticeability depends strongly on tropospheric aerosol optical depth (AOD) and the amount of SAI used. We aim to quantify the noticeability of changes in sky color and brightness due to SAI. We use a 3-D visible light radiative transfer package to generate cloudless sky images during high sun, sunset, and twilight under SAI from the reference point of a ground observer. We consider three aerosol types: H2SO4, CaCO3, and diamond. We consider stratospheric aerosol loadings required to produce radiative forcings of -1, -2, and -4 W m-2. We use population density and AOD data to compute the distribution of AODs people experience and then simulate sky images for the 10th, 50th, and 90th percentiles of that distribution. We compare the simulated changes in color and brightness to experimental measurements of minimum thresholds humans can detect. The three aerosol types cause similar changes, except most notably the diamond aerosol increases brightness of the solar aureole by roughly three to five times less than do H2SO4 or CaCO3. During high sun, sky whitening from sulfate SAI at -2 W m-2 is undetectable for roughly half of observers chosen randomly from the global population. For the remainder of the population, we expect whitening to still be unnoticeable for all but perhaps the most astute observers aided by color samples. Brightening and enlargement of the solar aureole is the most visible feature during high sun for H2SO4 and CaCO3, while changes near twilight would be the most noticeable impact of SAI. We cannot evaluate the fraction of the population who would notice these changes. Turning Deserts into Paradises: Geoengineering in Science, Practice, and Fiction in the 19th and Early 20th Centuries <https://diamond-oa.lib.cam.ac.uk/entities/publication/74494250-f7d6-406b-b157-71b5248dbfbb> Lagercrantz, O. (2024). Turning Deserts into Paradises: Geoengineering in Science, Practice, and Fiction in the 19th and Early 20th Centuries. *Abstract* This article studies the history of geoengineering in the West in the 19th and early 20th centuries in science, practice, and fiction. Visions of geoengineering at the time, it is argued, were shaped by the birth of climatology, colonial practices and ideals, and widespread techno-optimism. The mutual entanglement of humans and climate was recognised, inspiring speculation over utopian possibilities but also existential threats posed by geoengineering. In light of this history, it is suggested that there is a need to discard framings of geoengineering as a new approach to tackling climate change, rethink simplistic conceptions of Western modernity, and recognise the inherently political nature of technological visions. ------------------------------ WEB POSTSThe Solar Geoengineering Updates Newsletter (December'2024) Solar Geoengineering Updates The Solar Geoengineering Updates Newsletter (December'2024) <https://solargeoengineeringupdates.substack.com/p/the-solar-geoengineering-updates-ad7?utm_source=substack&utm_campaign=post_embed&utm_medium=email> If you find this work valuable, consider supporting us with a paid subscription. We put a lot of time, effort and money (£XXX each month) into compiling this resource for you… Read more <https://solargeoengineeringupdates.substack.com/p/the-solar-geoengineering-updates-ad7?utm_source=substack&utm_campaign=post_embed&utm_medium=email> 3 days ago · 2 likes · Andrew Lockley ------------------------------ UPCOMING EVENTS(NEW) Solar Climate Intervention Virtual Symposia #15 <https://sites.google.com/view/solargeo-symposium/home> | 17 January 2025 | Online*Solar radiation modification: What should Europe’s strategy be? by Scientific Advice Mechanism to the European Commission <https://us02web.zoom.us/webinar/register/WN_zMVEie0PThCasf0lFO_FSw#/registration> | 23 January 2025 | Online**Solar Radiation Modification: What’s at stake for society? by Scientific Advice Mechanism to the European Commission <https://us02web.zoom.us/webinar/register/WN_Sra0pIz1Q7KeHjzxHOaMFQ#/registration> | 03 February 2025 | Online**Climate Intervention: Distraction or Necessity? by Center for Climate Repair <https://www.climaterepair.cam.ac.uk/events/climate-intervention-distraction-or-necessity> | 21 March 2025**2025 Solar Radiation Management Annual Meeting by Simons Foundation <https://www.simonsfoundation.org/event/solar-radiation-management-annual-meeting-2025/> | 24-25 April 2025 | New York**The 2025 Degrees Global Forum <https://substack.com/redirect/8521c00b-652a-4d78-822f-7ae393c57068?j=eyJ1IjoiMjJrMHl3In0.wQQsFypG52typ8FI2nhnJ8eUoUIIkdCkuhmzxNYKtgE> | 12-16 May 2025 | Cape Town, South Africa**Artic Repair Conference 2025 by University of Cambridge & Center for Climate Repair <https://substack.com/redirect/90f81f14-d09c-4418-8d97-c6621d753433?j=eyJ1IjoiMjJrMHl3In0.wQQsFypG52typ8FI2nhnJ8eUoUIIkdCkuhmzxNYKtgE> | 26-28 June 2025 | Cambridge UK* Solar Geoengineering Events Calendar <https://teamup.com/ks64mmvtit583eitxx> ------------------------------ PODCASTSSRM experts' opinions - McEvoy | Reviewer 2 does geoengineering SRM experts' opinions - McEvoy Reviewer 2 does geoengineering 1:00:42 <https://podcasts.apple.com/us/podcast/srm-experts-opinions-mcevoy/id1529459393?i=1000682697196&uo=4> “David McEvoy discusses expert opinions on SRM. What do they think, and how do we know? The strategic and governance implications of solar radiation modification: perspectives from delegates of international climate negotiations Todd L Cherry et al 2025 Environ. Res. Lett. 20 014053 DOI 10.1088/1748-9326/ad9d62” ------------------------------ YOUTUBE VIDEOSCould there be a just solar geoengineering?—w/ Shuchi Talati, Founder of The Alliance for Just Deliberation on Solar Geoengineering | Reversing Climate Change <https://www.youtube.com/watch?v=kVXylzBrcMk> "Solar geoengineering. It's not just a question of whether or not to do it, but of how it might be done and why. This week we are joined by Shuchi Talati, founder of The Alliance for Just Deliberation on Solar Geoengineering, to talk about who is making decisions about solar geoengineering and whether or not populations most vulnerable to climate change have a seat at the table. Solar geoengineering or “Solar Radiation Modification/Management (SRM)” is the large-scale and intentional intervention to increase the amount of sunlight reflected back into space. The purpose is to temporarily limit temperature increase. Shuchi walks us through why the Alliance is not for or against SRM, why refusing to discuss or research RSM is potentially an inherently privileged standpoint, and why she believes we should center voices from regions already experiencing horrific climate impacts. Shuchi walks us through why the Alliance is not for or against SRM, why refusing to discuss or research RSM is potentially an inherently privileged standpoint, and why she believes we should center voices from regions already experiencing horrific climate impacts. Listen in to find out who is currently researching SRM, what the potential risks and benefits are, and how the Alliance plans to make such a controversial topic more open and accessible." ------------------------------ *Become a Paid Subscriber <https://solargeoengineeringupdates.substack.com/subscribe>* -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/geoengineering/CAHJsh99nbDErgUX_%2BtjSgK6N6dv0nn5MXPsSi%3D%3DGo0h8LOyjzg%40mail.gmail.com.
