| SOLAR GEOENGINEERING WEEKLY SUMMARY (18 NOVEMBER - 24 NOVEMBER 2024) Subscribe to our newsletter to receive monthly updates on Solar Geoengineering:
RESEARCH PAPERSFlamm, P., & Shibata, A. (2024). ‘Ice sheet conservation’and international discord: governing (potential) glacial geoengineering in Antarctica. International Affairs, iiae281. Abstract Should current unmitigated emissions continue, there is a growing chance of collapse of the West Antarctic Ice Sheet, one of the planetary climate tipping points at greatest risk of being crossed. Such a collapse would subject the world to an increase of several metres in average global sea-level rise over just a few centuries. In this context, there is an academic debate about the potential of supporting glacial stability through artificial infrastructures such as an undersea ‘curtain’. However, this ‘ice sheet conservation’ would come with significant yet unforeseeable technical and environmental risks. Moreover, in this debate governance risks have been either neglected or understated. We argue that the proposed infrastructures could negatively implicate the ‘peaceful purposes only’ obligation enshrined in the Antarctic Treaty. By affecting contentious areas of Antarctic geopolitics, such as authority, sovereignty and security, there is a significant risk that the project would make the Antarctic ‘the scene or object of international discord’. Even if the ice curtain idea were to be technically feasible and environmentally harmless, it would still create significant political and legal challenges for the current governance arrangements in the Antarctic.
He, H., Soden, B., Vecchi, G., & Yang, W. (2024). Weakening the CO2 Greenhouse Effect via Stratospheric Aerosol Injection. Abstract Stratospheric aerosol injection (SAI) represents one of the primary potential options for intentionally modifying the climate to offset the warming from increasing greenhouse gases. The hypothesized strategy typically involves the injection of scattering aerosols in the lower stratosphere to increase the amount of sunlight reflected to space, thereby reducing the amount of sunlight absorbed by Earth. We demonstrate a new and potentially more efficient approach to SAI, using it to induce a weakening of the Earth’s greenhouse effect. We show that the injection of absorptive aerosols in the upper stratosphere (~ 10 hPa) increases the emission of top-of-atmosphere infrared radiation. Warming the emission level of CO2 weakens the greenhouse effect by altering the thermal structure of the upper stratosphere rather than the concentration of greenhouse gases. Climate model simulations indicate that the reduction in global temperatures induced through this process is an order of magnitude larger (per unit aerosol mass) than the injection of more traditional reflective aerosols. These results argue for further research into the possible impacts, particularly unintended deleterious side effects, of injecting absorptive aerosols in the upper stratosphere as a potential alternative strategy for solar radiation management.
Hurrell, J. W., Haywood, J. M., Lawrence, P., Lennard, C. J., & Oschlies, A. Climate Intervention Research in the World Climate Research Programme A Perspective. Frontiers in Climate, 6, 1505860. Abstract The 2023 WCRP Open Science Conference underscored the critical need for increased climate change mitigation and adaptation efforts, along with enhanced climate knowledge and decision-making systems. This Perspective discusses climate intervention (CI) within WCRP's research framework, emphasizing three main approaches: terrestrial carbon dioxide removal (CDR), marine CDR, and solar radiation modification (SRM). As global anthropogenic greenhouse gas emissions continue to rise, CI strategies are increasingly recognized as potentially critical supplements to traditional mitigation methods. We call for WCRP to take a leadership role in CI research, highlighting the need for inclusivity and collaboration, especially with researchers from the Global South, to establish a firm scientific foundation for an equitable and comprehensive assessment of the benefits and risks of CI approaches relative to the risks of anthropogenic climate change.
THESISBaur, S. (2024). Representation of Unaccounted Physical Couplings in Peak-shaving Solar Radiation Modification Scenarios (Doctoral dissertation, University of Leeds). Abstract Solar Radiation Modification (SRM) is a proposed method to halt global warming and related impacts. This method is gaining interest in the climate change community as a potential supplement to conventional mitigation (emission reduction and carbon dioxide removal) to avoid surpassing a given temperature threshold in an overshoot pathway. In this so-called peak-shaving framework, SRM would lower global mean temperature to below the specified threshold during the otherwise occurring overshoot until mitigation has sufficiently brought down atmospheric CO2. At present, the peak-shaving framework assumes that SRM can be added independently to conventional mitigation. This additivity assumption disregards potential interlinkages between the critical components of overshoot pathways, emission reductions and net-negative emissions, and an SRM intervention. The aim of this thesis is to assess the importance of these currently unaccounted physical couplings between mitigation and SRM. It is demonstrated that the range of uncertainty in future emission reductions and net-negative emissions leads to a wide spectrum of different SRM deployment trajectories, highlighting the uncertainty currently implied by the peak-shaving framework and potential implications of non-additivity. The additivity assumption of SRM and mitigation is subsequently scrutinized by examining the impact of SRM on the practicality of decarbonization with renewable energy and the change in negative emission burden under SRM due to carbon feedback modification. I find that the potential to reduce emissions with wind and solar renewable energy sources may become more challenging with SRM. However, the model simulates temporarily enhanced land and ocean carbon sinks, which imply that the negative emission burden could be reduced during the upscaling of SRM deployment which may somewhat compensate for the reduced decarbonization potential. Nevertheless, this carbon uptake benefit is temporary and turns into an additional burden during later stages of SRM deployment. The results of this thesis therefore suggest that the additivity assumption does not hold in terms of physical impacts of SRM on mitigation, since the deployment of it can significantly change the underlying emissions trajectory. This provides a step away from the highly idealized concept of the current peak-shaving framework towards a more comprehensive outlook on the uncertainties implied by such a deployment. This is important because the certainty that peak-shaving SRM is predicated on could be misleading and needs to be taken into account when moving towards more integrated assessments of SRM. The current landscape of models for integrated climate policy scenarios is not well suited for this purpose due to a lack of direct feedback from the climate impact of SRM to the underlying mitigation trajectory. This thesis highlights how this missing feedback between models is a major limitation in SRM simulations and a barrier to comprehensive SRM scenario assessments.
WEB POSTS
PODCASTSCan we cool Earth by blocking the sun’s rays? And should we? | What On Earth | Can we cool Earth by blocking the sun’s rays? And should we? What On Earth 27:04 |
"Come with us to California where entrepreneurs are sending balloons full of sulfur dioxide into the stratosphere. It’s a form of solar geoengineering known as stratospheric aerosol injection, and the company Make Sunsets isn’t waiting for scientific consensus before they launch. We hear about their business model, and then from the researchers who question both the science and ethics of the practice."
YOUTUBE VIDEOSSolar geoengineering remains mired in controversy and debate | CNA "As the world struggles to cut back on greenhouse gas emissions, a plan to buy more time by redirecting sunlight into space to cool the earth is faltering. Despite increasing investment interest, stratospheric aerosol injection remains mired in controversy and debate. It is a concept of solar geoengineering, which scientists say is not fully understood and does not address the root cause of climate change. CNA’s Julie Yoo and Sally Patterson report."
How to Govern Solar Geoengineering - with Shuchi Talati | Climate Chat "In this Climate Chat episode, we will discuss the challenge of governing solar geoengineering (also called Solar Radiation Management or Sunlight Reflection Methods) with Shuchi Talati who is the Founder & Executive Director of The Alliance for Just Deliberation on Solar Geoengineering."
Shaun Fitzgerald speaks: Beyond Emissions Reduction | Centre for Climate Repair "Centre Director, Shaun Fitzgerald, speaks on a panel of experts regarding the need to go beyond emissions reduction to 'keep 1.5 alive'."
University of Montana Center for Ethics, "The science of Solar Radiation Management" | MCAT Community Media Session on Solar Geoengineering Governance @ Science Summit during UNGA79 | Solar Geoengineering Non-Use Agreement "This session explored the latest scientific and policy advancements in the rapidly evolving field of solar geoengineering as a future climate policy option. It convened a diverse array of speakers, including Indigenous community members, youth representatives, civil society members, government officials, and leading scientists. Together, they discussed how solar geoengineering could adversely affect the implementation and achievement of many interconnected Sustainable Development Goals (SDGs) — including those relating to climate action, inequality, and inclusive and effective global governance. The session also explored pathways for addressing these risks through effective, inclusive and restrictive global governance mechanisms."
DEADLINES
UPCOMING EVENTSGood COP, Bad COP: a post-COP29 assessment | 27 November 2024
Solar Geoengineering Events Calendar | |
