DOCSLIB.ORG

Consensus Study Report MARCH 2021 HIGHLIGHTS

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Consensus Study Report MARCH 2021 HIGHLIGHTS Reflecting Sunlight: Recommendations for Solar Geoengineering Research and Research Governance Climate change is creating impacts that are wide- a research program, a research agenda, and mecha- spread and severe—and in many cases irreversible— nisms for governing this research. for individuals, communities, economies, and eco- systems around the world. Without decisive action CURRENT LANDSCAPE FOR SOLAR and rapidly stabilizing global temperature, risks from GEOENGINEERING RESEARCH AND a changing climate will increase in the future, with RESEARCH GOVERNANCE potentially catastrophic consequences. Meeting the challenges of climate change requires There is currently no coordinated or system- a portfolio of options. The centerpiece of this portfolio atic governance of solar geoengineering research. should be reducing greenhouse gas emissions, along Solar geoengineering research to date is ad hoc and with removing and reliably sequestering carbon from fragmented, with substantial knowledge gaps and the atmosphere, and pursuing adaptation to climate uncertainties in many critical areas. There is a need for change impacts. Concerns that these options together greater transdisciplinary integration in research, link- are not being pursued at the level or pace needed to ing physical, social, and ethical dimensions. Research avoid the worst consequences of climate change have to understand the potential magnitude and distribu- led some to suggest the value of exploring additional tion of solar geoengineering impacts—on ecosystems, response strategies, including solar geoengineering. human health, political and economic systems, and While solar geoengineering could potentially help other issues of societal concern—is in a particularly reduce surface temperatures and ameliorate some nascent state. risks posed by climate change, it could also introduce While research to date has answered some an array of potential new risks—for instance, those important questions about solar geoengineering, related to critical atmospheric processes, aspects of scientific understanding remains limited. Research on regional climate, or numerous environmental, social, the efficacy and impacts of the three solar geoengi- political, and economic factors that can interact in neering strategies considered suggests the following: complex ways. This report provides an update to Stratospheric Aerosol Injection (SAI). Sub- Climate Intervention: Reflecting Sunlight to Cool Earth stantial modeling and empirical evidence (using vol- (NRC, 2015) regarding the understanding of three canic eruptions as a natural analog) indicate that SAI proposed solar geoengineering strategies (see Figure can induce cooling at a global scale; but significant 1) and makes recommendations for how to establish uncertainties remain regarding the cooling potential FIGURE 1. SOLAR GEOENGINEERING STRATEGIES Solar geoengineering refers to attempts to moderate warming by increas- ing the amount of sunlight that the atmosphere reflects back to space or by reducing the trapping of outgoing thermal radiation. This study considers the following solar geoengineering strategies: Stratospheric aerosol injection (SAI) is a strategy for increasing the number of small reflective particles (aerosols) in the stratosphere in order to increase the reflection of incoming sunlight. Marine cloud brightening (MCB) is a strategy for adding particles to the lower atmosphere (near the surface), in order to increase the reflectivity of low-lying clouds over particular regions of the oceans. Cirrus cloud thinning (CCT) is a strategy for modifying the properties of high-altitude ice clouds, increasing the atmosphere’s transparency to outgoing thermal radiation. and with regard to the amount of injected aerosols, should be a minor part of the overall U.S. research location, and type, and regarding the effects of an portfolio related to climate change, and it should increased aerosol burden on atmospheric chemistry, focus on advancing understanding of options for transport, and resulting regional and local effects on responding to climate change risks and developing climate. Such uncertainties contribute to uncertainty policy-relevant knowledge, rather than advancing a in climate response and resulting impacts around path for deployment. the world. A transdisciplinary domestic research program, Marine Cloud Brightening (MCB). Adding established in coordination with other countries, aerosols to marine clouds can increase cloud reflectiv- can help build the foundation of scientific insights ity in some circumstances, as is observed in studies of and information that will help decision makers and ship tracks. However, limited understanding of aero- stakeholders faced with choices about possible future sol/cloud interactions leads to significant uncertainty implementation of solar geoengineering. To this end, regarding where and by how much cloud albedo can the committee envisions an integrated framework be modified and whether feedback processes will (see Figure 2) that would enable research governance mask or amplify some of the effects. Key processes and research activities to evolve hand-in-hand, with occur at scales too small to include directly in global ongoing mechanisms for stakeholder engagement climate models, and these process uncertainties will and input. A research program needs to be sufficiently need to be reduced in order to develop reliable large- flexible to allow for improvements and adjustments scale climate impact projections. as our understanding grows. Cirrus cloud thinning (CCT). The efficacy Building an effective, transdisciplinary research of CCT is currently unknown due to very limited program will require coordination across multiple understanding of cirrus cloud properties and the agencies, national laboratories and cooperative insti- microphysical processes determining how cirrus tutes and coordination with other countries. The U.S. may be altered. Existing climate model simulations Global Change Research Program, charged with coor- of CCT have yielded contradictory results. dinating global change research across the federal science agencies, is the most logical entity for orches- PROPOSED FRAMEWORK FOR trating a solar geoengineering research program. RESEARCH AND RESEARCH GOVERNANCE The program and its outcomes should be reg- Given the urgency of the risks posed by climate ularly reviewed and assessed by a diverse, inclusive change, this report calls upon the United States both panel of experts and stakeholders (including consul- to implement a robust portfolio of climate mitigation tation with international counterparts) to determine and adaptation strategies and to establish a national whether continued research is justified and, if so, how solar geoengineering research program. This program goals and priorities should be updated. FIGURE 2. Schematic of solar geoengineering research and research governance environment. The stepwise, iterative nature of this framework is paramount. GOVERNANCE FOR SOLAR • Context and goals for solar geoengineer- GEOENGINEERING RESEARCH ing research, which includes research on the The recommended national solar geoengineer- goals and social context for solar geoengineering ing research program should operate under robust research, developing modeling scenarios, strate- research governance, and should support the devel- gies for decision making under uncertainty, and opment of international governance mechanisms. the capacity needed for all countries to engage The goals of research governance include advanc- meaningfully on this issue. ing and coordinating appropriate research, facilitat- • Impacts and technical dimensions, including ing inclusive and equitable public and stakeholder the properties of injected reflective particles and engagement, and addressing physical risks together their interactions with clouds and atmospheric pro- with social, ethical, and legal concerns. cesses, possible climate outcomes and subsequent A research governance program should include impacts on ecological and societal systems, tech- the following elements: a research code of con- nical requirements for advancing these technolo- duct, a public registry for research, regular program gies, and advancing monitoring and attribution assessment and review processes, permitting systems capabilities. for outdoor experiments, guidance on intellectual • Social dimensions, including research on public property, inclusive public and stakeholder engage- perceptions of and engagement with solar geoen- ment processes, mechanisms for advancing interna- gineering; domestic and international conflict and tional information sharing and collaboration (within cooperation; effective governance of solar geoen- research teams, among national scientific agencies), gineering; and integration of justice, ethics, and and establishment of an expert committee to advance equity considerations into work on this issue. discussions about international governance needs and strategies. Considerations for Outdoor Experiments Limited outdoor experimentation could help AN INTEGRATED AGENDA FOR advance the study of certain atmospheric processes SOLAR GEOENGINEERING RESEARCH that are critical for understanding solar geoengi- The research agenda for the U.S. solar geoen- neering. Such activities, however, are controversial, gineering research program should encompasses a with significant likelihood for public concerns and diverse array of 13 “research clusters”. As the
Recommended publications

  • Marine Cloud Brightening

    MARINE CLOUD BRIGHTENING Alan Gadian , John Latham, Mirek Andrejczuk, Keith Bower, Tom Choularton, Hugh Coe, Paul Connolly, Ben Parkes, Phillip Rasch, Stephen Salter, Hailong Wang and Rob Wood . Contents:- • Background to the philosophical approach • Some L.E.M . and climate model results • Technological issues. • Future plans and publications. Science Objectives:- • To explain the science of how stratocumulus clouds can have a significant effect on the earth’s radiation balance • To present some modelling results from Latham et al 2011 Marine Cloud Brightening, WRCP October 2011 1 Stratocumulus clouds cover more than 30% of ocean surface Stratocumulus clouds have a high reflectance, which depends on droplet number and mean droplet size. Twomey Effect .:- Smaller drops produce whiter clouds . Proposal :- To advertently to enhance the droplet concentration N in low-level maritime stratocumulus clouds, so increasing cloud albedo (Twomey, JAS, 1977 ) and longevity ( Albrecht, Science, 1989 ) Technique:- To disseminate sea-water droplets of diameter about 1um at the ocean surface. Some of these ascend via turbulence to cloud-base where they are activated to form cloud droplets, thereby enhancing cloud droplet number concentration, N (Latham, Nature 1990 ; Phil Trans Roy Soc 2008 and 2011, under review ) 2 Above:- Computed spherical albedo for increasing pollution in THIN, MEDIUM and THICK clouds. ( Twomey, JAS, 1977 ) Right:- Frequency distributions of the reflectances at 1,535 nm versus reflectances at 754 nm. From ACE-2. Isolines of geometrical thickness (H) and droplet number concentration (N): higher reflectance in polluted cloud, normalised by a similar geometrical thickness (Brenguier et al. 2000 ). 3 Figure 1. Panel (a): Map of MODIS-derived annual mean cloud droplet concentration N 0 for stratiform marine warm clouds.
  • Solar Geoengineering Reduces Atmospheric Carbon Burden David W

    Solar Geoengineering Reduces Atmospheric Carbon Burden David W

    opinion & comment COMMENTARY: Solar geoengineering reduces atmospheric carbon burden David W. Keith, Gernot Wagner and Claire L. Zabel Solar geoengineering is no substitute for cutting emissions, but could nevertheless help reduce the atmospheric carbon burden. In the extreme, if solar geoengineering were used to hold radiative forcing constant under RCP8.5, the carbon burden may be reduced by ~100 GTC, equivalent to 12–26% of twenty-first-century emissions at a cost of under US$0.5 per tCO2. ailure to address the accumulation of between a Representative Concentration carbon cycle feedback under assumptions atmospheric carbon is among the most Pathway (RCP) 8.5 scenario and one in that are similar — though not equal — to frequently noted disadvantages of solar which solar geoengineering is used to hold those that would be used to simulate solar F 1–3 geoengineering , an attempt to reflect a radiative forcing at current levels. This is geoengineering to stabilize radiative forcing small fraction of radiation back into space not a complete analysis, but rather a call for under an RCP8.5 scenario. We then combine to cool the planet. The latest US National further research. It is also a call for assessing the two ranges using equal weights and Academy of Science solar geoengineering solar geoengineering scenarios that go well uncorrelated error propagation to yield report1 states it “does nothing to reduce the beyond oft-modelled extreme scenarios that an overall estimate of the contribution 10 build-up of atmospheric CO2”. offset total anthropogenic radiative forcing . of the terrestrial biosphere and ocean of This is not so.
  • National Academies Press Solar Engineering Workshop Part 1

    National Academies Press Solar Engineering Workshop Part 1

    THE NATIONAL ACADEMIES PRESS This PDF is available at http://nap.edu/25815 SHARE Developing a Research Agenda for Solar Geoengineering Strategies: Proceedings of a Workshop in Brief (2020) DETAILS 14 pages | 8.5 x 11 | PDF ISBN 978-0-309-67808-7 | DOI 10.17226/25815 CONTRIBUTORS GET THIS BOOK Erin Markovich and Laurie Geller, Rapporteurs; Committee on Developing a Research Agenda and Research Governance Approaches for Climate Intervention Strategies That Reflect Sunlight to Cool Earth; Board on Atmospheric Sciences FIND RELATED TITLES and Climate; Committee on Science, Technology, and Law; Division on Earth and Life Studies; Policy and Global Affairs; National Academies of Sciences, SUGGESTEDEngineering, a nCITATIONd Medicine National Academies of Sciences, Engineering, and Medicine 2020. Developing a Research Agenda for Solar Geoengineering Strategies: Proceedings of a Workshop in Brief. Washington, DC: The National Academies Press. https://doi.org/10.17226/25815. Visit the National Academies Press at NAP.edu and login or register to get: – Access to free PDF downloads of thousands of scientific reports – 10% off the price of print titles – Email or social media notifications of new titles related to your interests – Special offers and discounts Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the National Academies Press. (Request Permission) Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of
  • Climate Intervention (July 2021)

    Climate Intervention (July 2021)

    State of the Science FACT SHEET Climate Intervention Climate Intervention (CI), also called climate engineering or geoengineering, refers to deliberate, large‐scale actions intended to counteract aspects of climate change. This Fact Sheet explains some of the fundamental principles and issues associated with CI (1). Why Might Climate Intervention Be Considered? The main driver of climate change over the past century has been anthropogenic emissions of carbon dioxide (CO2), a greenhouse gas (GHG). Increasing emission rates have caused present‐day atmospheric CO2 to reach the highest value in over a million years based on studies of emissions of atmospheric CO2 and its accumulation in the atmosphere, ocean, and terrestrial biosphere. The increased emissions of other GHGs, such as methane, nitrous oxide and ozone, also contribute to anthropogenic climate change. The increased accumulation of GHGs has led to warming over much of the globe, to acidification of ocean surface waters (from CO2) (2), and to many other well‐documented climate impacts (3). As climate change continues, if the world does not make the desired greenhouse gas emissions reductions (4) such as those initiated by the Paris agreement (5), governments and other entities might turn to CI to counteract increasing climate change impacts. CI could potentially be implemented by consensus or unilaterally; either way, a thorough understanding of CI methods, and their associated uncertainties and unintended side effects is essential. Principal CI methods are divided into two How might CDR be accomplished? general categories (6) (see figure): Oceanic sequestration: Adding nutrients, such as iron, to “ferti‐ lize” the ocean enhances biological growth (e.g., phytoplank‐ Carbon dioxide removal (CDR): CDR is a process to remove ton), which removes CO2 from surface waters and leads to lower CO2 from the atmosphere for long‐term storage on land or atmospheric levels.
  • Geoengineering: Basic Science and Ongoing Research Efforts in China

    Geoengineering: Basic Science and Ongoing Research Efforts in China

    Available online at www.sciencedirect.com ScienceDirect Advances in Climate Change Research 6 (2015) 188e196 www.keaipublishing.com/en/journals/accr/ Review Geoengineering: Basic science and ongoing research efforts in China CAO Longa,b,*, GAO Chao-Chaoc, ZHAO Li-Yunb a Department of Earth Sciences, Zhejiang University, Hangzhou 310027, China b College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China c Department of Environmental Science, Zhejiang University, Hangzhou 310027, China Received 8 July 2015; revised 17 August 2015; accepted 3 November 2015 Available online 14 November 2015 Abstract Geoengineering (also called climate engineering), which refers to large-scale intervention in the Earth's climate system to counteract greenhouse gas-induced warming, has been one of the most rapidly growing areas of climate research as a potential option for tackling global warming. Here, we provide an overview of the scientific background and research progress of proposed geoengineering schemes. Geo- engineering can be broadly divided into two categories: solar geoengineering (also called solar radiation management, or SRM), which aims to reflect more sunlight to space, and carbon dioxide removal (CDR), which aims to reduce the CO2 content in the atmosphere. First, we review different proposed geoengineering methods involved in the solar radiation management and carbon dioxide removal schemes. Then, we discuss the fundamental science underlying the climate response to the carbon dioxide removal and solar radiation management schemes. We focus on two basic issues: 1) climate response to the reduction in solar irradiance and 2) climate response to the reduction in atmospheric CO2. Next, we introduce an ongoing geoengineering research project in China that is supported by National Key Basic Research Program.
  • Marine Cloud Brightening

    Marine Cloud Brightening

    MARINE CLOUD BRIGHTENING Authors:- John Latham1,4 , Keith Bower4 , Tom Choularton4 , Hugh Coe4, Paul Connelly4 , Gary Cooper7 ,Tim Craft4, Jack Foster7, Alan Gadian5, Lee Galbraith7 Hector Iacovides4 , David Johnston7 , Brian Launder4, Brian Leslie7 , John Meyer7, Armand Neukermans7, Bob Ormond7, Ben Parkes5 , Phillip Rasch3, John Rush7, Stephen Salter6, Tom Stevenson6, Hailong Wang3, Qin Wang7 & Rob Wood2 . Affiliations:- 1 National Centre for Atmospheric Research, Boulder, CO. 2 U Washington, Seattle, 3 PNNL, Richland, WA., 4 U Manchester, 5 U of Leeds, 6 U of Edinburgh, 7 Silver Lining, CA. Abstract The idea behind the marine cloud brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre seawater particles could significantly enhance the cloud droplet number concentration thus increasing the cloud albedo and longevity – thereby producing a cooling, which computations suggest could be adequate to balance the warming associated with a doubling of atmospheric carbon dioxide. We review herein recent research on a number of critical issues associated with MCB: (1) general circulation model (GCM) studies, which are our primary tools to evaluate globally the effectiveness of marine cloud brightening and to assess its climate impacts on rainfall amounts and distribution, as well as on polar sea-ice cover and thickness: (2) high resolution modeling of the effects of seeding on marine stratocumulus, which are required to understand the complex array
  • Optimal Climate Strategy with Mitigation, Carbon Removal, and Solar Geoengineering

    Optimal Climate Strategy with Mitigation, Carbon Removal, and Solar Geoengineering

    Optimal Climate Strategy with Mitigation, Carbon Removal, and Solar Geoengineering Mariia Belaia Harvard John A. Paulson School of Engineering and Applied Sciences The John F. Kennedy School of Government Harvard University, Cambridge, MA 02138, USA Abstract Until recently, analysis of optimal global climate policy has focused on mitigation. Exploration of policies to meet the 1.5°C target have brought carbon dioxide removal (CDR), a second instrument, into the climate policy mainstream. Far less agreement exists regarding the role of solar geoengineering (SG), a third instrument to limit global climate risk. Integrated assessment modelling (IAM) studies offer little guidance on trade-offs between these three instruments because they have dealt with CDR and SG in isolation. Here, I extend the Dynamic Integrated model of Climate and Economy (DICE) to include both CDR and SG to explore the temporal ordering of the three instruments. Contrary to implicit assumptions that SG would be employed only after mitigation and CDR are exhausted, I find that SG is introduced parallel to mitigation temporary reducing climate risks during the era of peak CO2 concentrations. CDR reduces concentrations after mitigation is exhausted, enabling SG phasing out. Keywords: Integrated Assessment Modelling, climate policy, DICE, solar geoengineering, carbon dioxide removal 1 Introduction We need to understand our full potential to limit global climate risk. A wide range of climate policy instruments exists that, combined, equip us with the tools necessary to safeguard the global public good that is a stable climate. These instruments span across different economic sectors and can be market or non-market, private or public, international or regional.
  • A Specialised Delivery System for Stratospheric Sulphate Aerosols

    A Specialised Delivery System for Stratospheric Sulphate Aerosols

    Delft University of Technology A specialised delivery system for stratospheric sulphate aerosols (part 2) financial cost and equivalent CO2 emission DSE 16-02 DOI 10.1007/s10584-020-02686-6 Publication date 2020 Document Version Final published version Published in Climatic Change Citation (APA) DSE 16-02 (2020). A specialised delivery system for stratospheric sulphate aerosols (part 2): financial cost and equivalent CO emission. Climatic Change, 162(1), 87-103. https://doi.org/10.1007/s10584-020-02686- 6 2 Important note To cite this publication, please use the final published version (if applicable). Please check the document version above. Copyright Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons. Takedown policy Please contact us and provide details if you believe this document breaches copyrights. We will remove access to the work immediately and investigate your claim. This work is downloaded from Delft University of Technology. For technical reasons the number of authors shown on this cover page is limited to a maximum of 10. Climatic Change https://doi.org/10.1007/s10584-020-02686-6 A specialised delivery system for stratospheric sulphate aerosols (part 2): financial cost and equivalent CO2 emission I. E. de Vries1 · M. Janssens2 · S. J. Hulshoff2 · DSE 16-02 Received: 25 July 2019 / Accepted: 24 February 2020 / © The Author(s) 2020 Abstract Temporary stratospheric aerosol injection (SAI) using sulphate compounds could help avoid some of the adverse and irreversible impacts of global warming, but comprises many risks and uncertainties.
  • Potentially Dangerous Consequences for Biodiversity of Solar Geoengineering Implementation and Termination

    Potentially Dangerous Consequences for Biodiversity of Solar Geoengineering Implementation and Termination

    ARTICLES https://doi.org/10.1038/s41559-017-0431-0 Potentially dangerous consequences for biodiversity of solar geoengineering implementation and termination Christopher H. Trisos 1*, Giuseppe Amatulli2,3,4, Jessica Gurevitch 5, Alan Robock 6, Lili Xia6 and Brian Zambri 6 Solar geoengineering is receiving increased policy attention as a potential tool to offset climate warming. While climate responses to geoengineering have been studied in detail, the potential biodiversity consequences are largely unknown. To avoid extinction, species must either adapt or move to track shifting climates. Here, we assess the effects of the rapid implementa- tion, continuation and sudden termination of geoengineering on climate velocities—the speeds and directions that species would need to move to track changes in climate. Compared to a moderate climate change scenario (RCP4.5), rapid geoengineer- ing implementation reduces temperature velocities towards zero in terrestrial biodiversity hotspots. In contrast, sudden ter- mination increases both ocean and land temperature velocities to unprecedented speeds (global medians > 10 km yr−1) that are more than double the temperature velocities for recent and future climate change in global biodiversity hotspots. Furthermore, as climate velocities more than double in speed, rapid climate fragmentation occurs in biomes such as temperate grasslands and forests where temperature and precipitation velocity vectors diverge spatially by >90°. Rapid geoengineering termination would significantly increase the threats to biodiversity from climate change. he redistribution of species caused by climate change repre- take action given the current lack of regulatory constraints12,13. sents one of the greatest threats this century to biodiversity, Rapid termination is also feasible given the weakness of the global Taffecting ecosystem functioning and human wellbeing1.
  • (IPCC) Sixth Assessment Report (AR6) Working Group I: Climate Change 2021: the Physical Science Basis

    (IPCC) Sixth Assessment Report (AR6) Working Group I: Climate Change 2021: the Physical Science Basis

    Briefing Note on Solar Radiation Modification in the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6) Working Group I: Climate Change 2021: The Physical Science Basis The IPCC AR6 Working Group I (WG-I) report published on 9th August 2021 assesses the physical science of climate change, including the need for emissions reductions to net-zero, Carbon Dioxide Removal (CDR) and Solar Radiation Modification (SRM). Part I of this briefing note summarises key findings from the report’s assessment of SRM included in the main report and the Summary for Policymakers (SPM) as the basis. Part II provides C2G’s initial analysis of the policy implications.1 It will only be possible to make a full assessment of how AR6 deals with the issue of SRM in 2022, when the potential risks, ethics and public perceptions of the technique are expected to be assessed by WG-II (Impacts, Adaptation and Vulnerability) and SRM governance issues are expected to be addressed by both WG-II and WG-III (Mitigation of Climate Change). Part I: Summary of key findings on SRM from the WG-I Report • SRM techniques assessed in the IPCC report include Stratospheric Aerosol Injection (SAI), Marine Cloud Brightening (MCB), and surface albedo enhancements, all of which aim to cool the Earth by deflecting solar radiation back into space. Cirrus Cloud Thinning (CCT) seeks to lower temperatures by enabling more infrared radiation to escape from the Earth (see WG-I report, Chapter 4, table 4.7, p91 and section 4.6.3.3, p83 for more information). • SRM is not included in the report’s climate scenarios or in the Summary for Policymakers.
  • Emerging Risk Governance for Stratospheric Aerosol Injection As a Climate Management Technology

    Emerging Risk Governance for Stratospheric Aerosol Injection As a Climate Management Technology

    Environment Systems and Decisions https://doi.org/10.1007/s10669-019-09730-6 PERSPECTIVES Emerging risk governance for stratospheric aerosol injection as a climate management technology Khara D. Grieger1,2 · Tyler Felgenhauer2 · Ortwin Renn3 · Jonathan Wiener4 · Mark Borsuk2 © Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract Stratospheric aerosol injection (SAI) as a solar radiation management (SRM) technology may provide a cost-efective means of avoiding some of the worst impacts of climate change, being perhaps orders of magnitude less expensive than greenhouse gas emissions mitigation. At the same time, SAI technologies have deeply uncertain economic and environmental impacts and complex ethical, legal, political, and international relations ramifcations. Robust governance strategies are needed to manage the many potential benefts, risks, and uncertainties related to SAI. This perspective reviews the International Risk Governance Council (IRGC)’s guidelines for emerging risk governance (ERG) as an approach for responsible consideration of SAI, given the IRGC’s experience in governing other more conventional risks. We examine how the fve steps of the IRGC’s ERG guidelines would address the complex, uncertain, and ambiguous risks presented by SAI. Diverse risks are identifed in Step 1, scenarios to amplify or dissipate the risks are identifed in Step 2, and applicable risk management options identifed in Step 3. Steps 4 and 5 involve implementation and review by risk managers within an established organization. For full adoption and promulgation of the IRGC’s ERG guidelines, an international consortium or governing body (or set of bodies) should be tasked with governance and oversight. This Perspective provides a frst step at reviewing the risk governance tasks that such a body would undertake and contributes to the growing literature on best practices for SRM governance.
  • Geoengineering and Public Trust Doctrine Andrew Lockley, Gideon Futerman and D’Maris Coffman*

    Geoengineering and Public Trust Doctrine Andrew Lockley, Gideon Futerman and D’Maris Coffman*

    CCLR 2|2020 85 Geoengineering and Public Trust Doctrine Andrew Lockley, Gideon Futerman and D’Maris Coffman* Geoengineering (the deliberate modification of the climate system), has been discussed as a technique to control Anthropogenic Global Warming (AGW).1 Public Trust Doctrine (PTD) is used to hold assets that are not in private ownership in a form of collective ownership for public benefit; it is familiarly applied to the shoreline between tides. Several variants of PTD exist, yet all variants serve to limit private ownership. The version arising from Anglo-Amer- ican common law creates duties and responsibilities on the sovereign to maintain and pre- serve assets in public trust. We consider various types of geoengineering to protect example assets currently under PTD, finding a compelling case for action in a variety of contexts. This introduces a paradoxical situation, where it may theoretically be easier to compel states to undertake geoengineering to protect a beach, than to protect the whole planet. We note that, whilst PTD obligations are atomised in nature, the inherent commonality of the threat po- tentially serves to reduce this fragmentation, and to encourage common action amongst states. However, we note the failure of recent legal proceedings, which exposes practical lim- itations on the ability of PTD to compel climate action generally – and thus its applicabili- ty to geoengineering. I. Introduction – SRM: Solar Radiation Management is a suite of techniques based on the principle of modifying The difficulties in swiftly decarbonising the global the Earth’s radiation balance through partial re- economy have resulted in a renewed consideration flection of sunlight.