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Assessing Solar Geoengineering – What, Who, and How?
Abstract and Figures
Potential consequences of future SG deployment are assessed in a growing number of authoritative studies and reports, yet results are contested due to lack of clarity in three respects:
• Defining what SG deployment might be, requires making conscious choices throughout a pyramid of biophysical, socio-political, and value-laden assumptions.
• The prevalence of value-choices in assessments of SG deployment requires
clarity on whose perspectives ought to be considered.
• The question of how and by which criteria SG deployment may be assessed
requires clarity on relevant social objectives that SG deployment ought to
advance or avoid infringing upon.
Outcomes from deploying solar geoengineering (SG) would be determined by an intertwined set of factors: the bio-physical and political dimensions of the action taken, the design of the technology used, and broader accompanying circumstances.
To provide a widely accepted basis for decision-making, assessments of SG deployment therefore require clarity on three distinct but interdependent questions: First, what is SG deployment? Second, who may authoritatively assess it? And, third, how and by which criteria may SG deployment be assessed?
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... (named here SG, solar geoengineering), which represents uncertainties for governance considerations (Honegger, 2019) ...
Abstract
Some climate engineering technologies are being developed to remove CO2 from the atmosphere (carbon dioxide removal, CDR), which is expected to contribute to reducing and preventing climate change. Some other technologies (solar radiation modification, SRM) would artificially cool the planet and could reduce some symptoms and risks of climate change. Meaningful steps may need to be taken soon to lay a foundation for a decision process regarding research, policy, regulation and possible use. Driven by questions and needs from the international policymaking community to better understand the potential benefits as well as opportunities, risks, uncertainties and other challenges of CDR and SRM, at both technical and governance levels, this report reviews and compares technologies and their potential contributions, costs, risks, uncertainties, before surveying the current legal and institutional landscape of governance regarding climate engineering. It then addresses trade-offs between risks and discusses possible options for international governance, including criteria for evaluating options. The need for more inclusive approaches and the pros- and cons of institutional fragmentation are emphasized. Options for sites of international governance are discussed, for various technologies, as well as general principles and specific recommendations to: distinguish between CDR and SRM as well as among CDR techniques; accelerate authoritative, comprehensive, and international scientific assessment; encourage the research, development, and responsible use of some CDR techniques; internationally build capacity for evaluating CDR and SRM; facilitate non-state governance; and explore potential further governance of SRM while remaining agnostic concerning its use.
... (named here SG, solar geoengineering), which represents uncertainties for governance considerations (Honegger, 2019) ...
Climate change and climate-altering technologies pose an emerging risk governance challenge involving risk-risk trade-offs both regarding potential outcomes as well as governance choices. Trade-offs characterize not only various emergent governance and policy design choices but also how research is conducted and communicated. This chapter identifies numerous risks and trade-offs and offers several steps that could be pursued in the near- to medium-term to gradually overcome trade-offs and strengthen opportunities for governance strategies that attenuate multiple risks. Many of these steps aim at strengthening capacities for anticipation, cooperation, and joint decision-making, which would appear essential qualities for addressing the risk-risk trade-offs posed by climate change and countervailing risks associated with potential CDR and SRM applications. Suggested measures in the context of governance processes include: strengthening capacities for international inter-agency collaboration, coordination, and learning; proactively exploring how specific governance challenges match particular international agencies’ mandates; conducting policy impact assessments in the context of national mitigation policy planning. Suggested measures in the realm of research, research funding, and research governance include: enabling more diverse, transdisciplinary research; supporting the international exchange of expertise; enabling continuous science-policy conversations; conducting research to generate insights on potential interlinkages in the context of the Sustainable Development Goals.
... The corresponding value-judgments often go unmentioned in studies or assessments, even though they underpin assessments and governance. Figure 5 -A pyramid of value-laden assumptions underpinning assessments of SRM (named here SG, solar geoengineering), which represents uncertainties for governance considerations (Honegger, 2019) ...
Deliberate large-scale interventions in the Earth’s climate system – known collectively as ‘geoengineering’ – have been proposed in order to moderate anthropogenic climate change. This thesis explores one of the possible technologies, stratospheric aerosol injection solar radiation management (SAI). My original contribution to knowledge is to make a number of interlinked contributions to understanding how interested and affected parties frame and think about SAI risk, and, how its future governance may evolve. The qualitative study addresses two research questions: how might deployment risks be incorporated into SAI governance; and, might SAI governance be plural?
Governance framings are explored through the lens of the technical and social risks of SAI. A theorising of risk by Renn (2008) that incorporates the challenges of uncertainty, ignorance and incertitude, using a typology of risk and a linked risk management model is adopted to explore how SAI risks maybe be incorporated into SAI governance. A conceptual framework of SAI governance, drawing on Bulkeley’s (2012) climate change governance theories of consent, consensus and concord, is used to suggest how decisionmaking might be enacted, and authority negotiated, taken, and given during SAI governance.
Semi-structured stakeholder interviews were undertaken to discern perspectives on SAI risk and risk governance, identifying the underlying rationales, and, providing empirical evidence to assess the theoretical arguments.
Findings describe how SAI governance may take shape and its characteristics. They suggest complex understandings of risk will contribute to the construction of a plural, inclusive and deliberative process of governance that, critically, will evolve in an un-rushed manner over time. The research suggests that risk management theories may help inform how other socially constructed Earth systems might be governed. In addition, the modalities of authorisation and the transnational governing processes proposed by the governance framework appear to provide a useful tool that could help interested and affected parties’ understandings of, and participation in, future SAI governance.
The thesis suggests SAI is a useful case study to inform the broader environmental governance debate and the geoengineering-climate change interface. Some suggestions for further research in this direction are suggested.
This chapter has two parts. The first addresses the politics of radical population reduction. The second part addresses the politics of geoengineering. Geoengineering initiatives are only a means for slowing global warming. None address ocean acidification, increasing toxicity and species depletion and extinction; so, geoengineering cannot be taken to represent a means for ensuring humanity’s survival. Indeed, none of the policies that will be introduced to address the effects of catastrophic human-caused environment change are likely avert a trajectory toward and into the final hundred years of humanity. The threat to the status quo, however, requires that those in government act and are seen to act.
Solar geoengineering refers to deliberately reducing net radiative forcing by reflecting some sunlight back to space, in order to reduce anthropogenic climate changes; a possible such approach would be adding aerosols to the stratosphere. If future mitigation proves insufficient to limit the rise in global mean temperature to less than 1.5°C above preindustrial, it is plausible that some additional and limited deployment of solar geoengineering could reduce climate damages. That is, these approaches could eventually be considered as part of an overall strategy to manage the risks of climate change, combining emissions reduction, net-negative emissions technologies and solar geoengineering to meet climate goals. We first provide a physical-science review of current research, research trends and some of the key gaps in knowledge that would need to be addressed to support informed decisions. Next, since few climate model simulations have considered these limited-deployment scenarios, we synthesize prior results to assess the projected response if solar geoengineering were used to limit global mean temperature to 1.5°C above preindustrial in an overshoot scenario that would otherwise peak near 3°C. While there are some important differences, the resulting climate is closer in many respects to a climate where the 1.5°C target is achieved through mitigation alone than either is to the 3°C climate with no geoengineering. This holds for both regional temperature and precipitation changes; indeed, there are no regions where a majority of models project that this moderate level of geoengineering would produce a statistically significant shift in precipitation further away from preindustrial levels.
This article is part of the theme issue ‘The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels’.
If solar geoengineering were to be deployed so as to mask a high level of global warming, and then stopped suddenly, there would be a rapid and damaging rise in temperatures. This effect is often referred to as termination shock, and it is an influential concept. Based on studies of its potential impacts, commentators often cite termination shock as one of the greatest risks of solar geoengineering. However, there has been little consideration of the likelihood of termination shock, so that conclusions about its risk are premature. This paper explores the physical characteristics of termination shock, then uses simple scenario analysis to plot out the pathways by which different driver events (such as terrorist attacks, natural disasters, or political action) could lead to termination. It then considers where timely policies could intervene to avert termination shock. We conclude that some relatively simple policies could protect a solar geoengineering system against most of the plausible drivers. If backup deployment hardware were maintained and if solar geoengineering were implemented by agreement among just a few powerful countries, then the system should be resilient against all but the most extreme catastrophes. If this analysis is correct, then termination shock should be much less likely, and therefore much less of a risk, than has previously been assumed. Much more sophisticated scenario analysis—going beyond simulations purely of worst-case scenarios—will be needed to allow for more insightful policy conclusions.
Ten years ago, Nobel laureate Paul Crutzen called for research into the possibility of reflecting sunlight away from Earth by injecting sulfur particles into the stratosphere. Across academic disciplines, Crutzen's intervention caused a surge in interest in and research on proposals for what is often referred to as “geoengineering” - an unbounded set of heterogeneous proposals for intentionally intervening into the climate system to reduce the risks of climate change. To mark the 10 year anniversary of the publication of Paul Crutzen's seminal essay, this special issue reviews the developments in geoengineering research since Crutzen's intervention and reflects upon possible future directions that geoengineering research may take. In this introduction, we briefly outline the arguments made in Paul Crutzen's 2006 contribution and describe the key developments of the past 10 years. We then proceed to give an overview of some of the central issues in current discussions on geoengineering, and situate the contributions to this special issue within them. In particular, we contend that geoengineering research is characterized by an orientation toward speculative futures that fundamentally shapes how geoengineering is entering the collective imagination of scientists, policymakers, and publics, and a mode of knowledge production that recognizes the risks which may result from new knowledge and that struggles with its own socio-political dimensions.
Some scientists suggest that it might be possible to reflect a portion of incoming sunlight back into space to reduce climate change and its impacts. Others argue that such solar radiation management (SRM) geoengineering is inherently incompatible with democracy. In this article, we reject this incompatibility argument. First, we counterargue that technologies such as SRM lack innate political characteristics and predetermined social effects, and that democracy need not be deliberative to serve as a standard for governance. We then rebut each of the argument’s core claims, countering that (1) democratic institutions are sufficiently resilient to manage SRM, (2) opting out of governance decisions is not a fundamental democratic right, (3) SRM may not require an undue degree of technocracy, and (4) its implementation may not concentrate power and promote authoritarianism. Although we reject the incompatibility argument, we do not argue that SRM is necessarily, or even likely to be, democratic in practice.
Geoengineering is regarded by advocates as a creative and responsible technological option in the face of a climate emergency. Critics often see it as a hubristic attempt to play God, with disastrous consequences for the planet and humanity. These antipodal perspectives are represented by the ideal types of Prometheans and Gaians. Prometheans and Gaians typically talk past each other. The geoengineering debate can be made more fruitful by well articulating their respective positions and subsequently situating them in the discourse of sustainability. A sustainability orientation does not answer the troubling question whether geoengineering should be developed and deployed. But it can foster a ‘fusion of horizons’ between Prometheans and Gaians, providing common ground in an otherwise polarized debate and making a more productive dialogue possible.
Carbon Removal and Solar Geoengineering: Potential implications for Delivery of the Sustainable Development Goals. Carnegie Climate Geoengineering Governance Initiative. May. www.c2g2.net/wp-content/uploads/C2G2-Geoeng-SDGs_20180521.pdf
- M Honegger
- H Derwent
- N Harrison
- A Michaelowa
- S Schäfer
Honegger, M., H. Derwent, N. Harrison, A. Michaelowa, and S. Schäfer. 2018. Carbon
Removal and Solar Geoengineering: Potential implications for Delivery of the Sustainable
Development Goals. Carnegie Climate Geoengineering Governance Initiative. May.
www.c2g2.net/wp-content/uploads/C2G2-Geoeng-SDGs_20180521.pdf; see also
related web page: www.c2g2.net/geoeng-sdgs.