Solar geoengineering may lead to excessive cooling and high strategic uncertainty

Abstract

<jats:p>Climate engineering—the deliberate large-scale manipulation of the Earth’s climate system—is a set of technologies for reducing climate-change impacts and risks. It is controversial and raises novel governance challenges [T. C. Schelling,<jats:italic>Climatic Change</jats:italic>, 33, 303–307 (1996); J. Virgoe,<jats:italic>Climatic Change</jats:italic>, 95, 103–119 (2008)]. We focus on the strategic implications of solar geoengineering. When countries engineer the climate, conflict can arise because different countries might prefer different temperatures. This would result in too much geoengineering: the country with the highest preference for geoengineering cools the planet beyond what is socially optimal at the expense of the others—a theoretical possibility termed “free-driving” [M. L. Weitzman,<jats:italic>Scand. J. Econ.,</jats:italic>117, 1049–1068 (2015)]. This study is an empirical test of this hypothesis. We carry out an economic laboratory experiment based on a public “good or bad” game. We find compelling evidence of free-driving: global geoengineering exceeds the socially efficient level and leads to welfare losses. We also evaluate the possibility of counteracting the geoengineering efforts of others. Results show that countergeoengineering generates high payoff inequality as well as heavy welfare losses, resulting from both strategic and behavioral factors. Finally, we compare strategic behavior in bilateral and multilateral settings. We find that welfare deteriorates even more under multilateralism when countergeoengineering is a possibility. These results have general implications for governing global good or bad commons.</jats:p>

Learning to Manage the Multirisk World

“…These multiple evolutions from a single risk to a multirisk world-addressing multiple stressors, multiple impacts, and multiple decisions-are already underway, and as this essay has indicated, the community of risk analysts has contributed important insights. There are, to be sure, additional dimensions of moving from single to multiple, such as moving from one actor to multiple actors-multiple decisionmakers, perhaps representing multiple stakeholders with heterogeneous preferences-and the prospect of strategic behavior in addressing risks such as terrorism (Cox, 2009;Ezell, Bennett, Von Winterfeldt, Sokolowski, & Collins, 2010) or climate change and geoengineering (Abatayo, Bosettia, Casarid, Ghidonif, & Tavoni, 2020;Grieger, Felgenhauer, Renn, Wiener, & Borsuk, 2019;Sandler, 2018). This essay embodies the hope and confidence that as we improve our ability to understand and address the complex reality of a multirisk world, the science and profession of risk analysis can offer societies substantial progress in reducing overall risks and enhancing well-being.…”

Exploration of a novel geoengineering solution: lighting up tropical forests at night

“…Existing geoengineering proposals tend to align with two fundamentally different strategies: solar geoengineering (SG) (Abatayo et al, 2020;Proctor et al, 2018;Robock et al, 2009) and carbon capture and sequestration (CCS) (IPCC, 2005;Jones, 2008;Leung et al, 2014). SG and related techniques reduce the amount of incoming radiation from the sun, typically via stratospheric aerosol injection, subsequently affecting the planet's temperature.…”

“…SG and related techniques reduce the amount of incoming radiation from the sun, typically via stratospheric aerosol injection, subsequently affecting the planet's temperature. Although they may be able to offset temperature increase rapidly, previous studies indicate the potential for political instability (Abatayo et al, 2020) and negative impacts on human health (Robock et al, 2009) and agriculture (Proctor et al, 2018). Comparatively, CCS removes carbon from the global carbon cycle by using artificial machines and saves it for long-term storage or for industrial reutilization (IPCC, 2005).…”

Exploration of a novel geoengineering solution: lighting up tropical forests at night

“…Existing geoengineering proposals tend to align with two fundamentally different strategies: Solar Geoengineering (SG) (Abatayo et al, 2020;Proctor et al, 2018;Robock et al, 2009) and Carbon Capture and Sequestration (CCS) (IPCC, 2005;Jones, 2008;Leung et al, 2014). SG and related techniques reduce the amount of incoming radiation from the sun typically via stratospheric aerosol injection, subsequently affecting the planet's temperature.…”

“…SG and related techniques reduce the amount of incoming radiation from the sun typically via stratospheric aerosol injection, subsequently affecting the planet's temperature. Although they may be able to offset temperature increase rapidly, previous studies indicate the potential for political instability (Abatayo et al, 2020) and negative impacts on human health (Robock et al, 2009) and agriculture (Proctor et al, 2018). Comparatively, CCS removes carbon from the global carbon cycle by artificial machines and saves it for long-term storage or for industrial reutilization (IPCC, 2005).…”