Solar geoengineering could reduce climate change, but poses risks. This volume explores how it is, could, and should be governed.

Climate change is among the world's most important problems, and solutions based on emission cuts or adapting to new climates remain elusive. One set of proposals receiving increasing attention among scientists and policymakers is 'solar geoengineering', (also known as solar radiation modification) which would reflect a small portion of incoming sunlight to reduce climate change. Evidence indicates that this could be effective, inexpensive, and technically feasible, but it poses environmental risks and social challenges. Governance will thus be crucial. In The Governance of Solar Geoengineering, Jesse L. Reynolds draws on law, political science, and economics to show how solar geoengineering is, could, and should be governed. The book considers states' incentives and behavior, international and national law, intellectual property, compensation for possible harm, and non-state governance. It also recommends how solar geoengineering could be responsibly researched, developed, and - if appropriate - used in ways that would improve human well-being and ensure sustainability.

The National Research Council report Climate Intervention: Reflecting Sunlight to Cool Earth (NRC, 2015) reviewed the state of the science and provided high-level findings and recommendations regarding SG methods. This current study was tasked to update the 2015 assessment of the state of understanding and to provide recommendations for how to establish a research program, what to encompass in the research agenda, and what mechanisms to employ for governing this research.

The sobering reality of the disconnect between the resolve of the world community to effectively address climate change, and what actually needs to be done, has led to increasing impetus for consideration of a suite of approaches collectively known as “climate geoengineering,” or “climate engineering.” Indeed, the feckless response of the world community to climate change has transformed climate geoengineering from a fringe concept to a potentially mainstream policy option within the past decade. This volume will explore scientific, political and legal issues associated with the emerging field of climate geoengineering. The volume encompasses perspectives on both of the major categories of climate geoengineering approaches, carbon dioxide removal and solar radiation management.

The growing problem of changing environmental conditions caused by climate destabilization is well recognized as one of the defining issues of our time. The root problem is greenhouse gas emissions, and the fundamental solution is curbing those emissions. Climate geoengineering has often been considered to be a "last-ditch" response to climate change, to be used only if climate change damage should produce extreme hardship. Although the likelihood of eventually needing to resort to these efforts grows with every year of inaction on emissions control, there is a lack of information on these ways of potentially intervening in the climate system. As one of a two-book report, this volume of Climate Intervention discusses albedo modification - changing the fraction of incoming solar radiation that reaches the surface. This approach would deliberately modify the energy budget of Earth to produce a cooling designed to compensate for some of the effects of warming associated with greenhouse gas increases. The prospect of large-scale albedo modification raises political and governance issues at national and global levels, as well as ethical concerns. Climate Intervention: Reflecting Sunlight to Cool Earth discusses some of the social, political, and legal issues surrounding these proposed techniques. It is far easier to modify Earth's albedo than to determine whether it should be done or what the consequences might be of such an action. One serious concern is that such an action could be unilaterally undertaken by a small nation or smaller entity for its own benefit without international sanction and regardless of international consequences. Transparency in discussing this subject is critical. In the spirit of that transparency, Climate Intervention: Reflecting Sunlight to Cool Earth was based on peer-reviewed literature and the judgments of the authoring committee; no new research was done as part of this study and all data and information used are from entirely open sources. By helping to bring light to this topic area, this book will help leaders to be far more knowledgeable about the consequences of albedo modification approaches before they face a decision whether or not to use them.

The first book to focus on the legal aspects of climate engineering, making recommendations for future laws and governance.

Stabilizing the world’s climates means cutting carbon dioxide pollution. There’s no way around it. But what if that’s not enough? What if it’s too difficult to accomplish in the time allotted or, worse, what if it’s so late in the game that even cutting carbon emissions to zero, tomorrow, wouldn’t do? Enter solar geoengineering. The principle is simple: attempt to cool Earth by reflecting more sunlight back into space. The primary mechanism, shooting particles into the upper atmosphere, implies more pollution, not less. If that doesn’t sound scary, it should. There are lots of risks, unknowns, and unknowables. In Geoengineering: The Gamble, climate economist Gernot Wagner provides a balanced take on the possible benefits and all-too-real risks, especially the so-called “moral hazard” that researching or even just discussing (solar) geoengineering would undermine the push to cut carbon emissions in the first place. Despite those risks, he argues, solar geoengineering may only be a matter of time. Not if, but when. As the founding executive director of Harvard’s Solar Geoengineering Research Program, Wagner explores scenarios of a geoengineered future, offering an inside-view of the research already under way and the actions the world must take to guide it in a productive direction.