How Best to Govern Geoengineering in the Race to Save Earth's Climate

I want to comment on a topic that is rather controversial — at least among environmentalists and climate policy wonks — but at the same time is important: the governance of solar geoengineering deployment.

Solar geoengineering (which we’ll call SG) refers to the deliberate alteration of the Earth’s radiative balance in order to reduce the risks attributed to the accumulation of greenhouse gases in the atmosphere. According to my Harvard colleagues David Keith and Peter Irvine, technically plausible methods include adding aerosols to the stratosphere, where they reflect a small percentage of incoming sunlight back to space; adding cloud condensation nuclei, such as sea salt, to specific kinds of low-lying clouds over the ocean in order to increase their reflectivity or longevity; adding ice nuclei to high-altitude cirrus clouds in order to reduce their density; placement of space-based reflectors; and tropospheric aerosols.

Some types of SG will be associated with incentive structures that are the inverse of those associated with efforts to reduce greenhouse gas emissions. The latter is a global commons problem, which requires cooperation at the highest jurisdictional level (international) in order to advance significant mitigation. But, in contrast, certain types of SG can — in principle — be implemented effectively at relatively low financial cost — low enough to be borne by small states or even non-state entities acting on their own.

The impacts of such actions, however, might be substantial, at regional or even global scales. These could include the intended beneficial impacts — decreased global average surface temperatures — plus other, potentially adverse side effects. Given the incentive structure associated with SG, its potentially substantial impacts, and the uncertainty surrounding it, the governance of deployment will be challenging, to say the least, and is a very important topic for research.

With this in mind, last September the Harvard Project on Climate Agreements hosted a workshop on the “Governance of the Deployment of Solar Geoengineering,” with collaboration and support from Harvard’s Solar Geoengineering Research Program. Participants included 26 leading academic researchers addressing the workshop’s topic — as well as leading scholars who had considered the governance of other international regimes that might provide lessons and insights.

The workshop began with overviews of research on SG governance from two disciplinary perspectives — economics and law. Subsequent sessions addressed seven key questions, which arise, in part, from the incentive structure of SG governance.

First, who ought to or will specify criteria for SG deployment, and who ought to and/or is likely to decide when they are satisfied? Second, what will or should these criteria be? They might include regulations developed by policymakers; specifications by those who might engage in SG deployment; and physical, engineering, social, economic, ethical, and other perspectives. Third, how should decisions about deployment be made, and what decisionmaking process should or will be utilized?

Fourth, what institutions, either existing or new, are appropriate as decisionmaking venues? What will or should be the legal framework of such institutions? Fifth, how might SG complement or undermine national, regional, and multilateral institutions and policy to mitigate or adapt to climate change — and, more broadly, to manage climate risks? Sixth, SG is both a hedge against uncertain but potentially catastrophic risks of climate change, and has its own associated risks, known and unknown. How can we better understand these uncertainties and incorporate them into useful decisionmaking processes? Finally, how might we best define a research agenda for the governance of SG deployment?

In addition, a panel of international relations scholars discussed a set of global regimes — including nuclear arms control and cyber security — that may provide lessons for and insights into SG governance.

Given the very early stage of thinking about the issue, we did not attempt to provide definitive answers but sought to advance understanding of this issue and move the research community some steps further toward better identification of sound options for the governance of SG deployment.

Currently, each participant in the workshop is preparing a brief on an aspect of the topic of his or her interest. These briefs are designed to be readily accessible to environmental professionals — policymakers, climate negotiators, and leaders in the business and NGO communities. The entire volume will be released by the Harvard Project on Climate Agreements in February.