Exploring Democratic Governance of Solar Geoengineering Research

Program Areas – Science and Technology Policy, Complex Socio-technical Systems

Frequently Asked Questions

CSPO’s project to explore democratic governance of geoengineering research involves a lot of terms and concepts with which many people are unfamiliar. Below are some useful definitions and frequently asked questions about this project:


What is geoengineering?

Geoengineering refers to a set of emerging technologies that aim to deliberately intervene in the Earth’s climate. The goal of this intervention is to counteract the effects of greenhouse gas accumulations in the atmosphere. Geoengineering is also sometimes called “climate intervention,” “climate engineering,” “climate remediation,” etc. Scientists and policymakers have distinguished two broad categories of geoengineering:

  1. Solar geoengineering, also called solar radiation management or albedo modification, seeks to reflect sunlight back into space.
  2. Carbon dioxide removal, or CDR, removes and stores atmospheric carbon dioxide.

The focus of our project is on research into the first category, solar geoengineering.


What is solar geoengineering?

Solar geoengineering, often called solar radiation management (SRM) or albedo modification, is a type of geoengineering intended to reflect a small amount of light from the sun back out into space, thus reducing the rise in average global temperature caused by climate change. Solar geoengineering would not reduce concentrations of greenhouse gases in the atmosphere. Scientists have proposed several methods of solar geoengineering, each involving different suites of technologies and research programs. These include:

  1. Stratospheric aerosol injection would inject particles into a layer of the atmosphere called the stratosphere (10-50 km above the Earth’s surface) to increase scattering and reflection of incoming sunlight, thereby producing climatic cooling.
  2. Marine cloud brightening would spray sea salt particles into the lower troposphere, resulting in whiter, more reflective clouds. Brighter clouds would reflect a larger fraction of incoming sunlight back into space, resulting in climatic cooling.
  3. Cirrus cloud thinning would reduce the abundance and thickness of cirrus clouds, which are thought to absorb outgoing longwave radiation, thus achieving climatic cooling.
  4. Arctic ice management would pump Arctic Ocean water to the surface, rapidly freezing and thickening seasonal sea ice. Slowing or reversing the decline of this highly reflective ice would slow the rate of warming.

Some US government organizations have cautiously recommended proceeding with some forms of solar geoengineering research. They note, however, that such research must be responsibly governed and must proceed in concert with strong mitigation and adaptation efforts.


Why are some scientists interested in researching solar geoengineering?

Increased concentrations of greenhouse gases in the atmosphere are warming the climate, posing substantial risks to human welfare. Efforts to address climate change and its impacts have centered on two policy strategies. The first, called mitigation, aims to reduce the amount of greenhouse gases produced by human activities, such as energy production, agriculture, and transportation. The second strategy, adaptation, involves helping societies prepare for the anticipated effects of climate change, such as higher sea levels and changing weather patterns. Both of these approaches have proved technologically, economically, and politically difficult to implement at a global scale.

Some scientists and observers have proposed a third climate strategy to complement the first two: solar geoengineering, which by reflecting more sunlight back into space has the potential to rapidly offset some of the effects of climate change within a few years of deployment, and perhaps at a relatively low cost. Scientists know that for physical reasons, solar geoengineering could only ever be, at best, a complement to mitigation and adaptation strategies for addressing climate-related risks. Because the risks of intentionally changing the Earth’s atmosphere are poorly understood, some scientific organizations have cautiously supported research into solar geoengineering. By studying solar geoengineering with experiments and modeling, scientists hope to gain greater insight into its feasibility and risks, and a better understanding of basic climate processes.


What is the status of solar geoengineering research?

Following earlier experiments, the Stratospheric Particle Injection for Climate Engineering (SPICE) study, was funded by Research Councils UK (a public organization that coordinates science policy in the United Kingdom) in 2010. SPICE was an outdoor experiment that aimed to investigate the feasibility of solar geoengineering techniques, and involved injecting 150 liters of water into the atmosphere. Controversial from the start, the SPICE study was delayed by governance concerns and ultimately canceled due to uncertainties about intellectual property.

In the United States, very little field research has been funded to date. Some scientists are now moving forward with privately funded outdoor experiments. As a part of a larger interdisciplinary program on solar geoengineering research launched at Harvard University in 2017, a group of scientists are currently planning a field experiment to study how aerosols deployed in the atmosphere interact with lower stratospheric physical processes. Other researchers have expressed interest in field experimentation on different solar geoengineering ideas, including marine cloud brightening and cirrus cloud thinning.


Why is solar geoengineering research controversial?

Research into and the potential deployment of solar geoengineering is controversial for a variety of reasons. Several are listed here:

  • Moral hazard: Some observers have expressed concern that as a potentially quick and cheap technological fix to the climate problem, solar geoengineering may decrease pressure to cut emissions and reduce society’s reliance on fossil fuels, undermining existing climate policies. Climate experts typically argue that geoengineering cannot be considered independent of mitigation efforts to reduce greenhouse gas emissions.
  • Uncertainty: Social and natural scientists have also criticized the translation and usability of localized research into geoengineering options to large-scale deployment. Rose Cairns, a research fellow at the University of Sussex, contends that the social and physical effects of intervening in a system as complex as the global climate are “radically unknowable.” Proponents of solar geoengineering research maintain that deep uncertainties inhere whether or not the technology is pursued, but that research into solar geoengineering can reduce some of the technical uncertainties of its deployment.
  • Slippery slope/lock-in: Even in the case that research is unable to reduce uncertainties—let alone settle questions of ethics and values—attention from researchers can provide legitimacy and momentum to the deployment of solar geoengineering. This “slippery slope” argument is connected to the concept of technological “lock-in.” As particular solar geoengineering technologies are researched and tested, the concerns are twofold: 1) that “large-scale research and deployment become one and the same”; and 2) that solar geoengineering becomes “locked-in,” involving powerful economic interests and precluding alternate avenues of technological development or other ways to address the climate problem.
  • Governance: Most significantly for CSPO’s project are concerns about responsibly governing geoengineering research. Some have argued that features of SRM—its uncertainties, planetary impact, potential ease of deployment, etc.—make it incompatible with the principles of democratic governance. These principles include informed consent, legal redress, political pluralism, and national sovereignty. CSPO’s approach follows those who emphasize that consideration of geoengineering, including research, requires improved democratic decision making. Although principles for geoengineering research governance have been proposed at high levels, no country has developed comprehensive solar geoengineering research governance structures.


What is meant by the term “governance”?

Governance refers to a set of activities broader than, but inclusive of, those of public sector officials. It is not limited, for example, to public policy or legislation concerning geoengineering research, but includes a variety of actions that shape how and whether geoengineering research takes place. For the purposes of this project, governance captures a range of activities between the two extreme positions of undertaking solar geoengineering research and banning it. These governance activities and mechanisms include regulation, licensing, addressing liability concerns, intellectual property, treaties, codes of conduct, informal science education, public understanding of science, public engagement, and laboratory decisions. They involve a variety of local, national, and international actors including government, non-governmental organizations, academia, private industry, and professional societies.


What is participatory technology assessment?

Participatory technology assessment (pTA) is a method of public deliberation for eliciting informed lay citizen input prior to making decisions about science and technology. This type of assessment adds an additional perspective to the decision-making process, often contributing different insights than those coming from stakeholders with vested interests. The input provided by lay citizens is not a replacement for other decision-related information, such as expert opinion, empirical research, or stakeholder perspectives, but is an additional input that decision makers may find valuable. Because solar geoengineering is a technology with highly uncertain and planet-wide consequences, some researchers and observers have called for “participatory technology assessments, [which] can be used to ‘improve the outcomes of science and technology decision-making through dialog with informed citizens’ to enable them to have a voice in [solar geoengineering] research decisions.” This research project would be the first public deliberation on geoengineering research in the United States.