A new paper co-authored by IU Assistant Professor Ben Kravitz assesses the body of knowledge related to solar engineering, a form of climate engineering that aims to cool the surface of the earth by reflecting more sunlight back into space, and recommends a systematic effort to support decision-makers who may one day consider techniques to artificially cool the planet.

“Up to this point, a lot of the research into solar geoengineering has been curiosity-driven,” Kravitz said. “Understanding how much we know about solar geoengineering is essential not only for supporting future informed decisions but also for guiding future research.”

Specifically, the authors analyze the knowns and unknowns surrounding stratospheric aerosol geoengineering, a form of solar geoengineering in which tiny reflective sulfate particles are injected into the upper atmosphere, mimicking the cooling effect of a large volcanic eruption. Depending on how it is deployed, the technique could stave off the worst effects of climate change while humanity works to reduce carbon dioxide levels in the atmosphere. Models indicate, however, that stratospheric aerosol geoengineering comes with potentially large global tradeoffs in the form of shifts in precipitation patterns and regionalized effects on the climate.

In the review article, published in the January issue of Nature Reviews Earth and Environment, the authors call for a coordinated effort to map out the research community’s confidence in the potential effects of solar geoengineering and to identify research priorities to improve that confidence.

“One way to do that is using a risk register, a tool oftentimes used in major engineering projects,” Kravitz said. “Risk registers are systematic ways of prioritizing uncertainties. Right now, there is no objective basis for figuring out the most important uncertainties surrounding solar geoengineering.”

Read Kravitz’ interview with the ERI Explainer to learn more about the potential risks and rewards of solar geoengineering.