Sebastian Eastham

Sebastian Eastham, Sarah Doherty, David Keith, Jadwiga H. Richter, and Lili Xia. 2021. “Improving Models for Solar Climate Intervention Research.” Eos. Publisher's VersionAbstract

Solar climate intervention, also known as solar radiation modification, is an approach intended to mitigate the impacts of climate change by reducing the amount of solar energy that the Earth system traps. It sits alongside three other plausible responses to climate risk: emission cuts and decarbonization, atmospheric carbon dioxide (CO2) removal, and adaptation to a changing climate.

Unlike the other approaches, solar climate intervention (SCI), which comprises various techniques, aims to modify Earth’s radiation budget—the amounts and balance of solar energy that Earth absorbs and reflects—directly. Implementing SCI means either decreasing inbound solar (shortwave) radiation by reflecting it back into space before it is absorbed or increasing the amount of outbound terrestrial (longwave) radiation.

Potential methods of SCI include stratospheric aerosol injection (SAI), marine cloud brighteningcirrus cloud thinningsurface albedo modification, and space-based methods involving, for example, mirrors (Figure 1). At present, the potential efficacy and risks of implementing these approaches to reduce climate change are highly uncertain and likely depend on how they are implemented.

The Geoengineering Modeling Research Consortium (GMRC) was founded to coordinate SCI modeling research and to identify and resolve relevant issues with physical models, especially where existing climate research is unlikely to do so. Here we synthesize 2 years of GMRC meetings and research, and we offer specific recommendations for future model development.

Sebastian Eastham

Sebastian Eastham

Visiting Scientist, Harvard's Solar Geoengineering Research Program

Sebastian is a research scientist at the Massachusetts Institute of Technology's Laboratory for Aviation and the Environment (LAE). His previous work has covered development and application of global atmospheric chemistry and transport models, ranging from his work to implement stratospheric chemistry in the GEOS-Chem community atmospheric model, through to his recent paper discussing the possible health effects of solar geoengineering. He is currently working as a visiting scientist for the Harvard Solar Geoengineering Research Program, investigating the behavior of aircraft plumes in the stratosphere - including those which would be expected to form if stratospheric aerosol injection were ever deployed.