Improving Models for Solar Climate Intervention Research

[Andrew Lockley]

https://eos.org/science-updates/improving-models-for-solar-climate-intervention-research

Modern climate models were designed to simulate natural systems and changes mainly due to atmospheric carbon dioxide, rather than to predict effects of deliberate climate interventions.

View from an airplane flying above a layer of clouds

Solar climate intervention (SCI) methods, such as stratospheric aerosol deployments in aircraft plumes, are intended to modify the amount of sunlight that Earth absorbs and reflects. Credit: Jerry Xavier/Pixabay

By Sebastian Eastham, Sarah Doherty, David Keith, Jadwiga H. Richter, and Lili Xia  8 hours ago

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 brightening, cirrus cloud thinning, surface 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.