Planetary Aerosol Geoengineering Research Illuminates Earthbound Climate Engineering

For decades, insights from planetary aerosol research have pollinated geoscience research with ideas that carry significant societal relevance. Examples include how data from Mars dust storms helped inspire nuclear winter modeling—impacting Cold War arms control discussions—and how understanding the mechanisms linking asteroid impacts to mass extinctions motivated NASA’s successful Double Asteroid Redirection Test. Still, much basic work remains.

Initial studies on the deliberate warming of Mars using aerosols (Ansari et al., Science Advances, 2024) have already uncovered interesting new feedback that could have relevance to Earth solar geoengineering on Earth. Focusing on basic work that will have broad applicability, we will:

• Screen a wide range of naturally abundant or easily obtained solid materials for their warming or cooling potential, varying particle size (monodisperse) and aspect ratio to better understand their radiative effects.
• Test whether collective particle self-lofting enables full-scale aerosol deployment at low latitude from existing aircraft with existing engines. This task is motivated in part by recent Mars results (Richardson et al., arXiv:2504.01455). It has the potential to transform solar geoengineering deployment timelines and economics (Gao et al., Science Advances, 2021).
• Design aerosols with built-in trackability to mitigate the “attribution gap.” [This task is led by Co-Investigator Hooman Mohseni, Northwestern University]. How can we monitor plumes released by “intermediate-sized” experiments? It is difficult to attribute any short-term regional effects without knowing aerosol distribution. We will develop trackable, unpowered particles that would strongly interact with specific wavelengths of light while traveling with the climate-modifying aerosols—similar to corner-cube retroflectors. Trackability could also greatly enhance the science of precursor or test missions on Mars.