Stratospheric Aerosol Injection Using Oxygenated Organic Aerosols

Accelerating global warming has prompted urgent but controversial discussions about stratospheric aerosol injection (SAI), a proposed climate intervention that would disperse sulfuric acid aerosols (or their precursor gases) into the stratosphere to reflect incoming sunlight, mimicking the cooling effect observed after major volcanic eruptions. However, SAI’s conceptual appeal is undermined by two key challenges: first, there are large uncertainties in predicting SAI’s climate impacts due to oversimplified representations of aerosols in current models; and second, there are serious environmental risks associated with sulfuric acid aerosols, including stratospheric warming, ozone depletion, and acid rain. Deploying such a high-stakes intervention without a detailed understanding of aerosol processes and properties is akin to performing surgery blindfolded—a gamble that could worsen the very crisis it seeks to mitigate.

This research proposes to address these challenges by combining laboratory experiments and aerosol dynamics modeling to better understand the chemical reactions and microphysical processes that govern aerosol formation and aging under stratospheric conditions. Additionally, this research will leverage current understanding of natural aerosol formation analogs to investigate oxygenated organic aerosols as a potentially more efficient and environmentally safer alternative to SAI.

This work will provide detailed, process-level parameterizations of aerosol composition and physicochemical properties throughout their year-long lifetime in the stratosphere. These results will serve as critical inputs into climate models, enabling more accurate assessments of SAI’s environmental risks and broadening advancements in the understanding of aerosol-cloud-climate interactions, ultimately providing a scientific foundation for informed climate policymaking.