SoMAS to Host Symposium Honoring Accomplishments of Stephen Schwartz

Stephen Schwartz with images contrasting the warming influence of the greenhouse effect with the cooling influence of anthropogenic aerosols. Photo, Brookhaven National Laboratory.

Stony Brook University's School of Marine and Atmospheric Sciences (SoMAS) will host a symposium on June 1 and 2, 2026, in recognition of the scientific accomplishments of Adjunct Professor Stephen Schwartz on the occasion of his 85th birthday.

The symposium will consist of over 30 presentations by distinguished atmospheric scientists from around the world, chaired by Daniel Knopf of SoMAS and Ernie Lewis of Brookhaven National Laboratory.

Schwartz, who began his professional career at Stony Brook as an assistant professor in the chemistry department, spent most of his career at Brookhaven National Laboratory before returning to Stony Brook as an adjunct professor. His scientific focus was, and is, the effect of energy related emissions on the environment and climate.

His early research focused on the chemical mechanisms of acid rain formation. The key scientific question was how do the low solubility emitted pollutant gases get oxidized to the highly soluble acids that are incorporated in rain. The conventional wisdom at the time was that sulfur dioxide was oxidized in the gas phase and nitrogen oxides were oxidized in aqueous solution, in cloudwater. Through theory, laboratory experiments, field measurements and modeling Schwartz and his colleagues showed that in both cases the opposite was true. Their work went on to delineate the mechanisms and rates of the processes of oxidation and uptake into cloudwater.

In a paper published in Science in 1989, Schwartz made the argument that the cumulative effects of emissions of sulfur and nitrogen oxides from multiple sources, while not exceeding local air quality standards, in the aggregate resulted in acid deposition hundreds of miles from the emission sources. This study was highly influential on the drafting of the 1990 Amendments to the Clean Air Act. In that act Congress found that the problem of acid deposition to be of national and international significance and enacted legislation to decrease aggregate emissions.

Schwartz stated that it was of enormous significance that these findings and objectives were established in legislation that cannot simply be overturned by a future administration. Schwartz went on to exclaim, "And it worked! The problem of acid deposition has largely been solved."

In 2017 the Department of Energy recognized Schwartz's Science paper as one of 40 Research Milestones in the first 40 years of the department.

Stephen Schwartz with satellite image illustrating long range transport of atmospheric aerosols and their light scattering effects over the North Atlantic. Photo, Brookhaven National Laboratory.

A subsequent key thread of Schwartz's research has dealt with the climate influence of atmospheric aerosol particles (microscopic to submicroscopic particles suspended in air). These particles scatter sunlight and increase the reflectivity of clouds; consequently anthropogenic aerosols exert a cooling influence on climate, opposite to the warming effect of anthropogenic greenhouse gases.

A 1992 paper co-authored with others, including the late Professor Robert Cess, one of the founders of the Atmospheric Science Program at Stony Brook, provided first global estimates of these effects. That paper has influenced much research since its publication, having been cited over 5,000 times, putting it among the "best sellers" of research papers in atmospheric science in recent decades.

Schwartz's research has been recognized by fellowship in the American Association for the Advancement of Science and of the American Geophysical Union. In 2010 he received an Outstanding Leadership Award from the U.S. Department of Energy. In 2020 he was named International Aerosol Fellow by the International Aerosol Research Assembly. He was recipient of the 2020-2021 Haagen-Smit Clean Air Award of the California Air Resources Board.

Schwartz was one of the founding scientists who created the Department of Energy's Atmospheric Radiation Measurement (ARM) program; his 1994 paper published in the Bulletin of the American Meteorological Association describing that program has received over 1000 citations. From 2004 to 2009 he served as chief scientist of the Department of Energy's Atmospheric Science Program.

Schwartz received his bachelor's degree in chemistry from Harvard University and his PhD in chemistry from the University of California, Berkeley.

Redwing Blackbird buzzing eagle along the Forge River, Mastic Beach, NY. Photo, Stephen Schwartz.

Until recently, Schwartz lived on the Forge River in Center Moriches, where he indulged in his hobbies of canoeing and nature photography. A photo of his showing a redwing blackbird buzzing an eagle was winner in the "spirit" category of a recent SOMAS photo contest and hangs in the large seminar room at SOMAS.

View the symposium agenda.