He served from 2004 to 2009 as the Chief Scientist of the Atmospheric Science Program of the United States Department of Energy.
He is author of over 100 scientific publications dealing mainly with cloud chemistry and forcing of climate change by atmospheric aerosols.
The citation reads in part "Schwartz's findings gave the first clear picture of the nationwide impacts of different sulfur and nitrogen sources and led to changes to the Clean Air Act.
"[3] A 1992 article [4] authored with Robert Jay Charlson, James E. Hansen, and others provided the first global-scale estimates of radiative forcing by anthropogenic sulfate aerosol.
[5] In 1995, as a result of this work, the journal Science named sulfate aerosol as one of nine runners-up for Molecule of the Year.