Sulfur is the fourteenth most abundant element in the Earth's crust. Sulfur is consistently exchanged between the lithosphere, biopsphere, hydrosphere, and atmosphere. Sulfur in the atmosphere, in both gaseous and aerosol form, has imapcts on regional and global chemistry, climate change, and the health of living organisms. Sulfur gases can also affect stratospheric chemistry. Carbonyl sulfide (OCS) and volcanic emissions may affect Earth's radiation budget and climate as well as ozone destriction in the stratosphere.