Sulfur is the only element for which the anthropogenic contributions to the global atmospheric burden is much larger than the contribution of natural sources. Since this dominance of anthropogenic sulfur has occurred mostly in the past century the impacts on global climate also have occurred during the past century. This presentation will focus on the impacts of sulfur chemistry on local and global climate using the large body of work on this subject developed over the past 20 years. Much of this presentation will use results from numerous NASA and NSF airborne field programs flown over the past 10 years. Because these programs used high performance instruments developed in the 1980's, data from them account for most of our present knowledge of chemistry of sulfur in the global atmosphere. Sulfur dioxide will receive special attention because it is the most important sulfur gas of anthropogenic origin. The global distribution of sulfur dioxide will be discussed in detail. Background sulfur dioxide of anthropogenic origin will receive particular attention. Since there are no natural non-volcanic sources of sulfur dioxide we will focus on identifying the origin of sulfur dioxide in the background environment where anthropogenic sources have little impact. Finally we will discuss the physics and chemistry of sulfur in the background environment with special emphasis on how these processes impact local and global climate.