Atmospheric chemistry is central to understanding global changes — ozone depletion, appearance of the polar ozone holes, and compositional changes which worsen the greenhouse effect. Because of its importance, work is progressing on many fronts.This volume emphasizes the troposhere and stratosphere and has chapters on gas phase, condensed phase, and heterogeneous chemistry. Present progress is emphasized, and important future directions are also described.This book fills a need not satisfied by any others and will be popular for some years to come. It informs students and newcomers to the field of the many facets of atmospheric chemistry and can be used as a text for advanced students. It is also a valuable desk reference summarizing activities by quite a number of the most active research groups.Chapter 18 by Kolb et al. on heterogeneous chemistry is especially noteworthy because it represents a unique joint effort by several groups working on a very timely subject; they describe a conceptual framework and establish conventions which will be standard in future papers on this subject.