The Middle Atmosphere and its Evolution -- Chemical Concepts in the Atmosphere -- Dynamics and Transport -- Radiation -- Composition and Chemistry -- Ozone Perturbations -- The Ions. Since the Industrial Revolution the chemical composition of the atmosphere has changed at a rate unprecedented in recent history. Ozone depletion emerged as one of the most important environmental issues of the 20th century as evidence grew for substantial human influences on the atmospheric ozone abundances over much of the globe. The science of the ozone layer and its interactions with halogenated chemical compounds are the primary subjects of this book. The volume provides a comprehensive view of the chemical, dynamical, and radiative processes that affect ozone and other chemicals in the stratosphere and mesosphere. Over recent decades our understanding of these processes has increased dramatically. The discovery of the Antarctic ozone hole has shown that human activities can lead to major changes in our environment. From a review of a previous edition - "[...] an interesting and well-written overview of the current status of our knowledge of the composition of the middle atmosphere and the basic radiative, dynamical and photochemical processes which maintain it." (Bulletin American Meteorological Society)