With the Earth's atmosphere increasingly being used as a convenient sink for myriad pollutants, humanity faces the daunting problem of conserving a vital resource which, like the oceans, outer space and Antarctica, defies geographical boundary. In "The Endangered Atmosphere", Marvin S. Soroos considers how this resource is being altered and degraded by a rapidly growing and industrializing human population and what is being done to preserve its essential qualities. Soroos describes the atmosphere as a global commons, a domain in which limited, depletable resources are used by multiple parties for individual gain. He discusses the limited capacity of the atmosphere to absorb and disperse pollutants, the essential role that international scientific co-operation plays in understanding and protecting its unique characteristics, and the value of the term "environmental security" for directing attention to its worsening condition. In case studies of four international atmospheric agreements - governing atmospheric testing of nuclear weapons, acid precipitation, ozone-layer depletion and global climate change - Soroos demonstrates the uneven, piecemeal approach that the international community has taken. He draws conclusions regarding the circumstances that favour co-operation among states and ponders the likelihood that governments will pursue environmental security in a preventive, collaborative way rather than by depending on the self-reliant, defensive strategies that have proved so costly and counterproductive in the pursuit of military security.