During the past century, ecologists have described the increasing destruction or impairment of a wide variety of ecosystems in all continents. Public debate now centers on changes in the global climate that could have severe and irreversible effects on not only endangered species but on all life systems. Reports from multidisciplinary agencies such as the IPCC and Millenium Ecosystem Assessment as well as individual scientists and university research programs increasingly indicate dire consequences for human society if the current trajectory of ecosystem destruction continues. Observers from various scientific disciplines have identified human activity at various scales as a causative or exacerbating effect of these changes. The first of these is rapid, uncontrolled growth of the human population; the second is invasion, occupation, and destruction of previously undisturbed ecosystems; a third is colonization of all ecosystems on the planet by human beings. Humans have become a principal agent of ecosystem change at the local, regional, and planetary level. Human communities, especially urban agglomerations of up to 35 million people, now contain more than 50% of the human population and have become, at the macroscopic level, increasingly undifferentiated in appearance and function. In addition, human communities excrete wastes and metabolites that are toxic to other organisms and adjacent ecosystems. These characteristics of the human species – rapid, uncontrolled growth, invasion and destruction of adjacent ecosystems, distant colonization (metastasis), de-differentiation, and excretion of toxic metabolites – are all characteristics of a malignant process. But is this the diagnosis? What do ecologists think? What is an alternative diagnosis? Is the idea of a global “diagnosis” appropriate or mistaken? The purpose of raising these questions is to develop a hypothesis that explains the relationship of the human species to the global ecosystem and predicts events that will follow from this diagnosis. It is one thing to have a list of ecological disasters that are documented and fill the daily headlines, but it is another thing to identify the process underlying these phenomena. This symposium addresses the process underlying the multiscale global phenomena. It also discusses the policy implications of this process in terms of what is meant by a “sustainable society.” The symposium invites ecologists from a variety of disciplines to make a global ecological diagnosis, and it invites those who deal with the policy implications of ecological knowledge.