Welcome to the Arbustocene

Abstract

The beginning and end of each geological epoch is marked by a major, often cataclysmic, event affecting Earth?s biophysical environment. Most often major periods in Earth?s history requiring a new epoch to be named are remarkable by the mass extinction of dominant life forms and their eventual replacement by new groups of organisms which then dominate Earth?s ecosystems. Only once in pre-history were these spectacular evolutionary events precipitated by a physical or chemical change to Earth?s atmosphere as a result of biological activity. This occurred early in Earth?s history with the release of ?polluting? oxygen after the evolution of photosynthesis. More frequently, punctuations in the evolution of life have been brought on by some virtually instantaneous disruption to climate by extreme volcanic activity or an asteroid strike, such as that which heralded the end of dinosaurs and the dawn of the age of mammals. In these instances, changes to the capacity of Earth?s atmosphere to absorb and reflect light and heat from the Sun initiated a period of rapid global climate change leaving insufficient time for organisms to migrate or adapt.