"This book explains the scale, scope, pace, and character of environmental change around the world since the middle of the twentieth century as well as the reasons behind it. From the biology of the deep ocean to the chemistry of the stratosphere, and almost everywhere in between, human actions have led to ecological alterations great and small. While our species has exerted environmental impacts, occasionally substantial ones since the Paleolithic, never before has humankind had such an impact on the Earth. A massive uncontrolled experiment is underway. Where it might lead, no one can yet say. The reasons behind this environmental tumult are sometimes obvious and sometimes obscure. This book highlights the role of the modern energy system and the economic growth it has fostered, but pays heed as well to population growth, urbanization, migration, the Cold War, and environmentalisms, among other trends and phenomena that affected the global environment. The pace of indicators such as energy use, population growth, species extinctions, fresh water use, carbon dioxide emissions, and many more has led some students of environmental change to label the period after 1950 as The Great Acceleration. This book argues that concept is valid. In addition, it argues that the scale and scope of environmental change have altered basic biogeochemical cycles to the point where the Earth has entered a new period in its history: the Anthropocene. Humankind, too, has entered a new age in which it rivals natural forces in shaping the Earth, its biota, its climate, and its prospects."--Provided by publisher.