Peter K. Haff is Emeritus Professor of Geology and Civil and Environmental Engineering in the Division of Earth and Ocean Sciences and in the Nicholas School of the Environment at Duke University, North Carolina. His research focuses on the role of technology in the Anthropocene, the new geologic epoch. Some themes of his work are that technology is a geologic phenomenon; that large-scale technology defines a new addition—the technosphere—to the classical spheres of air, water, rock, and biology; and that technology has not been created independently by humans but represents a quasi-autonomous force that shapes the modern human condition.