The geologic record contains evidence of greenhouse climates in the earth's past, and by studying these past conditions, we can gain greater understanding of the forcing mechanisms and feedbacks that influence today's climate. Leading experts in paleoclimatology combine in one integrated volume new and state-of-the-art paleontological, geological, and theoretical studies to assess intervals of global warmth. The book reviews what is known about the causes and consequences of globally warm climates, demonstrates current directions of research on warm climates, and outlines the central problems that remain unresolved. The chapters present new research on a number of different warm climate intervals from the early Paleozoic to the early Cenozoic. The book will be of great interest to researchers in paleoclimatology, and it will also be useful as a supplementary text on advanced undergraduate or graduate level courses in paleoclimatology and earth science.