The changes in the Earth’s climate over the past 600 million years, from the Cambrian to the Quaternary, come under scrutiny in this book. The geological evidence for ancient climates is examined, such as the distribution of climate-sensitive sediments - including coals, evaporites and glacial deposits, the environmental tolerances of fossil plants and animals, and the geochemical record. The Earth’s climate has changed many times throughout the Phanerozoic. Thus in this book the climate history has been divided into Warm and Cool modes, intervals when either the Earth was in a former ‘greenhouse’ state with higher levels of atmospheric CO2 and polar regions free of ice, or the global climate was cooler and ice was present in high latitudes. What are the causes of climatic change? The studies presented here highlight the complex interactions between the carbon cycle, continental distribution, tectonics, sea level variation, ocean circulation and temperature change as well as other parameters. In particular, the potential of the carbon isotope records as an important signal of the past climates of the Earth is explored. This book will be useful to all students and researchers with an interest in palaeoclimates and palaeoenvironments.