Paleoclimatology is a review of the history of the climate of the Earth from the time of its formation four-and-a-half billion years ago to the present. The field, according to John Imbrie, a leading paleontologist at Brown University, is ripe for synthesis, with broad implications in geology, geophysics, geochemistry, oceanography, and the atmospheric sciences. In this work, the author addresses several topics rarely discussed in paleoclimate summaries, including the modeling of Paleozoic climates and the environmental consequences of asteroid impacts. Observational results are generally separated from modeling studies in the discussion of individual time periods. In fact, the entire issue of modeling past climate fluctuations is specifically examined, with an emphasis on those areas where models and data disagree. In addition to offering the principal results from paleoclimate studies, the book identifies areas for future research and offers a frame of reference for interpreting the likely consequences of greenhouse warming. The work will serve as an upper division or graduate-level text, and will also be useful to working scientists in a number of other fields.