This book stands as a ten-year milestone in the operation of PAGES. It provides a synthesis of the past decade of research into global changes that occurred in the earth system in the past. Focus is achieved by concentrating on those changes in the Earth's past environment that best inform our evaluation of current and future global changes and their consequences for human populations. It seeks to provide a quantitative understanding of the Earth's environment in the geologically recent past and to define the envelope of natural environmental variability against which anthropogenic impacts on the Earth System may be assessed. (ISBN 3-540-42402-4).