The possibility of global climatic change as a result of increasing numbers of people requiring higher stands of living has spawned an international controversy over the appropriateness of controls on deforestation and energy use. In order to address the political debate it is essential to understand the scientific background that underlies this problem. Laboratory Earth takes the reader on a journey from the dawn of earth's climate and biological evolution through the era of the dinosaurs, past the Ice Age and into the shadowy environmental future increasingly dominated by human activities. In the final analysis it will be human values more than scientific methods that must be applied to decide how to gamble with the fate of the earth.