The aim of the book is to examine the evidence of the last million years to determine naturally-induced mechanisms of climate change as a key to understanding present and future dimensions of change, both natural and anthropogenic. Climate change is examined both regionally and globally. The time cycles are short, medium and long-term. Particular attention is paid to the interplay of natural and human factors in greenhouse gas forcing, but other mechanisms of change such as orbital forcing are fully considered as well as the impact of climate change on sea-level and regional climates.