This book is the first major reference work in its field. Paleoclimate topics covered in the encyclopedia give the reader the perspective with which to place the observations of recent global warming in the context of longer-term natural climate fluctuations. 'Climate proxies'--natural archives of environmental change recorded in tree rings, corals, ice cores, lake varves, marine sediments, etc. help extend the centennial timescale of instrumental records to the ancient past and enable reconstruction of ancient climates. Significant elements of the encyclopedia include recent developments in paleoclimate modeling, paleo-ocean circulation, as well as the influence of geological processes (e.g., plate tectonics and mountain uplift), and biological feedbacks (through modulating atmospheric CO2 or CH4) on global climate change. New techniques in radiometric dating, geochemical analyses, and paleoecological reconstructions are also described. The encyclopedia enables the reader to gain an entry point into the literature on these and many other groundbreaking topics.