Megadrought and Collapse is the first book to treat in one volume the current paleoclimatic and archaeological evidence of megadrought events coincident with major prehistoric and historical examples of societal collapse. Previous works have offered multi-causal explanations for collapse, from overpopulation, overexploitation of resources, and warfare to poor leadership and failure to adapt to environmental changes. In earlier synthetic studies of major instances of collapse, the full force of climate change has often not been considered. This volume includes nine case studies that span the globe and stretch over fourteen thousand years, from the paleolithic hunter-gatherer collapse of the 12th millennium BC to the 15th century AD fall of the Khmer capital at Angkor. Together, the studies constitute a primary sourcebook in which principal investigators in archaeology and paleoclimatology present their original research. Each case study juxtaposes the latest paleoclimatic evidence of megadrought (so-called for its severity and its decades - to centuries-long duration) with available archaeological records of synchronous societal collapse. The megadrought data are derived from all five archival paleoclimate proxy sources: speleothems (cave stalagmites), tree rings, and lake, marine, and glacial cores. The archaeological records in each case are the most recently retrieved. With Megadrought and Collapse, Harvey Weiss and his team of expert contributors have assembled an authoritative investigation that is certain to engage environmental history readers across disciplines in the sciences and social sciences.