Harvey Weiss is an archaeologist who teaches at Yale University[1] and directs the excavations and surveys at Tell Leilan, Syria, during the summers. His most-discussed contribution to the Archaeological Anthropological field has been his hypothesis that certain major climate changes have done much to alter prehistoric and ancient societies' developmental trajectories, such as the abrupt climate change 4,200 years before present that reduced agricultural production in northern Mesopotamia, reduced and disrupted Akkadian imperial revenues there, and thereby forced the Akkadian political collapse in southern Mesopotamia Akkadian Empire.[1][2]