Recent research points to climate as the culprit in the widespread cultural upheaval during the transition from the Early Bronze Age to the Middle Bronze Age (2300–2000 B.C.E.). In 1993 Professor Harvey Weiss of Yale University announced that his excavations at Tell Leilan in Syria had uncovered evidence of a severe late third-millennium drought that, he says, caused the end of the Akkadian Empire in Mesopotamia.1 Weiss this joins an increasing number of scholars who recognize climatic change as a significant factor in the political and cultural changes that took place in the eastern Mediterranean around 2300–2000 B.C.E.
Previously, during a moist climatic phase in the eastern Mediterranean that began around 3500 B.C.E.,2 widespread urbanization developed in Early Bronze Age Greece, in Asia Minor, in Syria and in Palestine, as well as in the civilizations of Old Kingdom Egypt and Early Dynastic Mesopotamia. During the Early Bronze II–III period (c. 3050–3200 B.C.E.), large walled cities, often much larger than those of later times, flourished in Palestine and Transjordan. Settlements even expanded into the Negev and Sinai, areas that are now deserts.3
But virtually all of Palestinian Early Bronze villages were destroyed around 2300–2200 B.C.E. and lay abandoned for two or more centuries. In most parts of the Negev, sedentary occupation was not resumed until the Iron Age II, after 1000 B.C.E. At the same time as these third-millenium destructions, the flood level of the Nile was extremely low, causing famine and turmoil in Egypt, leading to the collapse of the Old Kingdom.4
There thus seems to have been a relatively dry period in the Near East during the Egyptian First Intermediate Period and the Palestinian Early Bronze IV (or the Early Bronze/Middle Bronze transition) about 2300–2000 B.C.E. It is evidence of this dry period that Weiss has uncovered at Tell Leilan. During this era, urban civilization virtually disappeared in Palestine. The population dropped drastically, leaving the land to groups of pastoral seminomads.
Major migrations also took place during this time. Seminomads invaded Mesopotamia, the Delta area of Egypt, and possibly Palestine.5 Indo-European speaking groups from the north moved into Asia Minor and Greece. In both areas cities were destroyed. The revival of urbanism in much of the eastern Mediterranean area occurred only after 2000 B.C.E., when moister weather seems to have returned.6