The entire sequence of human evolution (ca. 2.6 Ma) witnessed more than one climatic change. However, as humans until the emergence of sedentary communities were mobile hunter-gatherers, neither abrupt, nor long-term climatic changes made major impact. When climate became worse- people moved. Those who did not make the right decision in time probably perished. However, recognizing such extinctions in the Paleolithic records is difficult although prehistorians infrequently use this kind of explanation to suggest replacements of populations or the abandonments of large regions. Sedentary communities emerged during the Upper Paleolithic such as the Pavlovian culture best known from the site of Dolni Vestonice. They abandoned their lifeway with the onset of the Late Glacial Maximum (LGM 24-18 Ka cal BP). Similar phenomenon was recognized in the Levant where its southern sub-region was and is prone to droughts. Thus in the first centuries of the Younger Dryas (YD 13/12,800-11,700 cal BP) the Natufian society in the southern Levant increased mobility while others, in the north intensified sedentism, territorial control, and initiate cultivation as a buffer against annual or decadal fluctuations of winter precipitation that determined the abundance of plant and animal resources.
A more pronounced impact caused by a shorter climatic fluctuation was the response to the ‘8200 cal BP clod’ event. The information for the changing environmental conditions is recorded in the stalagmites of Soreq Cave and the Eastern Mediterranean deep-sea cores. Paleoclimatoligists demonstrated that cold and dry fluctuations did occur during several centuries before and after this date. Without demonstrating in details the achievements of the Levantine farming societies in the course of a major demographic population increase, labelled by archaeologists the PPNB (Pre-Pottery Neolithic B) culture, it seems that many villages, in the absence of central authorities that can distribute stored grain (such as chiefdoms) had to abandon their villages in the southern Levant and move north or return to a mobile foraging strategy. The importance of this event and its enduring impacts on the developments across Anatolia and Mesopotamia, or the colonization of Egypt, are well expressed archaeologically during the ensuing millennia. Archaeological sites, where the detailed calibrated radiocarbon chronology demonstrates the cultural break such as in Sebi Abiad, are yet few, but the overall phenomenon is accepted by a growing number of colleagues. Thus, climatic fluctuations, even minor ones, have major impacts on sedentary societies including urban centers and therefore the study of such calamities is critical for understanding human history during the Holocene, recently labelled as Athropocene.