Environmental context
The Near East covers a large area and is a remarkably varied landscape. Today much of it is environmentally degraded, but 12,000 years ago it was substantially different. The end of the Pleistocene and the beginning of the Holocene were times of dramatic climatic and temperature fluctuations, resulting in the expansion and contraction of favourable environments suitable for early farming.
Many of these changes occurred rapidly, and would have had human consequences over generations. Accordingly, there has been considerable discussion of whether climatic or environmental variables were causal factors for the Neolithic, or whether it was a purely cultural phenomenon. Specifically, debate has focused on whether the Neolithic developed under favourable or adverse conditions.Refinements in precise environmental reconstruction methods have greatly assisted in addressing this issue. For example, detailed analyses of speleothems (stable isotopic records obtained from cave deposits) from Soreq Cave in Israel provide very specific palaeoenvironmental data for much of the Neolithic.11 Other lines of evidence include GISP2 Greenland ice core studies, pollen cores in Greece, Turkey, and the Levant, Negev snail isotope variability, low Dead Sea levels, and geochemistry from Lake Van, Iran.
Based on such studies, it appears that the first experimentations with relatively substantial sedentary living, but not agriculture, started during the early Natufian under optimal post-Glacial conditions (although semi- sedentism is likely at earlier Epipalaeolithic sites such as Ohalo[394] [395]). The subsequent dramatic cooling and drying of the Younger Dryas (c. 11,00010,000 bp) may be partially linked to the general dispersal of many late Natufian groups to a more mobile settlement pattern.
During the early Neolithic, however, environmental conditions were optimal, often better than those prevailing today. While some lingering Younger Dryas conditions likely persisted into the early PPNA, much of this period correlates with a warming trend resulting in expanded and food-rich Mediterranean woodland and forest steppes and the increase of lakes and ponds, presenting new opportunities for human exploitation. The PPNB enjoyed only slightly less favourable climatic conditions. By c. 9,000 bp a Mediterranean climatic regime was apparently well established in the Levant (and likely elsewhere in the Near East). Landform changes occurred as well. At the onset of the Holocene, the coastal plain was considerably larger than at present, but a gradual rise in sea levels reduced it, with its modern configuration occurring around the Chalcolithic.Around 8,200-8,000 bp a brief but severe deterioration occurred, of a magnitude comparable to the Younger Dryas, resulting in an abrupt aridifica- tion in many parts of the world. This is important since it may roughly correspond to the end of the PPN, and could have been a causal variable. There are, however, some concerns relating to the variable use of calibrated and uncalibrated years for this event, and it could have occurred after the beginning of the PN.[396] In any event, during the PN, environmental conditions approximated those of today.1[397]