Claire Rambeau

Changes in Mediterranean climate during the Holocene: Insights from global and regional climate modelling

Palaeoproxy records alone are seldom sufficient to provide a full assessment of regional palaeoclimates. To better understand the possible changes in the Mediterranean climate during the Holocene, a series of palaeoclimate integrations for periods spanning the last 12 000 years have been performed and their results diagnosed. These simulations use the HadSM3 global climate model, which is then dynamically downscaled to approximately 50 km using a consistent regional climate model (HadRM3). Changes in the model’s seasonal-mean surface air temperatures and precipitation are discussed at both global and regional scales, along with the physical mechanisms underlying the changes. It is shown that the global model reproduces many of the large-scale features of the mid-Holocene climate (consistent with previous studies) and that the results suggest that many areas within the Mediterranean region were wetter during winter with a stronger seasonal cycle of surface air temperatures during the early Holocene. This precipitation signal in the regional model is strongest in the in the northeast Mediterranean (near Turkey), consistent with low-level wind patterns and earlier palaeosyntheses. It is, however, suggested that further work is required to fully understand the changes in the winter circulation patterns over the Mediterranean region.

Palaeoenvironmental reconstruction in the Southern Levant: synthesis, challenges, recent developments and perspectives

Palaeoenvironmental research in the Southern Levant presents a series of challenges, partly due to the unequal distribution of palaeoenvironmental records and potential archives throughout the region. Our knowledge of climatic evolution, during the last approximately 25 000 years, is of crucial importance to understand cultural developments. More local, well-dated, multi-proxy studies are much needed to obtain an accurate picture of environmental change in respect of the Late Pleistocene and the Holocene. This contribution reviews the current state of knowledge regarding Late Quaternary palaeoenvironmental changes in the Southern Levant, including some examples of more recent developments in palaeoenvironmental reconstruction in Israel and the Dead Sea area, and introduces the major challenges researchers face in the region. It also presents the first results of a new case study in Jordan, based on an analysis of peaty deposits located in the mountain slopes east of the Dead Sea. Such new studies help refine our knowledge of local environmental changes in the Southern Levant and especially the more arid areas, for which little information is presently available. More material suitable for palaeoenvironmental research, for example extensive tufa and travertine series, still awaits consideration in Jordan, opening up exciting perspectives for future research in the area.

Past, present and future precipitation in the Middle East: insights from models and observations

Anthropogenic changes in precipitation pose a serious threat to society—particularly in regions such as the Middle East that already face serious water shortages. However, climate model projections of regional precipitation remain highly uncertain. Moreover, standard resolution climate models have particular difficulty representing precipitation in the Middle East, which is modulated by complex topography, inland water bodies and proximity to the Mediterranean Sea. Here we compare precipitation changes over the twenty-first century against both millennial variability during the Holocene and interannual variability in the present day. In order to assess the climate model and to make consistent comparisons, this study uses new regional climate model simulations of the past, present and future in conjunction with proxy and historical observations. We show that the pattern of precipitation change within Europe and the Middle East projected by the end of the twenty-first century has some similarities to that which occurred during the Holocene. In both cases, a poleward shift of the North Atlantic storm track and a weakening of the Mediterranean storm track appear to cause decreased winter rainfall in southern Europe and the Middle East and increased rainfall further north. In contrast, on an interannual time scale, anomalously dry seasons in the Middle East are associated with a strengthening and focusing of the storm track in the north Mediterranean and hence wet conditions throughout southern Europe.

Palaeoenvironmental reconstruction at Beidha, southern Jordan (c. 18,000-8,500 BP): Implications for human occupation during the Natufian and Pre-Pottery Neolithic

The Beidha archaeological site in Southern Jordan was occupied during the Natufian (two discrete occupation phases, c. 15,200–14,200 cal. BP and c. 13,600– 13,200 cal. years BP) and Pre-Pottery B Neolithic periods (c. 10,300–8,600 cal. years BP). This chapter reconstructs the palaeoenvironments at Beidha during these periods, using sedimentological observations and the stable isotopic composition (oxygen and carbon) of carbonate deposits. Age control is provided by uranium-series and radiocarbon dating. Detailed analysis of a carbonate stratigraphic section related to a fossil spring close to the site, and a sequence of carbonate nodules from a section on the western edge of the archaeological site, permits a reconstruction of climatic variations between c. 18,000 and c. 8,500 years BP. The results of the palaeoenvironmental study are compared with the archaeological evidence, to explore the relationship between human occupation and climatic variability at Beidha. The results indicate a marked correspondence between more favourable (wetter) environmental conditions and phases of occupation at Beidha, and provide clues to the likely sources of water that sustained the settlement during the Late Pleistocene and early Holocene.

The Origins, Development and Practice of Economic and Social Strategies in the Middle East from Earliest Times to the Modern Day

We returned in spring 2009 to continue excavating the 40 × 15 m trench we opened in 2008. The team of 20 professional archaeologists was almost exactly the same as that in 2008, and this year Mohammad al-Najjar was able to be on site almost full-time, which allowed a fl ying start to the season. Our new representative from the DoA, Ashraf al-Khresheh, had little previous experience of prehistoric archaeology, but was an enthusiastic hard worker. There must have been something infectious about the team’s good spirit as our team of 25 Rashaydah, ‘Azazma and Sa‘idiyyin workmen, who normally fi nd the rather slow and fi ddly work on a prehistoric site increasingly tedious, all played an extremely positive and active role in the season. We were also very fortunate in the group of 16 students who joined us for the Easter vacation part of the season, who not only learned something of Neolithic archaeology, but also about Bedouin culture; sadly, although the humour translates very well it is not really suitable for putting into print. Friendships made in the fi eld are now easily maintained by mobile phone and SMS message, but it still surprises me to fi nd a group of Bedouin in Faynan roaring in laughter at a cryptic reference to one of their jokes being transmitted to them from a muddy archaeological trench in the UK.