Holocene climate, environment and cultural change in the circum-Mediterranean region

The Mediterranean basin, which lies between 30° and 46 °N, is the largest area of the world to experience a climate of summer drought, winter rain of cyclonic origin and a mean annual temperature of 15±5 °C (Köppen type Cs). Its flora is distinctive and adapted to both periodic desiccation and burning (Allen 2001). The region also has an exceptionally long and rich history of human use and abuse, stretching back to the advent of Neolithic farming in Southwest Asia at the start of the Holocene. The complex history of culturalenvironmental relations around the Mediterranean “Lake” can create serious difficulties in distinguishing climate change from human impact in many proxy-data records (Bottema et al. 1990; Grove and Rackham 2001; Roberts 2002). In particular, once complex societies emerged during the Bronze Age between 5000 and 3000 BP, vegetation disturbance starts to become clearly visible in pollen diagrams. In compensation, the region offers a wealth of written archival and archaeological records back to before 2500 BP.

In this chapter we are concerned with PEP III time-stream 1 (cf. Gasse and Battarbee (this volume)) for the Mediterranean sector and we summarise recent progress in addressing the following key objectives:

• (i) to obtain high resolution, accurately dated, proxy records of sub-decadal climate variability linked to the North Atlantic Oscillation (NAO), El Niño Southern Oscillation (ENSO), solar and other forcings, from tree-ring, historical, crater lake and other sources;

• (ii) to identify intra-regional patterns of climate variability, such as the east and west Mediterranean precipitation see-saw;

• (iii) to examine the expression and timing of climate changes coeval with the northern European Little Ice Age and MedievalWarm Period;

• (iv) to examine what is the nature and causes of periods of abrupt climate change that are evident from many lower latitude records (e.g., in inter-tropical African lake levels), and which may be linked to high magnitude events (e.g., major volcanic eruptions);

• (v) to assess how climate variability over recent millennia affected biota and natural ecosystems in the circum-Mediterranean lands;

• (vi) to consider how climate variability has affected human activity and society over these time-scales, and to assess how far climate change has been influential in the development of prehistoric and classical civilisations in the Mediterranean Basin.