wolf-dieter h
¨
utteroth
or mountains, have a certain range of climatic tolerance. Contemporary
observers must have had difficulties in recognising long-term changes, given
the absence of recorded yearly precipitations and temperatures. Even today,
normal differences from year to year are overinterpreted by the average lay
observer.
Before 1942–3, Gustav Gassner and Fritz Christiansen-Weniger investigated
hundreds of central Anatolian tree-rings, and their work showed that no major
changes had occurred during the previous few centuries.
7
Catastrophic years,
either too dry or else too cold, were not absent, but the dendro-chronological
evidence showed no general changes of climate. From other parts of the
Ottoman Empire or neighbouring regions no contrary observations have
emerged either. All known oscillations of climate have been situated within
the range of the long-term averages for the last three millennia at least.
Certainly there were some exceptionally cold winters in the sixteenth cen-
tury, in which theBosporus supposedlyfroze over.
8
Yet even if reliablyreported,
these events are not evidence for a general change of climate. A southward
shift of the circulation belts by a few degrees was probably responsible for
lowering average temperatures in Europe and increasing cyclonal activity in
the Near East. A further possible explanation, alternative or additional, is the
atmospheric dust caused by strong volcanic activity around the earth during
this period.
9
Archaeologists working on the Near East have taken it for granted
that ‘no major changes of climate [have occurred] since Assyrian times’.
10
The
geographer Xavier de Planhol and the vegetation historians Willem van Zeist
and Sytze Bottema have concurred.
11
Further evidence against long-term climatic deterioration is phytological.
There are well-known climatic limits for several agriculturally relevant plants,
and their geographic spread does not seem to have changed noticeably. The
average line of precipitation of 300 mm per annum was the approximate limit
of rain-fed agriculture against the dry steppe, and so it remained until the
7 Gustav Gassner and Fritz Christiansen-Weniger, ‘Dendroklimatologische Untersuchun-
gen
¨
uber die Jahresringentwicklung der Kiefern in Anatolien’, Nova Acta Leopoldina N. F.
12, 80 (1942/3).
8 Xavier de Planhol, Kulturgeographische Grundlagen der islamischen Geschichte, trans. Heinz
Halm (Zurich and Munich, 1975).
9 Flohn, ‘Klimaschwankungen’.
10 Peter J. Ergenzinger, Wolfgang Frey, Hartmut K
¨
uhne and Harald K
¨
urschner, ‘The Recon-
struction of Environment, Irrigation and Development of Settlement on the Habur in
North East Syria’, in Conceptual Issues in EnvironmentalArcheology, ed. John Bintliff, Donald
A. Davidson and Eric G. Grant (Edinburgh, 1988), pp. 108–28.
11 De Planhol, Kulturgeographische Grundlagen; Willem van Zeist and Sytze Bottema, ‘Late
Quaternary Vegetation of the Near East’, Beihefte zum T
¨
ubinger Atlas des Vorderen Orients,
A-18 (Wiesbaden, 1991).
22
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