6 The conditions in Africa and Eurasia
during the last glacial cycle
The global pattern
In this chapter I will focus my attention particularly on temperate and bo-
real Europe, the Mediterranean and Africa, which are the key areas that will be
examined in Chapter 7 with regard to the Neanderthal extinction and the coloni-
sation by Moderns. In Chapter 3 I described the pattern of increasing global
climatic deterioration and instability during the Pleistocene. This progressive
deterioration led, for example, to the contraction and extinction of tropical
and sub-tropical woodland in southern Europe and to the rise of xeric species
that culminated with a maximum expansion during the Last Glacial Maximum
(LGM) (Carrion et al., 2000). Smaller scale patterns, as will be discussed in
this chapter, have to be viewed within these larger-scale climate trends at the
scale of millions of years (Webb & Bartlein, 1992). The progressive glaciation
of the northern hemisphere commenced towards the end of the Pliocene al-
though cooling started as early as the Eocene. The Quaternary is characterised
by the alternation of cold glacial and warmer interglacial periods. There were at
least nine glacial–interglacial cycles between 2 Myr and 700 kyr (Shackleton &
Opdyke, 1973, 1976; Shackleton et al., 1984) with at least 10 after that (Imbrie
et al., 1984). Interglacials, which were often brief, started and finished abruptly
(Flohn, 1984; Broecker, 1984), and characterised only 10% of the Pleistocene
(Lambeck et al., 2002a & b). The amplitude of the climatic oscillations was
lower prior to 735 kyr (c. 41 kyr) than after (c. 100 kyr) (Ruddiman et al., 1986).
During glacial events, sea levels dropped to between 90 and 130 m below cur-
rent levels (Shackleton & Opdyke, 1976; Rohling et al., 1998; Lambeck et al.,
2002a). Superimposed on these cycles were shorter episodes of ice expan-
sion during interglacials (stadials), when conditions were cold and arid, and
of thermal improvement and increased humidity during glacials (interstadials)
(Voelker, 2002); at lower latitudes cycles of rainfall (pluvials) and aridity (inter-
pluvials) were typical. Transitions were often rapid, especially from glacial to
interglacial conditions (Webb & Bartlein, 1992). Global warming at the start of

much reduced in comparison with OIS 2 (Ukkonen et al., 1999; Arnold et al.,
2002).
Global climate has also fluctuated repeatedly and frequently even within
glacials and interglacials (van Andel & Tzedakis, 1996; Nimmergut et al., 1999;
Watts et al., 2000) although the degree of climatic variability of the last inter-
glacial is disputed (Kukla, 1997, 2000; Kukla et al., 1997; Cheddadi et al., 1998;
Frogley et al., 1999; Rose et al., 1999; Boettger et al., 2000). OIS 4 appears
to have been more climatically diverse than had been recognised and included
interstadial conditions (Watts et al., 2000). The GRIP ice core data (Dansgaard
et al., 1993; GRIP, 1993) reveals 20 warm events in the time period 105–20 kyr.
Such large and abrupt, high frequency, climate changes seem to have occurred
globally at annual, decadal, centennial and millennial intervals (Bond et al.,
1997; Allen et al., 1999; Alley et al., 1999; Alley, 2000; Stuiver & Grootes,
2000; Elliot et al., 2002; Helmke et al., 2002; Voelker, 2002), particularly during
OIS 3 (van Andel & Tzedakis, 1996). The Dansgaard–Oeschger (DO) temper-
ature oscillations (Dansgaard et al., 1993) are the dominant millennial-scale
climate-change signal and are associated with the alternation between warm
times and glacial maxima and stadials in the North Atlantic (Alley et al., 1999).
Heinrich Events (HE) are less frequent and are the result of massive ice dis-
charges into the North Atlantic related to the surging of the Laurentide Ice Sheet
Africa and Eurasia during the last glacial cycle 137
through the Hudson Strait (Heinrich, 1988; Bond & Lotti, 1995; Alley et al.,
1999). There were, additionally, brief warm events such as Oerel (58–54 kyr),
Glinde (51–48 kyr), Hengelo (39–36 kyr) and Denekamp (32–28 kyr) intervals.
These oscillations caused repeated advances of forest and open vegetation in
Europe and the Mediterranean and of Mediterranean forest and semi-desert in
north-west Africa (van Andel & Tzedakis, 1996).
Environmental change, indicated by vegetation dynamics, not only reflects
responses to global events translated into local climatic changes but is also a
function of the available pool of plant taxa, thus creating spatial and temporal

every 6 kyr, coinciding with Heinrich ice-rafting events (Lambeck & Chappell,
2001). There were then two major periods of rapid and sustained sea-level rise
138 Neanderthals and Modern Humans
(16–12.5 kyr and 11.5–8 kyr) at a rate of 15 m per 1 kyr (Lambeck & Chappell,
2001).
Superimposed on the global signals are regional and local changes that have
been caused by uplift and subsidence of the coastal zone or by regional and
local climate effects. Climatic, meteorological and tidal-driven changes are
particularly important at decadal, annual and even smaller scales and may lead to
significantly different patterns even between proximate locations (Lambeck &
Chappell, 2001).
Temperate and boreal Europe: the Eurasian Plain
The colonisation by trees of the Eurasian Plain during interglacials reflected
differences in source areas of individual species, different rates of migration and
also in the nature of the climatic signal so that the broad-leaved forest succession
varied regionally and between different interglacials (Zagwijn, 1992). In the
last interglacial (OIS 5e) much of Europe was covered by temperate mixed oak
forest (Vandenberghe et al., 1998; Turner, 2002; Kukla et al., 2002) contrasting
with the great reduction of forest and replacement by treeless vegetation types
during glacials (Reille et al., 2000; Kukla et al., 2002). This was an oceanic
interglacial, a rare form that only occupied 12% of the time span of the last
500 kyr and was characterised by a constant succession in the expansion of
elm Ulmus, oak Quercus,hazel Corylus,yewTaxus and hornbeam Carpinus
followed by fir Abies, spruce Picea and pine Pinus. Tree response was less
intense during continental warm episodes (Zagwijn, 1992).
In contrast, at the height of the LGM (OIS 2) in Europe, around 20 kyr,
glaciers covered around two-thirds of the British Isles, Scandinavia, the Baltic
and the Alps. Much of the remainder of Europe north of the Mediterranean had
a cover of permafrost (CLIMAP, 1976; Maarleveld, 1976). Away from the ice
sheets the vegetation cover was sparse with large areas of bare ground and an

interglacial maximum was replaced by open, harsh, loess-steppe with the onset
of the LGM (Rousseau et al., 2001). The latter part of OIS 3 is characterised
by decreasing temperature, increasing aridity and continentality (Soffer, 1985).
Extremely cold temperatures, aridity and permafrost characterised large parts.
The vegetation was a unique tundra-grassland with sparse arboreal vegetation
(pine, beech, oak) in the form of gallery forests along river valleys (Soffer,
1985). Conditions improved in relative terms between 33 and 24 kyr during the
Briansk Interstadial before the onset of full glacial conditions (Soffer, 1985;
Markova et al., 2002). Tundra, forest–tundra and tundra–steppe were widely
distributed across the Russian Plain during the Briansk Interstadial with the
southern limit of the range of a number of Arctic plants being 1200 km further
south than today (and a further 600 km during OIS 2). Steppe and forest–steppe
predominated in the south, for example around the Black Sea. In the south, the
added topographical heterogeneity (e.g. in Crimea) increased the diversity of
vegetation types (Markova et al., 2002). Climatic improvement is also detected
in northern Siberia from 48–25 kyr, with open larch forest with Alnus fruticosa
and Betula nana in the Taymyr Peninsula (Andreev et al., 2002).
In contrast to the northward migration of trees during warm episodes the ef-
fect of glacials was the extinction of trees except within glacial refugia (Willis,
1996; Tzedakis et al., 2002). By around 13 kyr thermal conditions had improved
in north-western Europe and the tundra and steppe were gradually replaced by
boreal woodland and then by spruce forest and by birch–conifer woodland
(Huntley & Birks, 1983). The cold Younger Dryas Stadial (11–10 kyr) repre-
sented a further deterioration of conditions with tundra once again stretching
from southern Sweden to much of France and the British Isles (Huntley & Birks,
1983). The rapid amelioration leading to the present interglacial (the Holocene)
followed after 10 kyr bp. These changes are reflected in sites with long pollen