Late Pleistocene foragers, c. 35,000-11,500 years ago

c. 27,000–19,500 bp and it is in this sense that the term LGM is used in this chapter (see Hastenrath 2009NOT IN REFS, 709; Wang et al. 2009). The LGM was probably the most extreme climatic episode of cold and aridity at a global scale that our species has ever experienced, followed by sustained global warming. Within this broad picture, one of the most important developments in palaeoclimatic studies in recent decades has been the recognition of the instability of Late Pleistocene climates and the abrupt nature of climatic shifts, with millennial-, centennial and even shorter-scale shifts being discerned in the North Atlantic MIS 2 records (e.g. Blockley et al. 2006; Clark et al. 2002; Taylor et al. 1993; Fig. 5.1). In the northern hemisphere, there was a major shift to warmer and wetter conditions following the LGM termed the BøllingAllerød interstadial (c. 14,700–12,800 bp), which was punctuated by at least two significant cold episodes, followed by a return to cold and dry near-glacial conditions, the Younger Dryas (c. 12,800–11,700 bp) before the shift to warmer climates that marked the Holocene. In the southern hemisphere, isotope studies of ice cores in Antarctica suggest a more continuous pattern of uninterrupted deglaciation and warming. It used to be thought that environmental change in the tropical lowlands of Southeast Asia during the Late Pleistocene must have been far less extreme than in northern latitudes, but it is now clear that many profound changes also took place in this region (Flenley 1997; Kershaw et al. 2007). The human populations of northern Borneo certainly had to cope with dramatic changes in the geography and ecology of the landscapes they inhabited in the Late Pleistocene, though as discussed in the next section their precise characteristics in the Niah region remain uncertain. Much important evidence about the climate, geography, and habitats of the region through this period derives from locations far distant from Niah. Within Introduction [HB, GB]