| Abstract: |
Although the Asian monsoon is the dominant source of precipitation across continental Southeast Asia, projections of future climate trends in this region remain unclear. This is partly because historic climate records are relatively short, precluding our ability to understand long-term climate dynamics and potential drivers of change. In this synthesis, 17 palaeorecords from sites located in continental Southeast Asia provide a synopsis of regional palaeoclimate dynamics over the last ~ 30,000 Cal yrs BP. The results indicate that over millennial timescales, the dominant control on Asian monsoon intensity is solar insolation linked to orbital changes. From ca. 30 to 11.9 Cal kyr BP, climatic conditions are interpreted to have been cold and arid
most probably dominated by a strong Asian winter monsoon. Marked changes occurred during the PleistoceneHolocene Transition, including a shift to warmer, wetter climatic conditions at ca. 11.5 Cal kyr BP, which was apparently synchronous across the region. During the early to mid Holocene, warmer, wetter climatic conditions were established, consistent with a strong Asian summer monsoon inferred from the Dongge Cave δ<sup>18</sup>O speleothem record. Intriguingly, contrasting sub-regional palaeoclimatic trends are captured in the synthesis
most notably during the Holocene, possibly due to differing sub-regional climatic and environmental influences (including differences in the role of the Asian monsoon, the Westerlies and/or topographical effects). However, because of uncertainties relating to the age control of many of the palaeorecords, it is not possible to make this interpretation with confidence. Further work involving comprehensive radiocarbon dating of sequences and the development of high-resolution palaeoclimatic reconstructions are urgently required if we are to identify decadal to centennial scale changes across continental Southeast Asia and test hypotheses of synchroneity in the region.
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