Climate changes on Chinese continent since 2.5 Ma: Evidence from fossil pollen records

Climate change during Quaternary has been a hot spot in geosciences for decades. However, discrepancies remain among scholars up to date. In this paper, 48 fossil pollen records from Chinese continent, which cover the whole period of Quaternary, were selected and synthesized for regional climate variations in order to better understand the historical evolution of Quaternary climate. Pollen data were interpolated and mapped using the method of Inverse Distance Weighting (IDW) for spatial distribution patterns. According to the fossil pollen records, Quaternary climate variation on Chinese continent could be summarized as follows. During the period of 2.5～1.5 Ma, the region was dominated by fluctuated cold and dry climate. During the period from 1.5 to 1.0 Ma, it was warm and wet in the eastern part but dry in the northwestern part and the Tibetan Plateau. More fluctuations appeared since 1.0 Ma. The climate variation revealed by pollen records shows a good consistance with the Quaternary monsoon evolution: Asian winter monsoon gradually strengthened after 2.5 Ma while the climate was relatively dry. The East Asian summer monsoon, however, intensified around 1.5 Ma, which probably brought in more precipitation and led to the overall wet climate. The region returned to a drying trend again since 1.0 Ma with the retreat of summer monsoon.