Contrasting impacts of mid-Holocene natural and future anthropogenic warmings on dune activities in northern China

Abstract

Deserts’ paleoenvironmental records not only reveal environmental changes during geological periods but also provide a scientific basis for addressing and predicting their response pathways to the ongoing global warming. Nevertheless, comparative studies examining the variability of dune activity in the deserts of northern China under different warming periods triggered by natural and anthropogenic factors remain scarce. Leveraging the Coupled Model Intercomparison Project Phase 6 multimodel ensemble, this study investigates the spatial patterns and underlying climatic drivers of dune activity in the deserts of northern China across distinct climatic epochs: the mid-Holocene (MH) and scenarios under three different future Shared Socioeconomic Pathways (SSP1-2.6, SSP2-4.5, and SSP5-8.5). The results reveal different spatial heterogeneity of dune activity in the deserts of northern China during MH and future scenarios. During the MH, dune activity decreased significantly in the eastern deserts while intensifying in the west. However, under the future scenarios, this trend would be reversed, with enhanced dune activity in the east and diminished activity in the west. The spatial disparities are directly attributable to changes in surface effective moisture and near-surface wind speed induced by large-scale atmospheric circulations. In the eastern sandy lands, a stronger East Asian Summer Monsoon increased surface moisture and limited aeolian processes during MH, while higher evaporation and stronger near-surface wind in the east would intensify dune activity under future scenarios. In the western sand seas, reduced precipitation due to weaker westerlies enhanced dune activity during MH, while increased precipitation and reduced near-surface wind speeds under future scenarios would lead to decrease in dune activity.