The southern Arabian Peninsula is an extreme environment sensitive to Indian Ocean monsoon fluctuations, yet the patterns and extent of these changes over the last millennium remain unclear. This study integrates multiple physical, chemical, and biological proxies from a sediment core in Lake Karif Shawran, a volcanic crater lake in southern Yemen, to reconstruct past climate variability.
Using a ~1 m sediment core dated to ~4400 yr BP, we analyzed elemental geochemistry, carbon content, grain size, ostracods, and biomarkers (n-alkanes). The results reveal alternating wet and dry periods, aligning with major climatic events. Wet phases are marked by aragonite-organic laminae, increased weathering (higher K/Ti), enhanced marine seepage (higher Br/Ti, TOC/TC), lower aquatic productivity (lower Paq), and reduced salinity, inferred from ostracod morphology. Dry intervals show increased salinity, halite and aragonite precipitation, and elevated aquatic productivity.
These climatic fluctuations correspond to globally recognized events. Wet periods align with the Medieval Climate Anomaly (MCA) and Roman Warming Period (RWP), while dry phases coincide with the Little Ice Age (LIA), Late Antique Little Ice Age (LALIA), and the 4.2k event. The data suggest that local kingdoms thrived during wet phases (MCA, RWP) but collapsed during dry periods (LIA, LALIA), highlighting the critical role of climate in shaping socio-political stability in the late Holocene.
This study underscores the sensitivity of agriculture-based economies in the Arabian Peninsula to climate variability, emphasizing the region’s reliance on monsoonal precipitation and the potential socio-political consequences of future climatic shifts.