Holocene extreme hydroclimate events in the Asian monsoon region were more frequent during cooler intervals

Abstract

The areas affected by the East and South Asian monsoons contain almost half the world’s population. Understanding natural variability in these monsoons under warmer climates is critical for managing future changes. Here we present a high-resolution record of Holocene drought events derived from lake level changes in the South Asian monsoon region. By combining the published storm events in the East Asian monsoon region, we demonstrate that extreme hydroclimate events frequently occurred within a ca. 500-year cycle during the cool early-late Holocene, exhibiting a fierce Asian monsoon. In contrast, there were fewer extreme hydroclimate events during the warm mid-Holocene period. We propose that tropical temperatures and air-sea interaction in the Indo-Pacific Oceans are responsible for the occurrences of centennial-scale extreme events. Our findings suggest that tropical influences can module climate responses in monsoon regions, and the Asian monsoon may be more peaceful than hitherto expected under future global warming scenarios.