Oral

IAMAS

JMP07 - Past climate changes and their relevance for the future

Early warning signals for Asian summer monsoon tipping and implications for future monsoon changes

Numerous climate systems on Earth have experienced reoccurrences of abrupt shifts (tippings) when crossing their distinctive tipping points, as shown by paleoclimate data and climate models, these abrupt shifts are often preceded by early warning signals (EWS). Particularly, a number of recent analyses arguably show apparent EWS in the Atlantic Meridional Overturning Circulation (AMOC), likely indicating a forthcoming collapse despite uncertainty concerning its prerequisites. On the other hand, little is known about whether the Asian summer monsoon (ASM) circulation, which is closely linked to the AMOC and affects the livelihoods of billions of people, may also manifest EWS suggesting a potential of tipping in the near future. In this study, we first analyzed three high-resolution speleothem oxygen isotope (��18O) records that span diverse abrupt ASM tipping points in the past, and show the evident that these past tipping points are preceded by significant EWS. We then further analyzed four recent high-resolution and precisely dated speleothem ��18O records over the past ~200 years, which also show strong EWS consistently in the recent decades, likely suggesting a potential of an imminent tipping (abrupt weakening) of the ASM circulation. In the context of the timing framework of ASM EWS and their subsequent tippings that had happened in the past, the recent EWS appear to suggest that a potential ASM tipping is expected to take place in the next few decades, calling for close attention and further research.