Tectonic and climatic drivers of Asian monsoon evolution

Abstract Asian Monsoon rainfall supports the livelihood of billions people, yet relative importance different drivers remains an issue great debate. Here, we present 30 million-year model-based reconstructions Indian summer monsoon and South East at millennial resolution. We show that precession is dominant direct driver orbital variability, although variability on obliquity timescales driven through ice sheets. Orographic development dominated evolution monsoon, but involved a complex mix contributions from orography (39%), (25%), atmospheric CO 2 (21%), ice-sheet state (5%) ocean gateways (5%). Prior to 15 Ma, was broadly stable, albeit with substantial variability. From Ma 5 strengthening by combination glaciation, while closure Panama gateway provided prerequisite for modern strengthened Atlantic meridional overturning circulation.