The Indo-Pacific warm pool is an important global source of heat and water vapor that plays a key role in climate systems. The opening and closing of the Indonesian seaway controls the transport of water and heat between the Indo-Pacific warm pools and has a significant influence. Since the Late Miocene, the Pacific Plate has subducted westward toward the Eurasian Plate, the Indian and the Eurasian plates have undergone strong land-land collision, and the Australian Plate has begun to subduct northward at 10 Ma. These tectonic movements have gradually closed the Indonesian seaway, changing the ocean circulation between the western Pacific Ocean and the eastern Indian Ocean. During the Pliocene, the source of the Indonesian Through Flow (ITF) changed from the high-temperature, high-salinity South Equatorial Pacific to the low-temperature, low-salinity North Equatorial Pacific. Consequently, the western Pacific warm pool gradually strengthened, the sea surface temperature of the eastern Indian Ocean decreased, and the subsurface salinity decreased. Changes in the ITF not only contributed to the aridification of northwestern Australia and eastern Africa but also reduced tropical heat transport to the higher latitudes of the Northern Hemisphere. The change in meridional heat transport likely promoted the formation of the Arctic ice sheet, but the specific mechanisms and magnitude of its impact need to be further studied.