ABSTRACT Global warming and ice melting in the “tripolar” regions, namely, Antarctica, the Arctic, and the Tibetan Plateau, might lead to a reorganization of the global climate system. Understanding the dynamic links between the “tripolar” environments and the Earth climate system is crucial to improving our capability to project future climate variability. “Tripolar” changes have influenced the onset and evolution of the Asian paleomonsoon system through various atmospheric and/or oceanic mechanisms. Here, we summarize previously reported Asian paleomonsoon variations that can be linked to “tripolar” environmental changes, from tectonic to millennial time scales, and explore linkages between the “tripolar” regions and global climate changes.

Abstract High-elevation tropical glaciers provide records of past climate from which current changes can be assessed. Comparisons among three ice-core records from tropical mountains on opposite sides of the Pacific Ocean reveal how climatic events are linked through large-scale processes such as El Niño–Southern Oscillation. Two distinctive trans-Pacific events in the mid-fourteenth and late-eighteenth centuries are distinguished by elevated aerosol concentrations in cores from the Peruvian Andes and the Tibetan Himalaya. Today aerosol sources for these areas are enhanced by droughts accompanying El Niños. In both locations, large-scale atmospheric circulation supports aerosol transport from likely source regions. Oxygen isotopic ratios from the ice cores are significantly linked with tropical Pacific sea-surface temperatures, especially in the NIÑO3.4 region. The arid periods in the fourteenth and eighteenth centuries reflect droughts that were possibly connected to strong and/or persistent El Niño conditions and Intertropical Convergence Zone migration. These ‘black swans’ are contemporaneous with climate-related population disruptions. Recent warming, particularly at high elevations, is posing a threat to tropical glaciers, many of which have been retreating at unprecedented rates over the last several thousand years. The diminishing ice in these alpine regions endangers water resources for populations in South Asia and South America.