The southern Andes contain a wealth of geomorphic and stratigraphic information on Quaternary glaciations that can be used to test hypotheses concerning paleoclimate changes and their causes. We summarize past glacier and climate changes at a range of timescales, including before marine isotope stage 2, and during the local last glacial maximum (LGM), late glacial, and Holocene. The focus is on studies that use cosmogenic dating of moraines, which has greatly expanded the spatial coverage of our knowledge of the glacial history of South America. Recent developments allow unprecedented precision and accuracy in the ¹⁰Be technique, which reduces discrepancies with ¹⁴C data and helps to define better the timing of Quaternary glacier fluctuations. We confirm that the ¹⁰Be production rate in the middle latitudes of the Southern Hemisphere, including in southern South America, is > 12% lower than the ‘global’ rate, which has been used in past studies.

¹⁰Be dating indicates that outlet glaciers expand out of the Andes in general during positive marine oxygen isotope stages, including before the ‘global LGM,’ although the timing and structure of millennial scale climate changes still needs to be resolved. The local LGM in southern South America spanned the period from ~40,000 years to 18,000-17,000 years ago. Subsequently, pronounced recession of the ice sheet occurred in phase with the Southern Hemisphere Termination. A prominent glacial expansion transpired between ~14,000 and ~12,700 years ago, coeval with the Antarctic Cold Reversal. Pronounced recession of outlet glaciers also occurred during the Northern Hemisphere Younger Dryas stadial. The southern Patagonian data add to a growing body of evidence for deglacial and late glacial climate patterns out-of-phase with that in the Northern Hemisphere. During Holocene time, ¹⁰Be (supported by ¹⁴C) ages obtained so far indicate glacial events at least around 4000-6000 years, 1400-1000 years, and during the last 600 years.