Holocene glaciation in the Americas

Most glaciers on Earth are currently retreating, but detailed scrutiny of glacier response to global climate change reveals considerable regional variability. To provide context for contemporary glacier recession and regionally variable glacier response to climate change, geologists have long sought to reconstruct past glacier behavior. When compared with temperature and precipitation proxy data, and model simulations of past climate change, glacier histories can be used to quantify the sensitivity of glaciers to temperature change and, more generally, to pinpoint forcing mechanisms of glacier change. Reconstructing glacier change during the Holocene (as opposed to earlier periods in Earth history) takes particular advantage of the best-preserved evidence for past glacier change, and lends itself to bridging geological reconstructions with historical documents and satellite observations for relatively long and seamless timelines of glacier change. Below, the historical context for the study of Neoglaciation and the Little Ice Age during the Holocene is provided, some of the commonly employed dating tools are discussed and some records of glacier change from key locations in the American Cordilleras are briefly summarised. This synthesis is not comprehensive. Instead, the aim is to highlight key advances made in recent years, ending by discussing patterns of glaciation across the American Cordilleras.