Glaciers are sensitive indicators of climate variability and in turn they can also affect climate by means of complex feedback mechanisms. After the Little Ice Age (LIA), a cold climate period reported mainly for the Northern Hemisphere that culminated in mid-late 19th century, glaciers started retreating on a global scale. Although some glaciers have advanced over the last century in some regions of the world, overall the glaciers show a clear retreat, primarily as a response to global warming. In this current warming scenario, glacier recession has been recognized as a key variable for climate change in terms of public awareness (IPCC, 2001). Worldwide, glaciers and ice sheets store 68.8m of global sea level (IPCC, 2001) and ~70% of the surface freshwater on Earth, the major part being concentrated in Antarctica and Greenland. Although the total sea level equivalent of South American glaciers to sea level is small (?3 cm), their contribution to sea level rise in terms of unit area is significant, being even larger than the contribution of Alaskan glaciers (Rignot et al., 2003).

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