Holocene and latest Pleistocene alpine glacier fluctuations: a global perspective

Alpine glacier fluctuations provide important paleoclimate proxies where other records such as ice cores, tree rings, and speleothems are not available. About 20 years have passed since a special issue of Quaternary Science Reviews was published to review the worldwide evidence for Holocene glacier fluctuations. Since that time, numerous sites have been discovered, new dating techniques have been developed, and refined climatic hypotheses have been proposed that contribute to a better understanding of Earth's climate system. This special volume includes 12 papers on Holocene and latest Pleistocene alpine glacier fluctuations that update the seven review papers from 1988.Major findings of these 12 papers include the following: many, but certainly not all, alpine areas record glacier advances during the Younger Dryas cold interval. Most areas in the Northern Hemisphere witnessed maximum glacier recession during the early Holocene, with some glaciers disappearing, although a few sites yield possible evidence for advances during the 8.2 ka cooling event. In contrast, some alpine areas in the Southern Hemisphere saw glaciers reach their maximum post-glacial extents during the early to middle Holocene. In many parts of the globe, glaciers reformed and/or advanced during Neoglaciation, beginning as early as 6.5 ka. Neoglacial advances commonly occurred with millennial-scale oscillations, with many alpine glaciers reaching their maximum Holocene extents during the Little Ice Age of the last few centuries. Although the pattern and rhythm of these glacier fluctuations remain uncertain, improved spatial coverage coupled with tighter age control for many events will provide a means to assess forcing mechanisms for Holocene and latest Pleistocene glacial activity and perhaps predict glacier response to future impacts from human-induced climate change.