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Little Ice Age Glacier Fluctuations in Bolivia
Reference
Rabatel, A., Jomelli, V., Naveau, P., Francou, B. and Grancher, D. 2005. Dating of Little Ice Age glacier fluctuations in the tropical Andes: Charquini glaciers, Bolivia, 16S. Comptes Rendus Geoscience 337: 1311-1322.

Background
Many proponents of CO2-induced global warming have long contended that the Little Ice Age was but a regional temperature anomaly that occurred in lands surrounding the North Atlantic Ocean. In introducing their study of Little Ice Age glacial behavior in Bolivia, however, Rabatal et al. state that "the presence of this event in other regions of the world, including tropical mountains, is now completely ascertained." With this fact no longer in question, therefore, they go on to compare Little Ice Age glacier fluctuations in Bolivia with those of the Northern Hemisphere.

What was done
Utilizing a lichenometric method for dating glacial moraines, the Bolivian and French researchers developed what they call "the first detailed chronology of glacier fluctuations in a tropical area during the Little Ice Age," focusing on fluctuations of the Charquini glaciers of the Cordillera Real in Bolivia, where they studied a set of ten moraines that extend below the present glacier termini.

What was learned
The researchers determined that the maximum glacier extension in Bolivia "occurred in the second half of the 17th century, as observed in many mountain areas of the Andes and the Northern Hemisphere [our italics]." In addition, they found that "this expansion has been of a comparable magnitude to that observed in the Northern Hemisphere, with the equilibrium line altitude depressed by 100-200 m during the glacier maximum." What is more, they state that "the synchronization of glacier expansion with the Maunder and Dalton minima supports the idea that solar activity could have cooled enough the tropical atmosphere to provoke this evolution."

What it means
The similar behaviors of glaciers in Bolivia and various parts of the Northern Hemisphere during the Little Ice Age give further credence to the fact that the Little Ice Age was global in extent and that it was likely solar-induced, perhaps as described by the recently developed theory of cosmoclimatology.

Reviewed 18 April 2007