Because of this glaring misuse of science, we have ever since continually scanned the emerging scientific literature for evidence that bears upon the crucial central question of whether or not the Little Ice Age and Medieval Warm Period that preceded it were truly significant global events; and in this review we summarize what we have learned in this regard about the Little Ice Age in South America, focusing on Argentina.

Cioccale (1999) reviewed what was known about the climatic history of the central region of Argentina near the turn of the last century. This exercise indicated that approximately 400 years prior to the start of the last millennium, a climatic "improvement" occurred, characterized by "a marked increase of environmental suitability, under a relatively homogeneous climate," and as a result of this climatic amelioration, which led to what is widely known as the Medieval Warm Period, the people that had previously lived in the lower valleys -- during what is now widely known as the Dark Ages Cold Period -- "ascended," according to Cioccale, "to higher areas in the Andes." Around AD 1320, however, a transition to the stressful and extreme climate of the Little Ice Age began; and the initial cold phase of this period, which extended from the first decades of the 15th century to the end of the 16th century, was accompanied by "a decrease in environmental suitability" that caused vegetation "to suffer the consequences of this climatic deterioration."

This first cold pulse, according to Cioccale, was followed by an intermediate benign period "of major climatic stability, with very scarce extraordinary floods and few droughts." From the start of the 18th century and lasting until the beginning of the 19th century, however, "glaciers in the Southern Andes underwent their main advance and the plains of the central region of the country suffered intense droughts." What is more, Cioccale says that "the intense cold caused a lowering of the upper limits of cultivation ... and residents abandoned the towns in the mountains."

As for the cause of these two Little Ice Age cold pulses, Cioccale's view was that they "can be related to the Sporer and Maunder Minimums respectively," thereby implicating solar variability as their primary instigator.

Also working in parts of Argentina, Valero-Garces et al. (2000) studied sediments obtained from saline lakes in the southern part of the Altiplano, a north-south-trending high volcanic plateau that runs from tropical to subtropical latitudes of South America, where they discovered evidence for "abrupt paleohydrological and paleoclimatic changes synchronous to the onset and termination of the Little Ice Age." So clear was the message of their data, in fact, they unequivocally stated -- as their final conclusion -- that "the Little Ice Age stands as a significant climatic event in the Altiplano and South America."

This conclusion was further reinforced by the subsequent Altiplano lake study of Valero-Garces et al. (2003), who additionally noted that other high-resolution records from the region, including ice caps, historical documents, dendrochronological and lake records, also "show abrupt paleohydrological and paleoclimatic changes synchronous to the onset and termination of the Little Ice Age." Hence, they reiterated their earlier conclusion that "the Little Ice Age stands out as a significant though complex climatic event in the Andean Altiplano."

Five years later, working with sediment cores extracted from Laguna Potrok Aike, which is one of the few permanently water-filled lakes in the dry-lands of Argentina's southern Patagonia region, Haberzettl et al. (2005) analyzed a host of proxy climate indicators that provided "an unprecedented sensitive continuous high resolution lake level, vegetation and climate record for southern Patagonia since AD 400." This history indicated that the climate of the region fluctuated rapidly from the beginning of the record right up to the start of the Medieval Warm Period, which was most strongly expressed in the Laguna Potrok Aike data from AD 1240 to 1410, during which time maxima of total inorganic carbon, total organic carbon, total nitrogen, carbon/nitrogen ratio and δ¹³Corg indicated, in the words of the ten researchers, "low lake levels and warm and dry climate." Thereafter, however, the Medieval Warm Period ended, as they describe it, "during the 15th century" and was "followed by the so called 'Little Ice Age'."

Taken together, these several studies clearly indicate, as Valero-Garces et al. (2000) have firmly stated, that in Argentina -- and actually in all of South America -- "the Little Ice Age stands as a significant climatic event."

For the full story, see the Journal Reviews and Summaries of South America's other countries listed under Little Ice Age (Regional - South America) in our Subject Index.

References
Cioccale, M.A. 1999. Climatic fluctuations in the Central Region of Argentina in the last 1000 years. Quaternary International 62: 35-47.

Haberzettl, T., Fey, M., Lucke, A., Maidana, N., Mayr, C., Ohlendorf, C. Schabitz, F., Schleser, G.H., Wille, M. and Zolitschka, B. 2005. Climatically induced lake level changes during the last two millennia as reflected in sediments of Laguna Potrok Aike, southern Patagonia (Santa Cruz, Argentina). Journal of Paleolimnology 33: 283-302.

Valero-Garces, B.L., Delgado-Huertas, A., Navas, A., Edwards, L., Schwalb, A. and Ratto, N. 2003. Patterns of regional hydrological variability in central-southern Altiplano (18°-26°S) lakes during the last 500 years. Palaeogeography, Palaeoclimatology, Palaeoecology 194: 319-338.

Valero-Garces, B.L., Delgado-Huertas, A., Ratto, N., Navas, A. and Edwards, L. 2000. Paleohydrology of Andean saline lakes from sedimentological and isotopic records, Northwestern Argentina. Journal of Paleolimnology 24: 343-359.