LIA In South America

By Paul Homewood

 

Glaciologist Lonnie Thompson is well known these days as an ardent warmist. It is therefore ironic that, back in 1986, he published a paper, “The Little Ice Age as Recorded in the Stratigraphy of the Tropical Quelccaya Ice Cap” , which found clear evidence of the Little Ice Age in Peru.

 

ABSTRACT

The analyses of two ice cores from a southern tropical ice cap provide a record of climatic conditions over 1000 years for a region where other proxy records are nearly absent. Annual variations in visible dust layers, oxygen isotopes, microparticle concentrations, conductivity, and identification of the historical (A.D. 1600) Huaynaputina ash permit accurate dating and time-scale verification. The fact that the Little Ice Age (about A.D. 1500 to 1900) stands out as a significant climatic event in the oxygen isotope and electrical conductivity records confirms the worldwide character of this event.

This study comes to similar conclusions to other research in South America. For instance, Areneda et al found in 2009 that:-

 

These data allow us to infer that the last maximum advance of Cipreses glacier, in Chile, attributable to the ‘Little Ice Age’ occurred around AD 1842. The first historical retreat was recorded in 1858 and, since then, the glacier has shown a clear retreating trend with no new advances. All this information was compared with the historical data gathered for San Rafael glacier, which shows the occurrence of a cold period contemporary with the European LIA.

And another paper from Areneda, regarding the San Rafael glacier in Chile found:-

 

Past ice lobe behaviour at Laguna San Rafael is described in documents provided by Spanish and then Chilean explorers from the late seventeenth to the early twentieth centuries. These records begin in AD 1675, when temperate conditions, probably similar to those at present, prevailed. At that point, the glacier was confined within its valley, not penetrating the Laguna. The glacier advanced noticeably during the nineteenth century and probably reached a maximum position for the `Little Ice Age’ around AD 1875. The historical sources suggest a slight retreat in AD 1904 in relation to the conditions prevailing 29 years earlier. The historical data show that the eighteenth to nineteenth century cooling period at San Rafael glacier was within the temporal window of the European `Little Ice Age’. This work provides independent, direct historical evidence for the occurrence of this event in southern Chile.

 

Lonnie Thompson, himself, has already admitted that MWP temperatures were higher than now on the Quelccaya. Is the recovery in temperature, and retreat of the glaciers, since the mid 19thC anymore than a return to pre LIA conditions?