Comment On Arnold Et Al. "Drought And The Collapse Of The Tiwanaku Civilization: New Evidence From Lake Orurillo, Peru" [Quat. Sci. Rev. 251 (2021): 106693]

This paper revives a fascinating debate: did a drought start before, during, or after the collapse of the Andean polity of Tiwanaku? Here we present an alternate age model that highlights the real issue: the data from Lake Orurillo, no matter the age model, are too imprecise to address the question. The authors neglect the significance of four-century error ranges (95% probability) for a drought that lasted a single century, according to their estimates. They are content to treat an imprecise correlation between drought and collapse as a causal relationship. Future efforts will require much greater attention to refining both paleoclimate and cultural chronologies, which is a necessary first step in understanding complex episodes of human-environment interaction. (C) 2021 Elsevier Ltd. All rights reserved.