SADA: South American Drought Atlas

MARIANO S. MORALES

San Rafael

Workshop; Increasing population, social complexity, climate change and why societies might fail to cope with these interrelated forces; 2018

PAGES3K

The PEOPLE 3000 working group focuses on integrating archaeological and paleoecological case studies with mathematical modeling. We seek to understand how co-evolving human societies and ecosystems can successfully cope with the interrelated forces of population growth, increasing social complexity and climate change, and why some societies subsequently collapse/reorganize when confronted by these processes.Our first workshop identified that human societies experienced periods of social and economic development followed by major reorganizations in those systems during the climate transition to the Little Ice Age. Thus, we developed an explanation for what appears to be a wide spread and climate driven pattern. In this case, population growth, increasing complexity, and increasing energy consumption reduce variation in human subsistence economies. This, in turn, results in systems where individuals are well adapted to a specific range of climate variation, but where those same strategies are easily disrupted by climate change outside the range to which a society has adapted.Our PAGES OSM poster presented evidence consistent with this hypothesis (Freeman et al. 2017, Past Global Changes Magazine), and a recent paper on energy consumption and the radiocarbon record provides a new way of interpreting the radiocarbon record that is relevant to testing this hypothesis (Freeman et al. 2017, Radiocarbon).In this workshop, we propose to engage in further data synthesis and expand our case studies to provide a more robust evaluation of this diversity reduction-increasing vulnerability to climate change hypothesis. We also plan to expand our regional coverage to include Australia and SE Asia.The proposed workshop will move our research forward by synthesizing the following datasets important to understanding the hypothesis posed above.1) Radiocarbon data ? these data document the timing of societal change.2) Paleoecological data ? tree ring, ice core, pollen, small mammal and sedimentological records provide data on paleoclimate change and subsequent ecosystem responses.3) Subsistence data ? faunal, botanical and stable isotope records enable the identification of shifts in subsistence strategies within the temporal and paleoecological contexts.4) Technological data ? lithic, perishable good, ceramic and infrastructure records can track shifts in social complexity within temporal and paleoecological contexts.