Tracing Human Response to Environmental Variability

Urban populations are projected to continuously increase for the foreseeable future. In urban societies, environmental deterioration produced by human and climatic factors is a significant stress agent. The archaeological record offers a wealth of long-term case studies indicating that climatic disruptions may have played an important role in the breakdown of urban societies.

However, environmental deterioration did not inevitably lead to collapse and past societies responded to environmental stress using different strategies. Understanding how societies coped with environmental variation could provide information for evaluating current urban risk factors under the present climatic scenario. To investigate past human responses to climate fluctuations, archaeologists correlate archaeological site data with spatially distant environmental proxy sources, producing challenging spatial and temporal uncertainty.

As a result, human-scale responses to environmental shifts remain elusive when studied with conventional archaeological approaches

To address this challenge, this project approaches the human-scale experience of past-climatic shifts using a combination of geoarchaeology, paleobotany, stable isotopes, and traditional excavation methods and aims to further clarify how past human-environmental interactions influenced technological, social, cultural, and political aspects of such societies. In multiple regions highly variable climate and gradient of ecological zones, abundance of urban sites, human modified landscapes, and cyclical wet and dry periods generated a diversity of adaptive exploitation strategies and new forms of social organization.

This project focuses on using both fossil and modern phytoliths to investigate how the inhabitants of such centers responded to environmental changes through time. The project emphasizes the use of geoarchaeological methods to identify site formation processes involved in phytolith accumulation and will use stable isotope values from charred plant remains and a battery of 14C dating to exponentially improve the resolution of climatic reconstructions.

The project results will be compared to the regional proxies, the material culture record, and the textual sources to provide information on urban resilience strategies at multiple chronological, social, cultural, and spatial scales. The project’s research and collaboration framework will offer training and educational opportunities for undergraduate and graduate students.

In regions where increasing aridity is affecting and will continue to affect millions in the foreseeable future, understanding how ancient societies negotiated environmental constrains provides the public with examples from the past on the risks urban societies faced during climatic shifts.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.